Milk | Animal Diseases | Transmission to Human Beings

Human beings are universally susceptible to infection with the bovine tubercle bacillus. Bovine TB is particularly common in children. It is the most common pathogen present in raw milk. The milk from single infected cow might contaminate the entire milk supply through mixing. The bovine tubercle bacillus is chiefly responsible for the non-pulmonary type infection in man. Children become infected most commonly in the alimentary tract, cervical lymph glands, bones and skin. Organisms enter milk directly from udder or from dung. Pasteurization kills the pathogen.

2. Foot and Mouth Disease

This virus produces gastro-intestinal disturbances on consumption of milk and dairy products like cream, butter and cheese prepared from milk of infected animals. Children are more susceptible. The virus is present in the fluid of the vesicles and from these vesicles, they gain entry into the saliva, feces, urine and milk. Lesions also occur in the udder, milk ducts and secreting portions of the udder is also involved. Pasteurization is a simple method to destroy the FMD virus.

3. Anthrax (Bacillus anthracis)

Anthrax disease has been reported in people following consumption of infected milk. Bacillus anthracis may be excreted in milk shortly before death of the animal. Samples of milk drawn from cows that died of Anthrax may show numerous anthrax bacilli.

4. Rabies

Rabies virus has been found to be excreted in the milk of infected animals, although the spread of this deadly disease through milk is rare. It has been found that milk from rabid animals is avirulent and is not capable of producing the disease. It is also reported that there is no danger in the ingestion of infected milk unless there are any abrasions on the lips or along the gastro intestinal (alimentary tract). However, as a precautionary measure, milk from suspected cows should not be used for human consumption. Pasteurization is effective in destroying the virus.

5. Cow Pox

Cow Pox is transmissible from infected cows to the human beings, especially to the young one. In the case of adults, the attack will be usually mild but in children, it results in fever and malaise. The contamination of milk is through the lesions on the udder. Pasteurization is effective in destroying the virus.

6. Undulant fever or Malta fever (Brucellosis)

Infection is primarily acquired from infected animals. The species involved are Brucella melitensis, Brucella abortus, and Brucella suis. Man is infected directly by contact with the diseased animal or their tissue or discharges or through consumption of raw milk and milk derivatives or diseased animal. The organisms get established in the udder and multiply there and are excreted in the milk in large numbers.

Brucella abortus can also get into the milk from unsanitary barns as the organism survives for long periods under a variety of conditions. The safest method of disease prevention is to discard the affected animal’s milk. Pasteurization is effective in destroying the microorganism.

7. Actinomycosis

The possibility of infection of human beings with Actinomycosis bovis is certainly remote, though not impossible. The microorganisms if present in milk, can affect the human body only by gaining entrance through raw wound, such as a new tooth cavity or intestinal ulcers etc. Milk should be discarded or at least pasteurized.

8. Digestive disturbances

Food poisoning cases have been reported following consumption of milk from cows suffering from intestinal disorders and the causative microorganisms might have reached the milk through feces. Pasteurization is effective in destroying most of the pathogenic microorganisms.

ANIMAL DISEASES TRANSMITTED TO HUMAN BEINGS THROUGH MILK