Study diagram.

<p>Flowchart detailing compliance levels and the number of participants included at baseline (2012) and at follow-up (2013 & 2014) among community members from eight villages in Preah Vihear province, Cambodia. Negative participants with one (out of four) or more missing diagnostic examinations were excluded from the analysis. Numbers in bold correspond to the size of the analyzed samples.</p

Risk factors for infection with <i>S</i>. <i>stercoralis</i> at baseline and follow-up.

<p>Risk factors for infection with <i>S</i>. <i>stercoralis</i> at baseline and follow-up.</p

Predicted risk of <i>S</i>. <i>stercoralis</i> infection risk at follow-up by village sanitation coverage level and defecation place.

<p>Data were obtained from longitudinal surveys carried out among 1,269 participants at follow-up in eight villages of Preah Vihear province, Cambodia, between 2013 and 2014. The prediction was adjusted for sex, age, level of education, occupation, shoe wearing, hand washing after defecating and infection status at baseline.</p

Rates of <i>S</i>. <i>stercoralis</i> infection at follow-up surveys among participants who tested positive or negative at baseline.

<p>Re-infections: <i>S</i>. <i>stercoralis</i> infection at follow-up among participants who tested positive at baseline. New infections: <i>S</i>. <i>stercoralis</i> infection at follow-up among participants who tested negative at baseline. Error bars indicate 95% confidence interval. Data were obtained from repeated surveys carried out among 1,269 participants at follow-up in eight villages of Preah Vihear province, Cambodia, in 2013 (follow-up 1) and 2014 (follow-up 2).</p

<i>Strongyloides stercoralis</i> is associated with significant morbidity in rural Cambodia, including stunting in children

<div><p>Background</p><p><i>Strongyloides stercoralis</i> is a soil-transmitted nematode that can replicate within its host, leading to long-lasting and potentially fatal infections. It is ubiquitous and highly prevalent in Cambodia. The extent of morbidity associated with <i>S</i>. <i>stercoralis</i> infection is difficult to assess due to the broad spectrum of symptoms and, thus, remains uncertain.</p><p>Methodology/Principal findings</p><p>Clinical signs were compared among <i>S</i>. <i>stercoralis</i> infected <i>vs</i>. non-infected participants in a cross-sectional survey conducted in 2012 in eight villages of Northern Cambodia, and before and after treatment with a single oral dose of ivermectin (200μg/kg BW) among participants harboring <i>S</i>. <i>stercoralis</i>. Growth retardation among schoolchildren and adolescents was assessed using height-for-age and thinness using body mass index-for-age. <i>S</i>. <i>stercoralis</i> prevalence was 31.1% among 2,744 participants. Urticaria (55% <i>vs</i>. 47%, OR: 1.4, 95% CI: 1.1–1.6) and itching (52% <i>vs</i>. 48%, OR: 1.2, 95% CI: 1.0–1.4) were more frequently reported by infected participants. Gastrointestinal, dermatological, and respiratory symptoms were less prevalent in 103 mono-infected participants after treatment. Urticaria (66% <i>vs</i>. 11%, OR: 0.03, 95% CI: 0.01–0.1) and abdominal pain (81 <i>vs</i>. 27%, OR: 0.07, 95% CI: 0.02–0.2) mostly resolved by treatment. <i>S</i>. <i>stercoralis</i> infection was associated with stunting, with 2.5-fold higher odds in case of heavy infection.</p><p>Conclusions/Significance</p><p>The morbidity associated with <i>S</i>. <i>stercoralis</i> confirmed the importance of gastrointestinal and dermatological symptoms unrelated to parasite load, and long-term chronic effects when associated with malnutrition. The combination of high prevalence and morbidity calls for the integration of <i>S</i>. <i>stercoralis</i> into ongoing STH control measures in Cambodia.</p></div

Association between symptoms and <i>S</i>. <i>stercoralis</i> infection among 853 positive and 1,891 negative participants.

<p>Association between symptoms and <i>S</i>. <i>stercoralis</i> infection among 853 positive and 1,891 negative participants.</p

Study flow chart.

<p>Flowchart detailing the number of participants included in the three sub-studies. Insufficient parasitological data corresponds to one (out of four) or more missing diagnostic examinations for <i>S</i>. <i>stercoralis</i>, to one (out of two) or more missing diagnostic examinations for other helminths, and to any missing diagnostic examination for protozoa.</p

Proportion of participants harboring <i>S</i>. <i>stercoralis</i> mono-infections and reporting abdominal pain, nausea, vomiting, diarrhea, urticaria, and cough before and 21 days after ivermectin (200 μg/kg BW) treatment.

<p>The decreases in the proportion of participants reporting any of the symptoms in the figure was significant at 5% level, as assessed by the McNemar’s test. <i>S</i>. <i>stercoralis</i> low parasite load: positive count and ≤ 1 larvae per gram (LPG). <i>S</i>. <i>stercoralis</i> moderate or high parasite load: > 1 LPG. Data were collected in 2012 in Preah Vihear Province, North Cambodia, from 103 participants in the post-treatment survey who harbored <i>S</i>. <i>stercoralis</i> mono-infection at both surveys and met the case definitions used in this work for all parasites.</p

Results of the multivariate logistic model assessing the association between stunting and <i>S</i>. <i>stercoralis</i> parasite load.

<p>Results of the multivariate logistic model assessing the association between stunting and <i>S</i>. <i>stercoralis</i> parasite load.</p