Establishment of critical control points of informally marketed raw milk in Kiambu and Nairobi districs based on microbiological safety.
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Mwangi, A. 2002. Establishment of critical control points of informally marketed raw milk in Kiambu and Nairobi districs based on microbiological safety. MSc thesis, University of Nairobi. 116 pp.
Permanent link to this item: http://hdl.handle.net/10568/1539
This study describes an analysis of the bacterial risks and factors associated with those risks in the informal milk market in Nairobi and Kiambu districts. The study was carried out as part of integrated studies on milk marketing and associated public health risks in Kenya with the aim of making recommendations to improve milk quality without loading unrealistic costs and restrictions on traders and the milk market. The specific objectives were to: 1) assess milk quality along raw milk marketing pathways and the risk factors involved; 2) identify the critical control points for along each major milk market pathway; and 3) adapt the Hazard Analysis and Critical Control Points (HACCP) system as a tool and guideline for improving milk quality along the informal milk marketing chain. The study was conducted among 162 raw milk traders of various cadres between March and May 1999. Traders were selected in a stratified random sample, stratified on proximity to consumers (Nairobi) and producers (Kiambu). Milk handling practices for each trader were both observed and recorded on a questionnaire. Milk samples were collected and assessed for total and coliform bacterial plate counts, addition of inhibitors and adulteration. The observed counts and levels were compared to quality thresholds based on Kenyan national standards. Critical control points (CCPs) and associated risk factors for not meeting these standards were identified. About 75% of milk samples were collected within two hours of their receipt by traders. The majority of respondents were milk shop/kiosk (27%) followed by milk bars (25%), mobile or itinerant (18%), collection centers (12.9%), cooperatives (9%) and milk bar/snack bar (8%). Market points with one or more intermediate steps comprised 41% of samples collected. Direct sales occurred between producers and dairy co-ops (20%), hawkers (15%), milk-/snack-bar (13%) and kiosks/shops (12%). Most respondents were male (64%) aged between 16 and 70 years (mean= 32 and 28 yrs for Kiambu and Nairobi, respectively). The majority of respondents (78%) did not have any form of training in milk handling and quality control, and 41% did not practice any form of quality control prior to purchasing their supplies. Approximately one-quarter (27%) of the milk traders had been medically examined as required by the Ministry of Health but none met the frequency of medical examination required (four times/year). Only 22% and 13% of milk collected from Kiambu and Nairobi, respectively, had total bacterial counts of acceptable standards according to Kenya Bureau of Standards (KBS). Applying the same standards for coliform counts, 56% and 29% of the samples collected from Kiambu and Nairobi, respectively, were acceptable. The proportion of milk samples that were adulterated was 14% and 12% in Nairobi and Kiambu, respectively. Overall, milk samples collected from Kiambu were of significantly better microbial quality than those from Nairobi. Two market channel types (retail agents other than dairy co-ops and multiple selling steps) and four risk factors: scooping of milk, higher milk temperature, piped water and use of plastic versus metal containers were associated with higher coliform counts (the former three risk factors were also associated with higher total bacterial counts). Against expectation, time in the market chain and distance to retail points showed no significant association with total or coliform counts. This most likely reflected the presence of a CCP between the dairy, farm and the first milk market agent. Though the majority of milk that reached consumers is below Kenyan national standards, bacterial health risks were determined to be minimal given the common consumer practice of boiling of milk prior to consumption.