We evaluated a personal protective equipment removal protocol designed to minimize wearer contamination with pathogens. Following this protocol often resulted in virus transfer to hands and clothing. An altered protocol or other measures are needed to prevent healthcare worker contamination.

Simple, effective and affordable methods are needed to treat and safely store non-piped, gathered household water. This study evaluated point-of-use chlorination and storage in special plastic containers of gathered household water for improving microbial quality and reducing diarrhoeal illness of consumers living under conditions of poor sanitation and hygiene. Community families were recruited and randomly divided into intervention (household water chlorination and storage in a special container) and control (no intervention) households. Microbes in stored household water were extensively inactivated by 1-5-mg/L doses of hypochlorite. Escherichia coli levels in stored household waters were <1/100 mL in most intervention households but readily detectable at high levels in control households. Stored water of intervention households was also lower in Clostridium perfringens and heterotrophic plate count bacteria than in control households. The intervention reduced household diarrhoeal illness. In Bolivia, monthly episodes of household diarrhoeal illness were 1.25 and 2.2 in intervention and control families, respectively (P = <0.002) indicating that 43% of community diarrhoea was preventable by using the intervention. In Bangladesh, mean episodes of child diarrhoea/1,000 d were 19.6 and 24.8 in intervention and control groups respectively (P = <0.03) indicating that about 24% of observed diarrhoea was preventable by using the intervention. Chlorine disinfection and storage in an appropriate container significantly improved the microbiological quality of non-piped household drinking water and reduced community diarrhoeal disease. Widespread use of this simple treatment and storage system for non-piped domestic water has the potential to dramatically reduce the global burden of waterborne diarrhoeal disease.

The survival of Escherichia coli, Salmonella typhi, Shigella sonnei, poliovirus type 1 and a parvovirus (Minute Virus of Mice) was determined in seawater. Seeded seawater was incubated in the laboratory at 6, 12, 20 and 28°C for up to 40 d. In-situ survival studies were done seasonally (winter, spring, summer and fall) using seeded microbial dialysis equipment placed in the Atlantic Ocean off coastal North Carolina at water depths of 3–10 m. In laboratory studies all test microbes survived longer at lower temperatures with typical times for 90% inactivation (T₉₀) of 1–3 d at the highest temperature and >10 d at the lowest temperature. Of the microbes tested, E. coli survived least well while S. typhi and Sh. sonnei survived similar to or greater than enteric viruses. Parvovirus survival was similar to that of poliovirus. Under in-situ conditions, E. coli also survived least well of all microbes tested with T₉₀ values of 0.9–3.9 d depending upon season. All other test microbes had generally similar survivals. Overall, microbial survival in seawater was greater under laboratory conditions than under in-situ conditions. There was no clear association between microbial survival and water temperature. The lower survival of E. coli compared to the bacterial and viral pathogens under laboratory conditions raises concerns because it is a key microbial indicator of faecal contamination.

The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (±1.56) and 7.5 (±0.02) log₁₀ for Escherichia coli, and between 2.8 (±0.10) and 4.5 (±1.04) log₁₀ for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO). According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.

Escherichia coli counts in household drinking water may or may not reliably indicate the presence of diarrheogenic pathogens originating in feces. The extent to which a bacterial indicator like E. coli predicts risks from all classes of pathogens (viruses and parasites as well as bacteria), especially in tropical waters, is uncertain. To investigate the association between E. coli in household drinking water and diarrheal diseases in Cambodia, we conducted a 22 week cohort study in a rural village in Kandal Province. Episodes of diarrhea (all) and bloody diarrhea (dysentery), water quality, water sources, and other covariates were monitored biweekly in 180 households. Households used a variety of water treatment, storage, and handling practices. Results suggest a weak but positive association between E. coli counts in household drinking water and diarrhea and for diarrhea with blood (dysentery), after adjusting for clustering within households and within individuals over time. Compared to households with 1,000 E. coli per 100 ml sample (LPR = 1.2, 95% CI 1.1–1.2 for diarrheal disease; LPR = 1.2, 95% CI 1.0–1.3 for dysentery). Unlike the results of some previous studies, diarrheal disease risks did not increase progressively in magnitude with increasing concentration of E. coli in drinking water.