SummaryWe conducted a longitudinal study among 827 pregnant women in Nyanza Province, western Kenya, to determine the effect of earth-eating on geohelminth reinfection after treatment. The women were recruited at a gestational age of 14-24 weeks (median: 17) and followed up to 6 months postpartum. The median age was 23 (range: 14-47) years, the median parity 2 (range: 0-11). After deworming with mebendazole (500 mg, single dose) of those found infected at 32 weeks gestation, 700 women were uninfected with Ascaris lumbricoides, 670 with Trichuris trichiura and 479 with hookworm. At delivery, 11.2%, 4.6% and 3.8% of these women were reinfected with hookworm, T. trichiura and A. lumbricoides respectively. The reinfection rate for hookworm was 14.8%, for T. trichiura 6.65, and for A. lumbricoides 5.2% at 3 months postpartum, and 16.0, 5.9 and 9.4% at 6 months postpartum. There was a significant difference in hookworm intensity at delivery between geophagous and non-geophagous women (P ¼ 0.03). Women who ate termite mound earth were more often and more intensely infected with hookworm at delivery than those eating other types of earth (P ¼ 0.07 and P ¼ 0.02 respectively). There were significant differences in the prevalence of A. lumbricoides between geophagous and non-geophagous women at 3 (P ¼ 0.001) and at 6 months postpartum (P ¼ 0.001). Women who ate termite mound earth had a higher prevalence of A. lumbricoides, compared with those eating other kinds of earth, at delivery (P ¼ 0.02), 3 months postpartum (P ¼ 0.001) and at 6 months postpartum (P ¼ 0.001).The intensity of infections with T. trichiura at 6 months postpartum was significantly different between geophagous and non-geophagous women (P ¼ 0.005). Our study shows that geophagy is associated with A. lumbricoides reinfection among pregnant and lactating women and that intensities built up more rapidly among geophagous women. Geophagy might be associated with reinfection with hookworm and T. trichiura, although these results were less unequivocal. These findings call for increased emphasis, in antenatal care, on the potential risks of earth-eating, and for deworming of women after delivery.

IntroductionIn recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most cost-effective treatment strategy and delivery system to achieve this goal?Methods and analysisTwo cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision—termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system.Ethics and disseminationStudy protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a dedicated web site.Trial registration numberNCT02397772.

Geophagy was studied among 827 pregnant women in western Kenya, during and after pregnancy. The women were recruited at a gestational age of 14-24 weeks and followed-up to 6 months post-partum. The median age (range) of the women was 23 years and median parity 2. At recruitment, 378 were eating earth, of which most (65%) reported earth-eating before pregnancy. The preferred type of earth eaten was soft stone, known locally as odowa (54.2%) and earth from termite mounds (42.8%). The prevalence remained high during pregnancy, and then declined to 34.5% and 29.6% at 3 and 6 months post-partum respectively (P < 0.001). The mean daily earth intake was 44.5 g during pregnancy, which declined to 25.5 g during lactation (P < 0.001). A random sample of 204 stools was collected from the women and analysed for silica content as a tracer for earth-eating. The mean silica content was 2.1% of the dry weight of stool. Geophagous women had a higher mean silica content than the non-geophagous ones (3.1% vs. 1.4%, P < 0.001). Faecal silica and reported geophagy were strongly correlated (P < 0.001).

BackgroundThe implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya.Materials and MethodsData on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels.Principal FindingsThe reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.ConclusionsThe study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.

Postpartum vitamin A supplementation of mothers and infants is recommended, but the efficacy has been questioned. In this double-blind, placebocontrolled trial, Kenyan mother-infant pairs were randomised to maternal vitamin A (400 000 IU) or placebo ,24 h postpartum, and infant vitamin A (100 000 IU) or placebo at 14 weeks. Milk retinol was determined at weeks 4, 14 and 26, and maternal and infant serum retinol at weeks 14 and 26. Infant retinol stores were assessed at week 26, using a modified relative dose response (MRDR) test. Among 564 women, serum retinol at 36 weeks gestation was 0·81 (SD 0·21) mmol/l, and 33·3 % were , 0·7 mmol/l. Maternal serum retinol was not different between groups, but milk retinol was higher in the vitamin A group: (0·67 v. 0·60 mmol/l; 0·52 v. 0·44 mmol/l; 0·50 v. 0·44 mmol/l at 4, 14 and 26 weeks, respectively). When expressed per gram fat, milk retinol was higher in the vitamin A group only at 4 weeks. Infant serum retinol was not different between groups. However, although most infants had deficient vitamin A stores (MRDR . 0·06 %) at 26 weeks, vitamin A to infants, but not mothers, resulted in a lower proportion of infants with deficient vitamin A stores (69 v. 78 %). High-dose postpartum vitamin A supplementation failed to increase serum retinol and infant stores, despite modest effects on milk retinol. Infant supplementation, however, increased stores. There is a need for a better understanding of factors affecting absorption and metabolism of vitamin A.

Between 2000 and 2004, a cross-sectional survey was conducted, as part of a prospective cohort study, among the women attending antenatal-care clinics in Bondo district, a malaria-endemic area of western Kenya. The aim was to assess the prevalence of iron deficiency and determine the predictors of haemoglobin and serum ferritin concentrations in the women who had a gestational age between 14 and 24 weeks. A standardized questionnaire was used to collect and store the relevant bio-data for the study. Haemoglobin and ferritin concentrations were evaluated, sickle-cell status was determined, and malarial parasitaemias were detected and evaluated, using blood samples collected at enrolment. Multiple regression analysis was then used to test for significant predictors of the haemoglobin and serum ferritin concentrations.Although 842 women were enrolled in the prospective cohort study, haemoglobin concentrations were evaluated for only 828 of them, serum ferritin levels for 621, and levels of parasitaemia for 812. The mean haemoglobin concentration recorded was 10.9 g/dl. Although 37.9% of the subjects had mild-moderate anaemia (7.0-10.5 g haemoglobin/dl), only 0.5% were severely anaemic (,7.0 g haemoglobin/dl). The geometric mean serum ferritin concentration recorded was 18.9 mg/litre, and 32.3% of the subjects evaluated had low serum concentrations of ferritin (,12 mg/litre). Among the parasitaemic primigravidae (but not the parasitaemic multigravidae), those found positive for sickle-cell trait had significantly lower haemoglobin concentrations than those found negative in a sickling test (P50.01). Among the pregnant women of Bondo district, gravidity, malarial infection and sickle cell appear to be key predictors of haemoglobin concentration.

Objective: To determine and describe the patterns of low birth weight in newborns of a cohort of mothers given intermittent presumptive treatment (IPT) for malaria prevention in a malaria endemic area of Kenya. Design: A longitudinal prospective cohort study.