Quantitative Microbiological Risk Assessment of drinking water produced in Ouagadougou, Burkina Faso

Drinking of safety water is of utmost importance for the good health of communities. Over years, in addition to tap water there has been an increase in the consumption of water packaging in bottles and sachets by the populations in Sahelian Africa.  This study aimed at assessing the safety of tap, bottle and sachet water produced and consumed in Ouagadougou, the capital city of Burkina Faso. A site inspection of the packaged water production units was carried out to assess the process and conditions for their production. The evaluation of water quality was made through household surveys by questionnaire according to the consumer and key informant interview. For assessing microbiological quality, a total of 330 samples water (including 257 packaged sachet water, 41 bottle water and 32 tap water) were submitted for laboratory analysis. With QMRA method, a quantitative estimate of the microbiological risk was carried out. The results showed a similar process and hygienic practices for the production of drinking water in Ouagadougou. However, possible hazardous events were found in the sachet water production units which may compromise water quality. The results of surveys have shown that, for all surveyed, the water produced at the tap and in the bottle is of good quality. While, for 49,52% of consumers packaged sachet water is not good quality. This opinion is confirmed by laboratory analyzes according to which 23% of the samples water in sachets do not comply with the standard respectively, do not comply with both Burkina Faso and WHO standard. Compared to the disease burden by Cryptosporidium parvum (7,37.10^-7 DALY), the disease burden by Escherichia coli O157: H7 (1,42.10^-1 DALY) and by rotavirus (4,79.10^-3 DALY) are higher and exceed the reasonable level of reference risk established by WHO (10^-6 DALY). Based on these, appropriate mitigation and monitoring were proposed for action in sachet water production units. This study will allow decisions to be made on the treatment and robust hygienic conditions for producing drinking water in Ouagadougou, Burkina Faso.