Lessons learned from fifteen drinking water treatment program evaluations in Haiti

Providing safe drinking water is a priority in emergencies. The 2010 earthquake in Haiti and subsequent cholera outbreak thus led to the implementation of numerous point-of-collection (PoC) and point-of-use (PoU) water treatment programs. We propose to present a synthesis of lessons learned from fifteen evaluations conducted in Haiti between 2010 and 2016, including four PoC and eleven PoU water treatment programs, to better understand which strategies have helped make programs effective and sustainable. Overall, it appears that PoU water treatment technologies were more effective than PoC water treatment programs in the Haitian context. Additionally, evaluation results suggest that programs achieving sustained effectiveness were those that:1) promoted technologies that were effective and familiar to beneficiaries; 2) had reliable supply chains for water treatment products; 3) worked with local partners; and, 4) included monitoring

Surface Cleaning and Disinfection: Efficacy Assessment of Four Chlorine Types Using Escherichia coli and the Ebola Surrogate Phi6.

In the 2014 West African Ebola outbreak, international organizations provided conflicting recommendations for disinfecting surfaces contaminated by uncontrolled patient spills. We compared the efficacy of four chlorine solutions (sodium hypochlorite, sodium dichloroisocyanurate, high-test hypochlorite, and generated hypochlorite) for disinfection of three surface types (stainless steel, heavy-duty tarp, and nitrile) with and without pre-cleaning practices (prewiping, covering, or both) and soil load. The test organisms were Escherichia coli and the Ebola surrogate Phi6. All tests achieved a minimum of 5.9 and 3.1 log removal in E. coli and Phi6, respectively. A 15 min exposure to 0.5% chlorine was sufficient to ensure <8 Phi6 plaque-forming unit (PFU)/cm2 in all tests. While chlorine types were equally efficacious with and without soil load, variation was seen by surface type. Wiping did not increase disinfection efficacy and is not recommended because it generates infectious waste. Covering spills decreased disinfection efficacy against E. coli on heavy-duty tarp but does prevent splashing, which is critical in Ebola contexts. Our results support the recommendation of a 15 min exposure to 0.5% chlorine, independently of chlorine type, surface, pre-cleaning practices, and organic matter, as an efficacious measure to interrupt disease transmission from uncontrolled spills in Ebola outbreaks

A systematic review of chlorine-based surface disinfection efficacy to inform recommendations for low-resource outbreak settings

BACKGROUND: Infectious diseases can be transmitted via fomites (contaminated surfaces/objects); disinfection can interrupt this transmission route. However, disinfection guidelines for low-resource outbreak settings are inconsistent and not evidence-based. METHODS: A systematic review of surface disinfection efficacy studies was conducted to inform low-resource outbreak guideline development. Due to variation in experimental procedures, outcomes were synthesized in a narrative summary focusing on chlorine-based disinfection against seven pathogens with potential to produce outbreaks in low-resource settings (Mycobacterium tuberculosis, Vibrio cholerae, Salmonella spp., hepatitis A virus, rotavirus, norovirus, Ebola virus). RESULTS: Data were extracted from 89 laboratory studies and made available, including 20 studies on relevant pathogens used in combination with surrogate data to determine minimum target concentrationxtime ("CT") factors. Stainless steel (68%) and chlorine-based disinfectants (56%) were most commonly tested. No consistent trend was seen in the influence of chlorine concentration and exposure time on disinfection efficacy. Disinfectant application mode; soil load; and surface type were frequently identified as influential factors in included studies. CONCLUSIONS: This review highlights that surface disinfection efficacy estimates are strongly influenced by each study's experimental conditions. We therefore recommend laboratory testing to be followed by field-based testing/monitoring to ensure effectiveness is achieved in situ

Residual Maintenance Using Sodium Hypochlorite, Sodium Dichloroisocyanurate, and Chlorine Dioxide in Laboratory Waters of Varying Turbidity

Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) are commonly used for household water treatment (HWT); chlorine dioxide (ClO2) is a potential new HWT option. We compared the residual maintenance of NaOCl, NaDCC, and ClO2 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 ClO2 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 ClO2, 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.</jats:p

Surface Cleaning and Disinfection: Efficacy Assessment of Four Chlorine Types Using Escherichia coli and the Ebola Surrogate Phi6.

In the 2014 West African Ebola outbreak, international organizations provided conflicting recommendations for disinfecting surfaces contaminated by uncontrolled patient spills. We compared the efficacy of four chlorine solutions (sodium hypochlorite, sodium dichloroisocyanurate, high-test hypochlorite, and generated hypochlorite) for disinfection of three surface types (stainless steel, heavy-duty tarp, and nitrile) with and without pre-cleaning practices (prewiping, covering, or both) and soil load. The test organisms were Escherichia coli and the Ebola surrogate Phi6. All tests achieved a minimum of 5.9 and 3.1 log removal in E. coli and Phi6, respectively. A 15 min exposure to 0.5% chlorine was sufficient to ensure <8 Phi6 plaque-forming unit (PFU)/cm2 in all tests. While chlorine types were equally efficacious with and without soil load, variation was seen by surface type. Wiping did not increase disinfection efficacy and is not recommended because it generates infectious waste. Covering spills decreased disinfection efficacy against E. coli on heavy-duty tarp but does prevent splashing, which is critical in Ebola contexts. Our results support the recommendation of a 15 min exposure to 0.5% chlorine, independently of chlorine type, surface, pre-cleaning practices, and organic matter, as an efficacious measure to interrupt disease transmission from uncontrolled spills in Ebola outbreaks

Determining the Efficacy, Safety and Suitability of Disinfectants to Prevent Emerging Infectious Disease Transmission

The scale of the 2014–2017 West African Ebola Virus Disease outbreak overwhelmed the international response capacity. This has led to inconsistencies in international guidance documents, particularly around chlorine disinfection of surfaces and hands to prevent transmission. To provide evidence for the disinfection recommendations, three research strands were conducted: (1) impacts of chlorine chemistry; (2) efficacy of surface cleaning recommendations; and (3) safety and efficacy of handwashing recommendations. Strand 1 research found that the compound chemistry of the chlorine source has an impact on the chlorine solution shelf-life (&lt;1 day–30 days), with testing of chlorine solutions recommended to ensure accuracy. Strand 2 research found that surface cleaning with 0.5% chlorine solutions with a 15-min exposure time is efficacious in reducing transmission risk. Strand 3 research found that community handwashing with chlorine solutions is as safe and efficacious as handwashing with soap and water or sanitizer, which offers a benefit of reducing pathogens in the rinsing water. Using calcium hypochlorite as the chlorine source compound provided a particularly good performance in chemistry and handwashing studies. The research was successful at providing information to align with the inconsistent international guidelines. Further research is needed to proactively establish the efficacy, safety and suitability of disinfection for the seven viral pathogens that are considered likely to cause severe outbreaks with few/no medical countermeasures.</jats:p

Household spraying in cholera outbreaks: Insights from three exploratory, mixed-methods field effectiveness evaluations.

Household spraying is a commonly implemented, yet an under-researched, cholera response intervention where a response team sprays surfaces in cholera patients' houses with chlorine. We conducted mixed-methods evaluations of three household spraying programs in the Democratic Republic of Congo and Haiti, including 18 key informant interviews, 14 household surveys and observations, and 418 surface samples collected before spraying, 30 minutes and 24 hours after spraying. The surfaces consistently most contaminated with Vibrio cholerae were food preparation areas, near the patient's bed and the latrine. Effectiveness varied between programs, with statistically significant reductions in V. cholerae concentrations 30 minutes after spraying in two programs. Surface contamination after 24 hours was variable between households and programs. Program challenges included difficulty locating households, transportation and funding limitations, and reaching households quickly after case presentation (disinfection occurred 2-6 days after reported cholera onset). Program advantages included the concurrent deployment of hygiene promotion activities. Further research is indicated on perception, recontamination, cost-effectiveness, viable but nonculturable V. cholerae, and epidemiological coverage. We recommend that, if spraying is implemented, spraying agents should: disinfect surfaces systematically until wet using 0.2/2.0% chlorine solution, including kitchen spaces, patients' beds, and latrines; arrive at households quickly; and, concurrently deploy hygiene promotion activities

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines.

INTRODUCTION: Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes. METHODS: We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission. RESULTS: Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both. CONCLUSIONS: Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies

A fuzzy inference-based index for piped water supply service quality in a complex, low-income urban setting.

Sustainable Development Goal (SDG) 6 calls for universal access to safely managed drinking water services. We studied the evolution of the water supply service between January 2017 and December 2021 in the town of Uvira (South Kivu, Democratic Republic of the Congo) where large investments were made to improve the water supply infrastructure during this period, including a new 2,000-m3 tank, 56 community taps and 1,191 private taps. Across 16 geographic clusters in the town, we assessed water service accessibility, water quantity, continuity, and affordability, based on data provided by the construction team and the utility. We combined these dimensions into a single index ranging 0-100% according to rules defined using the fuzzy inference Mamdani method. Our results show that despite substantial increases in accessibility (i.e. proportion of households with a private tap or within 200 m of a community tap), overall service quality remained unsatisfactory, with a maximum index value of 38.1%, and worsened in many parts of the town due to limitations of the water production capacity after major flooding events and persistent electricity supply issues. The estimated amount of water supplied per user per day remained under 20 L during >95% of the observation period, with a decreasing trend. Pumps operated 58% of the time on average and the frequency of days without electricity supply increased over time. Our study highlights the important gap between upgrades in water supply infrastructure and improvements in the quality of service. The analysis of potential future scenarios for Uvira indicates that increasing production capacity is priority to improve overall service quality. Our results demonstrate that meeting SDG6 will be challenging in complex urban settings and will not only require sustained investments in water supply infrastructure but also in systems management and in energy supply

Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water.

To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94-3.01 log reduction in E. coli concentration without, and 2.18-3.34 with, soil load; and a 2.44-3.06 log reduction in Phi6 without, and 2.71-3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28-4.77 log reduction in remaining E. coli without, and 0.21-4.49 with, soil load and a 1.26-2.02 log reduction in Phi6 without, and 1.30-2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence