The Survival of Vibrio cholerae in the Natural Environment of Zambia : Fish, the suspicious Gateway of Cholera Outbreak? / 国際保健医療

ABSTRACT

<b>Preface and Objectives</b><br> Cholera has recently become more serious in African countries. In southern Africa, a serious cholera outbreak was reported in 2008. Here we investigate <i>Vibrio cholerae</i> in aquatic environments, rivers, tube well waters, fish tissues, and aquatic plants in Zambia.<br><b>Methods</b><br> The sampling was conducted on Kafue and Zambezi rivers as well as at public wells. The samples included river water, mud, fish, floating grass, and well water. All samples were enriched in alkaline peptone water (APW) and streaked on thiosulfate citrate bilesalts saccharos (TCBS) Vibrio agar. Some types of colonies were isolated using polymyxin mannose tellurite (PMT) agar. All water samples were analyzed for enterobacteria as well as vibrio contamination. River and shallow tube well water samples were analyzed for <i>E. coli</i>.<br><b>Results</b><br> Samples, including fish tissues, river, and tube well waters, except for the fish intestines, were found to be contaminated with vibrios when cultured on TCBS Vibrio agar.<br> Deep tube well water was not contaminated with vibrios or <i>E. coli. V. cholerae</i> El Tor was not detected through sampling and culturing on PMT agar. <i>E. coli</i> was detected in river and shallow tube well water samples.<br><b>Discussion</b><br> Vibrios were detected in Zambia’s aquatic environments. Cholera outbreak may occur. Vibrio contaminations in fish have been reported from Bangladesh, Laos, Kenya, and India. Fish is a good source of protein to improve person’s nutritional status. However, it must be treated properly so that any contamination of residential areas is avoided. Therefore, people must pay attention to fish.<br><b>Conclusion</b><br> Here several types of <i>V. cholerae</i> were isolated from different aquatic environments. Fish is a nutritious diet, but contaminated Vibrios fish must be treated so that it will not contaminate residential areas. We must investigate the gateway of cholera outbreaks in Zambia.