title: Schistosoma mansoni in schoolchildren in a Madagascan highland school assessed by PCR and sedimentation microscopy and Bayesian estimation of sensitivities and specificities.
abstract: Madagascar is an endemic area for schistosomiasis, but recent prevalence data are scarce. We investigated stool samples of 410 children aged 4-18 years from a combined primary and secondary school in a Madagascan highland village near Ambositra in order to assess the prevalence of Schistosoma mansoni using microscopy and real-time polymerase chain reaction (PCR). A high prevalence of S. mansoni of 77.1% was detected by PCR, while only 15.2% of microscopic examinations of sedimentation-enriched stools were positive. We estimated the sensitivity and specificity of stool sedimentation microscopy (19.7% and 98.8%) and of PCR (98.9% and 89.3%) using a Bayesian approach for two dependant tests in one population without a reference standard. Our Bayesian posterior estimate of the prevalence is 80.2%. Simple sedimentation technique misses about 4/5 of all PCR-confirmed infections and is insufficient to determine the prevalence of S. mansoni. A survey comparing PCR with a classical standard technique (KatoKatz) is desirable.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany. Electronic address: schwarznorbert@bni-hamburg.de.
authors.forename: Norbert G
authors.initials: NG
authors.lastname: Schwarz
authors.affiliation: Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: rakrapha13@yahoo.fr.
authors.forename: Raphael
authors.initials: R
authors.lastname: Rakotozandrindrainy
authors.affiliation: Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: herijean007@yahoo.fr.
authors.forename: Jean N
authors.initials: JN
authors.lastname: Heriniaina
authors.affiliation: Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: njariharinjaka@yahoo.fr.
authors.forename: Njary
authors.initials: N
authors.lastname: Randriamampionona
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany. Electronic address: hahn@bnitm.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hahn
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany; Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: hogan@bni-hamburg.de.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hogan
authors.affiliation: Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg, Bernhard Nocht Street 74, D-20359 Hamburg, Germany; Institute for Medical Microbiology, Virology and Hygiene, University Hospital of Rostock, Schillingallee 70, D-18057 Rostock, Germany. Electronic address: Frickmann@bni-hamburg.de.
authors.forename: Hagen
authors.initials: H
authors.lastname: Frickmann
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany. Electronic address: dekker@bni-hamburg.de.
authors.forename: Denise
authors.initials: D
authors.lastname: Dekker
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany. Electronic address: poppert@bni-hamburg.de.
authors.forename: Sven
authors.initials: S
authors.lastname: Poppert
authors.affiliation: Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: rakouttsa@yahoo.fr.
authors.forename: Tsiriniaina
authors.initials: T
authors.lastname: Razafindrabe
authors.affiliation: Department of Microbiology and Parasitology, University of Antananarivo, B.P.175, Antananarivo, Madagascar. Electronic address: rakotophilibert@yahoo.fr.
authors.forename: Jean P
authors.initials: JP
authors.lastname: Rakotondrainiarivelo
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht street 74, D-20359 Hamburg, Germany. Electronic address: may@bni-hamburg.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: May
authors.affiliation: Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg, Bernhard Nocht Street 74, D-20359 Hamburg, Germany. Electronic address: hagen@bni-hamburg.de.
authors.forename: Ralf M
authors.initials: RM
authors.lastname: Hagen
mesh_terms: D000293:Adolescent; D000818:Animals; D002648:Child; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D008270:Madagascar / Q000453:epidemiology; D008297:Male; D008853:Microscopy / Q000379:methods*; D010274:Parasitology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015995:Prevalence; D012550:Schistosoma mansoni / Q000302:isolation & purification*; D012555:Schistosomiasis mansoni / Q000175:diagnosis* / Q000453:epidemiology*; D012574:Schools; D013334:Students
keywords: Madagascar; Microscopy; PCR; Prevalence; Schistosomiasis; Sensitivity and specificity