RESUMO
A single polymerase chain reaction (PCR) reaction targeting the spliced-leader intergenic region of Trypanosoma cruzi I was standardised by amplifying a 231 bp fragment in domestic (TcIDOM) strains or clones and 450 and 550 bp fragments in sylvatic strains or clones. This reaction was validated using 44 blind coded samples and 184 non-coded T. cruzi I clones isolated from sylvatic triatomines and the correspondence between the amplified fragments and their domestic or sylvatic origin was determined. Six of the nine strains isolated from acute cases suspected of oral infection had the sylvatic T. cruzi I profile. These results confirmed that the sylvatic T. cruzi I genotype is linked to cases of oral Chagas disease in Colombia. We therefore propose the use of this novel PCR reaction in strains or clones previously characterised as T. cruzi I to distinguish TcIDOMfrom sylvatic genotypes in studies of transmission dynamics, including the verification of population selection within hosts or detection of the frequency of mixed infections by both T. cruzi I genotypes in Colombia.
Assuntos
DNA Intergênico/genética , RNA Líder para Processamento/genética , Trypanosoma cruzi/genética , Animais , Doença de Chagas/transmissão , Colômbia , DNA de Protozoário/genética , Reservatórios de Doenças/parasitologia , Genótipo , Insetos Vetores/parasitologia , Reação em Cadeia da Polimerase , Triatoma/parasitologia , Triatominae/parasitologiaRESUMO
Many cases of infection caused by the oral transmission of Trypanosoma cruzi have been reported during the last decade. These have been due to the contamination of food by faeces from sylvatic triatomines or by leakage from reservoirs in areas where domiciliated vectors have been controlled or where there has been no prior background of domiciliation. The United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have used epidemiological, clinical and socioeconomic criteria for ranking parasites transmitted by the contamination of food in different areas of the world; T. cruzi was placed tenth in importance amongst a group of 24 parasites in such ranking. Environmental changes such as deforestation and global warming have affected ecotopes and the behaviour of T. cruzi vectors and reservoirs so that these have become displaced to new areas, thereby leading to such new transmission scenario caused by the contamination of food, which requires evaluation in Colombia. The current review deals with the oral transmission of Chagas' disease, emphasising studies aimed at identifying the pertinent risk factors, the triatomine species involved, the physiopathology of oral infection, the parasite's genotypes implicated in this type of transmission in Colombia and other Latin American regions, as well as the need for ongoing epidemiological surveillance and control policies.
Assuntos
Doença de Chagas/transmissão , Fezes/parasitologia , Parasitologia de Alimentos , Frutas/parasitologia , Insetos Vetores/parasitologia , Carne/parasitologia , Rhodnius/parasitologia , Trypanosoma cruzi/isolamento & purificação , Verduras/parasitologia , Animais , Animais Selvagens/parasitologia , Tatus/parasitologia , Bebidas/parasitologia , Doadores de Sangue , Doença de Chagas/congênito , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Colômbia , Reservatórios de Doenças/parasitologia , Feminino , Mucosa Gástrica/parasitologia , Genótipo , Habitação , Humanos , Mucosa Bucal/parasitologia , Parasitemia/parasitologia , Parasitemia/transmissão , Peptídeo Hidrolases/fisiologia , Gravidez , Complicações Infecciosas na Gravidez/parasitologia , Proteínas de Protozoários/química , Proteínas de Protozoários/fisiologia , Fatores de Risco , Reação Transfusional , Trypanosoma cruzi/genética , Trypanosoma cruzi/patogenicidade , Trypanosoma cruzi/fisiologia , Glicoproteínas Variantes de Superfície de Trypanosoma/química , Glicoproteínas Variantes de Superfície de Trypanosoma/fisiologiaRESUMO
Durante la última década se han reportado numerosos casos de infección por Trypanosoma cruzi por vía oral, debidos a la contaminación de alimentos con heces de triatominos silvestres o con secreciones de reservorios en áreas donde los vectores domiciliados han sido controlados o no hay antecedentes de domiciliación. Con base en criterios epidemiológicos, clínicos y socioeconómicos, la Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) y la Organización Mundial de la Salud (OMS) establecieron una clasificación de los parásitos transmitidos por contaminación de alimentos en diferentes regiones del mundo, en la cual T. cruzi ocupó el décimo lugar de importancia en un grupo de 24 parásitos. Los cambios ambientales, como la deforestación y el calentamiento global, han afectado los ecotopos y el comportamiento de los vectores y de los reservorios de T. cruzi , de manera que estos se han desplazado a nuevas zonas, generando una nueva forma de transmisión por contaminación de alimentos que requiere su evaluación en el país. La presente revisión aborda la transmisión oral de la enfermedad de Chagas con énfasis en los estudios orientados a identificar los factores de riesgo, las especies de triatominos involucrados, la fisiopatología de la infección oral y los genotipos del parásito que están implicados en esta forma de transmisión en Colombia y en otras regiones de América Latina, así como la necesidad de adoptar políticas para su control y vigilancia epidemiológica.
Many cases of infection caused by the oral transmission of Trypanosoma cruzi have been reported during the last decade. These have been due to the contamination of food by faeces from sylvatic triatomines or by leakage from reservoirs in areas where domiciliated vectors have been controlled or where there has been no prior background of domiciliation. The United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have used epidemiological, clinical and socioeconomic criteria for ranking parasites transmitted by the contamination of food in different areas of the world; T. cruzi was placed tenth in importance amongst a group of 24 parasites in such ranking. Environmental changes such as deforestation and global warming have affected ecotopes and the behaviour of T. cruzi vectors and reservoirs so that these have become displaced to new areas, thereby leading to such new transmission scenario caused by the contamination of food, which requires evaluation in Colombia. The current review deals with the oral transmission of Chagas´ disease, emphasising studies aimed at identifying the pertinent risk factors, the triatomine species involved, the physiopathology of oral infection, the parasite´s genotypes implicated in this type of transmission in Colombia and other Latin American regions, as well as the need for ongoing epidemiological surveillance and control policies.