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

Orally transmitted Chagas disease has become a matter of concern due to outbreaksreported in four Latin American countries. Although several mechanisms for orallytransmitted Chagas disease transmission have been proposed, food and beveragescontaminated with whole infected triatomines or their faeces, which containmetacyclic trypomastigotes of Trypanosoma cruzi, seems to be theprimary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagasdisease 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 haveoccurred. The absence of contact with the vector and of traditional cutaneous andRomana’s signs, together with a florid spectrum of clinical manifestations during theacute phase, confuse the diagnosis of orally transmitted Chagas disease with otherinfectious diseases. The simultaneous detection of IgG and IgM by ELISA and thesearch for parasites in all individuals at risk have been valuable diagnostic toolsfor detecting acute cases. Follow-up studies regarding the microepidemics primarilyaffecting children has resulted in 70% infection persistence six years afteranti-parasitic treatment. Panstrongylus geniculatus has been theincriminating vector in most cases. As a food-borne disease, this entity requiresepidemiological, clinical, diagnostic and therapeutic approaches that differ fromthose approaches used for traditional direct or cutaneous vector transmission.