Prevalence, intensity and associated risk factors of soil-transmitted helminth and schistosome infections in Kenya: Impact assessment after five rounds of mass drug administration in Kenya

Abstract

Background In Kenya, over five million school age children (SAC) are estimated to be at risk of parasitic worms causing soil-transmitted helminthiasis (STH) and schistosomiasis. As such, the Government of Kenya launched a National School Based Deworming (NSBD) program in 2012 targeting the at-risk SAC living in endemic regions, with the aim of reducing infections prevalence to a level where they no longer constitute a public health problem. The impact of the program has been consistently monitored from 2012 to 2017 through a robust and extensive monitoring and evaluation (M&E) program. The aim of the current study was to evaluate the parasitological outcomes and additionally investigate water, sanitation and hygiene (WASH) related factors associated with infection prevalence after five rounds of mass drug administration (MDA), to inform the program's next steps. Materials and methods We utilized a cross-sectional design in a representative, stratified, two-stage sample of school children across six regions in Kenya. A sample size of 100 schools with approximately 108 children per school was purposively selected based on the Year 5 STH infection endemicity prior to the survey. Stool samples were examined for the presence of STH and Schistosoma mansoni eggs using double-slide Kato-Katz technique, urine samples were processed using urine filtration technique for the presence of S. haematobium eggs. Survey questionnaires were administered to all the participating children to collect information on their demographic and individual, household and school level WASH characteristics.

Prevalence, Intensity, and Correlates of Soil-Transmitted Helminth Infections among School Children after a Decade of Preventive Chemotherapy in Western Rwanda

“…It is well recognized that the WHO intervention strategy and implementation of the global NTD program have contributed to reducing the disease burden. However, the long-term intervention measures taken so far by many endemic countries in sub-Saharan Africa, including Rwanda, have not managed to control and eliminate STH and other NTDs as a public health problem by 2020 [ 16 , 20 , 30 , 31 ]. Several factors may have contributed to this shortcoming [ 32 ].…”

Statistical Regression Model of Water, Sanitation, and Hygiene; Treatment Coverage; and Environmental Influences on School-Level Soil-Transmitted Helminths and Schistosome Prevalence in Kenya: Secondary Analysis of the National Deworming Program Data

“…The first 5 years (phase one) of the M&E program was implemented between 2012 and 2017, 8 , 9 , 12 and the second phase is currently ongoing. 17 The M&E program conducts impact evaluation through a series of repeat cross-sectional surveys in a representative, stratified, two-stage sample of schoolchildren across counties in Kenya to determine the national infection prevalence levels, as described in their first three surveys of phase one of the program: year 1, year 3, and year 5, 8 , 9 , 12 and year 6 for phase two. 17 During year 1 to year 5 surveys, an average of 199 schools per survey round in 16 counties in four regions: Western, Nyanza, Rift Valley, and Coast, were surveyed before treatment to measure the national infection levels.…”

“… 17 The M&E program conducts impact evaluation through a series of repeat cross-sectional surveys in a representative, stratified, two-stage sample of schoolchildren across counties in Kenya to determine the national infection prevalence levels, as described in their first three surveys of phase one of the program: year 1, year 3, and year 5, 8 , 9 , 12 and year 6 for phase two. 17 During year 1 to year 5 surveys, an average of 199 schools per survey round in 16 counties in four regions: Western, Nyanza, Rift Valley, and Coast, were surveyed before treatment to measure the national infection levels. However, only 100 schools (five schools per county) were sampled during year 6 survey in 20 counties in six regions; Western, Nyanza, Rift Valley, Coast, Eastern, and North Eastern.…”

Modeling the Interruption of the Transmission of Soil-Transmitted Helminths Infections in Kenya: Modeling Deworming, Water, and Sanitation Impacts

“…The current modeling analysis therefore is aimed at addressing the challenges the program faced on the first 5-years of implementation resulting in its inability to achieve community-wide treatment benefit. For a detailed description of this program's design, impact and challenges, please see previous M&E reports (19)(20)(21)(22). Specifically, we developed a full agestructured mathematical model to answer the earlier outlined questions and inform on the right mix of strategies for the control and elimination of STH infections in Kenya.…”

“…Kenya has been implementing annual MDA through the SBD platform since the year 2012 targeting school going children (19)(20)(21)(22). The aim of the Kenyan deworming program was to reduce the national STH infection burden to a level where the infections are no longer a public health problem [defined by a prevalence of below 1% (23)].…”