No abstract

Water, sanitation, and hygiene (WaSH) are foundational public health interventions for infectious disease control. Renewed efforts to end open defecation and provide universal access to safe drinking water, sanitation, and hygiene by 2030 are being enacted through the Sustainable Development Goals. However, results from clinical trials 1-3 question the efficacy of conventional rural WaSH approaches in low-income and middle-income countries (LMICs). Randomised trials in Bangladesh, 1 Kenya, 2 and Zimbabwe, 3 which introduced household pit latrines, hand-washing with soap, and point-of-use water chlorination, found no effect on child growth, and two of the three trials found no reductions in diarrhoea in children. We have, therefore, called for transformative WaSH approaches, 4 to more effectively reduce pathogen burden and promote child health and growth in LMICs. However, currently, it remains uncertain what transformative WaSH entails. We hypothesise that exposure to animal faeces is currently an under-recognised threat to human health. Estimates published in 2018 have highlighted the scale of animal faecal hazards, 5 which are not explicitly addressed by conventional WaSH strategies. Globally, 80% of the faecal load is estimated to come from livestock animals, including two-thirds of faeces at the household level. 5 Research addressing the effect of domestic and wild animal faeces on WaSH effectiveness is scarce 6,7 and collaboration between the WaSH, public health, and animal health sectors in LMICs insufficient. 6 As an interdisciplinary group of researchers, policy makers, and practitioners in One Health, epidemiology, veterinary medicine, child health, nutrition, microbiology, geography, social science, WaSH, and animal ecology, we met (on May 22-23, 2019) to focus attention on the neglected burden of domestic and wild animal faecal exposure among rural households in LMICs. We contend that without adding safe management of animal faeces to current programmes focused solely on human waste, rural WaSH programmes will insufficiently reduce faecal exposure from all sources to the extent needed to improve child health. To emphasise this, we propose a paradigm shift in WaSH terminology, by upgrading the

Intestinal parasitic infections are among the most widespread of human infections in developing countries, and children are the most vulnerable. The aim of this study was to determine the prevalence of the protozoa Cryptosporidium and Giardia, as well as prevalence and intensity of intestinal helminths in children attending pre-school or day-care centres in Kafue District, Zambia. Single stool samples were collected from 403 children from 10 pre-schools and were subjected to duplicate Kato-Katz thick smears to identify and quantify helminths. A commercial immunofluorescence kit was used to identify Cryptosporidium- and Giardia-positive samples. The overall prevalence of helminth infection was 17.9%. Ascarislumbricoides was found in 12.0%, hookworm in 8.3%, Taenia spp. in 0.9%, Hymenolepisnana in 0.6% and Schistosomamansoni in 0.3%. The overall prevalence of Cryptosporidium and Giardia was 28.0 and 29.0%, respectively, with more girls infected with Giardia (33.8%) than boys (22.7%) (P=0.02). Significant differences in infections with A. lumbricoides and Cryptosporidium were observed between the various pre-schools (P < 0.001). These findings indicate that intestinal parasites are prevalent in children enrolled in pre-schools in Zambia. Future studies should explore local factors associated with transmission of these infections, and consequently provide the necessary health education to parents and teachers.

The prevalence of Cryptosporidium and the possibility of zoonotic transmission on dairy farms were examined. Eighteen cases of cryptosporidiosis (prevalence 6%) were identified in 82 farm workers and 207 household members. Furthermore, 70 (34%) of 207 calf samples were positive. Based on the 70kDa heat shock protein and the 18S rDNA gene, Cryptosporidium parvum was identified in 75% of the positive farm workers and in 60% of the household members. Of the positive calves, 62% were infected with C. parvum, indicating a possible zoonotic transmission on these farms.

Prevalence, incidence and seasonal variation of Cryptosporidium and Giardia duodenalis were studied over a 12-month period in 100 children from four pre-schools in Kafue, Zambia. Questionnaire data and a single stool sample were collected monthly from each child. Samples were processed using a commercial kit (Meridian Diagnostics Inc., USA) and oo(cysts) visualised by immunofluorescence microscopy. Cryptosporidium was detected in 30.7% (241/786; 95% CI = 27.5-33.9) while G. duodenalis was detected in 29.0% (228/786; 95% CI = 25.8-32.2). A total of 86% experienced one or more episodes of cryptosporidiosis while 75% had giardiasis. Cumulative incidence per 100 children was 75.4 for Cryptosporidium and 49.0 for G. duodenalis. Both infections were significantly more common in the wet compared to the dry season (34.8%, 162/466 vs. 24.7%, 79/320, P = 0.003 and 35.2%, 164/466 vs. 20.0%, 64/320, P < 0.001, respectively). Thus, risk ratios (RR) were 1.41 (95% CI = 1.13-1.77) and 1.76 (95% CI = 1.38-2.27) for Cryptosporidium and Giardia, respectively. Diarrhoea was significantly associated with cryptosporidiosis (RR = 1.23, 95% CI = 1.03-1.47; P = 0.029) but not with giardiasis (RR = 1.12, 95% CI = 0.91-1.53; P = 0.26). We conclude that gastro-intestinal protozoal infections are highly prevalent among children attending pre-school in peri-urban Zambia highlighting the need for further studies of risk factors.