title: Diagnosis, treatment and risk factors of Strongyloides stercoralis in schoolchildren in Cambodia.
abstract: BACKGROUND
  Worldwide, an estimated 30 to 100 million people are infected with Strongyloides stercoralis, a soil-transmitted helminth. Information on the parasite is scarce in most settings. In semi-rural Cambodia, we determined infection rates and risk factors; compared two diagnostic methods (Koga agar plate [KAP] culture and Baermann technique) for detecting S. stercoralis infections, using a multiple stool examination approach; and assessed efficacy of ivermectin treatment.
  
  
  RESULTS
  We performed a cross-sectional study in 458 children from four primary schools in semi-rural villages in Kandal province, using three diagnostic procedures (Kato-Katz, KAP culture and Baermann technique) on three stool samples. Infected children were treated with ivermectin (100 µg/kg/day for two days) and re-examined three weeks after treatment. Hookworm, S. stercoralis, Trichuris trichiura, and small trematode eggs were most prevalent, with 24.4% of children being infected with S. stercoralis. The sensitivity of KAP culture and Baermann technique was 88.4% and 75.0%, respectively and their negative predictive values were 96.4% and 92.5%, respectively. The cumulative prevalence of S. stercoralis increased from 18.6% to 24.4%, after analyzing three stool samples, which was close to the modeled 'true' prevalence of 24.8%. Children who reported defecating in latrines were significantly less infected with S. stercoralis than those who did not use latrines (p<0.001). Itchy skin and diarrhea were significantly associated with S. stercoralis infection. The cure rate of ivermectin was 98.3%.
  
  
  CONCLUSIONS
  S. stercoralis infection is highly prevalent among semi-rural Cambodian schoolchildren. The sensitivity of KAP culture is higher than that of the Baermann technique. In the absence of a "gold standard", analysis of multiple stool samples by different diagnostic methods is required to achieve a satisfactory level of sensitivity. Almost three-quarters of the infections could have been avoided by proper sanitation. Ivermectin is highly efficacious against S. stercoralis but prohibitive costs render the drug inaccessible to most Cambodians.
authors: National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
authors: Virak
authors: V
authors: Khieu
authors: Fabian
authors: F
authors: Schär
authors: Hanspeter
authors: H
authors: Marti
authors: Somphou
authors: S
authors: Sayasone
authors: Socheat
authors: S
authors: Duong
authors: Sinuon
authors: S
authors: Muth
authors: Peter
authors: P
authors: Odermatt
mesh_terms: D000293:Adolescent; D000723:Ancylostomatoidea / Q000302:isolation & purification; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D002160:Cambodia / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine / Q000379:methods; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D007559:Ivermectin / Q000627:therapeutic use; D008297:Male; D010274:Parasitology / Q000379:methods; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors; D012574:Schools; D012680:Sensitivity and Specificity; D017171:Strongyloides stercoralis / Q000302:isolation & purification*; D013322:Strongyloidiasis / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D016896:Treatment Outcome; D014258:Trichuris / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D000871:Anthelmintics; D007559:Ivermectin