Bacterial contamination in dressed chickens in abattoirs and open market of Lusaka Province,Zambia

Abstract

The poultry industry has been expanding rapidly in Zambia with both eggs and table birds forming a major dietary protein source for the majority of the population. Despite this expansion, unhygienic rearing conditions have characterized the poultry industry at both small scale and commercial level. Of concern, is the high bacterial contamination, especially Escherichia coli and Salmonella that may have a serious public health implication. It was against this background that this study was formulated to assess the level of bacterial contamination and associated risk factors in dressed chickens at abattoirs and markets within Lusaka province. A cross sectional study was conducted across two poultry abattoirs and one major poultry market in Lusaka Province. Sampling was done at two major possible contamination points; after evisceration and after washing. At the market samples were collected at the point of sale of dressed chickens by surface swabbing. Risk associated data was collected using 261 questionnaires. Overall, the results indicated that there was a statistically significant difference (p <0.05) in the mean values of Total Coliform Counts (TCC) and E.coli when the sample sources, time of swabbing, origin of chickens and point of swabbing were accounted for. Specifically, both TCC and E.coli levels after washing were higher than at evisceration in both abattoirs. Additionally, out of the 80 dressed chickens swabbed in abattoirs at post evisceration, 34.8% of the carcasses were found to be contaminated. Further, after washing, 65.1% of the carcasses were found to be contaminated. The other 80 dressed chickens, swabbed at the market more contamination was observed on dressed chickens swabbed in the afternoon (100% ) than morning (41.2% ).Taking into account source of chickens, more contamination from chickens purchased directly from the farms 67.7% (p <0.001) than those that were purchased from abattoirs was observed. Potential risk factors that were identified to have significant influence to bacterial contamination at abattoir level were number of processed chickens per day. This was statistically significant even after adjusting for other variables (OR=4.5) at p<0.002. On the other hand at the open market only distance from water source was significant even after adjusting for other variables (OR = 0.79) at p<0.045. The results show evidence of plausible bacterial contamination at both abattoir and market level, with higher levels of contamination being observed at open markets. Further, from the results, higher levels of contamination were found after washing than immediately after evisceration, a point which needs further investigation. High levels of TCC, (E.coli) and Salmonella indicate unhygienic practices. The presence of Salmonella and E.coli organisms beyond acceptable limits is of concern given their potential to cause food borne infections.