Factors Associated with Prevalence of Antimicrobial Residues and Compositional Quality of Informally Marketed Raw Cow Milk in Lamu West Sub-County, Kenya

Abstract

Unadulterated milk, free of antimicrobial residues is important for industrial processing and consumers’ health. Antimicrobial residues in foods of animal origin can cause adverse public health effects like drug resistance and hypersensitivity. Milk produced in Lamu West sub-county is sold raw directly to consumers. A cross sectional study was carried out to estimate the compositional quality and prevalence of antimicrobial residues in informally marketed raw cow milk in Lamu West Sub-County, Kenya. One hundred and fifty two (152) vendors and 207 farmers were recruited from four randomly selected urban centres and interviewed using a pretested standardized questionnaire. A 100-ml raw milk sample was aseptically collected from each vendor and farmer and tested for antimicrobial residues using Charm Blue Yellow II kit following the European Union Maximum Residue Limits (EU-MRLs) while an Ekomilk® Analyzer was used to measure compositional quality. Samples with solid not fat (SNF) <8.5 or those with added water ≥0.01% or both were considered adulterated. Data was analyzed using univariate analysis and unconditional logistic regression to calculate odds ratios (OR) and 95% Confidence intervals (CI). Thirty-two (15.5%) of the 207 samples from farmers and 28 (18.4%) of the 152 samples from vendors had antimicrobial residues above the MRLs. Thirty-six (17.4 %) samples from farmers and 38 (25.0%) from vendors were found to be adulterated with water. Farmer awareness of the danger of consuming milk with antimicrobial residues and training on good milking practices were protective against selling milk with antimicrobial residues (adjusted OR and 95% CI 0.20, 0.07–0.55 and 0.33, 0.11–0.99, respectively). Farmers having secondary level of education and above (AOR 3.03, 95% CI: 1.44-6.39) and being a pastoralist farmer (AOR 3.20, 95% CI: 1.05-9.71) were retained as independent risk factors against marketing of milk of poor compositional quality. Being a male vendor was retained as the only independent risk factor associated with marketing of milk of poor compositional quality amongst vendors (AOR 2.73. 1.22-6.08) The antimicrobial residues above EU-MRLs and adulteration of raw marketed cow milk observed in this study provide evidence for routine testing of marketed milk and educating farmers to observe antimicrobial withdrawal period.