Oral transmission of Trypanosoma cruzi: a new epidemiological scenario for Chagas' disease in Colombia and other South American countries

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.