Milk from small-scale dairy farms in Northern Ghana plays a vital role in food security and nutrition but remains highly vulnerable to microbial contamination due to inadequate hygiene practices and poor post-harvest handling. This study investigated the microbial safety of raw milk by analysing contamination levels and identifying key pathogens linked to dairy farming practices. A total of 99 milk samples (79 farm-sourced, 20 vendor-sourced) were collected across the Tolon, Sagnarigu, and Savelugu districts and analyzed using standard plate count methods and biochemical assays. Results showed that 92% of samples contained coliform bacteria, with vendor milk exhibiting significantly higher contamination levels (33.6%) compared to farm milk (17%, p < 0.05). The most frequently isolated pathogens included Escherichia coli (39%), Bacillus cereus (32%), Klebsiella pneumoniae (10%), and Pseudomonas aeruginosa (6.7%), with emerging contaminants such as Stenotrophomonas maltophilia also detected. A strong inverse correlation (r = ？0.89, p = 0.0012) was observed between hygiene practices and contamination rates, underscoring the critical role of milk handling in microbial proliferation. These findings reveal substantial food safety risks associated with unregulated milk markets and highlight the urgent need for interventions, including improved hygiene protocols, veterinary oversight, and stricter monitoring of informal dairy supply chains. Given the presence of zoonotic pathogens, further research is needed to assess the long-term health implications of consuming contaminated milk in low-resource settings.
References
[1]
Ayele, Y., Gutema, F.D., Edao, B.M., Girma, R., Tufa, T.B., Beyene, T.J., et al. (2017) Assessment of Staphylococcus aureus along Milk Value Chain and Its Public Health Importance in Sebeta, Central Oromia, Ethiopia. BMC Microbiology, 17, Article No. 141. https://doi.org/10.1186/s12866-017-1048-9
[2]
Leone, C., Thippareddi, H., Ndiaye, C., Niang, I., Diallo, Y. and Singh, M. (2022) Safety and Quality of Milk and Milk Products in Senegal—A Review. Foods, 11, Article No. 3479. https://doi.org/10.3390/foods11213479
[3]
Xulu, N. and Naidoo, K. (2023) Traditional Milking Hygiene Practices and Their Effect on Raw Milk Quality of Rural Small-Scale Dairy Farmers in Kwa-Hlabisa, Kwazulu-Natal, South Africa. African Journal of Inter/Multidisciplinary Studies, 5, 1-13. https://doi.org/10.51415/ajims.v5i1.1127
[4]
Dairy World (2022) A Developing Dairy Industry in Ghana. https://www.dairyglobal.net/industry-and-markets/a-developing-dairy-industry-in-ghana/
[5]
Msalya, G. (2017) Contamination Levels and Identification of Bacteria in Milk Sampled from Three Regions of Tanzania: Evidence from Literature and Laboratory Analyses. Veterinary Medicine International, 2017, Article ID 9096149. https://doi.org/10.1155/2017/9096149
[6]
Knight-Jones, T., Hang’ombe, M., Songe, M., Sinkala, Y. and Grace, D. (2016) Microbial Contamination and Hygiene of Fresh Cow’s Milk Produced by Smallholders in Western Zambia. International Journal of Environmental Research and Public Health, 13, Article No. 737. https://doi.org/10.3390/ijerph13070737
[7]
Berhe, G., Wasihun, A.G., Kassaye, E. and Gebreselasie, K. (2020) Milk-Borne Bacterial Health Hazards in Milk Produced for Commercial Purpose in Tigray, Northern Ethiopia. BMC Public Health, 20, Article No. 894. https://doi.org/10.1186/s12889-020-09016-6
[8]
Grace, D., Wu, F. and Havelaar, A.H. (2020) MILK Symposium Review: Foodborne Diseases from Milk and Milk Products in Developing Countries—Review of Causes and Health and Economic Implications. Journal of Dairy Science, 103, 9715-9729. https://doi.org/10.3168/jds.2020-18323
[9]
Song, J., Xiang, W., Wang, Q., Yin, J., Tian, T., Yang, Q., et al. (2023) Prevalence and Risk Factors of Klebsiella Spp. in Milk Samples from Dairy Cows with Mastitis—A Global Systematic Review. Frontiers in Veterinary Science, 10, Article ID: 1143257. https://doi.org/10.3389/fvets.2023.1143257
[10]
Raza, A.S., Sial, A.U.R., Humayun, A., Rahim, M.F. and Khayam, U. (2023) Antimicrobial Resistance and Zoonotic Pathogens. In: Altaf, S., Khan, A. and Abbas, R.Z., Eds., Zoonosis, Vol. 4, Unique Scientific Publishers, 241-250. https://doi.org/10.47278/book.zoon/2023.150
[11]
Amentie, T., Eshetu, M., Mekasha, Y. and Kebede, A. (2016) Milk Postharvest Handling Practices across the Supply Chain in Eastern Ethiopia. Journal of Advanced Veterinary and Animal Research, 3, 112-126. https://doi.org/10.5455/javar.2016.c139
[12]
Gidiglo, K.F. (2014) Milk Production and Marketing in Ghana: The Case of Accra Plains. Journal of Biology, Agriculture and Healthcare, 4, 60-64.
[13]
Addo, K.K., Mensah, G.I., Aning, K.G., Nartey, N., Nipah, G.K., Bonsu, C., et al. (2010) Microbiological Quality and Antibiotic Residues in Informally Marketed Raw Cow Milk within the Coastal Savannah Zone of Ghana. Tropical Medicine & International Health, 16, 227-232. https://doi.org/10.1111/j.1365-3156.2010.02666.x
[14]
Ministry of Food and Agriculture (MOFA) (2018) Northern Ghana Agricultural Sector Review. MOFA Report.
[15]
Adzitey, F., Asiamah, P. and Boateng, E.F. (2020) Prevalence and Antibiotic Susceptibility of Salmonella enterica Isolated from Cow Milk, Milk Products and Hands of Sellers in the Tamale Metropolis of Ghana. Journal of Applied Sciences and Environmental Management, 24, Article No. 59. https://doi.org/10.4314/jasem.v24i1.8
[16]
FAO (2015) Dairy Development in West Africa. Food and Agriculture Organization of the United Nations.
[17]
Swai, E. and Schoonman, L. (2011) Microbial Quality and Associated Health Risks of Raw Milk Marketed in the Tanga Region of Tanzania. Asian Pacific Journal of Tropical Biomedicine, 1, 217-222. https://doi.org/10.1016/s2221-1691(11)60030-0
[18]
Mensah, G.I., Vicar, E.K., Feglo, P.K., Acquah, S.E.K., Saba, C.S.K., Addo, S.O., et al. (2019) Bacteriological Quality and Antibiotic Residues in Raw Cow Milk at Producer Level and Milk Products at Sale Points in the Northern Region of Ghana. International Journal of Tropical Disease & Health, 34, 1-10. https://doi.org/10.9734/ijtdh/2018/46626
[19]
Zeinhom, M.M.A., Hassan, G.M., Salem, H.A.M. and Corke, H. (2021) Prevalence and Survival of Stenotrophomonas Species in Milk and Dairy Products in Egypt. Foodborne Pathogens and Disease, 18, 337-345. https://doi.org/10.1089/fpd.2020.2893
[20]
Majalija, S., Tumwine, G., Kiguli, J., Bugeza, J., Ssemadaali, M.A., Kazoora, H.B., et al. (2020) Pastoral Community Practices, Microbial Quality and Associated Health Risks of Raw Milk in the Milk Value Chain of Nakasongola District, Uganda. Pastoralism, 10, Article No. 3. https://doi.org/10.1186/s13570-020-0158-4
[21]
Jeena, S., Venkateswaramurthy, N. and Sambathkumar, R. (2020) Antibiotic Residues in Milk Products: Impacts on Human Health. Research Journal of Pharmacology and Pharmacodynamics, 12, 15-20. https://doi.org/10.5958/2321-5836.2020.00004.x
[22]
Lister, P.D., Wolter, D.J. and Hanson, N.D. (2009) Antibacterial-Resistant Pseudomonas aeruginosa: Clinical Impact and Complex Regulation of Chromosomally Encoded Resistance Mechanisms. Clinical Microbiology Reviews, 22, 582-610. https://doi.org/10.1128/cmr.00040-09
[23]
WHO (2020) Antibiotic Resistance: Fact Sheet. World Health Organization.
[24]
FAO/WHO (2019) Codex Alimentarius Commission: Guidelines for Antibiotic Residues in Food. FAO/WHO Report, CA7998EN.
[25]
Al Sidawi, R., Urushadze, T. and Ploeger, A. (2021) Factors and Components Affecting Dairy Smallholder Farmers and the Local Value Chain—Kvemo Kartli as an Example. Sustainability, 13, Article No. 5749. https://doi.org/10.3390/su13105749
[26]
Asrat, D., Hiko, A. and Zewde, G. (2008) Occurrence of Escherichia coli O157:H7 in Retail Raw Meat Products in Ethiopia. The Journal of Infection in Developing Countries, 2, 389-293. https://doi.org/10.3855/jidc.203
[27]
Rechidi-Sidhoum, N., Dahou, A.A., Tahlaiti, H., Benameur, Q. and Homrani, A. (2021) Assessment of the Sanitary and Hygienic Quality of Raw Milk Marketed in the Urban Area of Mostaganem, Algeria. Asian Journal of Dairy and Food Research, 40, 345-348. https://doi.org/10.18805/ajdfr.dr-231
[28]
Mogotu, M.W., Abong, G.O., Mburu, J. and Ndambi, O.A. (2022) Assessment of Hygiene Practices and Microbial Safety of Milk Supplied by Smallholder Farmers to Processors in Selected Counties in Kenya. Tropical Animal Health and Production, 54, Article No. 220. https://doi.org/10.1007/s11250-022-03214-7
[29]
Zavala Nacul, H. and Revoredo-Giha, C. (2022) Food Safety and the Informal Milk Supply Chain in Kenya. Agriculture & Food Security, 11, Article No. 8. https://doi.org/10.1186/s40066-021-00349-y
[30]
Nyokabi, S., et al. (2020) Hand Milking Practices and Microbial Contamination of Raw Milk in Rwanda: A Cross-Sectional Study. BMC Public Health, 20, Article No. 1675.
[31]
Alhaji, N.B., Aliyu, M.B., Ghali-Mohammed, I. and Odetokun, I.A. (2019) Survey on Antimicrobial Usage in Local Dairy Cows in North-Central Nigeria: Drivers for Misuse and Public Health Threats. PLOS ONE, 14, e0224949. https://doi.org/10.1371/journal.pone.0224949
[32]
Rangel, J.M., Sparling, P.H., Crowe, C., Griffin, P.M. and Swerdlow, D.L. (2005) Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982-2002. Emerging Infectious Diseases, 11, 603-609. https://doi.org/10.3201/eid1104.040739
[33]
Oliver, S.P., Jayarao, B.M. and Almeida, R.A. (2005) Foodborne Pathogens in Milk and the Dairy Farm Environment: Food Safety and Public Health Implications. Foodborne Pathogens and Disease, 2, 115-129. https://doi.org/10.1089/fpd.2005.2.115
