Variation of Total Coliforms and Bacteria during Dry and Wet Seasons in Rivers of Sigor Division, West Pokot County, Kenya

Abstract

Aims: There has been an increase in gastro-intestinal and urinary infections in Sigor division, West Pokot, Kenya. These infections result from bacteria and coliforms which are majorly propagated in water systems. Residents of this area are pastoralists and small-scale farmers relying on river water for their consumption and economic needs. This study aimed at characterizing the strains and quantities of bacteria and coliforms in the four rivers during the wet and dry seasons.

Study Design: An independent measures design was used.

Place and Duration of Study: Samples were taken from four rivers (Weiwei, Chesogon, Lomut and Muruny) in Sigor division, West Pokot county, Kenya. The study was conducted between January and October 2013.

Methodology: Sampling was done at various points of the river in a stratified manner for characterization and analysis. Four main pathogens namely E. coli, V. cholerae, Shigella and Salmonella species as well as F. streptococci were isolated, cultured using different media and characterized. Further biochemical tests were conducted to confirm the exact strains present. Total viable counts for the bacteria and coliforms were then enumerated.

Results: The results found out that E. coli, V. cholerae, Salmonella and Shigella species were abundant in the rivers while F. streptococci were only observed during the wet season. Biochemical tests conducted on the isolates revealed that the strains co-existed in the water samples. Weiwei river had the greatest number of bacteria strains. Muruny river was found to have the largest population of bacteria colony forming units (cfu’s). There was a large disparity in cfu’s in the rivers during the dry seasons. Chesogon river had the highest population of coliform units.

Conclusion: The raw water in all the rivers were concluded to be unsafe for human consumption according to WHO standards.