Prevalence and intensity of <i>S</i>. mansoni infection for first year students in each arm at baseline (Year 1) and final evaluation (Year 5).

<p>Prevalence and intensity of <i>S</i>. mansoni infection for first year students in each arm at baseline (Year 1) and final evaluation (Year 5).</p

Cluster randomized trial comparing school-based mass drug administration schedules in areas of western Kenya with moderate initial prevalence of <i>Schistosoma mansoni</i> infections

<div><p>Background</p><p>Mass drug administration (MDA) using praziquantel is the WHO-recommended approach for control of schistosomiasis. However, few studies have compared the impact of different schedules of MDA on the resultant infection levels. We wished to evaluate whether annual MDA was more effective than less frequent treatments for reducing community-level prevalence and intensity of <i>Schistosoma mansoni</i> infections.</p><p>Methods</p><p>We performed a cluster randomized trial (ISRCTN 14849830) of 3 different MDA frequencies over a 5 year period in 75 villages with moderate (10%-24%) initial prevalence of <i>S</i>. <i>mansoni</i> in school children in western Kenya. Praziquantel was distributed by school teachers to students either annually, the first 2 years, or every other year over a 4 year period. Prevalence and intensity of infection were measured by stool examination in 9–12 year old students using the Kato-Katz method at baseline, each treatment year, and for the final evaluation at year 5. <i>S</i>. <i>mansoni</i> prevalence and intensity were also measured in first year students at baseline and year 5.</p><p>Results</p><p>Twenty-five schools were randomly assigned to each arm. <i>S</i>. <i>mansoni</i> prevalence and infection intensity in 9–12 year old students significantly decreased within each arm from baseline to year 5 but there were no differences between arms. There were no differences in infection levels in first year students either within or between arms.</p><p>Conclusions</p><p>Strategies employing 2 or 4 rounds of MDA had a similar impact in schools with moderate initial prevalence, suggesting that schistosomiasis control can be sustained by school-based MDA, even if provided only every other year.</p></div

Overall mean prevalence and mean prevalence by infection intensity category by arm and by year.

<p>Total bar height represents mean <i>S</i>. <i>mansoni</i> infection prevalence in each year. Light grey represents the prevalence of individuals with low intensity infections (1–99 epg); darker grey represents prevalence of moderate intensity infections (100–399 epg); and black represents prevalence of individuals with high intensity infections (≥ 400 epg).</p

Prevalence and intensity of infection in 9–12 year olds in each arm at baseline (Year 1) and final evaluation (Year 5).

<p>Prevalence and intensity of infection in 9–12 year olds in each arm at baseline (Year 1) and final evaluation (Year 5).</p

Exponential curve fitted to the data from the first phase (April—November 2010) of the African swine fever outbreaks in Gulu District, Uganda.

<p>Exponential curve fitted to the data from the first phase (April—November 2010) of the African swine fever outbreaks in Gulu District, Uganda.</p

Comparisons of 9–12 year old prevalence and intensity of <i>S</i>. <i>mansoni</i> infection between arms at year 5.

<p>Adjustment of PRs and AMRs are for age, sex, and village sample size.</p

Comparisons of change in 9–12 year old prevalence and intensity of <i>S</i>. <i>mansoni</i> infection between year 1 and year 5 for each arm, 25 villages per arm.

<p>Adjustment of PRs and AMRs are for age, sex, and village sample size.</p

Prevalence and intensity of <i>S</i>. mansoni infection for first year students in each arm at baseline (Year 1) and final evaluation (Year 5).

<p>Prevalence and intensity of <i>S</i>. mansoni infection for first year students in each arm at baseline (Year 1) and final evaluation (Year 5).</p

Estimated monthly SI/N, β and R_<i>0</i> during African Swine Fever outbreaks.

<p>Estimated monthly SI/N, β and R_<i>0</i> during African Swine Fever outbreaks.</p

Plots of selective sweep patterns for various pig populations.

<p>The -log10(FDR-adjusted P) values are plotted against chromosome number. The dashed lines indicate the significance threshold for the top 1% SNPs based on with |iHS| value. Selective sweeps (iHS) for (5A) Bush pigs, (5B) Homabay, (5C) for Busia population and warthogs.</p