Edgar Parra

First Report of Human Trypanosoma cruzi Infection Attributed to TcBat Genotype

Chagas disease is an endemic disease of the American continent caused by Trypanosoma cruzi and divided into six discrete typing units (TcI – TcVI). Nearly 10 million people harbour the infection representing a serious issue in public health. Epidemiological surveillance allowed us to detect a bat‐related T. cruzi genotype (henceforth named TcBat) in a 5‐year‐old female living in a forest area in northwestern Colombia. Molecular tools determined a mixed infection of T. cruzi I and TcBat genotypes. This represents the first report of TcBat infection in humans; the epidemiological consequences of this finding are discussed herein.

Chagas disease (Trypanosoma cruzi) and HIV co-infection in Colombia

Chagas disease is a complex zoonotic pathology caused by the kinetoplastid Trypanosoma cruzi. This parasite presents remarkable genetic variability and has been grouped into six discrete typing units (DTUs). The association between the DTUs and clinical outcome remains unknown. Chagas disease and co-infection with HIV/AIDS has been reported widely in Brazil and Argentina. Herein, we present the molecular analyses from a Chagas disease patient with HIV/AIDS co-infection in Colombia who presented severe cardiomyopathy, pleural effusion, and central nervous system involvement. A mixed infection by T. cruzi genotypes was detected. We suggest including T. cruzi in the list of opportunistic pathogens for the management of HIV patients in Colombia. The epidemiological implications of this finding are discussed.

Infestación por triatominos en comunidades indígenas de Valledupar, Colombia

OBJETIVO: Calcular indices de infestacao por barbeiros em comunidades indigenas da Colombia. METODOS: Estudo descritivo em 19 comunidades do municipio de Valledupar, departamento de Cesar, Colombia. A coleta de barbeiros foi realizada por busca ativa nas casas dos indigenas de junho e dezembro de 2007. A identificacao taxonomica foi feita conforme Lent & Wygodzinsky. A determinacao da infeccao foi realizada por processo de infeccao em modelo animal e analise enzimatica em fezes de barbeiros. RESULTADOS: Rhodnius prolixus apresentou nas casas das comunidades um indice de densidade 154,7%, Triatoma dimidiata de 102,45% e T. maculata de 109,25% e Panstrogylus geniculatus de 0,3%, cujo indice de infestacao foi de 40,54%, e indice de infeccao com T. cruzi de 9,4%. De cinco hemocultivos positivos para T. cruzi, tres caracterizam-se como T. cruzi grupo I. O estudo das biopsias revelou poucas caracteristicas patologicas da identificacao do processo de infeccao das cepas isoladas a partir de barbeiros domiciliados. CONCLUSOES: os altos indices de infestacao por barbeiros nas casas e o indice de infeccao por T. cruzi evidenciam a transmissao ativa da doenca de Chagas, situacao que merece a aplicacao de medidas de controle vetorial e um estudo seroepidemiologico da populacao sob risco. A caracterizacao genetica das cepas de T. cruzi como grupo I concorda com outros achados para cepas dessa regiao da Colombia.OBJECTIVE To calculate triatomine infestation indices in indigenous communities in Colombia. METHODS A descriptive study was carried out in 19 communities in Valledupar Municipality, Cesar Department, Colombia. During June to December, 2007, triatromine bugs were collected from their resting places in households. Taxonomic identification was made according to the keys by Lent & Wygodzinsky. An infection process in animal model and isozyme analysis of triatomine feces were performed. RESULTS Rhodnius prolixus showed a density index of 154.7%, for Triatoma dimidiata was 102.45%, T. maculata 109.25% and Panstrogylus geniculatus 0.3%. The mean infestation index was 40.54%, and mean Trypanosoma infection index was 9.4%. Of five hemocultures positive for T. cruzi, three were enzimatically identified as T. cruzi group I. Biopsies revealed few pathologic characteristics of infective process with these strains isolated from domiciliary triatomine bugs. CONCLUSIONS The high triatomine infestation indices in households and the T. cruzi infection index are evidence of active transmission of Chagas disease. The situation merits a vector control program and serological survey of the population at risk. The genetic characterization of T. cruzi strains as group I agrees with other findings on strains in this region of Colombia.

Infestation by triatomine bugs in indigenous communities of Valledupar, Colombia

OBJETIVO: Calcular indices de infestacao por barbeiros em comunidades indigenas da Colombia. METODOS: Estudo descritivo em 19 comunidades do municipio de Valledupar, departamento de Cesar, Colombia. A coleta de barbeiros foi realizada por busca ativa nas casas dos indigenas de junho e dezembro de 2007. A identificacao taxonomica foi feita conforme Lent & Wygodzinsky. A determinacao da infeccao foi realizada por processo de infeccao em modelo animal e analise enzimatica em fezes de barbeiros. RESULTADOS: Rhodnius prolixus apresentou nas casas das comunidades um indice de densidade 154,7%, Triatoma dimidiata de 102,45% e T. maculata de 109,25% e Panstrogylus geniculatus de 0,3%, cujo indice de infestacao foi de 40,54%, e indice de infeccao com T. cruzi de 9,4%. De cinco hemocultivos positivos para T. cruzi, tres caracterizam-se como T. cruzi grupo I. O estudo das biopsias revelou poucas caracteristicas patologicas da identificacao do processo de infeccao das cepas isoladas a partir de barbeiros domiciliados. CONCLUSOES: os altos indices de infestacao por barbeiros nas casas e o indice de infeccao por T. cruzi evidenciam a transmissao ativa da doenca de Chagas, situacao que merece a aplicacao de medidas de controle vetorial e um estudo seroepidemiologico da populacao sob risco. A caracterizacao genetica das cepas de T. cruzi como grupo I concorda com outros achados para cepas dessa regiao da Colombia.OBJECTIVE To calculate triatomine infestation indices in indigenous communities in Colombia. METHODS A descriptive study was carried out in 19 communities in Valledupar Municipality, Cesar Department, Colombia. During June to December, 2007, triatromine bugs were collected from their resting places in households. Taxonomic identification was made according to the keys by Lent & Wygodzinsky. An infection process in animal model and isozyme analysis of triatomine feces were performed. RESULTS Rhodnius prolixus showed a density index of 154.7%, for Triatoma dimidiata was 102.45%, T. maculata 109.25% and Panstrogylus geniculatus 0.3%. The mean infestation index was 40.54%, and mean Trypanosoma infection index was 9.4%. Of five hemocultures positive for T. cruzi, three were enzimatically identified as T. cruzi group I. Biopsies revealed few pathologic characteristics of infective process with these strains isolated from domiciliary triatomine bugs. CONCLUSIONS The high triatomine infestation indices in households and the T. cruzi infection index are evidence of active transmission of Chagas disease. The situation merits a vector control program and serological survey of the population at risk. The genetic characterization of T. cruzi strains as group I agrees with other findings on strains in this region of Colombia.

Murine models susceptibility to distinct Trypanosoma cruzi I genotypes infection.

Chagas disease is a complex zoonosis that affects around 8 million people worldwide. This pathology is caused by Trypanosoma cruzi, a kinetoplastid parasite that shows tremendous genetic diversity evinced in six distinct Discrete Typing Units (TcI-TcVI) including a recent genotype named as TcBat and associated with anthropogenic bats. TcI presents a broad geographical distribution and has been associated with chronic cardiomyopathy. Recent phylogenetic studies suggest the existence of two genotypes (Domestic (TcIDom) and sylvatic TcI) within TcI. The understanding of the course of the infection in different mouse models by these two genotypes is not yet known. Therefore, we infected 126 animals (ICR-CD1, National Institute of Health (NIH) and Balb/c) with two TcIDom strains and one sylvatic strain for a follow-up period of 60 days. We quantified the parasitaemia, immune response and histopathology observing that the maximum day of parasitaemia was achieved at day 21 post-infection. Domestic strains showed higher parasitaemia than the sylvatic strain in the three mouse models; however in the survival curves Balb/c mice were less susceptible to infection compared with NIH and ICR-CD1. Our results suggest that the genetic background plays a fundamental role in the natural history of the infection and the sympatric TcI genotypes have relevant implications in disease pathogenesis.

Comparative study of the biological properties of Trypanosoma cruzi I genotypes in a murine experimental model

Chagas disease is an endemic zoonosis in Latin America and caused by the parasite Trypanosoma cruzi. This kinetoplastid displays remarkable genetic variability, allowing its classification into six Discrete Typing Units (DTUs) from TcI to TcVI. T. cruzi I presents the broadest geographical distribution in the continent and has been associated to severe forms of cardiomyopathies. Recently, a particular genotype associated to human infections has been reported and named as TcIDOM (previously named TcIa-b). This genotype shows to be clonal and adapted to the domestic cycle but so far no studies have determined the biological properties of domestic (TcIDOM) and sylvatic TcI strains (previously named TcIc-e). Hence, the aim of this study was to untangle the biological features of these genotypes in murine models. We infected ICR-CD1 mice with five TcI strains (two domestic, two sylvatic and one natural mixture) and determined the course of infection during 91 days (acute and chronic phase of the disease) in terms of parasitemia, tissue tropism, immune response (IgG titers) and tissue invasion by means of histopathology studies. Statistically significant differences were observed in terms of parasitemia curves and prepatent period between domestic (TcIDOM) and sylvatic strains. There were no differences in terms of IgG antibodies response across the mice infected with the five strains. Regarding the histopathology, our results indicate that domestic strains present higher parasitemias and low levels of histopathological damage. In contrast, sylvatic strains showed lower parasitemias and high levels of histopathological damage. These results highlight the sympatric and behavioral differences of domestic and sylvatic TcI strains; the clinical and epidemiological implications are herein discussed.

Glucógeno hepático en dengue severo: análisis histopatológico

Background: Dengue virus affects various organs, but the liver is the main target of damage and where the most severe damage can occur. There are few studies on the histological changes in the liver during dengue infection. Aims: To analyze the histopathological post-mortem alterations in livers from patients with severe dengue.

Infestação por barbeiros em comunidades indígenas de Valledupar, Colômbia

OBJETIVO: Calcular indices de infestacao por barbeiros em comunidades indigenas da Colombia. METODOS: Estudo descritivo em 19 comunidades do municipio de Valledupar, departamento de Cesar, Colombia. A coleta de barbeiros foi realizada por busca ativa nas casas dos indigenas de junho e dezembro de 2007. A identificacao taxonomica foi feita conforme Lent & Wygodzinsky. A determinacao da infeccao foi realizada por processo de infeccao em modelo animal e analise enzimatica em fezes de barbeiros. RESULTADOS: Rhodnius prolixus apresentou nas casas das comunidades um indice de densidade 154,7%, Triatoma dimidiata de 102,45% e T. maculata de 109,25% e Panstrogylus geniculatus de 0,3%, cujo indice de infestacao foi de 40,54%, e indice de infeccao com T. cruzi de 9,4%. De cinco hemocultivos positivos para T. cruzi, tres caracterizam-se como T. cruzi grupo I. O estudo das biopsias revelou poucas caracteristicas patologicas da identificacao do processo de infeccao das cepas isoladas a partir de barbeiros domiciliados. CONCLUSOES: os altos indices de infestacao por barbeiros nas casas e o indice de infeccao por T. cruzi evidenciam a transmissao ativa da doenca de Chagas, situacao que merece a aplicacao de medidas de controle vetorial e um estudo seroepidemiologico da populacao sob risco. A caracterizacao genetica das cepas de T. cruzi como grupo I concorda com outros achados para cepas dessa regiao da Colombia.OBJECTIVE To calculate triatomine infestation indices in indigenous communities in Colombia. METHODS A descriptive study was carried out in 19 communities in Valledupar Municipality, Cesar Department, Colombia. During June to December, 2007, triatromine bugs were collected from their resting places in households. Taxonomic identification was made according to the keys by Lent & Wygodzinsky. An infection process in animal model and isozyme analysis of triatomine feces were performed. RESULTS Rhodnius prolixus showed a density index of 154.7%, for Triatoma dimidiata was 102.45%, T. maculata 109.25% and Panstrogylus geniculatus 0.3%. The mean infestation index was 40.54%, and mean Trypanosoma infection index was 9.4%. Of five hemocultures positive for T. cruzi, three were enzimatically identified as T. cruzi group I. Biopsies revealed few pathologic characteristics of infective process with these strains isolated from domiciliary triatomine bugs. CONCLUSIONS The high triatomine infestation indices in households and the T. cruzi infection index are evidence of active transmission of Chagas disease. The situation merits a vector control program and serological survey of the population at risk. The genetic characterization of T. cruzi strains as group I agrees with other findings on strains in this region of Colombia.

Morphological changes in lung tissue of victims associated with the 2009 A H1N1/v09 influenza pandemic in Colombia

INTRODUCTION Influenza is an acute respiratory infection that may be seasonal or pandemic. In 2009 The World Health Organization (WHO) declared an influenza pandemia; 3,876 cases and 239 deaths were reported in Colombia. OBJECTIVE The morphological changes in lung tissues associated with virus infection H1N1/v09 were described from autopsied victims. Materials and methods. Seventy-five cases were diagnosed by RT-PCR for influenza A H1N1/v09, of which the lungs of 20 were selected for morphological study by light microscopy, optical microscopy, high-resolution transmission electron microscopy and immunohistochemistry. RESULTS Of the 75 cases, 83% had viral pneumonitis and 17% alveolitis. Complications included intra-alveolar hemorrhage (66%), edema (89%), diffuse alveolar damage (2%), and bacterial co-infection (32%). Morphological changes were as follows: destruction of the alveolar epithelium and interstitium, edema, macrophages with vacuolated cytoplasm,and infiltration of polymorphonuclear leukocytes in the alveolar lumen and interstitium, vacuolization cytoplasmic type I pneumocytes and electronedense bodies in cellular debris in the alveolar lumen, and immunoreactivity of viral antigens in bronchiolar epithelial cells and alveolar infiltrate. CONCLUSION The low percentage of bacterial co-infection observed in these cases was a prominent feature, and suggested that the fatal result was probably not associated with secondary bacterial disease (Indicated by previous reports). The tissue lesions were attributed to tissue damage due to viral lesion, as well as the cellular and humoral inflammatory response associated with infiltration by polymorphonucleocytes and macrophages in the interstitium and alveolar lumen.