Tropical medicine is the branch of medicine that deals with health problems that either occur uniquely in tropical and subtropical regions or are either more widespread in the tropics or more difficult to prevent or control.

Many infections that are classified as "tropical diseases" used to be endemic in countries located in temperate or even cold areas. That was the case for leprosy, cholera, malaria, hookworm infestations, amoebiasis, among others. The disappearance of those diseases from developed countries was primarily caused by improvements in housing, diet, sanitation, and personal hygiene. Since climate is not the main reason why those infections remain endemic in tropical areas, there is a trend towards renaming this speciality as "Geographic Medicine".

See also

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• Tropical disease

Organizations

• The American Society of Tropical Medicine and Hygiene
• The Royal Society of Tropical Medicine and Hygiene

Medical specialties

More on [ Tropical medicine ]

pubmed: 0002-9637

Rapid Molecular Detection of Opisthorchis viverrini in Human Fecal Samples by Real-Time Polymerase Chain Reaction.
Intapan PM, Thanchomnang T, Lulitanond V, Pongsaskulchoti P, Maleewong W Rapid Molecular Detection of Opisthorchis viverrini in Human Fecal Samples by Real-Time Polymerase Chain Reaction. Am J Trop Med Hyg. 2009 Nov;81(5):917-20 Authors: Intapan PM, Thanchomnang T, Lulitanond V, Pongsaskulchoti P, Maleewong W Real-time fluorescence resonance energy transfer (FRET) polymerase chain reaction (PCR) supplemented with melting curve analysis is a highly sensitive and fast method offering a high throughput. We report the development of a real-time FRET PCR for molecular detection of Opisthorchis viverrini in human fecal samples. The diagnostic sensitivity, specificity, accuracy, and positive and negative predictive values of this method were 97.5%, 100%, 98.9%, 100%, and 98.2%, respectively. The sensitivity was not significantly different from that of the quantified formalin-ethyl acetate concentration technique, the gold standard (P > 0.05). The procedure has potential for diagnosis of human opisthorchiasis in disease-endemic areas, for large epidemiologic investigations involving at risk populations, and monitoring eradication programs of the liver fluke, which causes hepatobiliary diseases and induces cholangiocarcinoma. PMID: 19861632 [PubMed - in process]
Immunologic profiles of persons recruited for a randomized, placebo-controlled clinical trial of hookworm infection.
Blount D, Hooi D, Feary J, Venn A, Telford G, Brown A, Britton J, Pritchard D Immunologic profiles of persons recruited for a randomized, placebo-controlled clinical trial of hookworm infection. Am J Trop Med Hyg. 2009 Nov;81(5):911-6 Authors: Blount D, Hooi D, Feary J, Venn A, Telford G, Brown A, Britton J, Pritchard D Data from epidemiologic studies suggest that hookworm infections, in establishing an immunologic phenotype conducive to parasite survival, may protect against the development of allergic disease. We describe immunologic findings from a clinical study designed to investigate the safety of iatrogenic hookworm infection in participants with allergic rhinitis. The low, relatively safe level of hookworm infection used in this study was immunogenic, inducing eosinophilia and a significant specific IgG response. Importantly, no potentiation of IgE responses to the environmental allergens to which the participants were sensitized was seen. However, no evidence of systemic immune regulation was seen in infected participants. This finding may indicate that the level of infection or the frequency of infection may have to be altered in future trials to induce a therapeutically conducive immunologic phenotype. PMID: 19861631 [PubMed - in process]
Prevalence of Leptospira spp. in Urban Rodents from a Groceries Trade Center of Medellin, Colombia.
Agudelo-Flórez P, Londoño AF, Quiroz VH, Angel JC, Moreno N, Loaiza ET, Muñoz LF, Rodas JD Prevalence of Leptospira spp. in Urban Rodents from a Groceries Trade Center of Medellin, Colombia. Am J Trop Med Hyg. 2009 Nov;81(5):906-10 Authors: Agudelo-Flórez P, Londoño AF, Quiroz VH, Angel JC, Moreno N, Loaiza ET, Muñoz LF, Rodas JD Leptospirosis is a widely distributed zoonosis, and rats are its most common source of infection. Our goal was to determine the frequency for Leptospira infection in rodents in a farmers market in the city of Medellin. We performed a descriptive transversal study sampling 254 rodents. Rodents were bled and killed, and kidneys samples were taken. Supernatants of macerated kidneys were cultured on Fletcher medium. Microagglutination tests (MATs) with 11 serovars were also carried out in rat serum, and a polymerase chain reaction (PCR) specific for pathogenic species was used to test each bacterial culture. All animals were identified as Rattus norvegicus; 25% and 20% were positive by MAT and culture, respectively. PCR tests of 12 isolates were positive for pathogenic serovars, and 4 of them were confirmed as L. interrogans by sequencing. These data show the role of this natural carrier and shedder of pathogenic leptospires in the epidemiology of urban leptospirosis in Colombia. PMID: 19861630 [PubMed - in process]
Micro-Positron Emission Tomography in the Evaluation of Trypanosoma cruzi-Induced Heart Disease: Comparison with Other Modalities.
Prado CM, Fine EJ, Koba W, Zhao D, Rossi MA, Tanowitz HB, Jelicks LA Micro-Positron Emission Tomography in the Evaluation of Trypanosoma cruzi-Induced Heart Disease: Comparison with Other Modalities. Am J Trop Med Hyg. 2009 Nov;81(5):900-5 Authors: Prado CM, Fine EJ, Koba W, Zhao D, Rossi MA, Tanowitz HB, Jelicks LA Noninvasive assessment of cardiac structure and function is essential to understand the natural course of murine infection with Trypanosoma cruzi. Magnetic resonance imaging (MRI) and echocardiography have been used to monitor anatomy and function; positron emission tomography (PET) is ideal for monitoring metabolic events in the myocardium. Mice infected with T. cruzi (Brazil strain) were imaged 15-100 days post infection (dpi). Quantitative (18)F-FDG microPET imaging, MRI and echocardiography were performed and compared. Tracer ((18)F-FDG) uptake was significantly higher in infected mice at all days of infection, from 15 to 100 dpi. Dilatation of the right ventricular chamber was observed by MRI from 30 to 100 dpi in infected mice. Echocardiography revealed significantly reduced ejection fraction by 60 dpi. Combination of these three complementary imaging modalities makes it possible to noninvasively quantify cardiovascular function, morphology, and metabolism from the earliest days of infection through the chronic phase. PMID: 19861629 [PubMed - in process]
Long-Term Relapse Risk of Multibacillary Leprosy after Completion of 2 Years of Multiple Drug Therapy (WHO-MDT) in Cebu, Philippines.
Balagon MF, Cellona RV, Cruz ED, Burgos JA, Abalos RM, Walsh GP, Saunderson PR, Walsh DS Long-Term Relapse Risk of Multibacillary Leprosy after Completion of 2 Years of Multiple Drug Therapy (WHO-MDT) in Cebu, Philippines. Am J Trop Med Hyg. 2009 Nov;81(5):895-9 Authors: Balagon MF, Cellona RV, Cruz ED, Burgos JA, Abalos RM, Walsh GP, Saunderson PR, Walsh DS From 1987 to 1994, we enrolled 500 subjects completing 2-year WHO multiple drug therapy (MDT) for multibacillary leprosy in a prospective relapse study. Relapse was defined as new skin lesions and an increase in the bacterial index (BI) >/= 2+ (>/= 100x) at any single slit-skin smear site. At the study end in 2006, follow-up was 6,401 subject-years, a mean of 12.8 years/subject. We observed 23 relapses, 6-16 years after MDT (mean, 10.5 years; 95% confidence interval [CI], 9.2-11.8), peaking in Years 11-12 (> 1%/year). The cumulative risk was 6.6% (95% CI, 5.0-8.2%). In a subset of 181 subjects with pre-MDT average BI >/= 4+, 11 relapses occurred (cumulative risk, 10.1%). In mouse footpad assays, Mycobacterium leprae from relapsed subjects were rifampin and clofazimine sensitive. Taken together, the data suggest relapses are related to activation of dormant organisms (persisters) not killed by MDT rather than new infection. PMID: 19861628 [PubMed - in process]
Persistence of Mycobacterium ulcerans Disease (Buruli Ulcer) in the Historical Focus of Kasongo Territory, the Democratic Republic of Congo.
Suykerbuyk P, Wambacq J, Phanzu DM, Haruna H, Nakazawa Y, Ooms K, Kamango K, Stragier P, Singa JN, Ekwanzala F, De Herdt E, De Maeyer P, Kestens L, Portaels F Persistence of Mycobacterium ulcerans Disease (Buruli Ulcer) in the Historical Focus of Kasongo Territory, the Democratic Republic of Congo. Am J Trop Med Hyg. 2009 Nov;81(5):888-894 Authors: Suykerbuyk P, Wambacq J, Phanzu DM, Haruna H, Nakazawa Y, Ooms K, Kamango K, Stragier P, Singa JN, Ekwanzala F, De Herdt E, De Maeyer P, Kestens L, Portaels F Fifty years after the last report of Mycobacterium ulcerans infections (Buruli ulcer [BU]) in Kasongo Territory, Maniema Province, Democratic Republic of Congo (DRC), we conducted a small-scale cross-sectional survey to assess if this historical BU focus was still active and if so to explore the disease epidemiology. Seventy-five active and inactive BU cases were identified on clinical grounds of which two of 28 BU active cases were laboratory confirmed. We used a modified BU02 form to reconstruct the local disease dynamics and we believe that the horrific conflict in eastern DRC and exceptional flooding were the most likely causes of the re-emergence of the disease. There is a need in the DRC to decentralize and integrate surveillance and control activities at local level to increase the effectiveness of patient management. PMID: 19861627 [PubMed - as supplied by publisher]
Household characteristics associated with handwashing with soap in rural bangladesh.
Luby SP, Halder AK, Tronchet C, Akhter S, Bhuiya A, Johnston RB Household characteristics associated with handwashing with soap in rural bangladesh. Am J Trop Med Hyg. 2009 Nov;81(5):882-7 Authors: Luby SP, Halder AK, Tronchet C, Akhter S, Bhuiya A, Johnston RB Handwashing with soap prevents diarrhea and respiratory disease, but it is rarely practiced in high-need settings. Among 100 randomly selected villages in rural Bangladesh, field workers enrolled 10 households per village and observed and recorded household activities for 5 hours. Field workers observed 761 handwashing opportunities among household members in 527 households who had just defecated or who cleaned a child's anus who had defecated. In the final multivariate analysis, having water available at the place to wash hands after toileting (odds ratio = 2.2, 95% confidence interval 1.3, 4.0) and having soap available at the place to wash hands after toileting (odds ratio = 2.1, 95% confidence interval 1.3, 3.4) were associated with washing both hands with soap after fecal contact. Interventions that improve the presence of water and soap at the designated place to wash hands would be expected to improve handwashing behavior and health. PMID: 19861626 [PubMed - in process]
Population seroprevalence of hepatitis e virus antibodies in rural bangladesh.
Labrique AB, Zaman K, Hossain Z, Saha P, Yunus M, Hossain A, Ticehurst J, Nelson KE Population seroprevalence of hepatitis e virus antibodies in rural bangladesh. Am J Trop Med Hyg. 2009 Nov;81(5):875-81 Authors: Labrique AB, Zaman K, Hossain Z, Saha P, Yunus M, Hossain A, Ticehurst J, Nelson KE Hepatitis E virus (HEV) causes a substantial burden of sporadic and epidemic disease worldwide. HEV infections result in serious morbidity and mortality, especially among pregnant women, and have significant economic costs. Few population-based studies have characterized the epidemiology of HEV. A rural Bangladeshi population was studied to determine the age- and gender- specific population seroprevalence of antibodies to HEV. Of 1,134 specimens tested from a representative, random population sample, 255 (22.5%) were anti-HEV IgG seropositive. Seroprevalence was lower among women (19.7%) than among men (25.8%). We found anti-HBc (hepatitis B core) in 380 of 1080(35.2%) tested, anti-HCV (hepatitis C) in 14 of 917(1.5%) tested, and anti-HAV (hepatitis A) in 116 of 124(93.5%) tested individuals. Our data suggest that viral hepatitis, especially HEV, remains an under-recognized and significant public health problem in rural Bangladeshi populations, warranting further attention. PMID: 19861625 [PubMed - in process]
Coverage of and Influences on Timely Administration of Hepatitis B Vaccine Birth Dose in Remote Rural Areas of the People's Republic of China.
Zhou Y, Wang H, Zheng J, Zhu X, Xia W, Hipgrave DB Coverage of and Influences on Timely Administration of Hepatitis B Vaccine Birth Dose in Remote Rural Areas of the People's Republic of China. Am J Trop Med Hyg. 2009 Nov;81(5):869-74 Authors: Zhou Y, Wang H, Zheng J, Zhu X, Xia W, Hipgrave DB A survey was conducted in 2006 to assess the coverage and timeliness of the birth dose of hepatitis B vaccine (HepB(1)) and related influences among children in rural areas of Guangxi, Guizhou, Tibet, and Shaanxi provinces, People's Republic of China. A total of 3,390 children born in 2004 were surveyed in four counties in each province, where a project to strengthen routine immunization is being implemented by the China Ministry of Health, supported by the United National Children's Fund. Two-stage stratified cluster sampling was undertaken to select those surveyed. A questionnaire was administered to parents or guardians and vaccination records were assessed. HepB(1) administration was timely for 31.6% of the sample. Timeliness of HepB(1) for children delivered at home (13%) was lower than for children born at county-level or higher facilities (54%) (odds ratio [OR] = 6.52, (95% confidence interval [CI] = 5.29-8.04, P < 10 (-3)), at township hospitals (49%, OR = 7.14, 95% CI = 5.68-8.98, P < 10 (-3)), or private clinics (59%, OR = 5.64, 95% CI = 3.68-8.64, P < 10 (-3)). Children of Tibetan (24.8%, OR = 0.16, 95% CI = 0.12-0.21, P < 10 (-4)), Zhuang (27.8%, OR = 0.73, 95% CI = 0.57-0.94, P < 0.02) or Meng, Miao, and Hui ethnicity (14.2%, OR = 0.36, 95% CI = 0.29-0.45, P < 10 (-4)) were less likely than children of Han ethnicity (33.2%) to have received a timely birth dose. Children lacking vaccination registration cards (OR = 0.64, 95% CI = 0.51-0.80, P < 10 (-4)) and children whose parents or guardians did not know the importance of timely HepB immunization (OR = 0.62, 95% CI = 0.46-0.84, P < 10 (-2)) were also less likely to have received a timely birth dose. Parental knowledge and prioritization of birth-dosing was low among children who did not receive it. The timeliness of HepB(1) should improve with increasing rates of hospital delivery, training of birth attendants, increasing staff and community awareness of the importance of the birth dose, and by focusing on vulnerable groups. PMID: 19861624 [PubMed - in process]

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