Pete Kolsky

The public and domestic domains in the transmission of disease.

This paper discusses the distinction between the transmission of infectious diseases within the domestic domain (the area normally occupied by and under the control of a household) and that in the public domain, which includes public places of work, schooling, commerce and recreation as well as the streets and fields. Whereas transmission in the public domain can allow a single case to cause a large epidemic, transmission in the domestic domain is less dramatic and often ignored, although it may account for a substantial number of cases. Statistical methods are available to estimate the relative importance of the two. To control transmission in the public domain, intervention by public authorities is likely to be required. Two examples show how environmental interventions for disease control tend to address transmission in one or the other domain; interventions are needed in both domains in order to interrupt transmission.

A controlled, before-and-after trial of an urban sanitation intervention to reduce enteric infections in children: research protocol for the Maputo Sanitation (MapSan) study, Mozambique

Introduction Access to safe sanitation in low-income, informal settlements of Sub-Saharan Africa has not significantly improved since 1990. The combination of a high faecal-related disease burden and inadequate infrastructure suggests that investment in expanding sanitation access in densely populated urban slums can yield important public health gains. No rigorous, controlled intervention studies have evaluated the health effects of decentralised (non-sewerage) sanitation in an informal urban setting, despite the role that such technologies will likely play in scaling up access. Methods and analysis We have designed a controlled, before-and-after (CBA) trial to estimate the health impacts of an urban sanitation intervention in informal neighbourhoods of Maputo, Mozambique, including an assessment of whether exposures and health outcomes vary by localised population density. The intervention consists of private pour-flush latrines (to septic tank) shared by multiple households in compounds or household clusters. We will measure objective health outcomes in approximately 760 children (380 children with household access to interventions, 380 matched controls using existing shared private latrines in poor sanitary conditions), at 2 time points: immediately before the intervention and at follow-up after 12 months. The primary outcome is combined prevalence of selected enteric infections among children under 5 years of age. Secondary outcome measures include soil-transmitted helminth (STH) reinfection in children following baseline deworming and prevalence of reported diarrhoeal disease. We will use exposure assessment, faecal source tracking, and microbial transmission modelling to examine whether and how routes of exposure for diarrhoeagenic pathogens and STHs change following introduction of effective sanitation. Ethics Study protocols have been reviewed and approved by human subjects review boards at the London School of Hygiene and Tropical Medicine, the Georgia Institute of Technology, the University of North Carolina at Chapel Hill, and the Ministry of Health, Republic of Mozambique. Trial registration number NCT02362932.

Solids size distribution and transport capacity in an Indian drain

Abstract This note reports measurements of the depth and size distribution of solids in an open drain in Indore, Madhya Pradesh in India, and their implications for design. The observed particle-size distribution is an order of magnitude larger than those reported in European and UK drains. Application of solids transport relations suggest that, because of the greater size of the Indore solids, their transport at a given flow velocity is only half that expected for typical UK solids. This stresses the need for greater attention in the developing world to both solid waste management to keep solids out of the drain and surface routing of runoff.

Engineers and urban malaria: part of the solution, or part of the problem?

This paper describes the very serious health and other problems caused by different kinds of mosquito in urban areas of India, and how addressing diseases such as malaria, yellow fever and dengue fever requires controlling their breeding sites. It then describes how engineers rarely consider their role in mosquito control and how a series of workshops for engineers made clear this role especially in the management of construction sites which often serve as major breeding areas.

Modelling drainage performance in slums of developing countries: how good is good enough?

A model for the dual drainage system in a flat 20 hectare slum in Indore, India was developed to evaluate the factors which influence drainage performance. Performance was defined by the depth, extent, duration, and frequency of flooding during the 1994 monsoon. This paper reports on the conceptual problem of model validation, particularly for “flooding” or “not flooding”. The model9s predictions for maximum depth during verification were reasonable, as 72% of maximum depth predictions were within +/− 0.10 m of observed values. The predictions for the binary variable of flooding at a point were, however, poor. The model gave good predictions of freeboard violation, where the freeboard level was set at 50 mm below the lowest kerb. The paper offers some intuitive reasons as to why prediction of freeboard violation may be expected to be better than prediction of flooding. The authors conclude that where models cannot be validated for flooding prediction, it may be better to redefine performance criteria and validate the model for freeboard violation.

The true costs of participatory sanitation: Evidence from community-led total sanitation studies in Ghana and Ethiopia

Evidence on sanitation and hygiene program costs is used for many purposes. The few studies that report costs use top-down costing methods that are inaccurate and inappropriate. Community-led total sanitation (CLTS) is a participatory behavior-change approach that presents difficulties for cost analysis. We used implementation tracking and bottom-up, activity-based costing to assess the process, program costs, and local investments for four CLTS interventions in Ghana and Ethiopia. Data collection included implementation checklists, surveys, and financial records review. Financial costs and value-of-time spent on CLTS by different actors were assessed. Results are disaggregated by intervention, cost category, actor, geographic area, and project month. The average household size was 4.0 people in Ghana, and 5.8 people in Ethiopia. The program cost of CLTS was

Environmental health indicators and sanitation-related disease in developing countries: limitations to the use of routine data sources.

30.34–

RE: “WATER, WASTE, AND WELL-BEING: A MULTICOUNTRY STUDY”

81.56 per household targeted in Ghana, and

Financing on-site sanitation for the poor : a six country comparative review and analysis

14.15–

Performance indicators for urban storm drainage in developing countries

19.21 in Ethiopia. Most program costs were from training for three of four interventions. Local investments ranged from