Trypanosoma cruzi in food: detection by molecular methods (PCR)

Information 24/06/16.

Trypanosoma cruzi is the protozoan that causes Chagas disease , or American trypanosomiasis. The transmission usually occurs through the bite of an arthropod vector (triatómido) family Reduviidae, belonging to some species of Triatoma spp. (Triatoma infestans), Panstrongylus spp. (Panstrongilus megistus) or Rhodnius spp. (Rhodnius prolixus). These vectors by biting arthropods to feed a person tend to defecate and the consequent scratching by the person introduced into the solution of continuity of the skin metacyclic trypomastigotes eliminated by the arthropod with their droppings. With contaminated by scratching, hands can also be deposited in the conjunctival and penetrate through the ocular mucosa. In addition, it is also well known transmission through blood transfusions containing tripomastigotes, or through vertical transmission from mother to fetus.

Gastrointestinal infection through the oral route was known since 1960, but was not known in depth and was researched by 2004. In 2005 there was an outbreak in the Brazilian state of Santa Catarina, as well as several outbreaks in three years following (2006 to 2008) in the Brazilian Amazon related to the consumption of Amazon palm berries (Amazonian palm berry), so he paid attention to this type of transmission. In 2007 an outbreak occurred also in Caracas (Venezuela) by consumption of contaminated fruit juices. They have since been described many cases of infections by eating contaminated with feces of triatomine food.

Most cases have been linked to the consumption of açai juice (açai palm, Asai, Azai, huasai, Naidi, murrapo palm, palm manaca) (Euterpe oleracea Mart). The intake of this fruit is very common in the Amazon region in northern Brazil, and has gained importance, extending its use to other regions of Brazil, and other countries, to meet its beneficial effects for its phytochemical composition and antioxidant capacity.

All cases have occurred primarily in Brazil, inside and outside the Amazon region, and presented as an acute infection in groups of individuals, ingestion of the same type of food. Those affected develop a fever with own general manifestations of systemic infection (acute Chagas disease).

Pollution açai juice could come from the contamination of the fruit or its pulp, with animal excreta or vectors infected with Trypanosoma cruzi.

Brazil has become the largest producer, consumer and exporter of açai juice, with the regions of Para, Maranhao, Amapa, Rondonia and Acre producers and consumers the most. The product is exported to North America, Japan, China and Europe

Diagnostic methods

The presence of Trypanosoma cruzi in any sample can be detected by methods of microscopic observation, culture, xenodiagnosis or genomic screening. However, the difficulty of observation when few microorganisms in a sample, methods of microscopic observation are not currently used, unless the case of a peripheral blood sample or from an infected tissue of a patient, in which they are more likely watch. Farming methods have the disadvantage of having to prepare the media with fresh rabbit blood (NNN) or have special media (Schneider 's medium). Xenodiagnosis required to have arthropod vectors to feed the sample in which it is desired to detect, and subsequent observation of trypomastigotes in feces arthropod. For these reasons, currently, molecular methods have been imposed for detection.

Tests in IVAMI detection Typanosoma cruzi in fruit juices

Molecular detection by PCR.

Conservation of food samples

Chilled or frozen.

Delivery of results

24 to 48 hours.

Cost of testing