RESUMO
A seroepidemiologic survey conducted in 1971 in the rural Pacific coastal community of Chila in the Mexican state of Oaxaca showed an unusually high prevalence of antibody against the Chagas' disease agent Trypanosoma cruzi. Further studies were undertaken in 1973 and 1981 to (1) determine the pathologic impact of T. cruzi infection in humans, (2) investigate the natural history of the disease, (3) confirm that serologically positive persons were parasitologically positive, and (4) evaluate whether T. cruzi transmission continued into the next decade. This article reports results derived from those studies.
PIP: In 1971, health workers drew blood samples from 238 people living in the rural Pacific coastal village of Chile in Oaxaca State, Mexico to determine seroprevalence of antibodies against Trypanosoma cruzi--the parasite responsible for Chagas' disease. Seroprevalence was 5% in 16 year old children, but increased from 41% to 62% to a peak of 78% for 16-19, 20-29, and 30-39 year olds respectively then fell to 68% for 40-49 year olds only to climb again to 75% in 50-59 year olds and fell again to 47% for =or 60 year olds. Overall seroprevalence for adults was 67%. By 1981, adult seroprevalence had fallen to 33% and childhood prevalence to 0.7%. The very low levels of T. cruzi antibodies in children corresponded with insecticide (DDT) spraying for malaria control and with the disappearance of triatomine bugs from Chile. Medical histories revealed that seropositive individuals were more likely to exhibit acute signs and symptoms of initial bite lesions (Romana's sign), furuncle like skin lesions (Chagoma), and facial or body edema (p.05). They also tended to suffer from chronic fatigue and difficult breathing while lying down (p.05). 1973 electrocardiogram (ECG) results showed that seropositive individuals were significantly more likely to have complete right bundle branch block (p.005) and premature ventricular contractions (p.05) than seronegative individuals. There were no seroconversions among 57 people examined with ECGs between 1971-1983. Even though more seropositives (21%) experienced a progression of ECG abnormalities (3% rate/year) than seronegatives (7%), the difference was not significant. Despite reductions in seroprevalence and in triatomine bug population, serologic surveillance and monitoring to detect repopulation of houses by the bugs should be maintained.
Assuntos
Doença de Chagas/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Bloqueio de Ramo/epidemiologia , Bloqueio de Ramo/etiologia , Doença de Chagas/complicações , Doença de Chagas/imunologia , Criança , Pré-Escolar , Estudos Transversais , Eletrocardiografia , Feminino , Seguimentos , Humanos , Lactente , Estudos Longitudinais , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Saúde da População Rural , Trypanosoma cruzi/imunologiaRESUMO
A community-based, case-control study was conducted during the summer peak season for diarrhea in the highlands of Chiapas, Mexico, to identify risk and protective factors associated with acute diarrhea in children less than 6 years of age. To estimate the diarrheal morbidity rate, the community was divided into 13 sectors, each of about 20 households. A resident (volunteer mother) made daily visits to every household in her sector to identify new cases of diarrhea. During 3 weeks of surveillance, 63 children with diarrhea and 48 control children were identified. The diarrheal attack rate during this period for children less than 6 years of age was 30%. Analysis of 29 neighborhood-matched case-control pairs showed that children with diarrhea were more likely than their controls to have had a mother with diarrhea in the 2 weeks preceding the onset of the child's diarrhea (P less than 0.05; relative risk = 10). The association of childhood diarrhea with maternal diarrhea may serve as a focus for more detailed studies as well as an intervention that may be appropriate and effective for this community.
Assuntos
Diarreia Infantil/epidemiologia , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Diarreia/epidemiologia , Diarreia Infantil/etiologia , Diarreia Infantil/prevenção & controle , Feminino , Humanos , Lactente , Masculino , México/epidemiologia , Fatores de Risco , População Rural , Fatores SocioeconômicosRESUMO
A case-control study was conducted in the highlands of Chiapas, Mexico, to identify factors associated with acute diarrhea in children less than six years old. The study found that the diarrhea attack rate among the children surveyed during three weeks in the month of August (the peak diarrhea season) was approximately 30%, and that children whose mothers had diarrhea were especially likely to contract the illness themselves. The methods employed could prove relevant to studies in other areas, and the results obtained could provide the basis for more detailed study of the area involved--and for preventive action.
Assuntos
Diarreia Infantil/epidemiologia , Diarreia/epidemiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Diarreia/etiologia , Diarreia/prevenção & controle , Diarreia Infantil/etiologia , Diarreia Infantil/prevenção & controle , Feminino , Desinfecção das Mãos , Humanos , Lactente , Recém-Nascido , Masculino , México , Fatores de Risco , Estações do Ano , Inquéritos e QuestionáriosRESUMO
Las encuestas serológicas realizadas en 1971 en el estado de Oaxaca, México, revelaron niveles desusadamente altos de anticuerpos a Trypanosoma cruzi, agente de la enfermedad de Chagas, en ciertas comunidades. En Cerro del Aire resultaron positivas 76% de las 248 personas mayores de 20 años sometidas a pruebas serológicas. Sin embargo, solo 2% de los menores de 10 años dieron resultados seropositivos y la ausencia del vector indicó que la infección no se había transmitido en esa comunidad por un período de cerca de 10 años. En 1973 y 1980 se emprendieron nuevos estudios con fines de: 1) determinar los efectos patológicos de la infección en el hombre; 2) investigar la historia natural de la enfermedad; 3) comprobar que las personas con reacciones serológicas positivas eran parasitológicamente positivas, y 4) comparar los métodos de aislamiento de T. cruzi. De los 237 habitantes de Cerro del Aire (124 eran menores de 16 años) que se sometieron a las pruebas de hemaglutinación indirecta, aglutinación directa y fijación del complemento en 1980, 35% fueron seropositivos. Los exámenes clínicos y electrocardiográficos mostraron diferencias significativas entre 111 personas seropositivas y 65 seronegativas. Los sujetos seropositivos que proporcionaron sus historiales clínicos notificaron lesiones tipo chagoma o Romaña con más frecuencia que los seronegativos (p<0,02). Las diferencias también fueron significativas respecto de los dolores precordiales (p<0,05) y palpitaciones (p<0,02). Los electrocardiogramas revelaron uno o más tipos de anormalidades en 46% de los sujetos seropositivos, pero solo en 22% de los seronegativos (p<0,005). El bloqueo de rama derecha se presentó en 12% de los seropositivos y en 2% de los seronegativos (p<0,02), y las extrasístoles ventriculares en 6% de seropositivos y en ninguno de los seronegativos (p<0,05)...
Assuntos
Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Doença de Chagas/epidemiologia , Testes Sorológicos , Eletrocardiografia , Estudos Longitudinais , MéxicoAssuntos
Cardiomiopatia Chagásica/epidemiologia , Adolescente , Adulto , Bloqueio de Ramo/diagnóstico , Cardiomiopatia Chagásica/diagnóstico , Cardiomiopatia Chagásica/transmissão , Criança , Pré-Escolar , Eletrocardiografia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , México , Pessoa de Meia-Idade , População Rural , Testes Sorológicos , Trypanosoma cruzi/isolamento & purificaçãoAssuntos
Defecação , Comportamento Alimentar , Insetos Vetores , Triatoma/fisiologia , Triatominae/fisiologia , Animais , Feminino , Masculino , MéxicoAssuntos
Doença de Chagas/epidemiologia , Adolescente , Adulto , Anticorpos/análise , Doença de Chagas/imunologia , Criança , Pré-Escolar , Feminino , Geografia , Testes de Hemaglutinação , Humanos , Lactente , Masculino , México , Pessoa de Meia-IdadeRESUMO
Se efectuaron dos encuestas seroepidemiologicas en el estado de Chiapas, Mexico, con objeto de obtener informacion sobre la distribucion geografica de la enfermedad de Chagas. Durante la primera, que se hizo a toda la extension de dicho estado, tornaron 1.827 muestras de sangre de 29 comunidades.Se encontraron pruebas serologicas de infeccion en cinco de las comunidades, que estaban ubicadas en una zona semitropical de la region noreste de Chiapas.Fueron seropositivas 28 por ciento de las personas investigadas (80 en total) en la poblacion Agua Azul Chiquito, 14 por ciento (73 en total) de la de Leon Brindis, y 5.8 por ciento (353 en total) de las de otras tres comunidades. De los 150 ninos menores de diez anos de edad investigados en cinco comunidades, 4 por ciento fueron seropositivos, lo que indica que probablemente prosigue la transmision.En la segunda encuesta efectuada en 28 comunidades de la municipalidad de Margaritas, solamente cinco (0,3 por ciento) de las 1.476 personas investigadas fueron seropositivas