Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches

Abstract

Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana's signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission.

Fig. 1:. geographical distribution of oral transmitted Chagas disease outbreaks occurred in America: Brazil Amazonian Region [1: Acre (SVS 2011); 2: Amazonas (SVS 2011); 3: Pará (Valente et al. 2001, Beltrão et al. 2009, Nóbrega et al. 2009); 4: Amapá (Pinto et al. 2008, SVS 2011); 5: Maranhão (Pinto et al. 2008)], Brazil Non-Amazonian Region [6: Ceará (Cavalcanti et al. 2009); 7: Paraiba (Shikanai-Yasuda 1987); 8: Bahia (Maguire et al. 1986); 9: Santa Catarina (Steindel et al. 2008); 10: Rio Grande do Sul (Nery-Guimarães et al. 1968)], Colombia [1: Casanare (ProMED-mail 2014); 2: Santander (Hernández et al. 2009); 3: Antioquía (Ríos et al. 2011); 4: Norte de Santander (Bohórquez et al. 1992); 5: César (ProMED-mail 2010b); 6: Magdalena (Cáceres et al. 1999)], Venezuela [1: Vargas (Alarcón de Noya & Martínez 2009); 2: Caracas (Alarcón de Noya et al. 2010b, ProMED 2010a, 2012); 3: Miranda (2014, unpublished observations); 4: Falcón (2013, unpublished observations); 5: Mérida (Añez et al. 2013); 6: Táchira (Benítez et al. 2013, 20, 2014, unpublished observations)] and Bolivia [1: Beni (Santalla-Vargas et al. 2011)].

Fig. 2:. geographical distribution of oral transmitted Chagas disease outbreaks occurred in Venezuela (for references see Table I).