Loop-Mediated Isothermal Amplification of DNA for Point-of-Care Follow-Up of Anti-Parasitic Treatment of Chagas Disease.

A loop-mediated isothermal amplification assay was evaluated as a surrogate marker of treatment failure in Chagas disease (CD). A convenience series of 18 acute or reactivated CD patients who received anti-parasitic treatment with benznidazole was selected-namely, nine orally infected patients: three people living with HIV and CD reactivation, five chronic CD recipients with reactivation after organ transplantation and one seronegative recipient of a kidney and liver transplant from a CD donor. Fifty-four archival samples (venous blood treated with EDTA or guanidinium hydrochloride-EDTA buffer and cerebrospinal fluid) were extracted using a Spin-column manual kit and tested by Loopamp kit (Tc-LAMP, index test) and standardized real-time PCR (qPCR, comparator test).

Polymorphisms of the TLR4 gene: Risk factor for chronicity and severity in oral vectorial Chagas disease.

Chagas disease is one of the parasitic infections with the greatest socio-economic impact in Latin America. In Venezuela, epidemiological data has shown different sources of infection, such as the vectorial route by oral transmission. Given the importance of the TLR4 gene in the innate immune response triggered by infection with Trypanosoma cruzi, this work analyses the role of TLR4 polymorphisms and its possible effect on cytokine expression.

Ten-year follow-up of the largest oral Chagas disease outbreak. Laboratory biomarkers of infection as indicators of therapeutic failure.

Trypanosoma cruzi uses various mechanisms of infection to access humans. Since 1967, food contaminated with metacyclic trypomastigotes has triggered several outbreaks of acute infection of Chagas disease by oral transmission. Follow-up studies to assess the effectiveness of anti-parasitic treatment of oral outbreaks are rather scarce.

Nifurtimox response of isolates from an outbreak of Chagas disease in Caracas, Venezuela.

Background & Objectives: In Venezuela, Chagas disease (ChD) is considered a serious health problem, with about 6 million people at risk; and acute outbreaks due to oral transmission of Chagas Disease (OChD) are becoming increasingly important. In 2007 there was a major outbreak of OChD and although patients from this episode were treated with nifurtimox (Lampit®-Bayer), about 70% therapeutic failure was registered. These results led us to examine whether parasite's drug susceptibility was related to this therapeutic failure.

Purification of Glycosylphosphatidylinositol-Anchored Mucins from Trypanosoma cruzi Trypomastigotes and Synthesis of α-Gal-Containing Neoglycoproteins: Application as Biomarkers for Reliable Diagnosis and Early Assessment of Chemotherapeutic Outcomes of Chagas Disease.

Chagas disease (ChD), caused by the protozoan parasite Trypanosoma cruzi, affects millions of people worldwide. Chemotherapy is restricted to two drugs, which are partially effective and may cause severe side effects, leading to cessation of treatment in a significant number of patients. Currently, there are no biomarkers to assess therapeutic efficacy of these drugs in the chronic stage.

An ecological overview on the factors that drives to Trypanosoma cruzi oral transmission.

American trypanosomiasis is one of the few native parasites of this continent. As a zoonosis, Trypanosoma cruzi infects about 180 species out of 25 families of mammals. Its regular transmission is through triatomines, which can easily transmit parasites either by the skin route (contamination of mammals skin with their feces) or by oral route (ingestion of food contaminated with complete triatomines or their feces) and additionally through haematogenous via (congenital and transfusional) and by tissues (transplants).

Improvements and Variants of the Multiple Antigen Blot Assay-MABA: An Immunoenzymatic Technique for Simultaneous Antigen and Antibody Screening.

This simple, versatile, reliable, reproducible, multipurpose, and inexpensive technique is based on the adhesion of different antigens to a single nitrocellulose strip using, as template, an acrylic device containing 28 parallel channels. The inclusion of channels containing normal human serum improves the quality control of this assay. Antigen-sensitized nitrocellulose strips are cut perpendicularly to the antigen-rows, exposed to immune sera followed by the appropriate conjugate.

Analytical performance of a multiplex Real-Time PCR assay using TaqMan probes for quantification of Trypanosoma cruzi satellite DNA in blood samples.

Background: The analytical validation of sensitive, accurate and standardized Real-Time PCR methods for Trypanosoma cruzi quantification is crucial to provide a reliable laboratory tool for diagnosis of recent infections as well as for monitoring treatment efficacy.

Methods/principal Findings: We have standardized and validated a multiplex Real-Time quantitative PCR assay (qPCR) based on TaqMan technology, aiming to quantify T. cruzi satellite DNA as well as an internal amplification control (IAC) in a single-tube reaction.

Rapid detection of Trypanosoma cruzi in human serum by use of an immunochromatographic dipstick test.

We evaluated a commercially available immunochromatographic dipstick test to detect Trypanosoma cruzi infection in 366 human serum samples with known serological results from Argentina, Ecuador, Mexico, and Venezuela. One hundred forty-nine of 366 (40.7%) and 171/366 (46.

[Human fasciolosis in Mara municipality, Zulia state. Venezuela: prevalence and asociated factors].

In Venezuela, human Fasciolosis shows a low frequency. However, Mara Municipality is a highly endemic region for bovine fasciolosis and there are no reports of this parasite infection in humans. To determine the prevalence and associated factors to human fasciolosis in Mara municipality - Zulia state, a total of 51 blood and stool samples were collected.

[Pulmonary paragonimiasis. Case report].

Paragonimiasis is a zoonosis affecting wild and domestic animals and human beings, caused by species of trematodes of the genus Paragonimus. Humans become infected after ingestion of raw or poorly cooked fresh water crustaceans. The aim of the present work is the description of a case of a 3-years old child, coming from Guárico State in Venezuela with a year of residence in the seashore of the Provincia Manabí in Ecuador, where he ate crabs in "ceviche".

[A confirmatory diagnosis of antibodies anti-Trypanosoma cruzi in donors referred by blood banks in Venezuela].

To establish the confirmatory diagnosis of Trypanosoma cruzi infection, at least two immunoserological tests (ELISA, Indirect hamaglutination, IH, Complement Fixation Test, CFT) were carried out in 254 donors, from public and private blood banks of Venezuela, during 48 months between 1997-1998 and 2003-2004, referred to the Immunology Section of the Tropical Medicine Institute in Caracas. Antibodies anti-T. cruzi were detected in 129/254 (50,79%) by ELISA-IgG or IH and CFT.

Clinical and ultrasound findings before and after praziquantel treatment among Venezuelan schistosomiasis patients.

Abdominal ultrasound can be a useful tool for diagnosing periportal fibrosis related to Schistosoma mansoni infection, and also for planning and monitoring the evolution of hepatic morbidity following control measures. We evaluated the standardized ultrasound methodology proposed by the World Health Organization for detecting periportal fibrosis and portal hypertension, among patients from an endemic area in Venezuela, and the impact of praziquantel treatment 3-5 years later. After chemotherapy, complete reversal of periportal lesions was observed in 28.