Abstract
BackgroundSchistosomiasis constitutes a major public health problem, and 200 million people are estimated to be infected with schistosomiasis worldwide. In Brazil, schistosomiasis has been reported in 19 states, showing areas of high and medium endemicity and a wide range of areas of low endemicity (ALE). Barra Mansa in Rio de Janeiro state has an estimated prevalence of 1%. ALE represent a new challenge for the helminth control because about 75% of infected individuals are asymptomatic and infections occur with a low parasite load (<100 eggs per gram of feces), causing a decrease in sensitivity of stool parasitological techniques, which are a reference for the laboratory diagnosis of this helminth. The objective of this study was to evaluate the performance of a TaqMan quantitative polymerase chain reaction (qPCR) technique in serum and feces DNA samples using the techniques of Kato-Katz (KK), Hoffman, Pons and Janer (HH) as references, during an epidemiological survey using fecal samples and sera from randomized residents from an ALE.MethodsA cross-sectional study conducted from April to December 2011 using a probabilistic sampling that collected 572 fecal and serum samples. The laboratory diagnostic techniques used were: KK, HH and qPCR (feces and serum).ResultsWe obtained the following results using the different diagnostic techniques: KK and HH, 0.9% (n =5); qPCR-feces, 9.6% (n =55); and qPCR-serum, 1.4% (n =8). The qPCR-feces presented the highest positivity, whereas the techniques of HH and KK were the least sensitive to detect infections (0.8%). Compared to HH and KK, qPCR-feces showed a statistically significant difference in positivity (p <0.05), although with poor agreement.ConclusionThe positivity rate presented by the qPCR approach was far higher than that obtained by parasitological techniques. The lack of adequate surveillance in ALE of schistosomiasis indicates a high possibility of these areas being actually of medium and high endemicity. This study presents a control perspective, pointing to the possibility of using combined laboratory tools in the diagnosis of schistosomiasis in ALE.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0558-4) contains supplementary material, which is available to authorized users.
Highlights
Schistosomiasis constitutes a major public health problem, and 200 million people are estimated to be infected with schistosomiasis worldwide
The objective of this study was to compare the performance of quantitative polymerase chain reaction (qPCR)-based techniques using fecal and serum samples, with KK and HH techniques to diagnose cases of schistosomiasis due to S. mansoni in the outskirts of the municipality of Barra Mansa/RJ, Brazil
The following techniques were performed for each participant: qPCR-feces, qPCR-serum, KK, and HH
Summary
Schistosomiasis constitutes a major public health problem, and 200 million people are estimated to be infected with schistosomiasis worldwide. In Brazil, schistosomiasis has been reported in 19 states, showing areas of high and medium endemicity and a wide range of areas of low endemicity (ALE). Schistosomiasis constitutes a major public health problem, and 200 million people around the world are estimated to be infected [1,2]. In Brazil, the infection has been reported in 19 states [3], including areas of high, medium, and low endemicity. In areas of low endemicity, 80% of the individuals are asymptomatic or present only the mild form of the disease, which hinders the diagnosis of the infection [6]. One of the focal areas of schistosomiasis due to S. mansoni in Rio de Janeiro State is located in the municipality of Barra Mansa [7], which has an estimated prevalence of 1%. The endemic areas are within the urban perimeter, with a higher prevalence observed in the neighborhood of Siderlândia, followed by the neighborhoods of Santa Clara, São Luiz, Cantagalo, and Nova Esperança [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
