Tropical Animal Health and Production

, Volume 38, Issue 3, pp 185–194 | Cite as

Evaluation of the hygienic quality and associated public health hazards of raw milk marketed by smallholder dairy producers in the Dar es Salaam region, Tanzania

  • F. M. KivariaEmail author
  • J. P. T. M. Noordhuizen
  • A. M. Kapaga
Original Article


A cross-sectional study was conducted to determine three parameters of the quality of the raw milk marketed by milk selling points (MSPs) in Dar es Salaam region. Total bacterial count (TBC) was used as an indicator of the microbial quality of the milk; antimicrobial residues were determined; and the California mastitis test (CMT) was used to screen for milk somatic cells as an indication of the mastitis level in the cows that provided the milk. Moreover, a water sample at each MSP was taken for bacteriological culturing. Finally, a questionnaire survey was conducted with the milk sellers at the MSPs to identify risk factors for poor milk hygiene. A total of 128 milk samples and corresponding water samples were collected from randomly selected milk selling points in Dar es Salaam region. The mean TBC was (8.2± 1.9) × 106 cfu/ml, and major bacterial isolates from the milk samples were Escherichia coli (6.3%), Bacillus cereus (6.3%), Staphylococcus aureus (6.3%) and Streptococcus agalactiae (6.3%), Enterobacter aerogenes (5.6%) and Enterococcus faecalis (4.7%). In most cases, the organisms identified in milk corresponded to those isolated from the corresponding water samples. Of milk samples, 79.0% were positive to the CMT and 7.0% were positive for antimicrobial residues. TBC was normalized by log-transformation, and the possible predictors of TBC were identified by fitting two linear regression models. In a random effect model, water microbial quality, frequency of cleaning the milk containers, frequency of milk supply, milk storage time and the type of containers, and mixing of fresh and previous milk were significantly (p < 0.05) associated with the mean log TBC. In a fixed effect model, in addition to these indicators, water shortage, water source and the refrigerator condition were significantly (p ≤ 0.01) associated with log TBC. It was concluded that the milk sold in Dar es Salaam region is of poor quality and is of public health significance.


Antimicrobial residues CMT Microbiological quality Public health hazards TBC Dar es Salaam 



colony-forming unit


California mastitis test


milk selling point


total bacterial count


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  1. Aarestrup, F.M., 1999. Association between the consumption of antimicrobial agents in animal husbandry and the occurrence of resistant bacteria among food animals. International Journal of Antimicrobial Agents, 12, 279–285PubMedCrossRefGoogle Scholar
  2. Coia, J.E., Johnston, Y., Steers, N.J. and Hanson, M.F., 2001. A survey of the prevalence of Escherichia coli O157 in raw meats, raw cow's milk and raw-milk cheeses in south-east Scotland. International Journal of Food Microbiology, 66, 63–69PubMedCrossRefGoogle Scholar
  3. Cousins, C.M. and Bramley, J.A., 1985. The microbiology of raw milk. In: R.K. Robison (ed.), Dairy Microbiology, vol 1, (Elsevier Applied Science, London), 119–163Google Scholar
  4. Franz, C.M., Holzapfel, W.H., and Stiles, M.E., 1999. Enterococci at the crossroads of food safety? International Journal of Food Microbiology, 47, 1–24PubMedCrossRefGoogle Scholar
  5. Heeschen, W., Suhren, G. and Hahn, G., 1985. Mastitis—significance for processing of milk and public health aspects. Paper presented at the IDF seminar. Progress in the Control of Bovine Mastitis, 21–24 May 1985, Kiel, GermanyGoogle Scholar
  6. Hogan, S.J., Gonzalez, R.N., Harmon, J.R., Nickerson, S.C., Oliver, S.P., Pankey, J.W. and Smith, L.K., 1999. Laboratory Handbook on Bovine Mastitis, (National Mastitis Council, Inc., W D Hoard, Fort Atkinson, USA)Google Scholar
  7. International Dairy Federation, 1991. Detection and Confirmation of Inhibitors in Milk and Milk Products, (Bulletin No. 258, 2nd edn, IDF; Brussels)Google Scholar
  8. International Dairy Federation, 1996. Mastitis Newsletter No. 144, (IDF, Brussels)Google Scholar
  9. Kivaria, F.M., Noordhuizen, J.P.T.M. and Kapaga, A.M. Prospects and constraints of smallholder dairy husbandry in Dar es Salaam region, Tanzania. Outlook on Agriculture (in press)Google Scholar
  10. Kivaria, F.M., Noordhuizen, J.P.T.M. and Kapaga, A.M., 2004. Risk indicators associated with subclinical mastitis in smallholder dairy cows in Tanzania. Tropical Animal Health and Production, 36(6) 581–592PubMedCrossRefGoogle Scholar
  11. Kleinbaum, D.G., Kupper, L.L., Muller, K.E. and Nizam, A., 1998. Applied Regression Analysis and Other Multivariable Methods. (Duxbury Press, London), 186–211Google Scholar
  12. Kurwijila, R.L., Mdoe, N., Nyange, D.N., Auerbock, R.M. and Malya, H.N., 1995. Assessment of fresh milk and milk products and consumption in Dar es Salaam, Report to the Austro Project Association, (Austro Project Association, Dar es Salaam)Google Scholar
  13. Leclerc, V., Dufour, B., Lombard, B., Gauchard, F., Garin-Bastuji, B., Salvat, G., Brisabois, A., Poumeyrol, M., De Buyser, M.L., Gnanou-Besse, N. and Lahellec, C., 2002. Pathogens in meat and milk products: surveillance and impact on human health in France. Livestock Production Science, 76, 195–202CrossRefGoogle Scholar
  14. Mateu, E. and Martin, M., 2001. Why is anti-microbial resistance a veterinary problem as well? Journal of Veterinary Medicine B, 48, 569–581CrossRefGoogle Scholar
  15. Mullins, G.R., 1993. Market policy and market development: a comparison of dairy product consumption in Mombasa, Kenya and Dar es Salaam, Tanzania. Dairy Development Policy and Implementation: Sharing Experiences between Africa and Asia. (FAO, Rome, 12 July 1993)Google Scholar
  16. Noordhuizen, J.P.T.M. and Frankena, K., 1999. Epidemiology and quality assurance: applications at farm level. Preventive Veterinary Medicine, 39, 93–110PubMedCrossRefGoogle Scholar
  17. Peng, J.S., Tsai, W.C. and Chou, C.C., 2001. Surface characteristics of Bacillus cereus and its adhesion to stainless steel. International Journal of Food Microbiology, 65, 105–111PubMedCrossRefGoogle Scholar
  18. Pennington, H., 1997. The Pennington Group: Report on the circumstances leading to the 1996 outbreak of infection with E. coli O157 in Central Scotland, the implications for food safety and the lessons to be learned, (The Stationary Office, Edinburgh)Google Scholar
  19. Quinn, P.J., Carter, M.E., Markey, B.K. and Carter, G.R., 2000. Clinical Veterinary Microbiology, (Mosby-Year Book Europe, London)Google Scholar
  20. Ropkins, K. and Beck, A.J., 2000. Evaluation of worldwide approaches to the use of HACCP to control food safety. Trends in Food Science and Technology, 11, 10–21CrossRefGoogle Scholar
  21. Shirima, G.M., Kazwala, R.R. and Kambarage, D.M., 2003. Prevalence of bovine tuberculosis in cattle in different farming systems in the eastern zone of Tanzania. Preventive Veterinary Medicine, 57, 167–172PubMedCrossRefGoogle Scholar
  22. SPSS, 2002. SPSS for Windows, release 11.5.0, (SPSS Inc., Chicago, LA)Google Scholar
  23. Stiles, M.E., 1989. Less recognized or presumptive foodborne pathogenic bacteria. In: M.P. Doyle (ed.), Foodborne Bacterial Pathogens, (Marcel Dekker, New York), 674–735Google Scholar
  24. Sundlof, S.F., 1994. Antimicrobial drug residues in food-producing animals. In: J.F. Prescot, and J.D. Baggot (eds), Antimicrobial Therapy in Veterinary Medicine, 2nd edn, (Iowa State University Press, Ames, IA), 569–584Google Scholar
  25. Warburton, D.W., 1993. A review of the microbiological quality of bottled water sold in Canada. Part 2. The need for more stringent standards and regulations. Canadian Journal of Microbiology, 38, 158–168CrossRefGoogle Scholar
  26. Warburton, D.W.Google Scholar
  27. Weinhaupl, I., Schpf, K.C., Khaschabi, D., Kapaga, A.M. and Msami, H.M., 2000. Investigations on the prevalence of bovine tuberculosis and brucellosis in dairy cattle in Dar es Salaam region and in Zebu cattle in Lugoba area, Tanzania. Tropical Animal Health and Production, 32(3), 147–154PubMedCrossRefGoogle Scholar
  28. Whiting, R.C., Sackitey, S., Calderone, S., Morely, K. and Philips, J.G., 1996. Model for the survival of Staphylococcus aureus in non-growth environments. International Journal of Food Microbiology, 31, 231–243PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  • F. M. Kivaria
    • 1
    Email author
  • J. P. T. M. Noordhuizen
    • 2
  • A. M. Kapaga
    • 1
  1. 1.Animal Diseases Research InstituteDar es SalaamTanzania
  2. 2.Department of Farm Animal Health, Faculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands

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