[Investigation on the presence of salmonella in drinking water from water supplies and distribution systems in Togo (author's transl)].

Abstract

Bacteriological drinking water examination of samples from water works and wells as well as from their distribution systems revealed that from 26 samples, where Salmonella organisms could be isolated, in 16 cases E. coli- and coliforms could not be found and that in 9 of these cases even the colony count was below 100 colonies per ml at 20 degrees C and 37 degrees C incubation temperature. The common reasons for such contaminations are technical deficiencies, mostly faulty well-heads or broken covers of reservoirs. Rainbow lizzards (Agama agama), very common in these regions, can thus easily gain access to wells and reservoirs and pollute the groundwater. Rainbow lizzards do not posses a constant and uniform microbial flora of the intestine. Among lizzards which excrete Salmonella organisms in great numbers, relatively often individuals could be found which harbour either no E. coli- and/or coliforms at all or only in very reduced numbers. In the light of these results an efficient primary protection of all water supplies by a secure covering of well-heads and reservoirs in particular seems to be of paramount importance in tropical countries. This is very much in contrast to the situation most commonly seen in these areas. The necessary measures would have to be accompanied and supplemented by alterations of the installations in the house where the creation of open reservoirs must be avoided.