Objectives Diarrhoea is a common and well‐studied cause of illness afflicting international travellers. However, traveller's diarrhoea can also result from travel between high and low disease transmission regions within a country, which is the focus of this study. Methods We recruited participants for a case‐control study of diarrhoea at four sites along an urban‐rural gradient in Northern Ecuador: Quito, Esmeraldas, Borbón and rural communities outside of Borbón. At each of these sites, approximately 100 subjects with diarrhoea (cases) were recruited from Ministry of Health clinics and were age‐matched with subjects visiting the same clinics for other complaints (controls). Results Travellers to urban destinations had higher risk of diarrhoea and diarrhoeagenic Escherichia coli (DEC) infections. Travel to Quito was associated with diarrhoea (aOR = 2.01, 95% CI = 1.10–3.68) and travel to Guayaquil (another urban centre in Ecuador) was associated with Diffuse Adherent E. coli infection (OR = 2.09, 95% CI = 1.01–4.33). Compared to those not travelling, urban origins were also associated with greater risk of diarrhoea in Esmeraldas (aOR = 2.28, 95% CI = 1.20–4.41), and with higher risk of diarrhoeagenic E. coli infections in Quito (aOR = 2.61, 95% CI = 1.16–5.86), with >50% of travel from Quito and Esmeraldas specified to another urban destination. Conclusions This study suggests that individuals travelling from lower‐transmission regions (rural areas) to higher transmission regions (urban centres) within a single country are at a greater risk of acquiring a diarrhoea‐related illness. Investments to improve water, sanitation and hygiene conditions in urban areas could have impacts on outlying rural areas within a given country.

The provision of safely managed sanitation in informal settlements is a challenge, especially in schools that require durable, clean, sex-segregated facilities for a large number of children. In informal settlements in Nairobi, school sanitation facilities demand considerable capital costs, yet are prone to breakage and often unhygienic. The private sector may be able to provide quality facilities and services to schools at lower costs as an alternative to the sanitation that is traditionally provided by the government. We conducted a randomized trial comparing private sector service delivery (PSSD) of urine-diverting dry latrines with routine waste collection and maintenance and government standard delivery (GSD) of cistern-flush toilets or ventilated improved pit latrines. The primary outcomes were facility maintenance, use, exposure to fecal contamination, and cost. Schools were followed for one school year. There were few differences in maintenance and pathogen exposure between PSSD and GSD toilets. Use of the PSSD toilets was 128% higher than GSD toilets, as measured with electronic motion detectors. The initial cost of private sector service delivery was USD 2053 (KES 210,000) per school, which was lower than the average cost of rehabilitating the government standard flush-type toilets (USD 9306 (KES 922,638)) and constructing new facilities (USD 114,889 (KES 1,169,668)). The private sector delivery of dry sanitation provided a feasible alternative to the delivery of sewage sanitation in Nairobi informal settlements and might elsewhere in sub-Saharan Africa.

Little has been studied about the potential risks and hazards arising from the use and operation of container-based sanitation (CBS) systems. Building on existing risk assessment frameworks, this case study aimed to identify exposure risks from faecal pathogens and relevant control measures in a CBS service chain. The case study employed a mixed-methods approach that included environmental sampling, key informant interviews, and direct observation. This inclusion of a behavioural dimension reflects a socio-cultural approach to risk analysis that is less evident in overtly quantitative approaches to risk assessment that are typical of the health risk field. Data from this case study was collected in Naivasha, Kenya in July 2016. The hazard intensity and role of specific transmission routes was validated by environmental sampling, which found a high level of faecal contamination on toilet surfaces and a consequent high risk of hand-to-mouth infection for users and operators. The hazard analysis identified nine critical control points where exposure risks may be either prevented or reduced via the implementation of relevant control measures. We discovered that the production of exposure risks was related to multiple, interrelated causal mechanisms and risk factors, findings we expect will guide approaches to exposure risk management in the future.