Cholera Prevention and Control in Kenya

Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The reemergence of cholera in Kenya in the first months of 2015 suggests that cholera remains a public health threat. This study employed a mixed methods approach to investigate the successes and challenges of cholera prevention and control in Kenya through analysis of cholera surveillance data and key informant interviews. The goal of this study was to produce information that will be useful to the Government of Kenya in establishing or strengthening policies and programs that effectively prevent and control cholera. Key findings from analysis of cholera surveillance data indicate: (1) cholera has been recurrent in various geographic regions with differing climatic conditions, (2) cholera has affected some of the least densely populated rural areas as well as Kenya's largest cities, and (3) cholera occurrence appears to be associated with open defecation, access to improved sanitation, access to improved water sources, poverty, and level of education. Interventions, policies, and strategies that are perceived to be effective in cholera prevention and control include: (1) Community Led Total Sanitation, which aims to eliminate open defecation, (2) provision of clean water, and (3) the Integrated Disease Surveillance and Response strategy, which is Kenya's platform for implementation of the International Health Regulations. Key challenges include: (1) lack of access to improved water and sanitation for a large proportion of the population, (2) limited laboratory capacity to diagnose cholera, and (3) poor availability of intravenous fluids and oral rehydration solution. The findings of this study suggest that there is need to intensify efforts to expand access to improved sanitation and safe drinking water, to strengthen laboratory capacity and disease surveillance, to improve availability of basic medical supplies for rehydration, and to expand poverty reduction programs. Community Led Total Sanitation and the Integrated Disease Surveillance and Response strategy have created programs that should continue to be supported, strengthened and expanded. Devolution of government services from national to county level presents both opportunities and challenges for cholera prevention and control. Both levels of government have key roles to play, and effective collaboration is necessary for success.Doctor of Public Healt

Effect of Bromide Ion on Haloacetic Acid Speciation Resulting from Chlorination, Ozonation and Chloramination of Aquatic Humic Substances

The objective of this study was to investigate the effect of bromide ion concentration on the distribution of haloacetic acid (HAA) species resulting from chlorination, ozonation and chloramination of waters containing humic substances. HAAs are by-products of drinking water disinfection, and laboratory animal studies have suggested that these compounds are associated with carcinogenicity, developmental toxicity and reproductive toxicity. The potential risk to human health posed by HAAs and the varying toxicological significance of HAA species necessitate an understanding of the factors that affect HAA formation and speciation. In this study, waters were analyzed for all nine of the HAA species containing bromine and chlorine. Standards for bromodichloroacetic acid and dibromochloroacetic acid were not commercially available but were synthesized at the University of North Carolina and the University of Massachusetts. Aquatic humic substances were obtained by XAD-8 extraction from raw waters at Myrtle Beach, SC and Palm Beach County, FL. Model waters were prepared containing 4 mg/L total organic carbon, 2 mM inorganic carbon, and ten bromide concentrations ranging from 0-25 μM (0-2 mg/L). Samples were chlorinated at pH8 and pH6 with and without pre-ozonation. Additional samples were chloraminated at pH8 with and without pre-ozonation. Chlorinated and chloraminated samples were incubated at 20°C for 24 hours in the dark, after which time oxidant residuals were measured and quenched. The samples were extracted into ether, derivatized with diazomethane, then analyzed for the nine HAAs on a gas chromatograph with electron capture detector. Bromide ion concentration was an important factor in HAA speciation in chlorinated waters. Bromo-chloro species (bromochloroacetic acid, bromodichloroacetic acid and dibromochloroacetic acid) were readily formed from chlorination of bromide-containing waters, and they constituted at least 10% of the total HAAs in waters containing as little as 1.2 μM Br (0.1 mg/L). Distribution of the HAAs among mono-, di-, and trihalogenated species appeared to be independent of bromide ion concentration. In addition, bromide ion appeared to have similar effects on HAA speciation in both waters studied. Lowering the pH of chlorination from pH8 to pH6 enhanced the formation of several species; however, HAA speciation was little affected. Pre-ozonation appeared to enhance bromine incorporation into the HAAs produced from subsequent chlorination. Total HAA formation in chloraminated waters was decreased approximately 90% compared to total HAA formation in chlorinated waters. Dichloroacetic acid was the principal species formed in chloraminated waters. Chloramination of bromide-containing waters resulted in some formation of brominated species, principally bromoacetic acid, dibromoacetic acid and bromochloroacetic acid; little formation of trihalogenated species was observed from chloramination, both in the presence and absence of bromide ion. Pre-ozonation followed by chloramination enhanced total HAA formation compared to chloramination alone; however, total HAA formation was still decreased by approximately 90% compared to chlorination. The results suggest that the bromo-chloro HAAs, whose occurrence in finished drinking waters is presently not known, are readily formed during chlorination of bromide-containing waters. Chloramination and pre-ozonation followed by chloramination appear to be effective means of controlling HAA formation. In addition, the effect of bromide ion on HAA speciation may be independent of the source of humic substances.Master of Science in Public Healt

Factors associated with cholera in Kenya, 2008-2013

Introduction: Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The re-emergence of cholera in Kenya in 2015 indicates that cholera remains a public health threat. Understanding past outbreaks is important for preventing future outbreaks. This study investigated the relationship between cholera occurrence in Kenya and various environmental and demographic factors related to water, sanitation, socio-economic status, education, urbanization and availability of health facilities during the time period 2008-2013. Methods: The primary outcome analyzed was the number of cholera cases at the district level, obtained from the Kenya Ministry of Health's national cholera surveillance records. Values of independent variables were obtained from the 2009 Kenya Population and Housing Census and other national surveys. The data were analyzed using a zero-inflated negative binomial regression model. Results: Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05). No statistically significant association was found between cholera occurrence and education, percentage of population living in urban areas or population density. Conclusion: The Sustainable Development Goals and Kenya's blueprint for development, Kenya Vision 2030, call for access to sanitation facilities and clean water for all by 2030. Kenya has made important economic strides in recent years but continues to be affected by diseases like cholera that are associated with low socio-economic status. Further expansion of access to sanitation facilities and clean water is necessary for preventing cholera in Kenya