Increasing zoonotic milk borne pathogens a complex challenge to the growing dairy industry in eastern africa by dr. halid kirunda

Increasing zoonotic milk borne pathogens a complex challenge to the growing dairy industry in eastern africa by dr. halid kirunda

• 1.
  Increasing zoonotic milk-borne pathogens:a complex challenge to the growing dairy industry in Eastern Africa H. Kirunda, N. Muwereza, T. Kabuuka, S.D. Kerfua, P. Emudong and P.D. Kasaija African Livestock Conference and Exhibition (ALiCE), June 18th -20th 2014, Speke Resort and Conference Center, Munyonyo, Kampala, Uganda
• 2.
  Livestock farming inUganda  Many African countries do not have adequate food security, yet some are already weakened by conditions such as: malaria HIV/AIDS  Different program are being undertaken to increase livestock production  Although very gradual, some of the Eastern Africa countries continue to achieve increase in milk production
• 3.
  Trend of milkproduction in Eastern Africa Source: FAOSTAT, 2014
• 4.
  Supply of wholemilk Source: FAOSTAT, 2014
• 5.
  Export of freshmilk Source: FAOSTAT, 2014
• 6.
  Livestock farming inUganda  Efforts to improve food security are threatened by foodborne diseases  Each year foodborne diarrhoeal diseases kill an estimated 2.2 m people especially on the African continent  Eastern and Southern Africa face estimated 1,400m diarrhoea episodes annually  Control of these diseases face challenges of globalization of the food market, climate change and changing patterns of human consumption
• 7.
  Livestock farming inUganda  Milk is a good medium of growth of pathogens that cause disease in humans  Contamination affects milk safety/spoilage; negatively impacting on growth of developing dairy industries in Eastern Africa  While processing may reduce the level of milk contamination with such agents, milk marketing dominated by the informal sector  Only 10-20% of milk sold is through the formal market chains
• 8.
  Livestock farming inUganda  Due to lower quality requirements in the informal markets, these markets account for 80% - 95% of milk marketed in the region  Up to 80% of the marketed milk the bulk of the milk is consumed in raw form, yet milk in the region is still highly contaminated  There is high preference for liquid milk in the region except in Ethiopia where bulk of the milk is processed into butter
• 9.
  Zoonotic milk-borne pathogens Common zoonotic milk-borne pathogens: Brucella abortus Mycobacterium bovis  Recently, un common zoonotic pathogens have been isolated in milk of cattle  The paper reviews the recently isolated milk-borne zoonotic pathogens in countries of Eastern Africa.
• 10.
  Milk contamination withB. abortus and B. melitensis  Brucella abortus was previously the only pathogen isolated from milk of cattle, while B. melitensis was known in goats  B. melitensis has been isolated from cattle alongside B. arbutus in Kenya  B. melitensis and B. abortus are all capable of causing human infections, B. melitensis now most common and cause a more serious disease  Rearing small ruminants alongside cattle has previously been associated with infection of cattle with B. melitensis  Brucella organisms are transmitted to humans through direct contact with livestock or by ingestion of unpasteurized milk 10
• 11.
  Milk Contamination with EnterotoxigenicE. coli O157:H7  Cattle are the reservoirs of shiga toxin-producing E. coli (STEC) including the zoonotic STEC, EHEC strains  EHEC strains produce diarrhea-causing enterotoxin and among them E. coli O157:H7 is the predominant cause illness  In Eastern Africa, the annual food poisoning cases due to E. coli are between 100,172 in Burundi and 769,248 in Ethiopia  EHEC O157:H7 has not been isolated in a number of countries, but has been isolated in Kenya, Tanzania, Ethiopia and Uganda  At farm level, the degree of E. coli contamination is 2.0 x 106 CFUs/mL, and can increase 150-fold during transportation 11
• 12.
  Contamination of milkwith Mycobacterium bovis  Bovine tuberculosis is an infectious disease primarily caused by Mycobacterium bovis. Cattle are the primary host of M. bovis  M. bovis is a member of Mycobacterium tuberculosis complex, which also includes M. tuberculosis  There has been persistent isolation of M. bovis from cattle in Ethiopia, Kenya and Uganda  A clonal complex of M. bovis , African 2 (Af2) has been identified to be localized in Eastern Africa region  Represent >70% of the isolates from cattle in Uganda, Burundi, Tanzania and Ethiopia. Has never isolated elsewhere in the world  Infections in man are through consumption of unpasteurized contaminated milk 12
• 13.
  Challenges in controlof B. melitensis and B. abortus  Isolation of both B. melitensis and B. abortus in milk of cattle  While serology is the easiest approach to disease detection, no single serological test is reliable for detecting brucella infection  Most of the milk is produced among pastoralist communities where control is most challenging  Several complex risk factors exist and these are tightly linked and intrinsic to the farming practices  Traditional beliefs and practices that interfere with acceptance of disease control measures exist in such communities  Vaccines can induce abortion, have limited ability to prevent infection and seroconversion after exposure 13
• 14.
  Challenges in controlof EHEC O157:H7  Colonisation of the gut of cattle by EHEC O157:H7 is not clearly understood  Information on identification and characterization of the non- O157 STEC strains in milk is lacking.  Non-O157 STEC strains are more difficult to detect in samples than EHEC O157:H7  Vaccine against EHEC is not currently in use in any of the Eastern Africa countries  Use of PCR requires testing of extracts from primary cultures, which are only possible by use of selective/differential media  STEC strains are becoming resistance of to several antibiotics14
• 15.
  Challenges in controlof EHEC O157:H7  Larger herds of bovines have been linked to increased likelihood of occurrence of bovine tuberculosis  Exotic breeds have been reported to have a higher risk of infection with M. bovis compared to the native cattle breeds  The efficacy of promising candidate bTB vaccines are just undergoing evaluation in Eastern Africa  The tests used in detection of M. bovis are slow, cumbersome, unreliable, and time-consuming  Molecular tools have not gained much use in field laboratories and the need for extraction of DNA from primary cultures  The effect and consequences of M. bovis Af2 not understood 15
• 16.
  General challenges tocontrol of zoonotic pathogens In Eastern Africa, it is less likely to have appropriate; 1.Disease surveillance system 2.Diagnostic capabilities 3.Research 4.Regulatory framework 5.Programme management 6.Animal identification (traceability) 7.Regional cooperation 8.Social cooperation Without change, minimising milk contamination with zoonotic pathogens would prove very difficult or almost impossible 16
• 17.
  17