[Aeromonas hydrophila in the drinking water in Djibouti: commensal germ or diarrhea-causing agent?]

To investigate the bacteriological quality of drinking water used by inhabitants of the Republic of Djibouti who were not supplied with piped running water, we analysed 16 fresh-water samples from various sources. Only 3 samples were sterile; they were taken from village pumps and from a water-truck. Eleven samples yielded colonies of Aeromonas hydrophila too numerous to be counted; they were taken from water tanks, metal barrels, or wells dug in either dry river beds or along the seashore. We speculate that this high isolation frequency of Aeromonas hydrophila in fresh water samples may be related to conditions that are exceptionally favourable for the growth of the bacterium (e.g. high temperature and elevated concentrations of certain salts and minerals in the fresh water of Djibouti). We wonder nevertheless whether the infected water supplies were a source of diarrhoea for humans. Indeed, antibiotic resistance patterns were dissimilar when the 11 environmental strains were compared to 7 strains of Aeromonas hydrophila isolated from diarrhoeal patients in Djibouti during the same period. More studies are needed to determine if Aeromonas hydrophila is always a commensal inhabitant of fresh water in Djibouti, or if it can be a cause of infectious diarrhoea. Accordingly, Public Health authorities in Djibouti will be able to decide if water from wells and tanks is safe for drinking, or if it needs disinfection before consumption.