Evaluación de la función y sincronía de la contracción ventricular en pacientes con enfermedad de Chagas en estadio de latencia / Evaluation of the function and ventricular synchrony in patients with latency stage of Chagas' disease

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.

Insecticide and community interventions to control Triatoma dimidiata in localities of the State of Veracruz, Mexico

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 percent in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10 percent at t3 in 3 localities; the colonization index was reduced to 0 percent in only 1 locality at t3, and the natural infection index was reduced to 0 percent 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.

Frecuencia de Toxocara canis en perros y áreas verdes del sur de la ciudad de México Distrito Federal / Frequency of Toxocara canis in dogs and green area in the south of Mexico City

El objetivo de este trabajo fue determinar la frecuencia de contaminación de áreas verdes por perros parasitados con Toxocara canisen seis delegaciones políticas del sur de la ciudad de México, Distrito Federal. Se colectaron 935 muestras de suelo de 200 g cada una en 187 áreas de estudio de dicha zona. Las muestras se obtuvieron en Coyoacán, Iztapalapa, Milpa Alta, Tláhuac, Tlalpan y Xochimilco. La colecta de muestras de suelos se realizó en 82 parques, 22 jardines y 83 camellones. También se estudiaron 710 muestras de materia fecal de perros, 500 de éstos tenían dueño y 210 eran animales vagabundos que habitaban en la misma zona. Las muestras de suelo se procesaron con la técnica de Ferreira, modificada con gradiente de concentración de sulfato de zinc 1:200, las heces se procesaron mediante el método de Faust, El 14.6 por ciento de las muestras de suelos estudiadas resultaron positivas con huevos de T. Canis. La frecuencia de contaminación con estos huevecillos en las muestras de suelos por delegación, Fue: Xochimilco, 16.8 por ciento; Tláhuac, 15.4 por ciento; Iztapalapa, 14.5 por ciento; Coyoacán, 10.9 por ciento; Tlalpan, 9.5 por ciento; y Milpa Alta, 8.3 por ciento. La frecuencia de T. Canis en las heces de perros con dueño fue de 21.2 por ciento y en los perros callejeros de 12.4 por ciento. Las elevadas frecuencias de contaminación de áreas verdes, así como el alto porcentaje de este parásito, hacen necesario legislar estrictas medidas de control de excretas tanto de perros con dueño como de perros vagabundos; de esta forma, los seres humanos tendrán menor riesgo de adquirir toxocariasis al frecuentar lugares de esparcimiento

Verduras de consumo humano como probable fuente de infección de toxocara sp. para el hombre / Vegetables for human consumption as probable source of toxocara sp. infection to man

Although Toxocara canis life cycle is known, other possible mechanisms dynamically involved in its transmission to man are still ignored. The object of the present investigation was to search the occurrence of Toxocara sp. eggs in vegetables which humans consume. Five hundred and thirty six vegetables from a supply distribution center in Mexico City (Distrito Federal) were examined. Those included 212 carrots, 76 potatoes, 31 radishes, 22 mushrooms, 27 lettuces, 20 sweet potatoes and 66 bundles of spinaches, 32 bundles of salt-worts, 29 bundles of coriander, and 21 bundles of purslane. Each unit or bundle was @ashed with 50 ml of sterilized water, allowing sedimentation at room temperatura for 8 hours. Five ml of sediment were centrifugated at 3,000 r.p.m. for 5 minutes. Sediment was examined in lugol stained fresh plates through light microscopy, which tumed to be Toxocara sp. eggs were found only in two vegetables: 1.9 percent of car-rots and 6.5 percent of radishes. Toxocara sp. eggs were: 66.7 percent recently emitted and 33.3 percent embryonated. Other parasite elements were: Ascaris lumbricoides eggs 1.9 percent in carrots, 2.6 percent in potatoes, 9. 1 percent in mushrooms, 6.9 percent in corianders, 20.0 percent in sweet potatoes and 6. 1 percent in spinachs. Entamoeba histolytica cyts were found in 0.9 percent of carrots. Soil contamination with Toxocara sp. eggs from parasitized dogs or cats, or with either sewage systems or contaminated water where vegetables for human consumption are grown, play a role as a transmission mechanism must be deeperly studied since 33.3 percent of Toxocara sp. eggs found contained larvae, potentially infective to man

Contaminación de suelos por huevos de toxocara sp en parques públicos y jardines de casas-habitación de la ciudad de México / Soil contamination with toxocara sp eggs in public parks and home gardens from Mexico city

Due to the high number of stray dogs and cats which defecate in public places in Mexico city (3 millions approximately), in addition to domestic dogs and cats, exists the potential risk to man of infection by toxocara sp eggs. A study to determine the contamination frequency by toxocara sp eggs in public parks, public flower beds, and home gardens in Mexico City, Distrito Federal, was carried out in the 1995 first semester. Fourteen hundred and five soil samples were collected from 156 public parks, 83 public flower beds and 42 home gardens across the 16 delegations in Mexico City, Distrito Federal. Samples were processed by the zinc sulfate centrifugal flotation method, and supernatants read by microscopy. Out of the whole 281 sampled sites, 12,5 percent were found contaminated with toxocara sp eggs. Positivity found was: 10,9 percent in public parks, 13,3 percent in public flower beds and 16,7 in home gardens. Ninety percent of the eggs were embryonated or larvaeted measuring 60 to 90 micrometers. The high contamination frecuencies found make necessary to prompt for public health measures granted the risk of infection acquisition spread on the most exposed population (children) provided that it is acquired via geophagia.