Abstract:
Background: Milk is an important source of nutrition but is also highly susceptible to microbial
contamination and adulteration if not handled with hygiene. In Ethiopia, raw milk has been
studied extensively, but little is known about the microbial safety of treated milk (boiled or
steamed) consumed in urban establishments such as cafes and hotels.
Objective: To assess the quality of raw and treated milk samples collected from food and drink
establishments and milk distribution centers of Jimma city, southwest Ethiopia.
Method: A cross-sectional study was conducted among 201 milk samples collected from food
and drink establishments and milk distribution centers from September to October 2024.
Stratified systematic random sampling was used, with one milk sample collected per
establishment. Laboratory analyses assessed total bacterial count (TBC), total coliform count
(TCC) and specific gravity for adulteration. Structured questionnaires and observational
checklists captured milk handling practices. Quality assurance included negative controls
(uninoculated media, sterile water) were performed. Data were analyzed using Kruskal-Wallis
tests, logistic regression and adjusted odds ratios (AOR).
Result: A total of 15 raw, 68 boiled, and 118 steamed milk samples were analyzed. Both raw
and treated milk frequently exceeded Ethiopian Standards for TBC and TCC, with
Staphylococcus aureus and Escherichia coli as dominant isolates. Adulteration was detected in
>40% of samples, particularly from steamed milk establishments. Hygiene practices were poor:
none of the handlers used personal protective equipment (PPE) and only 22.9% had received
training. Observed hygiene did not always align with self-reported practices. Multivariate
analysis identified milk adulteration and cooler temperature management as significant
predictors of poor milk quality.
Conclusion and recommendation: Milk sold in Jimma City is compromised by microbial
contamination and adulteration due to poor milk handling practice. Strengthened regulatory
enforcement, improved cold chain infrastructure and mandatory handler training are
recommended to safeguard consumer health.
