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.

Abdominal ultrasound can be a useful tool for diagnosing periportal fibrosis related to

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.

Non-invasive markers of fibrosis have been used to diagnose liver fibrosis in a variety of diseases. Hyaluronic acid (HA) and collagen IV (C-IV

No abstract

Orally transmitted Chagas disease (ChD), which is a well-known entity in the Brazilian Amazon Region, was first documented in Venezuela in December 2007, when In Venezuela, effective control measures successfully reduced the annual incidence of Trypanosoma cruzi infections from 10/1,000 individuals in the 1950s to 1/1,000 in the 1980s (Feliciangeli et al. 2003). Since then, the recorded outbreaks of acute Chagas disease (ChD) have been as follows: between 1988-1996, 59 cases occurred in the western states of Venezuela (Añez et al. 1999), after which nine cases involving two deaths occurred during the period of January 2006-March 2007 in the same endemic area (Añez et al. 2007). In 2004 and 2006, the deaths of two children near Caracas were documented ). Nevertheless, an outbreak of orally transmitted ChD (OChD) in a school in a middle class neighbourhood in Caracas was the warning signal that ChD was re-emerging via a different mode of transmission, i.e., the oral route (Alarcón de Noya et al. 2010b Noya et al. 2010b), an outbreak occurred in an urban school that was presumably linked to the ingestion of contaminated home-made juice that had been prepared in a different part of the city where triatomines were present.The aim of this study is to provide information about the parasitological, immunological and molecular laboratory tests used in diagnosing ChD to gleam further knowledge from the largest OChD outbreak ever reported. SUBJECTS, MATERIALS AND METHODSStudy population -The study population consisted of students, teachers and administrative personnel from a school located in the municipality of Chacao in Caracas, Venezuela. Once the primary case was diagnosed (Martín et al. 2009) and the epidemiological link to another case was established (Alarcón de Noya et al. 2010c), parasitological examinations and serological tests were carried out in these cases, in addition to other symptomatic patients who voluntarily requested medical attention at the Tropical Medicine Institute (IMT), Universidad Central de Venezuela in Caracas. After the death of a five-year-old student, most of the school community was managed as part of an on-site emergency, both in the school and at the hospital, where several of the patients were hospitalised. T. cruzi infection was diagnosed by collecting only one tube of blood for serological testing, except for in people who were symptomatic at the time of the interview and from whom additional blood was taken for parasitological or molecular testing (Supplementary data). For logistical and ethical reasons, a unique protocol could not be followed and, consequently, the results are simply presented as they were obtained over time. It was not possible to re-sample the blood of individuals with positive serological tests to isolate the parasite before treatment because the treatment had to begin before the group dispersed for the Christmas holiday.Direct parasitological tests -Observations of the parasite were performed using fresh blood smears as well as Giemsa-stained preparations (W...