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Latin America and Caribbean Mexico, Caribbean Islands, Tropical Latin America, Temperate South America & Andes Mountains, Latin America as a Whole

Mexico

Amebiasis: See full discussion (Worldwide): Amebiasis is an amebic gastrointestinal infection (sometimes affecting other systems) that may be asymptomatic, chronic, or acute. Symptoms may include abdominal pain, diarrhea (with blood), weight loss, dehydration. Systemic dissemination is usually to the liver, but may also involve the brain, heart (pericarditis), lungs, and genitalia. Invasive amebiasis is treated with metronidazole and colonization without symptoms is treated with paromomycin or iodoquinol.

Anisakiasis (Mexico, Central and South America, Japan): Anisakiasis is a nematode (roundworm) infection of the stomach or intestinal wall with Anisakis. Manifestions vary according to primary site of infection and improvement usually occurs within a few weeks. Acute gastric anisakiasis has an acute onset of progressive epigastric pain, nausea, and vomiting within hours of ingesting lavae. Acute intestinal manifests as low-grade fever, colicky lower (or diffuse) abdominal pain, nausea, vomiting, and diarrhea. Chronic anisakiasis produces chronic symptoms similar to gastritis, peptic ulcer disease, inflammatory bowel disease, and other GI disorders. Treatment is symptomatic, and in a few cases, surgical.

Blastomycosis (Limited areas of south central and midwestern U.S. and Canada, Africa, Mexico ): Blastomycosis is a mycotic (Blastomyces dermatitidis) infection of lungs, skin, bones, or genitourinary system. The infection may be asymptomatic or may present with cough, fever, dyspnea, and chest pain that may resolve or progress to hemoptysis, fever, lymphadenopathy, weight loss, and collapse. Rough, warty skin lesions occur, as does destruction of bone (ribs and vertebrae) and GU problems among males. Blastomycosis must be differentiated from chromomycosis (see below). Treatment is with itraconazole or amphoteracin B. Also see paracoccidioidomycosis (South American Blastomycosis).

Coccidioidomycosis (United States, Mexico, and parts of Central and South America): Coccidioidomycosis is a fungal infection with Coccidioides immitis, usually pulmonary (cough, fever, chest pain, weight loss, malaise), but also of CNS, skin, lymph system, or liver. C. immitis occurs naturally in some soils (semi-arid with short rainy season) and is inhaled. Immunocompromised persons are at increased risk. Treatment is with amphotericin B or fluconazole or itraconazole. Maintenance therapy utilizes the same medications, especially fluconazole or itraconazole.

Dengue Fever: See full discussion (East and West Africa, Southeast and East Asia, Pacific Islands, Eastern Australia, Central and South America, Mexico, South Texas, Caribbean Islands - with distribution increasing, especially in urban areas): Dengue Fever is a flavivirus (several serotypes) infection transmitted by mosquitos. There is increasing incidence and prevalence of cocirculation of multiple serotypes. Dengue is usually a self-limited illness characterized by abrupt onset high (biphasic) fever, chills, headache, rash, signs of bleeding, changes in taste, sore throat, nausea, vomiting, diarrhea, anorexia, severe aching myalgia and arthralgia (hence "bone-break" fever), and depression. Complications include meningoencephalitis, dengue hemorrhagic fever (DHF), and dengue shock syndrom (DSS). Treatment is supportive and convalescence tends to be lengthy.

Leishmaniasis: See full discussion or brief discussions of the various types (visceral, cutaneous, mucocutaneous) (East and North Africa, Middle East, Southern Europe, Central, South, and East Asia, South America, West Mexico): The protozoal parasite species Leishmania is transmitted by sandflies. Major types of leishmaniasis include visceral leishmaniasis or kala-azar, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia). Incubation is usually 2-6 months or longer and relapse may occur as many as 10 years after first episode. Signs and symptoms vary according to the type of leishmaniasis. See visceral leishmaniasis, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia).

Leprosy: See full discussion (Tropical and sub-tropical Africa, Asia, Pacific Islands, South America, Central America, and Mexico): Leprosy is caused by the acid-fast rod Mycobacterium leprae which is transmitted probably via the respiratory route through prolonged exposure in childhood. Incubation is usually 2-5 years; and up to 20 years. There are two basic types of leprosy: lepromatous leprosy (LL) and tuberculoid leprosy (TL) and either of these may be classified as borderline or indeterminate. Most initial infections involve few symptoms and spontaneous recovery is common with a minority of patients developing clinical disease. LL is a progressive malignant process including skin lesions/changes; as well as nerve damage and disability. TL is not as disabling as LL and includes skin lesions and nerve damage. Borderline leprosy may have features of both LL and TL, and may evolve into either form. Indeterminate leprosy is manifested by one or several macules or poorly defined skin lesions, that may heal spontaneously, remain stable, or progress to forms described above. Multi-drug therapy is the current accepted standard for all types of leprosy, and for LL generally includes dapsone, clofazamine, and rifampin daily for at least 2-3 years until all biopsies are negative for acid-fast bacilli. Patients with indeterminate or tuberculoid leprosy may be treated with dapsone and rifampin as above for 6-12 months, followed by dapsone alone for a total of at least two years of therapy. Antigen-antibody complex reactions (to therapy) are common and are treated with prednisone or thalidomide.

Paracoccidioidomycosis (South American Blastomycosis) (Mexico, Central and South America): Paracoccidioidomycosis is an ulcerating mycotic infection (caused by Paracoccidioides brasiliensis) usually first involving the naso-oropharynx, and later adjacent areas, including the skin and face; and progressing to the lungs, liver, and elsewhere in the GI system. Lymphadenopathy, pulmonary symptoms, and cachexia may occur. Treatment is with itraconazole unless the illness is serious enough for hospitalization, in which case, IV amphotericin B is given, followed by itraconazole.

Typhoid and paratyphoid fever (sometimes termed enteric fever) (Most of the developing world, especially Africa, Asia, and Latin America, including Mexico): Typhoid fever is an acute systemic febrile illness caused by Salmonella typhi and other anaerobic gram-negative Salmonella serovars, e.g., S. paratyphi, which causes the less severe paratyphoid fever. Typhoid is usually spread by feces-contaminated food or water. Note that vaccination is not completely effective. Incubation is highly variable, ranging from 3-60 days. The hallmark sign is the gradual onset of steadily increasing and then persistently high fever (though children may experience abrupt onset). Early manifestations are fever, chills, malaise, headache, sore throat, cough, and sometimes abdominal pain and constipation or diarrhea. As the illness progresses, prostration, abdominal distension, hepatosplenomegaly, anorexia, and weight loss are common. Untreated typhoid may result in complications in any of the body systems. The severity of illness varies according to immunocompetence, infectious dose of microorganisms, and other factors. Treatment is with chloramphenicol 3-4 g/d po for adults and 50-75 mg/kg/d po for children. When the patient becomes afebrile, the dose may be decreased to 2 g/d for adults and 30 mg/kg/d for children. The total duration of treatment is two weeks. In the U.S., the more common treatment is amoxicillin 4-6 g/d po in four divided (1-1.5 g) daily doses for adults and 100 mg/kg po in four divided daily doses for children. Trimethoprim-sulfamethoxazole, ciprofloxacin, or ofloxacin are also used. Early effective treatment results in increased frequency of (usually mild) relapse.

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Caribbean Islands

Angiostrongyliasis (Caribbean, Southeast Asia, Pacific Islands): Angiostrongyliasis includes several distinct nematode (roundworm) infections caused by Angiostrongylus sp. as follows. (1) Nematode (rat lungworm) infection with A. cantonensis that often is subclinical. Larvae migrate to the CNS and may cause eosinophilic meningoencephalitis. Symptoms may include severe headache (most common symptom), stiff neck, low grade fever, nausea, vomiting, abdominal discomfort, paresthesias of trunk and extremities, and other neurologic signs, including unilateral facial paralysis. The disease is usually self-limiting. Treatment is supportive, and includes corticosteroids, spinal taps, and analgesics. Antihelminthics are not used because of host reaction to dead worms in the CNS. (2) Nematode infection with A. costaricensis of the gastrointestinal tract with cutaneous, intestinal, and pulmonary manifestations (related to the nematode life cycle in the host body); and in some cases, hyperinfection syndrome. Cutaneous manifestations include edema, inflammation, and pruritis. Intestinal manifestations include abdominal and flank pain, fever, malaise, anorexia, nausea, vomiting, and weight loss. Pulmonary manifestations include cough, rales, wheezing, low grade fever, and hemoptysis. Hyperinfection syndrome includes severe pulmonary, cardiac, neurologic symptoms, progressing to septicemia and death. Treatment includes supportive therapy and glucocorticoids; and in some cases ivermectin or thiabendazole or albendazole.

Arbovirus encephalitis (Worldwide - according to specific disease): The most important (highest case- fatality rates) arbovirus or arthropod-borne encephalitides are (1) Japanese encephalitis (JE), which is found throughout Asia and the Pacific; (2) Murray Valley (MV), which is found in Australia and New Guinea; and (3) eastern equine encephalomyelitis (EEE), which is found in the Americas and Caribbean. Severe infections are usually characterized by acute onset of fever, meningeal signs (headache, stiff neck, irritability, nausea and vomiting, delirium, >vital signs), tremors, convulsions, and stupor progressing to coma. Treatment is primarily supportive.

Chromomycosis (Worldwide; greatest in Costa Rica and Madagascar): Chromomycosis is a chronic mycosis of the skin and subcutaneous tissue most common among people (primarily adults) who walk barefoot or are exposed to thorn or similar wounds. The disease begins with a warty papule or pustule, plaque, or ulcer. The lesion progresses to a verrucoid (warty) plaque that thickens with time. Lesions tend to spread by inoculation rather than growing peripherally. Chromomycosis must be differentiated from blastomycosis. Superinfection leads to cutaneous and other complications.

Dengue Fever: See full discussion (East and West Africa, Southeast and East Asia, Pacific Islands, Eastern Australia, Central and South America, Mexico, South Texas, Caribbean Islands - with distribution increasing, especially in urban areas): Dengue Fever is a flavivirus (several serotypes) infection transmitted by mosquitos. There is increasing incidence and prevalence of cocirculation of multiple serotypes. Dengue is usually a self-limited illness characterized by abrupt onset high (biphasic) fever, chills, headache, rash, signs of bleeding, changes in taste, sore throat, nausea, vomiting, diarrhea, anorexia, severe aching myalgia and arthralgia (hence "bone-break" fever), and depression. Complications include meningoencephalitis, dengue hemorrhagic fever (DHF), and dengue shock syndrom (DSS). Treatment is supportive and convalescence tends to be lengthy.

Granuloma inguinale or Donovanosis (Tropics, especially Southern India, Southern Africa, Pacific Islands, Papua, New Guinea, Caribbean Islands): Granuloma inguinale is a sexually transmitted disease caused by Calymmatobacterium granulomatous and characterized by an initial papule on the penis or labia. The papule ulcerates and develops into a painless granulomatous (beefy red and friable) raised area that spreads. Secondary anaeorobic infections are common and result in pain and foul-smelling drainage. Extension to the inguinal region may produce swelling similar in appearance to bubos. Early lesions of granuloma inguinale may be mistaken for syphilis, ulcerative stages mistaken for lymphogranuloma venereum, and the granulomatous tissue may be mistaken for carcinoma. Treatment is with TMP/SMX, azithromycin, tetracyclines, or newer quinolones.

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Tropical Latin America

Cryptococcosis (U.S., Australia, tropical Asia, Africa, South America): Cryptococcosis is a yeast (Cryptococcus neoformans) infection beginning in the lungs and spreading to the CNS and thus resulting in meningitis and in some cases, disseminated disease. Immunocompromised persons are at increased risk. Treatment is with amphotericin B alone or in combination with flucytosine. Mild cases may be treated with fluconazole; and fluconazole is also used for maintenance therapy.

Cryptosporidiosis (Worldwide, with increased prevalence in tropical areas): Cryptosporidiosis is a protozoan (Cryptosporidium sp.) infection of the GI tract causing diarrhea which ranges from self-limited to chronic secretory, high volume and ultimately fatal. Immunocompromised persons are at increased risk. There is not currently a satisfactory treatment.

Dracunculiasis (Guinea worm disease) (Primarily West Africa [Nigeria] and Sudan; other areas of tropical Asia and Africa, Middle East, South America): Dracunculiasis is a tissue nematode infection with Dracunculus medinensis, the largest (up to one meter in length) filarial worm affecting humans. Infection occurs when small Cyclops (crustaceans) that contain larvae are ingested in contaminated fresh water such as that from large open wells. Infected persons are asymptomatic for approximately one year. Then, as the female worm reaches maturity, a papule, or in some cases, a sepinginous elevation of the skin develops - usually on a lower extremity. The papule progresses to a painful and pruritic blister, then an ulcer, and then the prolapsed uterus of the worm becomes visible and on contact with water releases larvae in a milky fluid. After repeated emptying, the worm dies and can then be slowly pulled forth and wound around a stick over a period of several weeks. Metronidazole 250 mg po tid for 10 days is used as an adjunct to mechanical removal. In most cases one to two worms emerge/year. Most people with dracunculiasis are incapacitated for about a month. Secondary bacterial infections are the most common complication.

Filariasis: See full discussion (Distribution given below). The filarial parasites are tissue-dwelling roundworms whose microfilarial (mf) larvae are transmitted by several species of mosquitos or flies. The most problematic forms of filariasis are (1) Bancroftian filariasis and Malayan filariasis (much of the tropical and subtropical world between the Tropics of Cancer and Capricorn) which involve the lymphatic system and result in elephantiasisis; (2) loiasis or loa loa (tropical Africa) in which worms live in subcutaneous tissue; and (3) Onchocerciasis (tropical Africa and to a lesser extent Central and South America) which causes river blindness and skin disorders. Treatment in most cases is effective only against the mf, hence the infection continues and repeated treatment (with ivermectin and/or DEC) may be necessary.

Leprosy: See full discussion (Tropical and sub-tropical Africa, Asia, Pacific Islands, South America, Central America, and Mexico): Leprosy is caused by the acid-fast rod Mycobacterium leprae which is transmitted probably via the respiratory route through prolonged exposure in childhood. Incubation is usually 2-5 years; and up to 20 years. There are two basic types of leprosy: lepromatous leprosy (LL) and tuberculoid leprosy (TL) and either of these may be classified as borderline or indeterminate. Most initial infections involve few symptoms and spontaneous recovery is common with a minority of patients developing clinical disease. LL is a progressive malignant process including skin lesions/changes; as well as nerve damage and disability. TL is not as disabling as LL and includes skin lesions and nerve damage. Borderline leprosy may have features of both LL and TL, and may evolve into either form. Indeterminate leprosy is manifested by one or several macules or poorly defined skin lesions, that may heal spontaneously, remain stable, or progress to forms described above. Multi-drug therapy is the current accepted standard for all types of leprosy, and for LL generally includes dapsone, clofazamine, and rifampin daily for at least 2-3 years until all biopsies are negative for acid-fast bacilli. Patients with indeterminate or tuberculoid leprosy may be treated with dapsone and rifampin as above for 6-12 months, followed by dapsone alone for a total of at least two years of therapy. Antigen-antibody complex reactions (to therapy) are common and are treated with prednisone or thalidomide.

Leptospirosis: See full discussion (Worldwide, especially tropical areas of Latin America and Southeast Asia): Leptospirosis is a spirochette (Leptospira interrogans) infection transmitted primarily through exposure to water contaminated with urine from infected animals. Leptospirosis varies from asymptomatic to a severe or fatal illness. There are two common forms (anicteric and icteric or Weil's syndrome). Anicteric leptospirosis is the more common and milder form, and often is biphasic, with the first phase characterized by sudden onset high fever with chills, headache, conjunctival suffusion, cough and pulmonary chest pain, abdominal pain, nausea and vomiting, and myalgia. The illness may resolve after about one week with no further manifestations; or, after one to three days, recur with milder and more varied symptoms than in the first phase - except that aseptic meningitis may occur. Icteric leptospirosis or Weil's syndrome is the more severe form and is characterized by symptoms as described above (except not usually biphasic); and after about one week, the development of decreased renal function, pulmonary complications, jaundice, and/or hemorrhagic manifestations. Treatment includes antibiotics (doxycycline, penicillin, or others) and support.

Malaria: See full discussion (Tropical Africa, Asia, South and Central Americas; East China, Middle East): Malaria is caused by the protozoas Plasmodium falciporum, P. vivax, P. ovale, and P. malariae and is transmitted by mosquito bite, parenteral injection, or congenitally. Malaria is usually characterized by sudden onset of high fever, sweating, chills, uncontrollable shaking, headache, and splenomegaly. Fever tends to wax and wane in 48-72 hour cycles, though cycles may be irregular, especially with infection by P. falciporum. Onset may also be insidious, with less dramatic symptoms such as fever, headache, dyspnea, abdominal pain, nausea, diarrhea, myalgias, and splenomegaly. P. falciporum may cause parasitemia resulting in a life-threatening condition characterized by hemolysis, jaundice, anemia, acute renal failure, and hemoglobinuria. Cerebral malaria, also life-threatening, is characterized by gradual onset of severe headache, drowsiness, delerium, and coma. Seizures may also occur and are most common in children. P. faciporum causes death in as many as 25% of untreated cases. Treatment depends on the organism, immune status of the patient, and severity of the attack. Oral chloroquine is a mainstay of treatment except for infection with chloroquine-resistant P. falciporum. P. falciporum presents the greatest challenge because of severity of attacks as well as the existence of multidrug (especially chloroquine)-resistant strains. Combination drug treatment is common, e.g., mefloquine combined with artesunate for multidrug-resistant strains as described in the full discussion.

Mucocutaneous Leishmaniasis (Espundia): See full discussion of leishmaniasis (Latin America): Mucocutaneous leishmaniasis is a sequela of new world cutaneous leishmanaiasis and results from spread to the nasal or oral mucosa, with naso-oropharyngeal symptoms sometimes appearing several years after resolution of the primary lesion(s) and sometimes while the primary lesions are present. Manifestations include chronic nasal symptoms, especially of the anterior nasal septum, progressing to naso-oropharyngeal destruction. Secondary bacterial (or fungal) infections and associated problems are common. Treatment is difficult and cure rates decrease with advanced disease. Treatment is as for cutaneous leishmaniasis.

Mycetoma - also known as maduramycosis (Worldwide, especially tropics): Fungal infection, that begins as a small abscess, papule, or nodule and progresses to localized larger and multiple abscesses with sinuses; and ultimately to destruction of deep tissue, fascia, and bone. The usual route of infection is via a break in the skin (commonly from a thorn wound) through which the fungus is implanted from contaminated soil or plant. Secondary bacterial infection may occur. The foot is the most common site of infection, leading to "madura foot." Eumycetoma is infection due to filamentous fungi and is resistant to treatment. Actinomycetoma is infection due to actinomycetes and treatment is often effective. Treatment is with long-term combination therapy, e.g., streptomycin + dapsone or TMP/SMX. Surgical debridement + long-term ketoconazole or itraconazole is also used in treatment.

Paracoccidioidomycosis (South American Blastomycosis) (Mexico, Central and South America): Paracoccidioidomycosis is an ulcerating mycotic infection (caused by Paracoccidioides brasiliensis) usually first involving the naso-oropharynx, and later adjacent areas, including the skin and face; and progressing to the lungs, liver, and elsewhere in the GI system. Lymphadenopathy, pulmonary symptoms, and cachexia may occur. Treatment is with itraconazole unless the illness is serious enough for hospitalization, in which case, IV amphotericin B is given, followed by itraconazole.

Strongylodiasis (Most of the tropical world): Strongylodiasis is a nematode (roundworm) infection by Strongyloides stercoralis following larval penetration of the skin. A minority of infected persons are asymptomatic. Cutaneous manifestions may occur at the site of penetration (often feet), and include inflammation, serpiginous or urticarial tracts, and pruritis. Intestinal manifestations follow cutaneous, and include abdominal pain, nausea, flatulence, and diarrhea. Larval migration to lungs results in a variety of pulmonary symptoms, ranging from cough to pneumonia, pleural effusion, and miliary abscesses. Hyperinfection syndrome causes life-threatening CNS, cardiac, and wide-ranging gastrointestinal problems. Treatment is with ivermectin 200 mcg/kg/day po for two days. Albendazole and thiabendazole have also been used.

Trichuriasis (trichocephaliasis or whipworm) (Worldwide, especially tropical and subtropical areas): Trichuriasis is a nematode (roundworm) infection with Trichuris trichiura. Heavy infections may result in abdominal cramping, nausea, vomiting, flatulence, diarrhea, tenesmus, and weight loss. Mild infections are usually asymptomatic. Treatment is with albendazole single po dose of 400 mg (not FDA approved) or mebendazole 100 mg po bid for 3 days. Ivermectin is sometimes also used in combination with albendazole.

Tungiasis (tropical areas of Africa and the Americas): Tungiasis is infestation with Tunga penetrans (sand fleas, jiggers), usually of the foot. Other fleas also bite humans and can transmit a variety of diseases.

Yaws (frambesia) (tropical areas worldwide): Yaws is a chronic childhood illness caused by Treponoma pallidum ssp. pertenue (see other treponematoses) spread primarily by skin to skin contact. Yaws is characterized by an initial papule, which enlarges and becomes papillomatous. The lesion erodes and infectious crusting exudate appears, as well as lymphadenopathy. The initial or "mother" lesion heals, but before or after healing of the initial lesion, secondary lesions appear in a variety of forms. Late or chronic yaws appear in about 10% of patients five or more years after the initial infection. Late yaws is characterized gummatous (granulomatous) lesions of the skin and subcutaneous tissues. The bones are also affected and eventually there is erosion of the nose and facial bones. The preferred treatment is 2.4 million units of IM benzathine penicillin G for adults and 1.2 million units for children.

Yellow fever (most of tropical and subtropical South America and Africa): Yellow fever (YF) is caused by an arbovirus transmitted by the Aedes aegypti mosquito from one human to another (the urban form of YF) or from monkeys to humans (the jungle or sylvan form of YF). YF is characterized by sudden onset flu-like (non-specific) symptoms occurring in two stages with a short intervening remission. The first stage of severe YF has a sudden onset of fever, chills, intense headache, lumbosacral back pain, myalgia, nausea and vomiting, conjunctival injection, dark urine, and bradycardia in relation to fever. After a 12-24 hour remission, there is an "intoxication" or hepatorenal stage that features reemergence of generalized symptoms including increased temperature, increased nausea and vomiting, abdominal pain, jaundice, and prostration. Complications of severe YF include jaundice, dehydration, decreased renal function, delirium, and hemorrhagic symptoms. Terminal signs include progressive tachycardia, intractable hiccups, and shock. Lab findings include albuminuria, leukopenia, abnormal liver function, increased prothrombin times. Treatment is supportive, i.e, control of fever, vomiting, dehydration, and pain.

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Temperate South America and Andes Mountains

Bartonellosis (Oroya fever) (South America/Andes Mountains): Bartonellosis is a gram negative bacterial systemic infection with Bartonella bacilliformis, which is transmitted by sandflies. Infection is characterized by insidious onset of fever, malaise, headache, myalgia; or in other cases, acute onset high fever, chills, drenching sweats, lymphadenopathy, hemolytic anemia, liver involvement and altered consciousness. Essential features are fever, progressive hemolytic anemia, generalized lymphadenopathy, and exposure to sandflies. Salmonellosis is a common complication of bartonellosis. Nodular (and often ulcerated) lesions occur one to three months after the onset of illness. Treatment is with penicillin, tetracycline, streptomycin, or chloramphenicol.

Chagas' Disease or American trypanosomiais: See full discussion (Most of Latin America): Chagas' disease is a protozoan infection with Trypanosoma cruzi transmitted by insect bite. Patients may be asymptomatic or have a lesion at the site of the bite; and symptoms of prolonged fever, tachycardia, fatigue, weakness, splenomegaly, and lymphadenopathy. Myocarditis or meningoencephalitis may also occur. Most patients experience spontaneous remission of symptoms, followed by a lifelong low-grade parasitemia. There is not currently a satisfactory treatment for any stage of Chagas' disease. Current treatment includes nifurtimox 8-10 mg/kg/day po qid for 90-120 days or benznidazole 5 mg/kg/day po for 60 days. These long-term therapies are toxic to some patients. In the United States, nifurtimox is available only from the Centers for Disease Control and benznidazole is not available in the U.S.

Echinococcosis (Hydatid disease): See full discussion (Most of the world; endemic in South America, North Africa, Middle East, Southern Europe - especially in areas where sheep are raised). Echinococcosis or hydatid disease is a tapeworm infection that often is asymptomatic, especially in the lengthy early stages. Echinococcus embryos trapped in various organs (especially the liver or lung) develop into hydatid cyst(s), which grow and eventually cause dysfunction according to the function or area of the organ(s). Surgical excision of the cyst remains the treatment of choice. Albendazole is given pre and post-operatively. Drug treatment includes albendazole or mebendazole or praziquantel - all with poor cure rates.

Hantavirus pulmonary syndrome: See full discussion of HFs (North America, especially Southern; South America, especially Andes): Hantavirus infection is thought to occur through inhalation of infected rodent droppings. Incubation ranges from 7-28 days. In Latin America, hantaviruses cause HFs as described in the full discussion of HFs; and in the U.S., cause the hantavirus pulmonary syndrome (HPS). HPS is characterized by flu-like febrile illness that rapidly progresses to shock and adult respiratory distress syndrome with thrombocytopenia, hemoconcentration, and leukocytosis. Treatment is supportive as discussed in hemorrhagic fevers. Ventilation may be necessary within 24 hours of onset.

Hemorrhagic fevers, South American: See full discussion of HFs, including Junin HF (Argentina), Machupo HF (Bolivia), and other HFs: Incubation in South American HFs ranges from 7-14 days. South American HFs are characterized by the gradual onset of fever, myalgia, and signs and symptoms as described above under general signs and symptoms. Thrombocytopenia, bleeding, and neurological dysfunction (confusion, tremors, and cerebellar signs) are common in South American HFs. Treatment is supportive and also includes IV ribavirin as discussed in the full discussion of hemorrhagic fevers.

Leishmaniasis: See full discussion or brief discussions of the various types (visceral, cutaneous, mucocutaneous) (East and North Africa, Middle East, Southern Europe, Central, South, and East Asia, South America, West Mexico): The protozoal parasite species Leishmania is transmitted by sandflies. Major types of leishmaniasis include visceral leishmaniasis or kala-azar, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia). Incubation is usually 2-6 months or longer and relapse may occur as many as 10 years after first episode. Signs and symptoms vary according to the type of leishmaniasis. See visceral leishmaniasis, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia).

Plague (Worldwide, but primarily rural and lightly populated areas in undeveloped countries): Plague is an acute febrile zoonotic disease caused by Yersinia pestis, a microaerophilic coccobacillus of the family Enterobacteriaceae. Plague is transmitted primarily by flea (from rodents) bite, but also from direct inoculation through handling infected mammal carcasses or via the respiratory route from infected droplets from a patient with pneumonic plague. The most recent pandemic was in the late 19th and early 20th centuries and resulted in estimated 12,000,000 deaths. In recent years (1970s-1990s), most cases have been reported in Africa, Asia, and the Americas. There are three common forms of plague: bubonic (most common), pneumonic (most rapid and most frequently fatal), and septicemic - with the latter two either primary or secondary to metastatic spread. Plague is manifested by abrupt onset of high fever, severe headache, severe myalgias, prostration, and in some cases, delirium. The incubation period is 2-10 days. An ulcer may develop at the inoculation site. Lymphadenitis is followed by painful, draining bubo(s). Pneumonic plague produces fulminant pneumonitis with frothy bloody sputum and sepsis. Hematogenous spread or septicemic plague is characterized by rapid decline, coma, and purpura - hence the term "black plague." Treatment must be quickly instituted in all cases. IM streptomycin is the first line treatment, though IM or IV gentamicin is frequently used. IV or po tetracycline or doxycycline are also used.

Trematodes, liver-dwelling cause fascioliasis (Worldwide where sheep and cattle are raised): Infection occurs after ingestion of contaminated water or water-dwelling vegetation, e.g., watercress. Acute fascioliasis is characterized by fever, abdominal pain (especially hepatic), nausea, diarrhea, and hepatomegaly. Cough may also occur. Liver enzymes and erythrocyte sedimentation rates are usually elevated, and anemia is common. Chronic disease results in a variety liver and gallbladder abnormalities. Bithionol 30-50 mg/kg orally qod for 10-15 doses is the treatment of choice as this is written. Bithionol is available in the U.S. from CDC. Triclabendazole in a single dose of 10 mg/kg may become the drug of choice when available in the U.S. (Rosenblatt, 1999).

Typhus: See full discussion (numerous areas of the world as noted in discussion below): The typhus group of illnesses are one of several rickettsioses or febrile exanthematous illnesses caused by bites of rickettsial-infected arthropods or exposure to their feces. The three most important typhus group diseases are: epidemic louse-borne typhus, scrub typhus, and endemic (murine) typhus. (1) Epidemic louse-borne typhus is caused by Rickettsia prowazekii, with infection favored by crowded, unsanitary living conditions such as in concentration or the more primitive refugee camps - especially those in cold areas. Epidemic louse-borne typhus is currently most prevalent in mountainous areas of Africa, Asia, and Latin America. It is characterized by a prodrome of headache and constitutional symptoms; then the abrupt onset of high fever, chills, and prostration; then a macular rash progressing to maculopapular and petechial. Other common manifestations are delirium, conjunctival injection, photophobia, eye pain, flushed facies, hearing loss, hypotension, pulmonary involvement, renal insufficiency, and splenomegaly. Recovery may be spontaneous, or complications, including pneumonia, circulatory collapse, myocarditis, and uremia may lead to death. Treatment is with doxycycline 200 mg in a single dose or until the patient is afebrile for 24 hours. (2) Scrub typhus is transmitted by the bite of infected mites or chiggers, and is found in most areas of Asia. Scrub typhus illness ranges from mild to severe, and is characterized by gradual onset of fever, chills, headache, myalgia (backache), cough, nausea and abdominal pain, eschar at the site of the infecting bite, regional lymphadenopathy and a maculopapular rash. Severe scrub typhus is characterized by encephalitis and pneumonia. Scrub typhus is treated with doxycycline 100 mg bid po for 7-14 days; or chloramphenicol 500 mg qid po for 7-14 days. Azithromycin is also effective. (3) Endemic (murine) typhus is transmitted by the bite of infected fleas and is found worldwide. Endemic typhus is characterized by several days of prodromal constitutional symptoms, followed by the abrupt onset of fever, chills, and nausea and vomiting. Pulmonary involvement is common and may include interstitial pneumonia, pleural effusion, and/or pulmonary edema. Treatment is with doxycycline 100 mg bid po for 7-14 days; or chloramphenicol 500 mg qid po for 7-14 days.

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Latin America as a Whole

Amebiasis: See full discussion (Worldwide): Amebiasis is an amebic gastrointestinal infection (sometimes affecting other systems) that may be asymptomatic, chronic, or acute. Symptoms may include abdominal pain, diarrhea (with blood), weight loss, dehydration. Systemic dissemination is usually to the liver, but may also involve the brain, heart (pericarditis), lungs, and genitalia. Invasive amebiasis is treated with metronidazole and colonization without symptoms is treated with paromomycin or iodoquinol.

Anisakiasis (Mexico, Central and South America, Japan): Anisakiasis is a nematode (roundworm) infection of the stomach or intestinal wall with Anisakis. Manifestions vary according to primary site of infection and improvement usually occurs within a few weeks. Acute gastric anisakiasis has an acute onset of progressive epigastric pain, nausea, and vomiting within hours of ingesting lavae. Acute intestinal manifests as low-grade fever, colicky lower (or diffuse) abdominal pain, nausea, vomiting, and diarrhea. Chronic anisakiasis produces chronic symptoms similar to gastritis, peptic ulcer disease, inflammatory bowel disease, and other GI disorders. Treatment is symptomatic, and in a few cases, surgical.

Arbovirus encephalitis (Worldwide - according to specific disease): The most important (highest case- fatality rates) arbovirus or arthropod-borne encephalitides are (1) Japanese encephalitis (JE), which is found throughout Asia and the Pacific; (2) Murray Valley (MV), which is found in Australia and New Guinea; and (3) eastern equine encephalomyelitis (EEE), which is found in the Americas and Caribbean. Severe infections are usually characterized by acute onset of fever, meningeal signs (headache, stiff neck, irritability, nausea and vomiting, delirium, >vital signs), tremors, convulsions, and stupor progressing to coma. Treatment is primarily supportive.

Ascariasis: See full discussion (Worldwide): Ascariasis is a nematode or roundworm infection with Ascaris lumbricoides causing transient respiratory symptoms initially and chronic gastrointestinal symptoms. The adult worms are more than 20 cm. in length, hence are easily seen in stool and may also emerge from the nose or mouth as a result of coughing or vomiting. Treatment is with albendazole single dose of 400 mg po (not FDA approved) or mebendazole or pyrantel pamoate.

Bacillus cereus (Worldwide): Bacillus cereus is a pathogen causing self-limited food poisoning with vomiting or diarrhea and abdominal cramps.

Botulism (Worldwide): Botulism is a severe food poisoning resulting from ingesting the neurotoxin produced by Clostridium botulinum in canned or preserved foods (such as those produced under unsanitary conditions and imported). Symptoms include abdominal pain, vomiting, and CNS disturbances.

Campylobacter enteritis (Worldwide): Campylobacter enteritis is caused by gram negative non-spore forming rods (Campylobacter sp.) resulting in acute gastroenteritis characterized by fever, abdominal pain, and acute watery diarrhea. Campylobacter fetus causes systemic infections that are sometimes fatal.

Cestode infections: See tapeworm.

Chagas' Disease or American trypanosomiais: See full discussion (Most of Latin America): Chagas' disease is a protozoan infection with Trypanosoma cruzi transmitted by insect bite. Patients may be asymptomatic or have a lesion at the site of the bite; and symptoms of prolonged fever, tachycardia, fatigue, weakness, splenomegaly, and lymphadenopathy. Myocarditis or meningoencephalitis may also occur. Most patients experience spontaneous remission of symptoms, followed by a lifelong low-grade parasitemia. There is not currently a satisfactory treatment for any stage of Chagas' disease. Current treatment includes nifurtimox 8-10 mg/kg/day po qid for 90-120 days or benznidazole 5 mg/kg/day po for 60 days. These long-term therapies are toxic to some patients. In the United States, nifurtimox is available only from the Centers for Disease Control and benznidazole is not available in the U.S.

Clostridium botulinum and C. perfringens (Worldwide): C. botulinum causes botulism (see above) and C. perfringens causes gas gangrene and also enteritis or food poisoning especially from poultry.

Coccidioidomycosis (United States, Mexico, and parts of Central and South America): Coccidioidomycosis is a fungal infection with Coccidioides immitis, usually pulmonary (cough, fever, chest pain, weight loss, malaise), but also of CNS, skin, lymph system, or liver. C. immitis occurs naturally in some soils (semi-arid with short rainy season) and is inhaled. Immunocompromised persons are at increased risk. Treatment is with amphotericin B or fluconazole or itraconazole. Maintenance therapy utilizes the same medications, especially fluconazole or itraconazole.

Cryptococcosis (U.S., Australia, tropical Asia, Africa, South America): Cryptococcosis is a yeast (Cryptococcus neoformans) infection beginning in the lungs and spreading to the CNS and thus resulting in meningitis and in some cases, disseminated disease. Immunocompromised persons are at increased risk. Treatment is with amphotericin B alone or in combination with flucytosine. Mild cases may be treated with fluconazole; and fluconazole is also used for maintenance therapy.

Cryptosporidiosis (Worldwide, with increased prevalence in tropical areas): Cryptosporidiosis is a protozoan (Cryptosporidium sp.) infection of the GI tract causing diarrhea which ranges from self-limited to chronic secretory, high volume and ultimately fatal. Immunocompromised persons are at increased risk. There is not currently a satisfactory treatment.

Cutaneous larva migrans (Worldwide, including Southeastern U.S.): Cutaneous larva migrans is a distinctive serpinginous dermatitis caused by hookworm larval penetration of the skin. See hookworm.

Dengue Fever: See full discussion (East and West Africa, Southeast and East Asia, Pacific Islands, Eastern Australia, Central and South America, Mexico, South Texas, Caribbean Islands - with distribution increasing, especially in urban areas): Dengue Fever is a flavivirus (several serotypes) infection transmitted by mosquitos. There is increasing incidence and prevalence of cocirculation of multiple serotypes. Dengue is usually a self-limited illness characterized by abrupt onset high (biphasic) fever, chills, headache, rash, signs of bleeding, changes in taste, sore throat, nausea, vomiting, diarrhea, anorexia, severe aching myalgia and arthralgia (hence "bone-break" fever), and depression. Complications include meningoencephalitis, dengue hemorrhagic fever (DHF), and dengue shock syndrom (DSS). Treatment is supportive and convalescence tends to be lengthy.

Diphtheria (Worldwide): Diphtheria is an acute upper respiratory infection caused by virulent strains of the toxin-producing gram positive bacillus, Cornybacterium diphtheriae. Symptoms include fever, serosanguinous nasal discharge, sore throat, and gray pseudomembrane in the pharynx, nasopharynx, and/or trachea. Complications include respiratory tract obstruction, pneumonia, peripheral neuritis, and/or myocarditis. Immunization is essentially universal among younger people in the U.S., but some refugees and immigrants may not be immunized. Treatment includes (1) diptheria antitoxin within 48 hours of onset (after testing for sensitivity to antitoxin); (2) procaine penicillin G 600,000 units IM bid for 14 days (150,000 units/kg/day IV for 10 days for pediatric patients) or erythromycin 500 mg parenterally or po qid; (3) bedrest and supportive care; and (4) isolation until secretions are noncontagious. With some differences in regime, carriers are also treated.

Encephalitis (see Arbovirus encephalitis): Causes of encephalitis among refugees and immigrants include arborvirus infections (mosquito or tick-borne - especially cerebral malaria), trypanosomiasis, relapsing fever, trichinosis, cysticerosis, toxocariasis, and angiostrongyliasis.

Enteric fever: See typhoid fever.

Enterobiasis or Pinworm infection (Worldwide; most common helminthic infection in Western Europe and U.S.): Enterobiasis is a nematode infection of the intestinal tract caused by Enterobius vermicularis eggs which are ingested via contaminated food or soiled hands. Manifestations/associated problems include perianal pruritis, vulvovaginitis in prepubertal girls, and secondary enuresis and urinary tract infection. Treatment is with mebendazole single dose of 100 mg po, repeated in 2 weeks or albendazole single dose of 400 mg po, repeated in 2 weeks (Not FDA approved for this use).

Enterovirus exanthems: Enterovirus exanthems are rashes secondary to gastrointestinal tract infection by picornaviruses, including poliovirus, coxsackieviruses, and echoviruses.

Escherichia coli (Woldwide): E. coli are gram negative motile or nonmotile short rods that are a common cause of urinary tract and epidemic diarrheal diseases.

Giardiasis: See full discussion (Worldwide): Giardiasis or giardia is caused Giardia lamblia, a protozoan transmitted via water or food contaminated with human feces; and is also transmitted sexually (usually anal-oral). Many infected persons are asymptomatic, while others experience diarrhea as the primary symptom. Diarrhea ranges from one loose stool/day to frequent copious watery stools, may be acute or chronic, and continuous or intermittent (with bouts of constipation). When copious, stools often contain mucous, but seldom blood, and are greasy/steatorrheic, frothy and foul-smelling. Other common symptoms are abdominal pain, nausea and vomiting, anorexia, flatulence, fatigue, and weight loss. The acute phase may last days or weeks, with resolution usually spontaneous. Some patients develop chronic giardiasis, which persists for many years. Metronidazole 250 mg. tid x 5 days is a common treatment. Alternatives include furazolidone, albendazole, and paramomycin. Empiric treatment is common.

Histoplasmosis (Africa, Americas, East Asia, Australia): Best known in the West as an opportunistic infection of HIV, histoplasmosis is found among immigrants as the classic small-form histoplasmosis (primarily pulmonary) and as African histoplasmosis (primarily bone and cutaneous). Treatment is with amphotericin B initially, and itraconazole or fluconazole are used for maintenance therapy.

HIV/AIDS: HIV/AIDS is found world-wide, and is especially common in sub-Saharan Africa, Southeast Asia, and India. Heterosexual transmission is common in these areas. Readers are referred to the CDC and other current sources of information (See links).

Hookworm: See full discussion (Most tropical and subtropical areas of the world). An important cause of anemia, hookworms are intestinal parasites (nematodes, including Ancylostoma duodenale, Unicinaria stenocephala, and Necator americanus) whose larvae are transmitted from soil through the skin. Incubation is 2-8 weeks. Most people (with small parasite loads) are asymptomatic. Entry points are sometimes pruritic. Higher loads result in anorexia or increased appetite, abdominal discomfort, weight loss, nausea and vomiting, diarrhea and/or constipation, and anemia. Respiratory symptoms occur in a few patients. Infants and children may experience severe anemia, protein deficiency, and developmental delays. Treatment is with mebendazole, albendazole, or pyrantel pamoate. None of these are safe in pregnancy and neither mebendazole nor albendazole should be given to children under 1 year of age. The anemia should be treated with ferrous sulfate.

Hydatid disease: See echinococcus or full discussion.

Hymenolepiasis (Americas, Mediterranean, Near East, India, Australia): Hymenolepsis nana is the smallest and most common tapeworm (cestode) parasitizing humans. H. nana is spread by the fecal-oral route and is especially common in institutions. Most infected persons are asymptomatic, but very high loads may produce anorexia, abdominal pain, and diarrhea. Treatment is with praziquantel 25 mg/kg in one po dose.

Leishmaniasis: See full discussion or brief discussions of the various types (visceral, cutaneous, mucocutaneous) (East and North Africa, Middle East, Southern Europe, Central, South, and East Asia, South America, West Mexico): The protozoal parasite species Leishmania is transmitted by sandflies. Major types of leishmaniasis include visceral leishmaniasis or kala-azar, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia). Incubation is usually 2-6 months or longer and relapse may occur as many as 10 years after first episode. Signs and symptoms vary according to the type of leishmaniasis. See visceral leishmaniasis, cutaneous leishmaniasis, and mucocutaneous leishmaniasis (espundia).

Leprosy: See full discussion (Tropical and sub-tropical Africa, Asia, Pacific Islands, South America, Central America, and Mexico): Leprosy is caused by the acid-fast rod Mycobacterium leprae which is transmitted probably via the respiratory route through prolonged exposure in childhood. Incubation is usually 2-5 years; and up to 20 years. There are two basic types of leprosy: lepromatous leprosy (LL) and tuberculoid leprosy (TL) and either of these may be classified as borderline or indeterminate. Most initial infections involve few symptoms and spontaneous recovery is common with a minority of patients developing clinical disease. LL is a progressive malignant process including skin lesions/changes; as well as nerve damage and disability. TL is not as disabling as LL and includes skin lesions and nerve damage. Borderline leprosy may have features of both LL and TL, and may evolve into either form. Indeterminate leprosy is manifested by one or several macules or poorly defined skin lesions, that may heal spontaneously, remain stable, or progress to forms described above. Multi-drug therapy is the current accepted standard for all types of leprosy, and for LL generally includes dapsone, clofazamine, and rifampin daily for at least 2-3 years until all biopsies are negative for acid-fast bacilli. Patients with indeterminate or tuberculoid leprosy may be treated with dapsone and rifampin as above for 6-12 months, followed by dapsone alone for a total of at least two years of therapy. Antigen-antibody complex reactions (to therapy) are common and are treated with prednisone or thalidomide.

Malnutrition: Though not a communicable disease, malnutrition bears mention here as a common problem among refugees and, to a lesser extent, immigrants. We tend to see more malnourished people from Central America than Mexico. We expect at some time to have a full discussion of malnutrition. Malnutrition may be the result of decreased intake of one or all food groups or to decreased absorption. Metabolic disorders, diarrheal illnesses, or the indirect effects of chronic illnesses are common causes of decreased absorption. Malnutrition has long-term deleterious effects on the person suffering from decreased intake or absorption; or on the fetus or on the children of the person with malnutrition. Loss of intellectual potential, incomplete physical or mental development, and vulnerability to illness are among the long-term effects of malnutrition. Basic types of malnutrition include marasmus, protein malnutrition (Kwashiorkor), and cachexia. Though not often a problem among refugees, obesity may also be viewed as malnutrition. Marasmus is due to inadequate caloric intake and is characterized by failure to gain weight, then weight loss with resultant emaciation. Loss of subcutaneous fat causes poor turgor and wrinkling of skin. With advanced marasmus, the basal metabolic rate slows with resulting decreased vital signs and profound weakness. Children with marasmus often are the subject of the most dramatic photographs of Somali, Ethiopian, and other children of famine. Kwashiorkor or protein-calorie malnutrition (PCM) may be due to inadequate intake or absorption (or loss) of protein. Kwashiorkor is more common and the clinical picture is less dramatic than the emaciation of marasmus. Initially, inadequate protein causes lethargy or irritability. As the condition progresses, anorexia develops, weakness increases, muscle tissue decreases, and growth is retarded. Hepatomegaly occurs, kidney function decreases, and cardiac function is impaired. Edema is common and may mask other aspects of the disorder. Skin changes include dermatitis, changes in pigmentation, and changes in hair. Typically, hair is sparse, thin, and often streaked with red or gray color. Immune function is decreased and infection is common and often is the cause of death. Treatment of marasmus and Kwashiorkor includes fluid replacement, gradual protein and calorie replacement (fats are poorly tolerated in Kwashiorkor), and correction of vitamin and other deficiencies. A concern in both refugee camps and countries of second asylum, is the tendency of parents to overfeed when food becomes available. Cachexia is a metabolic disorder marked by general ill health and malnutrition, with weakness and emaciation; and is common in cancer, AIDS and other severe illnesses. In contradistinction to anorexia or starvation, in cachexia, there is approximately equal loss of fat and muscle, significant loss of bone mineral content, and cachexia does not respond to nutritional supplements or increased intake.

Meningitis, chronic and recurrent, is common worldwide, often as a complication of communicable diseases caused by a variety of pathogens as follows: (1) Bacterial causes include incompletely treated suppurative meningitis, parameningeal infection, Lyme disease, mycobacterium tuberculosis, syphilis; and less commonly actinomycosis brucellosis, leptospirosis, nocardial infection, and Whipple's disease. (2) Fungal infections with the potential to cause meningitis include aspergillosis, blastomycosis, cryptococcus, coccidiomycosis, candidiasis, histoplasma, and sporotrichosis. (3) Protozoal causes include toxoplasmosis and trypanosomiasis. (4) Helminthic causes include angiostrongyliasis, cysticercosis, gnathostomiasis, and trichinosis. (5) Viral causes include echoviral infections, herpes, HIV, lymphocytic choriomeningitis, and mumps. Viral or aseptic meningitis is characterized by sudden onset of fever and signs and symptoms of meningeal involvement (headache, neck stiffness, irritability/malaise, and sometimes rash and nausea and vomiting (from Chin, 2000; Koroshetz & Swartz, 1998).

Meningoencephalitis is relatively common worldwide and in some cases occurs as a complication of communicable diseases. Viruses are the most common pathogen, especially enteroviruses, but also arboviruses, herpesviruses, and other pathogens in illnesses including African trypanosomiasis, amebiasis, angiostrongyliasis, candidiasis, Chagas' disease, cryptococcosis, cytomegalovirus, dengue fever, hemorrhagic fevers, herpes, listeria, toxoplasmosis, and others. Young age and immunocompromise increase the risk of meningoencephalitis.

Mucocutaneous Leishmaniasis (Espundia): See full discussion of leishmaniasis (Latin America): Mucocutaneous leishmaniasis is a sequela of new world cutaneous leishmanaiasis and results from spread to the nasal or oral mucosa, with naso-oropharyngeal symptoms sometimes appearing several years after resolution of the primary lesion(s) and sometimes while the primary lesions are present. Manifestations include chronic nasal symptoms, especially of the anterior nasal septum, progressing to naso-oropharyngeal destruction. Secondary bacterial (or fungal) infections and associated problems are common. Treatment is difficult and cure rates decrease with advanced disease. Treatment is as for cutaneous leishmaniasis.

Mycetoma - also known as maduramycosis (Worldwide, especially tropics): Fungal infection, that begins as a small abscess, papule, or nodule and progresses to localized larger and multiple abscesses with sinuses; and ultimately to destruction of deep tissue, fascia, and bone. The usual route of infection is via a break in the skin (commonly from a thorn wound) through which the fungus is implanted from contaminated soil or plant. Secondary bacterial infection may occur. The foot is the most common site of infection, leading to "madura foot." Eumycetoma is infection due to filamentous fungi and is resistant to treatment. Actinomycetoma is infection due to actinomycetes and treatment is often effective. Treatment is with long-term combination therapy, e.g., streptomycin + dapsone or TMP/SMX. Surgical debridement + long-term ketoconazole or itraconazole is also used in treatment.

Myiasis (Worldwide - uncommon in countries of second asylum): Myiasis is the infestation of a wound with larvae of flies.

Naegleria infection (Worldwide): Naegleria fowleri (a protozoal) infection is the cause of amebic meningoencephalitis, which currently is rare. There are two forms: (1) acute and often fatal CNS infection in otherwise healthy persons and (2) granulomatous infection in immunocompromised persons. Meningoencephalitis is also related to other illnesses. See meningoencephalitis above.

Paracoccidioidomycosis (South American Blastomycosis) (Mexico, Central and South America): Paracoccidioidomycosis is an ulcerating mycotic infection (caused by Paracoccidioides brasiliensis) usually first involving the naso-oropharynx, and later adjacent areas, including the skin and face; and progressing to the lungs, liver, and elsewhere in the GI system. Lymphadenopathy, pulmonary symptoms, and cachexia may occur. Treatment is with itraconazole unless the illness is serious enough for hospitalization, in which case, IV amphotericin B is given, followed by itraconazole.

Pertussis or whooping cough (Worldwide): Most refugees and immigrants arrive in the U.S. with at least the first series of immunizations. However, not all records are accurate and some small risk exists for pertussis and other such illnesses. The infectious agent is Bordetella pertussis. Pertussis occurs in three stages: (1) The catarrhal stage is manifested by gradual onset of slight fever, dry cough, coryza, sneezing, malaise, and anorexia. (2) The paroxysmal stage begins 10-14 days after onset of symptoms and lasts 4-6 weeks. This stage includes the characteristic whooping cough (paroxysmal violent coughing spells with respiratory distress and without intervening inhalation and then a high-pitched inspiratory crowing whoop). Mucous is copious, clear, and tenacious; and vomiting may follow coughing. Coughing is most severe for the first 10-14 days of the paroxysmal stage and then severity gradually decreases. Paroxysms of coughing and the whoop are not always present in older children or adults. (3) The convalescent stage is marked by a chronic cough lasting as long as two years. Treatment includes respiratory isolation until the patient has received at least five days of a 14 day course of antibiotics; erythromycin (estolate form preferred) 50 mg/kg/day in 2-4 divided doses with a maximum of 2 gm/day for 14 days; supportive care is given in the hospital for younger and older patients. Cough suppressants are ineffective.

Pinta (mal de pinto, carate) (Rural areas of Latin America): Pinta is a spirochetal (Treponema carateum) skin infection characterized by a painless scaling papule with regional lymphadenopathy progressing to non-ulcerating maculopapular erythematous areas. Spread is by extension and by secondary lesions (pintides), which may be numerous. Pintides may be psoriatic or circinate in configuration. Initially the pintides are red, then slate blue, and then loss of pigmentation occurs, resulting first in brown areas, and eventually in mottled white skin. Lesions appear in various stages of development and are seen most commonly on the extremities and face. Pinta is decreasing in incidence and prevalence. The preferred treatment is 2.4 million units of IM benzathine penicillin G for adults and 1.2 million units for children.

Pinworms: See enterobiasis.

Pneumonia: See anthrax, ascariasis, blastomycosis, coccidioidomycosis, histoplasmosis, HIV/AIDS, legionellosis, paragonimiasis, plague, psittacosis, Q fever, typhus, strongyloidiasis, tuberculosis. Note other, more common causes.

Psittacosis (Worldwide): Psittacosis is Chlamydia psittaci infection contracted from infected birds. Psittacosis is characterized by rapid onset of fever, chills, headache, dry cough, myalgia; and later development of dyspnea and atypical pneumonia. Complications include endocarditis, hepatitis, or neurologic complications. Except for contact with birds, psittacosis is indistinguishable from viral, mycoplasmic, or other atypical pneumonias. Treatment is with tetracycline or erythromycin.

Q fever (Worldwide): Q fever is a rickettsial zoonosis (infection with gram negative Coxiella burnetii) contracted primarily from inhalation of dust contaminated by infected animals, especially sheep, cattle, and goats; and also other mammals. Other routes of infection include contact with milk and tissue from infected animals. Manifestations of acute Q fever include fever, fatigue, headache, cough, abdominal pain, nausea, diarrhea, and myalgia. Pneumonia develops in a small number of patients. Other complications are hepatitis, pericarditis, myocarditis, and meningoencephalitis. Hepato/splenomegaly and endocarditis are common in chronic Q fever. Endocarditis is frequently associated with purpuric rash, renal insufficiency, stroke, and heart failure. Treatment of acute Q fever is with doxycycline or a quinolone. Chronic Q fever requires combination therapy such as rifampin and doxycycline.

Rickettsioses (Worldwide): The rickettsioses are febrile exanthematous illnesses caused by arthropod carried rickettsiae. Rickettsioses include the typhus group, spotted fever group, Q fever, trench fever, and erlichiosis. See Boutonneuse fever, Q fever, spotted fevers, trench fever, and typhus.

Rotavirus (Worldwide): Rotavirus noninflammatory diarrhea is the most common cause of dehydrating diarrhea in children worldwide. Rotavirus gastroenteritis is more severe in children than adults. Treatment is supportive.

Salmonellosis (Worldwide): Salmonella sp. infections are well known in the Western world. In addition to the usual mild GI Salmonella sp. infections (more severe in the elderly), the more virulent Salmonella typhi causes typhoid fever.

Shigellosis or bacillary dysentary (Worldwide): Acute diarrheal illness from Shigella sp. transmitted via fecal-oral route. Shigellosis is especially common in children. Treatment is supportive and focused on prevention of dehydration.

Sporotrichosis (Worldwide): Sporotrichosis is a mycotic infection from inoculation of tissue with Sporothrix schenckii mold via an open wound - often associated with gardening activities. Sporotrichosis occurs in several forms, including (1) plaque sporotrichosis - a non-tender maculopapular granuloma at the site of inoculation; (2) lymphangitic sporotrichosis - a papule at the site of inoculation, followed by draining nodules along proximal lymphatic channels; (3) osteoarticular sporotrichosis - polyarticular arthritis that develops slowly and may include draining sinuses at joints. Treatment for plaque sporotrichosis is with potassium iodide or itraconazole. Treatment for lymphangitic or osteoarticular sporotrichosis is with a prolonged course of itraconazole and only about 50% of patients are cured.

Staphylococcus aureus infection (Worldwide): S. aureus produces an eneterotoxin that causes an acute and short-lived gastroenteritis, for which treatment is supportive.

Strongylodiasis (Most of the tropical world): Strongylodiasis is a nematode (roundworm) infection by Strongyloides stercoralis following larval penetration of the skin. A minority of infected persons are asymptomatic. Cutaneous manifestions may occur at the site of penetration (often feet), and include inflammation, serpiginous or urticarial tracts, and pruritis. Intestinal manifestations follow cutaneous, and include abdominal pain, nausea, flatulence, and diarrhea. Larval migration to lungs results in a variety of pulmonary symptoms, ranging from cough to pneumonia, pleural effusion, and miliary abscesses. Hyperinfection syndrome causes life-threatening CNS, cardiac, and wide-ranging gastrointestinal problems. Treatment is with ivermectin 200 mcg/kg/day po for two days. Albendazole and thiabendazole have also been used.

Subcutaneous mycotic infection: See mycetoma.

Syphilis (Worldwide): There are both venereal and endemic forms of syphilis, with the latter being primarily an illness of childhood caused by Treponoma pallidum ssp. endemicum (vs. T. pallidum ssp. pallidum, the infectious agent in syphilis) and occurring primarily in arid climates of the developing world. The prevalence of (endemic) syphilis infection among children <10 years of age ranges up to 19% among some nomadic groups in Africa. T. pallidum ssp. endemicum cannot be distinguished from T. pallidum ssp. pallidum in the laboratory.

Tapeworms and cysticercosis (Worldwide, but endemic in certain areas): Tapeworm or cestode infections result from the ingestion of Taeniasis sp. eggs, often found in undercooked meat or excreted proglottids (segments) of the adult tapeworm. Depending on the species, adult tapeworms reach a length of eight meters and live as long as 25 years. The beef tapeworm (Taeniasis saginata) usually causes gastrointestinal discomfort and weight loss. Awareness of infection often is through discovery of proglottids in the stool. Manifestations of intestinal infection with the pork tapeworm (Taeniasis solium) are similar to those of the beef tapeworm. However, ingestion of food that is fecally contaminated with T. solium eggs results in cysticercosis. The symptoms of cysticercosis are caused by the presence of cysticeri (encapsulated larvae) and the resulting inflammatory reaction or space-occupying lesions. The incubation period is as long as five years. Manifestions are most commonly varied neurologic problems, including fever, headache, CVA, hydrocephalus, seizures, and other symptoms of increased intracranial pressure. Visual manifestations may be from increased intracranial pressure or a cyst in the eye. Cysts are also found in subcutaneous and muscle tissue. Treatment of intestinal tapeworms is with a single dose of praziquantel 5-10 mg/kg. Treatment of cysticercosis is with albendazole 5 mg/kg po tid for 8-30 days or praziquantel 20 mg/kg po tid for 14 days. Therapy may increase symptoms, in which case dexamethasone helps reduce distress. Also see echinococcosis and hymenolepiasis.

Tetanus (Worldwide): Tetanus is a neurological disorder caused by the neurotoxin elaborated by the ubiquitous soil-dwelling anaerobic bacillus Clostridium tetani. Infection occurs as a result of introduction of Clostridium spores into wounds. Early manifestations are stiffness of the neck and jaw (lockjaw), dysphagia, and irritability. Pain and tingling at the wound site, followed by regional fasciculations may also be presenting symptoms. Progression includes trismus (jaw muscle spasms), facial muscle rigidity, life-threatening airway /pulmonary muscle spasms, and neck, back, and abdominal muscle spasms, and tonic convulsions. Treatment is in an acute care facility and includes antibiotic therapy, antitoxin, and neurological, pulmonary, and other supportive care - often in a critical care unit. Illness does not confer immunity, hence immunization is included in treatment.

Toxocariasis (Worldwide): Toxocariasis is the most common visceral larva migrans and is due to infection with the tissue nematode (roundworm) toxocara canis or T. cati. Toxocariasis is most common among children who eat feces-contaminated dirt. Most infections are small load and asymptomatic except for mild eosinophilia. Heavy worm loads, decreased immune competence, and other factors may lead to malaise, fever, cough and wheezing, hepatomegaly, anorexia, and weight loss. Ocular toxocariasis also occurs and usually leads to decreased vision. For symptomatic infections, the treatment of choice is diethylcarbamazine 6 mg/kg/day po tid for 10 days. Asymptomatic infections are not necessary to treat.

Toxoplasmosis (Worldwide): Toxoplasmosis is infection with Toxoplasma gondii, an obligate intracellular parasite (protozoan) usually transmitted by ingestion of undercooked meat or contaminated soil. There are two forms of toxoplasmosis, congenital and acquired. Congenital toxoplasmosis is associated with maternal infection shortly before conception, and is characterized by CNS involvement (convulsions, microcephaly or hydrocephaly, mental retardation and blindness) and liver involvement. Choreoretinitis is also common. Acquired toxoplasmosis is a well-known problem among immunocompromised persons, leading commonly to encephalitis, multiple organ infection, and death if not quickly treated. Among immunocompetent persons, toxoplasmosis is most commonly manifested by cervical lymphadenopathy, and less frequently by malaise, fatigue, fever, and headache. Choreoretinitis is common among both immunocompromised and immunocompetent persons. Treatment depends on immunocompetence and degree of symptomatology, and includes multi-drug regimes (commonly pyrimethamine + sulfadiazine or clindamycin) for 4-52 weeks; and in immunocompromised patients, lifelong maintenance therapy.

Trichinosis (trichinella) (Worldwide): Trichinosis is a nematode (roundworm) infection with Trichinella sp. from ingestion of meat that contains cysts, especially undercooked pork or meat from a carnivore. Infection ranges from light and asymptomatic to heavy and life-threatening. Manifestations vary according to the life cycle of the worms: Initially there is malaise, nausea, cramping abdominal pain, and diarrhea. Gastrointestinal symptoms are followed in 1-6 weeks by fever, eosinophilia, periorbital and facial edema, conjunctivitis, dysphagia, dyspnea, cough, myalgia, and muscle spasms. Complications include meningitis and other neurological disorders, myocarditis, pneumonia, and nephritis. The current treatment of choice is mebendazole 300 mg po tid for 10 days (sometimes with prednisone to control symptoms).

Trichuriasis (trichocephaliasis or whipworm) (Worldwide, especially tropical and subtropical areas): Trichuriasis is a nematode (roundworm) infection with Trichuris trichiura. Heavy infections may result in abdominal cramping, nausea, vomiting, flatulence, diarrhea, tenesmus, and weight loss. Mild infections are usually asymptomatic. Treatment is with albendazole single po dose of 400 mg (not FDA approved) or mebendazole 100 mg po bid for 3 days. Ivermectin is sometimes also used in combination with albendazole.

Tuberculosis (Worldwide): Tuberculosis (TB) is a chronic infection - most commonly pulmonary - caused by the acid-fast bacillus, Mycobacterium tuberculosis. Infection is usually acquired through inhalation of infected droplets expelled by cough from a person with active disease. Most cases (85%) of TB are pulmonary. Pulmonary symptoms include cough, chest pain, and hemoptysis. Constitutional symptoms are often present in pulmonary disease, and include fever, chills, night sweats, fatigue, decreased appetite, and weight loss. Symptoms of extrapulmonary TB depend on the site(s) of infection. Tuberculosis should always be ruled out in any person at-risk or with the above symptoms. Medical evaluation includes complete medical and family/close contacts/travel history, physical examination, Mantoux tuberculin skin test, chest x-ray, and appropriate bacteriologic or histologic examinations, e.g., smear and culture of sputum. Treatment is according to (1) classification of disease, e.g., exposure without infection, infection without disease, current TB disease, previous TB disease, or TB suspected; (2) whether disease is drug-resistant; (3) immune status of the patient; and (4) other factors. The treatment of TB is complex and is evolving at a rapid pace. Readers are referred to the U.S. Centers for Disease Control and Prevention: http://www.cdc.gov/ for current standards of testing and treatment.

Tungiasis (tropical areas of Africa and the Americas): Tungiasis is infestation with Tunga penetrans (sand fleas, jiggers), usually of the foot. Other fleas also bite humans and can transmit a variety of diseases.

Typhoid and paratyphoid fever (sometimes termed enteric fever) (Most of the developing world, especially Africa, Asia, and Latin America, including Mexico): Typhoid fever is an acute systemic febrile illness caused by Salmonella typhi and other anaerobic gram-negative Salmonella serovars, e.g., S. paratyphi, which causes the less severe paratyphoid fever. Typhoid is usually spread by feces-contaminated food or water. Note that vaccination is not completely effective. Incubation is highly variable, ranging from 3-60 days. The hallmark sign is the gradual onset of steadily increasing and then persistently high fever (though children may experience abrupt onset). Early manifestations are fever, chills, malaise, headache, sore throat, cough, and sometimes abdominal pain and constipation or diarrhea. As the illness progresses, prostration, abdominal distension, hepatosplenomegaly, anorexia, and weight loss are common. Untreated typhoid may result in complications in any of the body systems. The severity of illness varies according to immunocompetence, infectious dose of microorganisms, and other factors. Treatment is with chloramphenicol 3-4 g/d po for adults and 50-75 mg/kg/d po for children. When the patient becomes afebrile, the dose may be decreased to 2 g/d for adults and 30 mg/kg/d for children. The total duration of treatment is two weeks. In the U.S., the more common treatment is amoxicillin 4-6 g/d po in four divided (1-1.5 g) daily doses for adults and 100 mg/kg po in four divided daily doses for children. Trimethoprim-sulfamethoxazole, ciprofloxacin, or ofloxacin are also used. Early effective treatment results in increased frequency of (usually mild) relapse.

Vibrio parahaemolyticus and other vibrio species (worldwide): Vibrio are motile, anaerobic, curved, gram-negative rods that cause (according to species) gastrointestinal (notably cholera) and septic illnesses; and wound, skin, and opthalmic infections. In the U.S., Vibrio parahaemolyticus is transmitted by ingestion of undercooked seafood. In the U.S., infection results in abdominal pain, nausea, vomiting, and watery diarrhea; while in South Asia, infection causes more serious dysentery, but is seldom life-threatening. Treatment is supportive.

Yaws (frambesia) (tropical areas worldwide): Yaws is a chronic childhood illness caused by Treponoma pallidum ssp. pertenue (see other treponematoses) spread primarily by skin to skin contact. Yaws is characterized by an initial papule, which enlarges and becomes papillomatous. The lesion erodes and infectious crusting exudate appears, as well as lymphadenopathy. The initial or "mother" lesion heals, but before or after healing of the initial lesion, secondary lesions appear in a variety of forms. Late or chronic yaws appear in about 10% of patients five or more years after the initial infection. Late yaws is characterized gummatous (granulomatous) lesions of the skin and subcutaneous tissues. The bones are also affected and eventually there is erosion of the nose and facial bones. The preferred treatment is 2.4 million units of IM benzathine penicillin G for adults and 1.2 million units for children.

Yellow fever (most of tropical and subtropical South America and Africa): Yellow fever (YF) is caused by an arbovirus transmitted by the Aedes aegypti mosquito from one human to another (the urban form of YF) or from monkeys to humans (the jungle or sylvan form of YF). YF is characterized by sudden onset flu-like (non-specific) symptoms occurring in two stages with a short intervening remission. The first stage of severe YF has a sudden onset of fever, chills, intense headache, lumbosacral back pain, myalgia, nausea and vomiting, conjunctival injection, dark urine, and bradycardia in relation to fever. After a 12-24 hour remission, there is an "intoxication" or hepatorenal stage that features reemergence of generalized symptoms including increased temperature, increased nausea and vomiting, abdominal pain, jaundice, and prostration. Complications of severe YF include jaundice, dehydration, decreased renal function, delirium, and hemorrhagic symptoms. Terminal signs include progressive tachycardia, intractable hiccups, and shock. Lab findings include albuminuria, leukopenia, abnormal liver function, increased prothrombin times. Treatment is supportive, i.e, control of fever, vomiting, dehydration, and pain.

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