Blog
About

0
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

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

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          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.

          Author summary

          Cholera remains a global health concern, with an estimated 2.9 million cases and 95,000 deaths per year. Household spraying is an outbreak response activity where the houses of cholera patients are disinfected by spraying chlorine to interrupt cholera transmission within households. The effectiveness and appropriateness of this intervention have been questioned but it remains widely implemented. We conducted three mixed-methods evaluations of household spraying programs in the Democratic Republic of the Congo and in Haiti. By sampling surfaces before, 30 minutes and 24 hours after spraying, we were able to identify household surfaces that were consistently the most contaminated at baseline (namely food preparation areas, patients’ beds, and latrines). We also found that spraying chlorine could inactivate bacteria on household surfaces but that effectiveness was inconsistent, likely due to differences in spraying protocols between programs such as the amount of chlorine applied onto surfaces. Through key informant interviews, structured observations and household surveys, we also gained insights into the advantages and challenges of each program. This work contributes to the scientific evidence base necessary to optimize cholera response strategies; the combination of microbiological and qualitative information allowed us to formulate concrete recommendations for outbreak response programs.

          Related collections

          Most cited references 32

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Updated Global Burden of Cholera in Endemic Countries

          Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Cholera.

            Intestinal infection with Vibrio cholerae results in the loss of large volumes of watery stool, leading to severe and rapidly progressing dehydration and shock. Without adequate and appropriate rehydration therapy, severe cholera kills about half of affected individuals. Cholera toxin, a potent stimulator of adenylate cyclase, causes the intestine to secrete watery fluid rich in sodium, bicarbonate, and potassium, in volumes far exceeding the intestinal absorptive capacity. Cholera has spread from the Indian subcontinent where it is endemic to involve nearly the whole world seven times during the past 185 years. V cholerae serogroup O1, biotype El Tor, has moved from Asia to cause pandemic disease in Africa and South America during the past 35 years. A new serogroup, O139, appeared in south Asia in 1992, has become endemic there, and threatens to start the next pandemic. Research on case management of cholera led to the development of rehydration therapy for dehydrating diarrhoea in general, including the proper use of intravenous and oral rehydration solutions. Appropriate case management has reduced deaths from diarrhoeal disease by an estimated 3 million per year compared with 20 years ago. Vaccination was thought to have no role for cholera, but new oral vaccines are showing great promise.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Cholera transmission: the host, pathogen and bacteriophage dynamic.

              Zimbabwe offers the most recent example of the tragedy that befalls a country and its people when cholera strikes. The 2008-2009 outbreak rapidly spread across every province and brought rates of mortality similar to those witnessed as a consequence of cholera infections a hundred years ago. In this Review we highlight the advances that will help to unravel how interactions between the host, the bacterial pathogen and the lytic bacteriophage might propel and quench cholera outbreaks in endemic settings and in emergent epidemic regions such as Zimbabwe.
                Bookmark

                Author and article information

                Contributors
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: Project administrationRole: VisualizationRole: Writing – original draftRole: Writing – review & editing
                Role: Data curationRole: Formal analysisRole: InvestigationRole: Writing – review & editing
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: InvestigationRole: MethodologyRole: Writing – review & editing
                Role: ConceptualizationRole: Formal analysisRole: MethodologyRole: Project administrationRole: SupervisionRole: ValidationRole: Writing – review & editing
                Role: ConceptualizationRole: Funding acquisitionRole: MethodologyRole: Project administrationRole: ResourcesRole: SupervisionRole: ValidationRole: Writing – review & editing
                Role: Editor
                Journal
                PLoS Negl Trop Dis
                PLoS Negl Trop Dis
                plos
                plosntds
                PLoS Neglected Tropical Diseases
                Public Library of Science (San Francisco, CA USA )
                1935-2727
                1935-2735
                31 August 2020
                August 2020
                : 14
                : 8
                Affiliations
                [1 ] Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America
                [2 ] Department of Disease Control, London School of Hygiene and Tropical Medicine, United Kingdom
                Wayne State University, UNITED STATES
                Author notes

                The authors have declared that no competing interests exist.

                Article
                PNTD-D-20-00870
                10.1371/journal.pntd.0008661
                7485970
                32866145
                © 2020 Gallandat et al

                This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                Page count
                Figures: 2, Tables: 2, Pages: 18
                Product
                Funding
                Funded by: Research for Health in Humanitarian Crises (R2HC)
                Award ID: 28374
                Award Recipient :
                Funded by: funder-id http://dx.doi.org/10.13039/501100001711, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung;
                Award ID: P1SKP2_174771; P1SKP2_181335
                Award Recipient :
                Funded by: P.E.O. Foundation
                Award Recipient :
                This work was funded by Research for Health in Humanitarian Crises (R2HC, grant awarded to DSL, Ref. 28374), by the Swiss National Science Foundation (fellowships awarded to KG, Ref. P1SKP2_174771 and P1SKP2_181335) and by the P.E.O. Foundation (scholarship awarded to KG, years 2016-2017). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
                Categories
                Research Article
                Medicine and Health Sciences
                Medical Conditions
                Infectious Diseases
                Bacterial Diseases
                Cholera
                Medicine and Health Sciences
                Medical Conditions
                Tropical Diseases
                Neglected Tropical Diseases
                Cholera
                Physical Sciences
                Chemistry
                Chemical Elements
                Chlorine
                Biology and Life Sciences
                Microbiology
                Medical Microbiology
                Microbial Pathogens
                Bacterial Pathogens
                Vibrio Cholerae
                Medicine and Health Sciences
                Pathology and Laboratory Medicine
                Pathogens
                Microbial Pathogens
                Bacterial Pathogens
                Vibrio Cholerae
                Biology and Life Sciences
                Organisms
                Bacteria
                Vibrio
                Vibrio Cholerae
                Medicine and Health Sciences
                Public and Occupational Health
                Hygiene
                Medicine and Health Sciences
                Health Care
                Sanitization
                Disinfection
                Medicine and Health Sciences
                Medical Conditions
                Infectious Diseases
                Infectious Disease Control
                Sanitization
                Disinfection
                Medicine and Health Sciences
                Public and Occupational Health
                Preventive Medicine
                Sanitization
                Disinfection
                Medicine and Health Sciences
                Epidemiology
                Medical Risk Factors
                Physical Sciences
                Chemistry
                Chemical Compounds
                Salts
                Hypochlorites
                Research and Analysis Methods
                Animal Studies
                Experimental Organism Systems
                Model Organisms
                Escherichia Coli
                Research and Analysis Methods
                Model Organisms
                Escherichia Coli
                Biology and Life Sciences
                Microbiology
                Medical Microbiology
                Microbial Pathogens
                Bacterial Pathogens
                Escherichia Coli
                Medicine and Health Sciences
                Pathology and Laboratory Medicine
                Pathogens
                Microbial Pathogens
                Bacterial Pathogens
                Escherichia Coli
                Biology and Life Sciences
                Organisms
                Bacteria
                Enterobacteriaceae
                Escherichia
                Escherichia Coli
                Biology and Life Sciences
                Organisms
                Bacteria
                Gut Bacteria
                Escherichia
                Escherichia Coli
                Research and Analysis Methods
                Animal Studies
                Experimental Organism Systems
                Prokaryotic Models
                Escherichia Coli
                Custom metadata
                vor-update-to-uncorrected-proof
                2020-09-11
                All chlorine measurements and microbiological data files are available online on Open Science Framework via the following link: https://osf.io/jwtne/?view_only=70ecb4352baa4da3819f9815d4a6680f. All relevant data from qualitative interviews and household surveys are within the manuscript. Observation and interview guides, and our survey questionnaire are also shared in editable format (XLS) in S1 File.

                Infectious disease & Microbiology

                Comments

                Comment on this article