www.mdpi.com/journal/ijerph Review Microbial Monitoring of Surface Water in South Africa: An Overview

Abstract: Infrastructural problems force South African households to supplement their drinking water consumption from water resources of inadequate microbial quality. Microbial water quality monitoring is currently based on the Colilert 18 system which leads to rapidly available results. Using Escherichia coli as the indicator microorganism limits the influence of environmental sources on the reported results. The current system allows for understanding of long-term trends of microbial surface water quality and the related public health risks. However, rates of false positive for the Colilert 18-derived concentrations have been reported to range from 7.4 % to 36.4%. At the same time, rates of false negative results vary from 3.5 % to 12.5%; and the Colilert medium has been reported to provide for cultivation of only 56.8 % of relevant strains. Identification of unknown sources of faecal contamination is not currently feasible. Based on literature review, calibration of the antibiotic-resistance spectra of Escherichia coli or the bifidobacterial tracking ratio should be investigated locally for potential implementation into the existin