Bacterial Contaminations of Informally Marketed Raw Milk in Ghana

Abstract

Background: Milk has an outstanding nutritional quality but is also an excellent medium for bacterial growth and an important source of bacterial infection when consumed without pasteurization. Objective: To estimate the bacterial health risk of milk consumption in Accra and Kumasi, the two major cities in Ghana. Method: A total of 96 raw milk samples collected in 2002 from the two sites were cultured and the isolated organisms identified by standard bacteriological methods. Results: Overall, the organisms identified and their prevalence rates were Yersinia spp. (19.8%), Klebsiella spp (16.7%), Proteus spp. (7.3%), Enterobacter spp. (6.3%), Escherichia coli (2.1%), and Staphylococcus spp (14.6%), Bacillus spp. (11.5%) and Mycobacterium spp. (1%). Most of the organisms identified were enterobacteria indicating probable faecal contamination of the milk as a result of poor hygiene. Most of the bacteria identified in the milk sampled are potential foodborne pathogens, and though some of them occurred in few samples, the practice of pooling milk from different sources by traders, and the absence of pasteurization generally observed among them could increase the risk posed by such organisms. Conclusion: The study has shown that informally marketed raw milk in the two cities could be an important source of infection with a wide range of organisms, particularly enterobacteria. There is the need for instituting effective control measures including improved hygienic handling of milk and its pasteurization to protect public health.