ABSTRACT
INTRODUCTION: Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas' disease in the different geographical regions of Perú are still unknown. OBJECTIVE: To detect and type T. cruzi DTUs from the faeces of seven species of triatomines (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni and T. infestans) captured in eight departments from different natural regions of Perú. MATERIALS AND METHODS: We examined 197 insects for detecting trypanosomes. DNA was extracted from each insect intestinal contents and PCR amplification of kDNA, SL-IR, 24Sα rRNA and 18Sα RNA was performed for detecting T. cruzi DTUs. RESULTS: Five T. rangeli and 113 T. cruzi infections were detected; 95 of the latter were identified as TcI (two in P. chinai, one in P. geniculatus, 68 in P. herreri, four in R. pictipes, seven in R. robustus, one in T. carrioni, 12 in T. infestans), five as TcII (four in P. herreri, one in T. infestans), four as TcIII (three in P. herreri, one in R. robustus) and four TcIV infections in P. herreri. CONCLUSIONS: This is the first study which has attempted a large-scale characterization of T. cruzi found in the intestine of epidemiologically important vectors in Perú, thus providing basic information that will facilitate a better understanding of the dynamics of T. cruzi vector transmission in Perú.
Subject(s)
DNA, Protozoan/genetics , Insect Vectors/classification , Triatominae/parasitology , Trypanosoma cruzi/classification , Animal Distribution , Animals , Chagas Disease/epidemiology , Chagas Disease/transmission , Child, Preschool , DNA, Protozoan/analysis , Feces/parasitology , Genotype , Geography, Medical , Housing , Humans , Insect Vectors/genetics , Peru , Reverse Transcriptase Polymerase Chain Reaction , Ribotyping , Species Specificity , Triatominae/growth & development , Trypanosoma cruzi/geneticsABSTRACT
Resumen Introducción. Trypanosoma cruzi se ha dividido en seis unidades taxonómicas discretas (Discreet Typing Units, DTU) denominadas TcI, TcII, TcIII, TcIV, TcV y TcVI. Aún se desconocen los factores determinantes de la dinámica de la transmisión vectorial de los genotipos de T. cruzi en las diferentes regiones geográficas de distribución de la enfermedad de Chagas en Perú. Objetivo. Detectar y tipificar las unidades taxonómicas discretas de T. cruzi en las heces de siete especies de triatominos (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni y T. infestans), capturados en ocho departamentos de diferentes regiones naturales de Perú. Materiales y métodos. Se examinaron 197 insectos para la detección de tripanosomas. Se extrajo el ADN del contenido intestinal de cada insecto y se amplificó mediante reacción en cadena de la polimerasa (PCR) de los genes kDNA, SL-IR, 24Sa rRNA y 18Sa RNA para detectar las DTU de T. cruzi. Resultados. Se detectaron cinco infecciones con T. rangeli y 113 con T. cruzi. De estas últimas, fue posible identificar 95 de TcI (dos en P. chinai, una en P. geniculatus, 68 en P. herreri, cuatro en R. pictipes, siete en R. robustus, una en T. carrioni, y 12 en T. infestans); cinco de TcII (cuatro en P. herreri, una en T. infestans); cuatro de TcIII (tres en P. herreri, una en R. robustus) y cuatro infecciones de TcIV en P. herreri. Conclusión. Este es el primer trabajo de caracterización a gran escala de T. cruzi en el intestino de vectores de importancia epidemiológica en Perú, orientado a generar información básica que permita entender la dinámica de la transmisión vectorial de T. cruzi en esta región del continente.
Abstract Introduction: Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas' disease in the different geographical regions of Perú are still unknown. Objective: To detect and type T. cruzi DTUs from the faeces of seven species of triatomines (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni and T. infestans) captured in eight departments from different natural regions of Perú. Materials and methods: We examined 197 insects for detecting trypanosomes. DNA was extracted from each insect intestinal contents and PCR amplification of kDNA, SL-IR, 24Sa rRNA and 18Sa RNAwas performed for detecting T. cruzi DTUs. Results: Five T. rangeli and 113 T. cruzi infections were detected; 95 of the latter were identified as TcI (two in P. chinai, one in P. geniculatus, 68 in P. herreri, four in R. pictipes, seven in R. robustus, one in T. carrioni, 12 in T. infestans), five as TcII (four in P. herreri, one in T. infestans), four as TcIII (three in P. herreri, one in R. robustus) and four TcIV infections in P. herreri. Conclusions: This is the first study which has attempted a large-scale characterization of T. cruzi found in the intestine of epidemiologically important vectors in Perú, thus providing basic information that will facilitate a better understanding of the dynamics of T. cruzi vector transmission in Perú.
