Bacteriology of sachet water sold in Lagos, Nigeria.

OBJECTIVES

To investigate the health risks associated with methods of hawking of sachet water in the streets of Lagos.

DESIGN

Eight brands of sachet water were collected from four different receptacles; unopen packs from factory, pail and wheelbarrow containing ice-blocks as coolants, and domestic refrigerators. Bacterial cultures were set up for the following samples; water contained in sachet, surface of the sachet, swabs from compartments of the refrigerators and wastewater of defrosted ice in pail and wheelbarrow.

SETTING

This was a community based-study including three urban centers with high population density.

MAIN OUTCOME MEASURES

The qualitative and quantitative differences in bacterial isolates from the different samples were analyzed for statistical significance. Septic and aseptic methods of sampling were adopted to investigate whether surface contaminants may impact significantly on the bacteriological quality of the sachet water.

RESULTS

Enteric pathogens and Escherichia coli were not isolated from any samples and brands of sachet water but formed significant part of the isolates on the sachet surfaces of samples collected from the cooling receptacles (pail, wheelbarrow and refrigerator). Similar species of bacteria were isolated from wastewater and surface of the sachets with the wastewater containing a significant higher numbers of bacteria (p < 0.05). Aseptic technique of sampling did not significantly contribute to microbial load of the sachet water (p > 0.05).

CONCLUSION

Organisms contained in the wastewater were inevitably the source of contaminants on the sachet surface. The water vendors and their patrons contributed to the overall contamination of hawked sachet water.