We conducted a systematic review of hygiene intervention effectiveness against SARS-CoV-2, including developing inclusion criteria, conducting the search, selecting articles for inclusion, and summarizing included articles. Overall, 96 268 articles were screened and 78 articles met inclusion criteria with outcomes in surface contamination, stability, and disinfection. Surface contamination was assessed on 3343 surfaces using presence/absence methods. Laboratories had the highest percent positive surfaces (21%, n = 83), followed by patient-room healthcare facility surfaces (17%, n = 1170), non-COVID-patient-room healthcare facility surfaces (12%, n = 1429), and household surfaces (3%, n = 161). Surface stability was assessed using infectivity, SARS-CoV-2 survived on stainless steel, plastic, and nitrile for half-life 2.3–17.9 h. Half-life decreased with temperature and humidity increases, and was unvaried by surface type. Ten surface disinfection tests with SARS-CoV-2, and 15 tests with surrogates, indicated sunlight, ultraviolet light, ethanol, hydrogen peroxide, and hypochlorite attain 99.9% reduction. Overall there was (1) an inability to align SARS-CoV-2 contaminated surfaces with survivability data and effective surface disinfection methods for these surfaces; (2) a knowledge gap on fomite contribution to SARS-COV-2 transmission; (3) a need for testing method standardization to ensure data comparability; and (4) a need for research on hygiene interventions besides surfaces, particularly handwashing, to continue developing recommendations for interrupting SARS-CoV-2 transmission.

Water Safety Plans (WSPs) are a comprehensive risk assessment and management approach to water delivery that were internationally recommended in 2004. WSPs consist of five implementation steps, followed by evaluation. To date, approximately 90 countries have implemented WSPs; however widespread uptake is limited by lack of documented outcomes and impacts. We conducted a systematic review to collate outcomes, impacts, and lessons learned from WSPs developed in general, rural, and three case-study country contexts. Overall, 53 documents met inclusion criteria. In general contexts, the need for institutional support during WSP implementation was highlighted. In rural applications, the need to simplify the WSP process and provide community support was emphasized. In case-study countries, we found the WSP process was selectively adapted and integrated within existing programs. In outcome and impact evaluations, financial outcomes have the clearest evidence base, while operational outcomes are documented most frequently, particularly in relation to infrastructure improvements. However, evidence is lacking on institutional and policy outcomes and impacts of WSPs. To ensure WSPs reach their potential for improving water delivery and management, support should be provided to implementers, outcomes and impacts of urban, peri-urban, and rural WSP implementations should be evaluated, and adaptation of WSPs locally encouraged.

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Initial recommendations for surface disinfection to prevent SARS-CoV-2 transmission were developed using previous evidence from potential surrogates. To the best of our knowledge, no appropriate surrogate for SARS-CoV-2 has been identified or confirmed for chlorine and antimicrobial surface disinfection. We completed a study to evaluate the efficacy of two hypothesized antimicrobial surfaces, and four chlorine solutions on nonporous and porous surfaces, against SARS-CoV-2 and three potential SARS-CoV-2 surrogates [coronavirus mouse hepatitis virus (MHV) and bacteriophages Phi6 and MS2], to identify a BSL-1 or BSL-2 virus to use in future studies. We found SARS-CoV-2 can be reduced >4 log 10 on porous and nonporous surfaces within 30 s upon exposure to 0.5% NaOCl. The results indicate coronavirus MHV-GFP is inactivated faster than SARS-CoV-2 (MHV-GFP ≥ 6.08 log 10 ; SARS-CoV-2 = 0.66 log 10 at 30 s with 0.05% NaOCl on steel) and MS2 is inactivated more slowly. Phi6 is inactivated like SARS-CoV-2, and we propose Phi6 as a slightly conservative surrogate for SARS-CoV-2 chlorine disinfection. Additionally, disinfection of bacteriophages on wood was challenging, and exposure to antimicrobial surfaces had no disinfection efficacy as tested. We recommend using 0.5% chlorine on surfaces for a minimum of 30 s of contact to disinfect SARS-CoV-2 and recommend additional research on Phi6 disinfection with varied surfaces and conditions.

Disinfecting surfaces with chlorine is commonly conducted in cholera outbreaks to prevent ongoing fomite-based transmission, yet evidence gaps have led to contradictory guidance. In this study, we tested the efficacy of spraying and wiping chlorine on five representatives non-porous and five porous surfaces to remove Vibrio cholerae. In total, 120 disinfection tests were run in replicate on carriers inoculated with 1.02 × 107–1.73 × 108V. cholerae CFU/cm2. Surfaces disinfected by spraying 0.2% chlorine had >3 log reduction value (LRV) on 7/10 and 9/10 surfaces at 1 and 10 min, respectively; and 2.0% chlorine on 9/10 and 10/10 surfaces at 1 and 10 min, respectively. Surfaces disinfected by wiping 0.2% chlorine had >3 LRV on 3/10 and 7/10 surfaces at 1 and 10 min, respectively; and 2.0% chlorine on 8/10 surfaces at 1 and 10 min. We found no significant differences between chlorine types (p < 0.05), higher reductions with spraying compared to wiping (p = 0.001), and lower reductions on porous compared to non-porous surfaces (p = 0.006 spraying and p < 0.001 wiping). Our results support using 0.2% chlorine sprayed on all surfaces, or wiped on most non-heavily soiled surfaces, and a 2.0% concentration on contaminated porous surfaces; and emphasize surfaces must be visibly wetted to achieve disinfection.

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Water trucking is a commonly implemented, but severely under-researched, drinking water supply intervention in humanitarian response. To fill this research gap, we conducted three mixed-methods water trucking program evaluations in the Democratic Republic of the Congo and Bangladesh, including interviews, water point observations, household surveys, focus groups, and water quality testing. Results indicated that the programs had complex implementation structures involving multiple agencies and limited infrastructure to properly collect, treat, and deliver water. All programs met queueing time and distance indicators, did not meet water quantity indicators, and inconsistently met water quality indicators. Free chlorine residual (FCR) declined through the water chain, and household water Escherichia coli concentrations were associated with household FCR, receiving behavior change messages, storage container type, and distance from the distribution point. Users appreciated water trucking, especially compared to previous water sources, and expressed desires for increased quantity, improved quality, and consistent delivery. If water trucking programs are implemented, it is recommended to have the financial resources to install sanitary collection and distribution infrastructure, establish a management team of all implementation partners, ensure sufficient water quantity is delivered, ensure recommended FCR levels at distribution points, monitor FCR throughout distribution, and complete behavior change communication activities about the program and safe water storage with users.

Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) are commonly used for household water treatment (HWT); chlorine dioxide (ClO 2 ) is a potential new HWT option. We compared the residual maintenance of NaOCl, NaDCC, and ClO 2 over 24 hours using recommended dosages (2 and 4 mg/L) in waters of varying turbidity (0-300 NTU, from kaolin clay or creek-bottom sediments) and total organic carbon (TOC) concentrations (0-100 mg/L), for a total of 324 reactors. NaOCl and NaDCC had similar free chlorine decay rates, and ClO 2 decayed more rapidly across all of the tested conditions. Little variability was observed across clay-based turbidity levels and TOC concentrations. With a dosage of 2 mg/L, a residual ≥0.2 mg/L was maintained at 30 NTU for NaOCl and 100 NTU for NaDCC; for ClO 2 , 4 mg/L were required to maintain ≥0.2 mg/L under all conditions except at zero turbidity. Comparisons with data from the literature suggest that the three compounds would inactivate E. coli, rotavirus, and Giardia cysts within 1 hour under all conditions, except 300 NTU for NaOCl and NaDCC. All three disinfectants are similarly efficacious for this usage; however, differences are seen in decay rates that may influence disinfectant selection depending on water storage time.