ABSTRACT
Toxoplasmosis, an infection caused by Toxoplasma gondii, which is found worldwide, can affect human and animal health in different ways. This study aimed to estimate the infection prevalence in humans and to determine risk factors related to urban and rural areas in a municipality in the Brazilian Amazon where an outbreak had been registered. Blood samples for serological analysis were obtained, and interviews were performed to fill out an epidemiological questionnaire. A total of 1140 individuals were included, of which 70.6% (804/1140; 95% CI: 67.9-73.2%) were positive for IgG anti-T. gondii antibodies. In rural areas, the prevalence was 62.6% (95% CI: 58.9-66.3%), while in urban areas, it was 81.9% (95% CI: 78.4-85.4%). The risk of becoming infected in urban areas was 2.7 times higher (95% CI = 2.0-3.6%) than that in rural areas. When comparing the prevalence in the age group from 1 to 10 years in both areas, the rate was 28.6% (42/147; 95% CI: 21.3-35.9%) for rural areas and 69.4% (61/88; CI 95%: 59.7-79.0%) for urban areas. Therefore, it is concluded that parasite exposure starts in the first years of life in urban areas and that disordered urban area expansion may cause an increase in exposure to the different strains of T. gondii present in the Amazon.
Subject(s)
Toxoplasma , Toxoplasmosis , Animals , Antibodies, Protozoan , Brazil/epidemiology , Child , Child, Preschool , Cross-Sectional Studies , Humans , Infant , Prevalence , Risk Factors , Seroepidemiologic Studies , Toxoplasmosis/epidemiologyABSTRACT
OBJETIVO: Relatar um surto de toxoplasmose humana ocorrido no Distrito de Monte Dourado, Município de Almeirim, Pará, Brasil. MATERIAIS E MÉTODOS: Após diagnóstico confirmatório de cinco pacientes-índices com sintomas sugestivos de toxoplasmose aguda, teve início uma investigação clínica e soroepidemiológica de toxoplasmose na localidade de procedência dos pacientes. Foram avaliados 186 indivíduos, incluindo pacientes sintomáticos, seus familiares e/ou contatos próximos. Todos, espontaneamente, submeteram-se a inquérito epidemiológico, avaliação clínica e sorologia pelo ensaio imunoenzimático (ELISA) para detecção de anticorpos IgG e IgM anti-Toxoplasma gondii. RESULTADOS: Quarenta indivíduos (21,5 por cento) apresentaram perfil sorológico de toxoplasmose aguda, considerando-se IgM e IgG reagentes em elevados títulos. A análise epidemiológica indicou que os casos poderiam estar vinculados à infecção com oocistos eliminados pelos gatos, cuja população era elevada. A hipótese provável de transmissão seria pelo contato direto com oocistos do parasito, na ingestão de alimentos contaminados, ou, possivelmente, até por inalação dessas formas presentes no solo. A possibilidade de transmissão hídrica por meio do sistema de distribuição de água local foi descartada,já que o sistema é inacessível aos gatos. Os indivíduos doentes foram tratados nos serviços de saúde do Município. Asautoridades sanitárias locais foram orientadas para implementar medidas de controle de gatos errantes, visando prevenir novos casos ou surtos. CONCLUSÃO: O surto ocorrido entre fevereiro e março de 2004, em Monte Dourado-PA, foi causado pelo T. gondii. Admite-se que houve uma somatória de fatores que mantêm a hipótese sustentada da contaminação via oocistos, tais como: elevada população de gatos no Distrito; procedimentos frequentes de jardinagem; e ausência de relatos de ingestão de carne crua ou mal cozida.
OBJECTIVE: To report an outbreak of human toxoplasmosis that occurred in the District of Monte Dourado, Municipality of Almeirim, Pará State, Brazil. MATERIALS AND METHODS: After the positive diagnosis of five patients with symptoms suggestive of toxoplasmosis, clinical research and epidemiology were executed in the locality. A total of 186 individualswere evaluated, including symptomatic patients, their relatives and/or close contacts. All subjects underwent epidemiological inquiry, clinical assessment and serology by enzyme-linked immunosorbent assay (ELISA) for detection of anti-Toxoplasma gondii IgG and IgM. RESULTS: A total of 40 individuals presented a serological profile of acute toxoplasmosis. Epidemiological analysis indicated that the cases could be related to infection with oocysts eliminated bycats, whose population density was very high in the surveyed locality. The most likely hypothesis of transmission would be through direct contact with oocysts of the parasite, either by the ingestion of contaminated food or by the inhalation of these forms in the soil. The possibility of water transmission through the local supply system was discarded because the system is inaccessible to cats. Infected individuals were treated at the local health care units. Moreover, local health authorities were instructed to implement measures to control stray cats in order to prevent new cases or outbreaks. CONCLUSION: The outbreak that occurred between February and March 2004 in Monte Dourado was caused by T. gondii. The hypothesis of contamination via oocysts of the parasite is supported by several factors, such as a high population density of cats in the surveyed District, frequent gardening habits and a lack of reports of ingestion of raw or undercooked meat.
