Resetting our priorities in environmental health: an example from the South-North partnership in Lake Chapala, Mexico.

Lake Chapala is a major source of water for crop irrigation and subsistence fishing for a population of 300,000 people in central Mexico. Economic activities have created increasing pollution and pressure on the whole watershed resources. Previous reports of mercury concentrations detected in fish caught in Lake Chapala have raised concerns about health risks to local families who rely on fish for both their livelihood and traditional diet. Our own data has indicated that 27% of women of childbearing age have elevated hair mercury levels, and multivariable analysis indicated that frequent consumption of carp (i.e., once a week or more) was associated with significantly higher hair mercury concentrations. In this paper we describe a range of environmental health research projects. Our main priorities are to build the necessary capacities to identify sources of water pollution, enhance early detection of environmental hazardous exposures, and deliver feasible health protection measures targeting children and pregnant women. Our projects are led by the Children's Environmental Health Specialty Unit nested in the University of Guadalajara, in collaboration with the Department of Environmental Health of Harvard School of Public Health and Department of Pediatrics of the New York School of Medicine. Our partnership focuses on translation of knowledge, building capacity, advocacy and accountability. Communication will be enhanced among women's advocacy coalitions and the Ministries of Environment and Health. We see this initiative as an important pilot program with potential to be strengthened and replicated regionally and internationally.

Identification in triatomine vectors of feeding sources and Trypanosoma cruzi variants by heteroduplex assay and a multiplex miniexon polymerase chain reaction.

Feeding sources of triatomine vectors (Triatoma longipennis) collected in peridomiciles in Mexico were identified by a heteroduplex assay developed with triatomine blood meals. Trypanosoma cruzi parasites were also characterized in the same blood meal samples by multiplex-polymerase chain reaction assay of mini-exon gene inter-genic regions. The main blood meal source was from rats, but the bugs were able to feed on a wide variety of hosts, and human blood meals were identified. Trypanosoma cruzi was the only flagellate species identified in the blood meals. All populations belong to the T. cruzi I lineage, a result that is consistent with the previously assumed predominance of this lineage in Mexico. This combination of blood meal and T. cruzi lineage identification provides a powerful tool for understanding T. cruzi transmission cycles.

Feeding patterns of Triatoma longipennis Usinger (Hemiptera, Reduviidae) in peridomestic habitats of a rural community in Jalisco State, Mexico.

We analyzed triatomine blood feeding patterns to evaluate the role of peridomiciles in Trypanosoma cruzi transmission at the rural village of Tepehuaje de Morelos at Jalisco State, Mexico (1999). A total of 206 bugs were collected in 11 out of 26 households (42.3%). Nymphs predominated in the collections (64.9% of the total). Except for one Triatoma barberi female, a species that belongs to the protracta species complex, all adults were Triatoma longipennis, a species of the phyllosoma complex. Triatomines were exclusively present in peridomestic sites mainly piles of tiles and bricks, and none were found indoors. Overall infection rate was 56.6% and no significant differences (P > 0.05) were observed between nymphs and adults or males and females. Identified blood meals were chicken (29.4%), opossum (20.9%), pig (24.5%), murid (20.9%), dog (3.5%), and armadillo (0.7%). No gut content reacted against anti-human, anti-bovine, anti-rabbit, and anti-cat sera. In contrast to fifth nymphs and adults, 87% of the small nymphs fed on one host, indicating that they are less mobile than other stages. Most fifth nymphs and adults fed on domestic hosts, while small nymphs mainly fed on opossum and murid. Infection blood-meal indexes were around 50% for single meals on opossum and murid, stressing their importance as trypanosome donors. Peridomiciles in Tepehuaje could be regarded as interaction sites among domestic and wild and synanthropic mammals and triatomines, which would facilitate circulation of the same T. cruzi strains between domestic and sylvatic cycles. Stone-made walls and building materials, which hold synanthropic rodents and opossums, should be considered as targets for vector control measures.

Doença de Chagas aguda em mulher de 80 anos no México: relato anatomopatológico / Acute Chagas' disease in woman of 80 years in Mexico: an anatomopathological report

Mulher de 80 anos de idade, com doença de Chagas aguda diagnosticada à necrópsia, adquirida, provavelmente, através de triatomíneos de Zacoelo de Torres, no Estado de Jalisco, México. Assinala-se a raridade do encontro de casos de doença de Chagas agudo, na faixa etária da paciente. O exame anatomopatológico mostrou comprometimento do coraçäo, esôfago e intestino grosso. Encontrou-se lesöes no sistema nervoso autônomo intramural do esôfago e do intestino grosso, sendo estes achados de interesse, por ocorrer em área geográfica onde os megas tem sido pouco relatados

Prevalencia de infeccion a Trypanosoma cruzi en donadores de sangre en el estado de Jalisco, Mexico / The prevalence of Trypanosoma cruzi infection in blood donors in the state of Jalisco, Mexico

Durante el periodo de Octubre de 1991 a Marzo de 1992, se tomaron 3419 muestras de donadores de sangre de 12 localidades rurales y de 8 hospitales urbanos a los que se les realizó un estudio serológico mediante la reacción de hemaglutinación indirecta encontrádose anticuerpos contra Trypanosoma cruzi em 44 indivíduos 39 masculinos y 5 femininos. El 90,9 por cento de donantes fueron masculinos. De acuerdo a su procedencia, el 73,5 por ciento fué del área urbana y el 26,5 por ciento del área rural. De acuerdo a los resultados el riesgo de transmisión de T. cruzi por transfusion sanguinea está latente por la creciente urbanización de la enfermedad de Chagas