Los transmisores de Trypanosoma cruzi, flagelado causante de la enfermedad, se dividen en intradomiciliados, peridomiciliados y silvestres. Entre los intradomiciliados se encuentran, Triatoma barberi y Triatoma dimidiata, que son los que representan un mayor riesgo para la Salud Pública, en México. Aunque Triatoma dimidiata se encuentra principalmente dentro de la vivienda, en Yucatán tiene un comportamiento peridomiciliar, dentro de este grupo se encuentran la mayoría de los transmisores de la enfermedad de Chagas Meccus longipennis, M. mazzottii, M. pallidipennis, M. phyllosomus, M. picturatus, Triatoma gerstaeckeri, T. mexicana, T. rubida, Dipetalogaster máxima, Panstrongylus rufotuberculatus y Rhodnius prolixus. Los transmisores peridomiciliados son de menor riesgo en la dinámica de transmisión comparados con los intradomiciliados. Para el control de los transmisores intradomiciliados, se deben emplear programas de educación para la salud, mejoramiento de vivienda e insecticidas; mientras que para los vectores visitantes o peridomiciliados, son necesarios programas de educación para la salud, uso de mosquiteros, pabellones y cementación de las bardas de piedra.

Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic and sylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest health risk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but in Yucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors are found: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatoma gerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted to the domicile), Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodnius prolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmission dynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health education programs, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, health education programs are required, as well as the use of mosquito nets on doors and windows and around beds, aside from cementing the stone wall fences.

Objective: To compare the left ventricular function and the ventricular synchrony in patients with Chagas disease in latency stage respect to a control group. Methods: We analyze a prospective, comparative, transversal and non randomized study of the left ventricular function (LVF) and the ventricular contraction synchronicity (VCS) in 36 subjects with positive serology for Chagas disease (18 males and 18 females), with mean of 15 ± 5 years old. The findings were compared with respect to 23 control volunteers (11 males and 12 females) with mean of 28 ± 5 years old. LVF and VCS were evaluated using equilibrium radionuclide angiography images (ERNA). The comparison of both Chagas and control populations was carried out by t Student test for independent samples, considering a statistically significant value of p < 0.05. Results: The parameters of the ventricular function and the ventricular synchronicity in subjects with positive serology for Chagas disease were not statistically different with respect to the parameters of the control group. However, although they have a homogeneous contraction, the mean time of contraction for the right and the left ventricle is statistically smaller with respect to the control group. Conclusions: In clinically incipient stages of Chagas disease we do not found abnormalities in the ventricular function and the ventricular synchronicity. It's necessary to consider the follow up of the studied populations using indices for the identification of abnormalities of the autonomic nervous system.

Objetivo: Comparar la función ventricular izquierda y la sincronía de la contracción ventricular en un grupo de sujetos con enfermedad de Chagas en estadio de latencia respecto a un grupo de individuos control. Método: Se realizó un estudio prospectivo, transversal, comparativo y no aleatorio de la función ventricular izquierda (FVI) y la sincronía de la contracción ventricular (SCV) en 36 personas con serología positiva de enfermedad de Chagas (18 varones y 18 mujeres) cuya edad promedio fue de 15 ± 5 años. Los hallazgos se compararon respecto a un grupo de 23 voluntarios considerados normales (11 varones y 12 mujeres) con edad promedio de 28 ± 5 años. La FVI y la SCV fueron evaluadas mediante la modalidad de imagen denominada ventriculografía radioisotópica en equilibrio (VRIE). Para comparar las poblaciones se utilizó la prueba estadística t de Student para muestras independientes, y se consideró un valor de significancia de p < 0.05. Resultados: Los parámetros utilizados para evaluar la FVI y la SCV en los sujetos con serología positiva para enfermedad de Chagas no fueron diferentes desde el punto de vista estadístico a los calculados para los sujetos control. Sin embargo, aunque la contracción es homogénea, el tiempo promedio en que se realiza la contracción del ventrículo derecho (VD) y del ventrículo izquierdo (VI) sí es menor estadísticamente respecto al grupo de sujetos control. Conclusiones: En estadios clínicamente incipientes de la enfermedad de Chagas no se detectaron anormalidades en la FVI ni signos de asincronía interventricular o intraventricular. Es necesario realizar el seguimiento de la población estudiada con índices que permitan identificar anormalidades en el sistema nervioso autónomo.

Three different interventions to control Triatoma dimidiata in the State of Veracruz were implemented: X-1 = whole dwelling spraying, X-2 = middle wall spraying, X-3 = household cleaning. Cyfluthrin was sprayed 3 times with 8 month intervals. After each spraying, insects were collected and sent to the laboratory to be recorded and to determine genus and species of the adult triatomine bugs, and nymphs were counted. Trypanosoma cruzi presence was determined. With X-1, the infestation, colonization, and natural infection indexes were reduced to 0% in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10% at t3 in 3 localities; the colonization index was reduced to 0% in only 1 locality at t3, and the natural infection index was reduced to 0% at t3. With X-3 the 3 indexes were not effectively reduced but they decreased with respect to the baseline study. Insecticide application to the whole dwelling is a more efficient intervention than its application to only the lower half of the walls and to the cleaning of houses.