title: Can human schistosomiasis mansoni control be sustained in high-risk transmission foci in Egypt?
abstract: BACKGROUND
  Control of human schistosomiasis remains a longstanding issue on the agenda of the Egyptian Ministry of Health and Population (MOHP). Substantial impact on morbidity and prevalence of S. mansoni was widely reported after the National Schistosomiasis Control Program (NSCP) extended selective treatment with praziquantel (PZQ) to the Nile Delta in 1992 and upgrading this approach to mass drug administration (MDA) in 1997. Disease elimination, however, eludes NSCP as the micro-level includes many high-risk foci that sustain transmission, which has not been subjected to investigation.
  
  
  METHODS
  The study included five high-risk Nile Delta villages situated in the Kafr El-Sheikh Governorate. The total sample size amounted to 2382 individuals of both sexes and all ages. Diagnosis was based on four Kato-Katz slides from two consecutive stool samples. Data were investigated using SPSS, comparing proportions with the Chi square test and means with the Student t test, while strength of the associations were subjected to Odds Ratio (OR) analysis.
  
  
  RESULTS
  The overall prevalence of schistosomiasis in the study area was found to be 29%, while the mean geometric mean egg count (GMEC) was low (66.78 ± 4.4) indicating low intensity of infection. The mean village prevalence rates ranged from 16.5% to 49.5% and the GMECs from 35.2 to 86.2 eggs per gram (EPG) of stool. The difference of prevalence between villages was statistically significant at P < 0.05, and the prevalence was significantly higher among males than among females, P < 0.05, OR =1.4 and 95% CI (1.16-1.60). Infection peaked in the next youngest age group (5- ≤ 10 years of age) at an average prevalence of 50.8% with the GMEC reaching 209 EPG of stool in the village with the highest prevalence. The average prevalence and GMEC among children <5 years were 20.6% and 92.7 EPG, respectively.
  
  
  CONCLUSIONS
  Transmission of S mansoni in high-risk areas in the Nile Delta remains uninterrupted calling for improved, more comprehensive control strategies. Further investigations are needed to find out whether these results are due to inefficacy of PZQ, surviving immature worms or drug resistance.
authors.affiliation: Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt. elmorshedyh@hotmail.com.
authors.forename: Hala
authors.initials: H
authors.lastname: Elmorshedy
authors.affiliation: Ingerod, Brastad, Sweden & University of Basel, Basel, Switzerland. robert.bergquist@outlook.com.
authors.forename: Robert
authors.initials: R
authors.lastname: Bergquist
authors.affiliation: Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt. nadia_emam2004@yahoo.com.
authors.forename: Nadia Emam Abou
authors.initials: NE
authors.lastname: El-Ela
authors.affiliation: Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt. safaamohamed46@yahoo.com.
authors.forename: Safaa Mohamed
authors.initials: SM
authors.lastname: Eassa
authors.affiliation: Department of Pediatric, Faculty of Medicine, Alexandria University, 165 Alhorreya Avenue, Alexandria, Egypt. dr.elhamelsakka@yahoo.com.
authors.forename: Elham Elsayed
authors.initials: EE
authors.lastname: Elsakka
authors.affiliation: Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt.
authors.forename: Rashida
authors.initials: R
authors.lastname: Barakat
mesh_terms: D000293:Adolescent; D000328:Adult; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004534:Egypt / Q000453:epidemiology; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010270:Parasite Egg Count; D011223:Praziquantel / Q000008:administration & dosage / Q000627:therapeutic use*; D015995:Prevalence; D012555:Schistosomiasis mansoni / Q000453:epidemiology* / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D000871:Anthelmintics; D011223:Praziquantel