Paul M.  Wanjala, Battan M.  Khaemba, Alfred I.  Luoba, 
    Prevalence and Intensity of Infection of Intestinal Schistosomiasis and Reinfection after Intervention in Budalangi Endemic Focus of Western Kenya,
    International Journal of Tropical Medicine,
    Volume 8,Issue 3,
    2013,
    Pages 71-80,
    ISSN 1816-3319,
    ijtmed.2013.71.80,
    (https://makhillpublications.co/view-article.php?doi=ijtmed.2013.71.80)
    Abstract: Human schistosomiasis or bilharziasis is a water borne disease 
  of man caused by trematodes of the genus <I>Schistosoma</I> and transmitted 
  by fresh water snails. It is one of the most widespread parasitic infections 
  being second only to malaria in its socioeconomic and public health importance 
  in tropical and subtropical areas. Intestinal schistosomiasis is endemic only 
  in areas with certain physical characteristics and risk factors. A 2 years study 
  was conducted in the Budalangi endemic focus of Western Kenya to determine prevalence 
  and intensity of infection and reinfection in the risk population with a view 
  of instituting a deworming programme in primary schools. Stool samples collected 
  from 972 school children aged 5-14 years in 18 randomly selected schools were 
  examined for ova of <I>S. mansoni</I>. A questionnaire was used to obtain demographic 
  information and to quantify exposure to infested surface waters. The mean prevalence 
  of infection in all schools (32.1%; range 0.0-65.0%) was significantly higher 
  in females (58.0%) than in males sampled (42.0%) (&#967;<SUP>2</SUP>; p&lt;0.05). 
  Intensity of infection was predominantly light with 65.1% of the infected population 
  harbouring GMEC 1-99 epg. The prevalence of infection significantly varied with 
  age groups (&#967;<SUP>2</SUP>-test; p&lt;0.05). The 8-11 years age group accounted 
  for 49.5% of the potential contamination of contact sites by ova of <I>S. mansoni</I>. 
  The prevalence and intensity of infection significantly dropped (Studentised 
  t-test; p&lt;0.05) after treatment with praziquantel coupled with training in 
  primary hygiene. Proximity to the lake shoreline (R<SUP>2</SUP> = 0.89, p&lt;0.05), 
  contact with lake water (&#967;<SUP>2</SUP>; p&lt;0.05) and specific water-related 
  activities including swimming (OR = 1.70; 95% CI = 1.03-2.81), fishing (OR = 
  3.23; 95% CI = 1.70-6.15) and washing clothes in the lake (OR = 2.07; 95% CI 
  = 1.27-3.38) were all associated with high risks of infection. The studies showed 
  that there was a continuous low level of transmission of <I>S. mansoni</I> in 
  the study area among the various exposure groups attributable to inevitable 
  contact with permanent water bodies which the vector snail used for breeding. 
  The level of infection in the human population determined in these studies could 
  be used for planning and implementing combined mass treatment of people who 
  reside in the study area in order to enhance control of the parasite.
    Keywords: Intesinal schistosomiasis;prevalence;intensity;deworming;reinfection