Real-time polymerase chain reaction for detection of low-intensity Schistosoma japonicum infections in China.
More sensitive methods for diagnosing infection with Schistosoma japonicum are needed as control becomes more effective. We compared a real-time polymerase chain reaction (PCR) for stool samples with conventional diagnostic methods in a study of 1,727 persons from Anhui Province, China. Seroprevalence determined by using an indirect hemagglutination assay (IHA) was much higher (26.1%) than the prevalence in stool-based tests, which were 5.3%, 3.2%, and 3.0% for PCR, hatching test, and Kato-Katz thick smear, respectively. A large proportion of the positive stool samples were only positive in one or two tests. The PCR showed better agreement with IHA than the other two stool-based tests. A commonly used diagnostic algorithm with initial screening for antibodies and subsequent testing with the Kato-Katz thick smear of the seropositive results would have resulted in treatment of 22 people compared with 50 people if the PCR replaced the Kato-Katz thick smear. As prevalence and intensity decrease, the benefit of increased sensitivity using the PCR must be weighed against additional costs.
Lier
Tore
T
Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway. tore.lier@unn.no
Simonsen
Gunnar S
GS
Wang
Tianping
T
Lu
Dabing
D
Haukland
Hanne H
HH
Vennervald
Birgitte J
BJ
Hegstad
Joachim
J
Johansen
Maria V
MV
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002681:China / Q000453:epidemiology; D005243:Feces / Q000469:parasitology; D005260:Female; D006386:Hemagglutination Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D010270:Parasite Egg Count; D016133:Polymerase Chain Reaction / Q000379:methods*; D012554:Schistosomiasis japonica / Q000175:diagnosis* / Q000453:epidemiology*; D012680:Sensitivity and Specificity; D055815:Young Adult