ABSTRACT
Schistosomiasis is a major health problem in Egypt with high socioeconomical impact. For effective Schistosoma mansoni (S. mansoni) control, sensitive and specific methods of diagnosis are required. The aim of the present study was to detect the prevalence of S. mansoni in one of the endemic areas, Tookh villages, using Kato-Katz technique and to evaluate the diagnostic value of polymerase chain reaction (PCR) as an alternative tool for diagnosing schistosomiasis in stool specimens from individuals at high risk of infection by S. mansoni. A total of 370 stool samples were tested for S. mansoni infection using 3 Kato-Katz smears. Of them 49 samples were tested using primers targeted to a highly repeated 121-base pair sequence of S. mansoni. The samples were divided into 2 groups according to parasitic status of the individual as follows: 10 individuals with active schistosomiasis and free from other parasitic infections as proved by Kato-Katz thick smear and 39 individuals with negative parasitological examination. The results revealed a prevalence of 2.7% (10 out of 370) for S. mansoni infection using Kato-Katz technique . They also showed a high sensitivity for PCR as S. mansoni DNA was detected in 48.72% (19/39) of the samples with negative Kato-Katz and in 100% (10/10) of the samples with positive Kato-Katz analyzed. In conclusion, PCR is an important tool for detecting S. mansoni infection in individuals excreting few eggs in feces and Kato-Katz is not enough to diagnose positive S. mansoni cases in individuals at high risk of infection.
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