Rattus norvegicus as an indicator of circulation of Capillaria hepatica and Taenia taeniaeformis on a groceries trade center of Medellín, Colombia Rattus norvegicus como indicador de la circulación de Capillaria hepatica y Taenia taeniaeformis en la Plaza Minorista de Medellín, Colombia

Introduction. Rattus norvegicus plays a pivotal role in the maintenance and spread of some zoonotic bacterial, viral and parasitic pathogens of public health interest. The presence of helminthic infections near to susceptible populations under appropriate environmental conditions might become a risk factor for their transmission.Objective. To report the frequency of infection with Capillaria hepatica and larval forms of Taenia taeniaeformis on wild rats (R. norvegicus), captured in an urban zone of Medellín.Materials and methods. 254 adult specimens of R. norvegicus were collected. The livers of 54 specimens that showed macroscopic hepatic lesions during necropsy were examined by conventional histopathology.Results. The frequency of infestation with C. hepatica was 20.1% (51/254). Six livers were also positive for larvae of T. taeniaeformis, a frequency of 2.4% (6/254). Livers infested with C. hepatica, exhibited adult or juvenile parasites, and oval eggs with bipolar opercula, associated with mild to moderate multifocal granulomatous hepatitis, accompanied by leukocitary infiltrate. We found also resolving granulomatous lesions without adult parasites and eggs and residual fibrosis or containing-eggs calcified lesions. On those animals that had cysticerci of T. taeniaeformis, the most frequent finding was the presence of hepatic cysts containing larvae and inflammatory and fibrotic lesions.Conclusion. These results indicate that potentially zoonotic helminths circulate in R. norvegicus in urban environments. The current study suggests that more research about the distribution of these parasites is required in order to determine whether this is a real or potential threat for human and animal susceptible populations. Introducción. Rattus norvegicus cumple un papel epidemiológico en el mantenimiento y dispersión de agentes zoonóticos bacterianos, virales y parasitarios de interés en salud pública. La presencia de infección por helmintos en especies de Rattus cercanas a poblaciones susceptibles en condiciones ambientales propicias, puede convertirse en un factor de riesgo de transmisión.Objetivo. Reportar la frecuencia de infección con Capillaria hepatica y formas larvarias de Taenia taeniaeformis en ratas silvestres (R. norvegicus) capturadas en una zona urbana de Medellín.Materiales y métodos. Se capturaron 254 ejemplares de R. norvegicus. Los hígados de 54 ejemplares que presentaron lesión hepática macroscópica durante la necropsia, fueron examinados por histopatología convencional.Resultados. La frecuencia de infección por C. hepatica fue de 20,1% (51/2