title: A cross-sectional study on schistosomiasis and soil-transmitted helminths in Mbita district, western Kenya using different copromicroscopic techniques.
abstract: BACKGROUND
  Identification of populations to be targeted for individual treatment and broad-spectrum therapy in schistosomiasis-endemic areas, assessment of therapy efficacy, morbidity, and evaluation of control strategies need to be based on reliable diagnostic tools. Kato-Katz is routinely used and remains the standard diagnostic technique for schistosomiasis, despite its many challenges. This study was conducted in Nyamanga village, Mbita, western Kenya, and evaluated the diagnostic performance of Kato-Katz, Mini-Parasep and modified Mini-FLOTAC techniques in detection of Schistosoma mansoni and soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) ova.
  
  
  METHODS
  Stool samples from 132 individuals were screened for eggs of S. mansoni by the 3 techniques. Mini-Parasep faecal parasite concentrator (Apacor Ltd, England), a single-use diagnostic device with a built-in filter for faecal concentration of helminth eggs by sedimentation was employed on stool samples fixed in 10% formalin. A modified Mini-FLOTAC (University of Naples, Italy) was based on floatation of helminths eggs with two different solutions (FS2 and FS7) using a closed system (Fill-FLOTAC) with 5% formalin. Kato-Katz was performed following WHO recommendation. Prevalence of S. mansoni and STH, sensitivity and degree of agreement among the 3 techniques were determined.
  
  
  RESULTS
  Prevalence of S. mansoni was 47.0%, 34.1% and 20.5% by Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7 techniques, respectively. Prevalence of any STH infection was 6.1%, 3.0%, 6.1% and 6.8% by Mini-Parasep, Kato-Katz, modified Mini-FLOTAC FS2 and modified Mini-FLOTAC FS7 techniques, respectively. Considering the pooled results of the three methods (Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7) as diagnostic 'gold' standard, the sensitivity of Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7 for S. mansoni was 77.5%, 56.1%, and 33.8%, respectively. Mini-Parasep and modified Mini-FLOTAC FS7 techniques had moderate (κ = 0.46) and fairly good (κ = 0.25) agreements with Kato-Katz for S. mansoni, respectively. Mini-Parasep detected a higher proportion of light intensity S. mansoni infections compared to Kato-Katz, which detected high proportions of heavy infections. Mini-Parasep detected a similar mean number of S. mansoni eggs per gram (EPG) of stool compared to the standard Kato-Katz (62.9 vs 97.3; t (131) = -0.49, P = 0.6265) and significantly higher EPG compared to the modified Mini-FLOTAC FS7 (62.9 vs 34.6; t (131) = 5.39, P < 0.0001).
  
  
  CONCLUSIONS
  The high sensitivity of Mini-Parasep suggests its promising potential as an alternative tool in enhancing diagnosis and in monitoring schistosomiasis transmission and determining endpoint of intervention programs, especially in low endemicity areas. Mini-Parasep is also easy to operate, safe and also permits work with fresh stool.
authors.affiliation: Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, P. O. Box 1578-40100, Kisumu, Kenya. annettengetich@gmail.com.|Department of Zoology, Maseno University, PRIVATE BAG, Maseno, Kenya. annettengetich@gmail.com.
authors.forename: Annette I
authors.initials: AI
authors.lastname: Ng'etich
authors.affiliation: Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, P. O. Box 1578-40100, Kisumu, Kenya. FRawago@kemricdc.org.
authors.forename: Fredrick O
authors.initials: FO
authors.lastname: Rawago
authors.affiliation: Department of Zoology, Maseno University, PRIVATE BAG, Maseno, Kenya. profwajura@ymail.com.
authors.forename: Walter G Z O
authors.initials: WG
authors.lastname: Jura
authors.affiliation: Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, P. O. Box 1578-40100, Kisumu, Kenya. PMwinzi@kemricdc.org.
authors.forename: Pauline N
authors.initials: PN
authors.lastname: Mwinzi
authors.affiliation: Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA. kfw7@cdc.gov.
authors.forename: Kimberly Y
authors.initials: KY
authors.lastname: Won
authors.affiliation: Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, P. O. Box 1578-40100, Kisumu, Kenya. MOdiere@kemricdc.org.
authors.forename: Maurice R
authors.initials: MR
authors.lastname: Odiere
mesh_terms: D000818:Animals; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology*; D006373:Helminthiasis / Q000453:epidemiology* / Q000469:parasitology*; D006376:Helminths / Q000145:classification / Q000302:isolation & purification*; D007411:Intestinal Diseases, Parasitic / Q000453:epidemiology* / Q000469:parasitology*; D007630:Kenya / Q000453:epidemiology; D008853:Microscopy / Q000379:methods*; D012680:Sensitivity and Specificity