Fine-scale predictions of distributions of Chagas disease vectors in the state of Guanajuato, Mexico

One of the most daunting challenges for Chagas disease surveillance and control in Mexico is the lack of community level data on vector distributions. Although many states now have assembled representative domestic triatomine collections, only two triatomine specimens had been collected and reported previously from the state of Guanajuato. Field personnel from the stateÕs Secretarõ´a de Salud conducted health promotion activities in 43 of the 46 counties in the state and received donations of a total of 2,522 triatomine specimens between 1998 and 2002. All specimens were identiÞed, and live insects examined for Trypanosoma cruzi. In an effort to develop Þne-scale distributional data for Guanajuato, collection localities were georeferenced and ecological niches were modeled for each species by using evolutionary-computing approaches. Five species were collected: Triatoma mexicana (Herrich-Schaeffer), Triatoma longipennis (Usinger), Triatoma pallidipennis (Stål), Triatoma barberi (Usinger), and Triatoma dimidiata (Latreille) from 201 communities located at elevations of 870Ð2,200 m. Based on collection success, T. mexicana had the broadest dispersion, although niche mapping indicates that T. barberi represents the greatest risk for transmission of Chagas disease in the state. T. dimidiata was represented in collections by a single adult collected from one village outside the predicted area for all species. For humans, an estimated 3,755,380 individuals are at risk for vector transmission in the state, with an incidence of 3,500 new cases per year; overall seroprevalences of 2.6% indicate that 97,640 individuals are infected with T. cruzi at present, including 29,300 chronic cases

Revisión de 13 especies de la familia Triatominae (Hemiptera: Reduviidae) vectores de la enfermedad de Chagas, en México

Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic andsylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest healthrisk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but inYucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors arefound: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatomagerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted tothe domicile), Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodniusprolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmissiondynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health educationprograms, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, healtheducation programs are required, as well as the use of mosquito nets on doors and windows and around beds, asidefrom cementing the stone wall fences.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, queson los que representan un mayor riesgo para la Salud Pública, en México. Aunque Triatoma dimidiata se encuentraprincipalmente dentro de la vivienda, en Yucatán tiene un comportamiento peridomiciliar, dentro de este grupo seencuentran 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 ladinámica 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 paralos vectores visitantes o peridomiciliados, son necesarios programas de educación para la salud, uso de mosquiteros,pabellones y cementación de las bardas de piedra

Phylogeographic pattern and extensive mitochondrial DNA divergence disclose a species complex within the Chagas disease vector Triatoma dimidiata.

ABSTARCT: Previous studies have shown that "bioequivalent" generic products of vancomycin are less effective in vivo against Staphylococcus aureus than the innovator compound. Considering that suboptimal bactericidal effect has been associated with emergence of resistance, we aimed to assess in vivo the impact of exposure to innovator and generic products of vancomycin on S. aureus susceptibility. A clinical methicillin-resistant S. aureus (MRSA) strain from a liver transplant patient with persistent bacteremia was used for which MIC, minimum bactericidal concentration (MBC), and autolytic properties were determined. Susceptibility was also assessed by determining a population analysis profile (PAP) with vancomycin concentrations from 0 to 5 mg/liter. ICR neutropenic mice were inoculated in each thigh with ∼7.0 log(10) CFU. Treatment with the different vancomycin products (innovator and three generics; 1,200 mg/kg of body weight/day every 3 h) started 2 h later while the control group received sterile saline. After 24 h, mice were euthanized, and the thigh homogenates were plated. Recovered colonies were reinoculated to new groups of animals, and the exposure-recovery process was repeated until 12 cycles were completed. The evolution of resistance was assessed by PAP after cycles 5, 10, 11, and 12. The initial isolate displayed reduced autolysis and higher resistance frequencies than S. aureus ATCC 29213 but without vancomycin-intermediate S. aureus (VISA) subpopulations. After 12 cycles, innovator vancomycin had significantly reduced resistant subpopulations at 1, 2, and 3 mg/liter, while the generic products had enriched them progressively by orders of magnitude. The great capacity of generic vancomycin to select for less susceptible organisms raises concerns about the role of therapeutic inequivalence of any antimicrobial on the epidemiology of resistance worldwide

First case of natural infection in pigs. Review of Trypanosoma cruzi reservoirs in Mexico

An epidemiological research project was performed in the State of Morelos including collection of samples for blood smears and culture, serological tests, and xenodiagnoses from a total of 76 domestic and peridomestic mammals. Two strains of Trypanosoma cruzi were isolated by haemocultures; one from a pig (Sus scrofa), the first case of natural infection reported in Mexico, and the other from a dog (Canis familiaris). This study summarizes current information in Mexico concerning confirmed reservoirs of T. cruzi

Triatoma mexicana Herrich-Schaeffer (Hemiptera: Reduviidae: Triatominae) Descripción de la Genitalia Externa del Macho y Morfología Externa de la Hembra

Triatoma mexicana was originally described in 1848 by Herrich-Schaeffer, naming Conorhinus mexicanus Herrich-Schaeffer. Its finding is currently registered in the States of Guanajuato, Hidalgo, Querétaro, and San Luis Potosí. Studies about the spatial distribution, the entomological indices, it presence indoor an outdoor in houses, it biology and risk of transmission of Trypanosoma cruzi Chagas show that it is an important species from the point of view of public health. With the purpose of extending the biological knowledge of this species, the present study is the description of the female as well as the external male genitalia, in specimens captured in the State of Guanajuato.Triatoma mexicana fue descrita originalmente en 1848 por Herrich-Schaeffer nombrándola Conorhinus mexicanus Herrich-Schaeffer. Actualmente se registra su hallazgo en los estados de Guanajuato, Hidalgo Querétaro y San Luis Potosí. Los estudios sobre su distribución espacial, índices entomológicos, presencia en el intradomicilio y peridomicilio, biología y riesgo de transmisión de Trypanosoma cruzi Chagas demuestran que es una especie importante desde el punto de vista de salud pública. Con el propósito de ampliar el conocimiento biológico sobre la especie, en el presente estudio se hace la descripción de la hembra así como la genitalia externa del macho, en ejemplares capturados en el estado de Guanajuato

Unusual prevalence of the Giardia intestinalis A-II subtype amongst isolates from humans and domestic animals in Mexico

Copyright © 2002 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd.Martha Ponce-Macotel, Mario N. Martínez-Gordillo, Rosa Maria Bermúdez-Cruz, Paz Maria Salazar-Schettino, Guadalupe Ortega-Pierres and Peter L. Eyhttp://www.elsevier.com/wps/find/journaldescription.cws_home/353/description#descriptio

Evaluación de la función y sincronía de la contracción ventricular en pacientes con enfermedad de Chagas en estadio de latencia

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

A revision of thirteen species of Triatominae (Hemiptera: Reduviidae) vectors of Chagas disease in Mexico

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