This outbreak was unique, because it affected a large, urban, predominantly young, middle-class, otherwise healthy population and resulted in an unprecedented public health emergency. Rapid diagnosis and treatment avoided higher lethality. Food-borne transmission of T. cruzi may occur more often than is currently recognized.

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.

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In areas of low transmission of schistosomiasis, the evaluation of the success of control depends on reliable diagnostic tests. Under such conditions, some of the serological tests better estimate the real prevalence of this parasitosis than the classical stool examinations. On the search of highly sensitive and specific antigenic fractions for use in serological tests, an immunoblot technique with a luminescent substrate was used in order to evaluate, under dissociating and reducing conditions, the Schistosoma mansoni adult worm antigen (AWA). The sera of 30 infected Venezuelan children were assayed for specific recognition of AWA by IgG, IgM, IgE, IgA, and the four IgG subclasses. Eight highly specific polypeptide molecules from the parasite of 118, 114, 105, 74, 71, 45, 36, and 30 kDa were recognized by total IgG. Additionally, IgG1 and IgG2 recognized a molecule of 100 kDa and IgM one of 77 kDa. The present data suggests that certain molecules from the adult worm, specially the 36 kDa, might be relevant in the specific immunodiagnosis of this parasitic disease. The fact that the children antibodies were able to recognize the primary structure of these antigens, will allow us to chemically synthesize the relevant linear epitopes.

Oral transmission of Trypanosoma cruzi is a frequent cause of acute Chagas disease (ChD). In the present cross-sectional study, we report the epidemiological, clinical, serological and molecular outcomes of the second largest outbreak of oral ChD described in the literature. It occurred in March 2009 in Chichiriviche de la Costa, a rural seashore community at the central littoral in Venezuela. The vehicle was an artisanal guava juice prepared at the local school and Panstrongylus geniculatus was the vector involved. TcI genotype was isolated from patients and vector; some showed a mixture of haplotypes. Using molecular markers, parasitic loads were high. Eighty-nine cases were diagnosed, the majority (87.5%) in school children 6–15 years of age. Frequency of symptomatic patients was high (89.9%) with long-standing fever in 87.5%; 82.3% had pericardial effusion detected by echocardiogram and 41% had EKG abnormalities. Three children, a pregnant woman and her stillborn child died (5.6% mortality). The community was addressed by simultaneous determination of specific IgG and IgM, confirmed with indirect hemagglutination and lytic antibodies. Determination of IgG and IgA in saliva had low sensitivity. No individual parasitological or serological technique diagnosed 100% of cases. Culture and PCR detected T. cruzi in 95.5% of examined individuals. Based on the increasing incidence of oral acute cases of ChD, it appears that food is becoming one of the most important modes of transmission in the Amazon, Caribbean and Andes regions of America.

Frequency and severity of side effects during treatment of acute oral infection by T. cruzi demand direct supervision and close follow-up, even in those asymptomatic, to prevent life-threatening situations.