ABSTRACT
Observations made in the field and in the laboratory on three vectors of Trypanosoma cruzi: Triatoma barberi, T. pallidipennis and T. dimidiata are here presented. Results are compared in relation with their ecotopes, vectorial capacity, biological characteristic, entomological indexes and capture places. In relation with their ecotopos T. barberi has preference for the interior of the human home, in walls, directly in contact with beds; T. pallidipennis, when it is inside the houses, prefers floors and among clothes, although their main ecotope is wild; T. dimidiata has localization in floors, specially under the beds, in the angle between wall and floor; T. barberi and T. dimidiata are attracted by the light. The cycles of life were of 523, 171 and 510 days, respectively for Triatoma barberi, T. pallidipennis and T. dimidiata. The vectorial capacity was determined according to the time taken in defecating during or after its sucking blood: T. barberi defecates during its feeding, while T. pallidipennis and T. dimidiata make it from 10 to 20 and of 20 to 30 minutes after starting the process, respectively. The indexes of natural infection were of 56.6 for T. barberi, 29 for T. pallidipennis and 15.6 for T. dimidiata, The metacyclogenics indexes that indicate percentages of metacyclics trypomastigotes in later intestine of vectors was in T. barberi 76.6, T. pallidipennis 15 and T. dimidiata 26, with what it can be concluded that the first species is the best transmitter of T. cruzi in Mexico.
Se presentan observaciones hechas en el campo y en el laboratorio sobre tres vectores de Trypanosoma cruzi: Triatoma barberi, T. pallidipennis y T. dimidiata. Se comparan resultados en relación con sus ecotopos, capacidad vectorial, características biológicas, índices entomológicos y sitios de captura. En relación con sus ecotopos, T. barberi tiene preferencia por el interior del domicilio humano, en paredes, directamente en contacto con las camas; T. pallidipennis, cuando se encuentra dentro de las casas, prefiere pisos y entre la ropa, aunque su principal ecotopo es silvestre; T. dimidiata tiene localización en pisos, especialmente bajo las camas, en el ángulo entre pared y piso; T. barberi y T. dimidiata son atraídas por la luz. Los ciclos de vida fueron de 523, 171 y 510 días, respectivamente para Triatoma barberi, T. pallidipennis y T. dimidiata. La capacidad vectorial se determinósegún el tiempo que tarda en defecar durante o después de su ingesta de sangre: T. barberi defeca durantesu alimentación, mientras que T. pallidipennis y T. dimidiata lo hacen de 10 a 20 y de 20 a 30 minutos después de iniciado el proceso, respectivamente. Los índices de infección natural fueron de 56.6 para T.barberi, 29 para T.pallidipennis y 15.6 para T. dimidiata. Los índices metaciclogénicos, que indican porcentajes de tripomastigotesmetacíclicos en intestino posterior de los vectores fueron en T. barberi 76.6, T. pallidipennis 15 y T. dimidiata 26,con lo que se concluye que la primera especie es el mejor transmisor de T. cruzi en México.
Subject(s)
Animals , Female , Humans , Male , Insect Vectors/classification , Trypanosoma cruzi , Triatoma/classification , Mexico , Residence CharacteristicsABSTRACT
Observations made in the field and in the laboratory on three vectors of Trypanosoma cruzi: Triatoma barberi, T. pallidipennis and T. dimidiata are here presented. Results are compared in relation with their ecotopes, vectorial capacity, biological characteristic, entomological indexes and capture places. In relation with their ecotopos T. barberi has preference for the interior of the human home, in walls, directly in contact with beds; T. pallidipennis, when it is inside the houses, prefers floors and among clothes, although their main ecotope is wild; T. dimidiata has localization in floors, specially under the beds, in the angle between wall and floor; T. barberi and T. dimidiata are attracted by the light. The cycles of life were of 523, 171 and 510 days, respectively for Triatoma barberi, T. pallidipennis and T. dimidiata. The vectorial capacity was determined according to the time taken in defecating during or after its sucking blood: T. barberi defecates during its feeding, while T. pallidipennis and T. dimidiata make it from 10 to 20 and of 20 to 30 minutes after starting the process, respectively. The indexes of natural infection were of 56.6 for T. barberi, 29 for T. pallidipennis and 15.6 for T. dimidiata, The metacyclogenics indexes that indicate percentages of metacyclics trypomastigotes in later intestine of vectors was in T. barberi 76.6, T. pallidipennis 15 and T. dimidiata 26, with what it can be concluded that the first species is the best transmitter of T. cruzi in Mexico.(AU)
Se presentan observaciones hechas en el campo y en el laboratorio sobre tres vectores de Trypanosoma cruzi: Triatoma barberi, T. pallidipennis y T. dimidiata. Se comparan resultados en relación con sus ecotopos, capacidad vectorial, características biológicas, índices entomológicos y sitios de captura. En relación con sus ecotopos, T. barberi tiene preferencia por el interior del domicilio humano, en paredes, directamente en contacto con las camas; T. pallidipennis, cuando se encuentra dentro de las casas, prefiere pisos y entre la ropa, aunque su principal ecotopo es silvestre; T. dimidiata tiene localización en pisos, especialmente bajo las camas, en el ángulo entre pared y piso; T. barberi y T. dimidiata son atraídas por la luz. Los ciclos de vida fueron de 523, 171 y 510 días, respectivamente para Triatoma barberi, T. pallidipennis y T. dimidiata. La capacidad vectorial se determinósegún el tiempo que tarda en defecar durante o después de su ingesta de sangre: T. barberi defeca durantesu alimentación, mientras que T. pallidipennis y T. dimidiata lo hacen de 10 a 20 y de 20 a 30 minutos después de iniciado el proceso, respectivamente. Los índices de infección natural fueron de 56.6 para T.barberi, 29 para T.pallidipennis y 15.6 para T. dimidiata. Los índices metaciclogénicos, que indican porcentajes de tripomastigotesmetacíclicos en intestino posterior de los vectores fueron en T. barberi 76.6, T. pallidipennis 15 y T. dimidiata 26,con lo que se concluye que la primera especie es el mejor transmisor de T. cruzi en México.(AU)
Subject(s)
Animals , Female , Humans , Male , Insect Vectors/classification , Triatoma/classification , Trypanosoma cruzi , Mexico , DemographyABSTRACT
We performed a transversal-type epidemiological study in the state of Morelos, Mexico, to determine the presence of triatomines, their ecotopes, and importance in transmission of Trypanosoma cruzi Chagas. Sampling sites included domestic, peridomestic, and wild areas with collection based on the person per hour technique. We determined the entomological indices related to infestation, density, overcrowding, colonization, infection, and dispersion, which were used to calculate transmission risk. During the study, observations were made on the predominant building material, presence of cracks and illumination as factors fostering colonization. The most important results were related to infection indices, which were higher for domestic type triatomines (29%), whereas it was 4% for peridomestic sites, and 20% for sylvatic areas. The actual risk of human contact with the vector was of 0.51%, and the predominating ecotopes were stone heaps.
Subject(s)
Insect Vectors , Triatoma , Trypanosoma cruzi , Animals , Female , Humans , Male , MexicoABSTRACT
The purpose of this paper is to show up the importance of the standardization concepts in American Trypanosomiasis epidemiological studies. The consistence in the measurement of some dwelling characteristics was evaluated. A validation of the Queretaro antigen for indirect hemagglutination reaction as a diagnostic test and the interobserver concordance for the serologic readings were also made. The observers were instructed in some sessions. The pretests were made in the laboratory with positive and negative sera, with sera from the studied population. Results show that the interobserver concordance after the instruction, for the dwelling variables ranged from 70% to 100%. Sensitivity of the Queretaro antigen was 100%, specificity 55%, the predictive value of a positive test 55%, and the predictive value of a negative test 93%. The interobserver concordance was 47%. The pretest and the pilot study are very important in getting the objectives of the principal study.
Subject(s)
Chagas Disease/epidemiology , Data Collection , Lighting , Mexico/epidemiology , Pilot Projects , Predictive Value of Tests , Sensitivity and Specificity , VentilationABSTRACT
A seasonal research was carried out in Irapuato, Guanajuato and Zamora, Michoacan, Mexico, the location of the most important producers of strawberries, in order to assess fecal contamination through the finding of protozoan cysts and helminth eggs, specifically of Taenia sp eggs. Three techniques were used: direct observation, flotation and sedimentation. Low numbers of protozoan cysts and only one Ascaris egg were found. What is most interesting is that no Taenia eggs were identified. Results indicate that although strawberries are contaminated with human feces, contamination is minimal.
Subject(s)
Fruit/parasitology , Feces/parasitology , Humans , MexicoABSTRACT
We present a review of the biological aspects of taeniasis-cysticercosis binomial, emphasizing those related to its biotic potential, resistance, and viability of eggs in the environment, as well as the morphological features of the corresponding adults, which are instrumental for the diagnosis of taeniasis. A new infection mechanism through the ingestion of posoncospheres present in macerated meat is discussed. The significance of unifying epidemiological criteria to control this important binomial is pointed out.
Subject(s)
Cysticercosis/parasitology , Taeniasis/parasitology , Animals , Cysticercus/growth & development , Taenia/growth & developmentABSTRACT
Mexico - the northernmost country of Latin America - has long been thought to have an unusually low prevalence of Chagas disease compared with other Latin American countries. This has seemed unusual because of the large number of vector species and subspecies reported from the country, and the social and ecological conditions that seem to parallel those in other countries where Chagas disease is recognized as a major public health priority. This review seeks to clarify the question, and suggests that the epidemiological, parasitological, and entomological pattern of Chagas disease in Mexico may also parallel that of other endemic regions, but has been masked by poor awareness of the disease both at local and institutional levels.
