Main Menu

The risks of contracting brucellosis, ‘ugonjwa wa maziwa’

More by this Author

Owing to sensitisation programmes and campaigns by both the animal and public health authorities, it is widely known in Kenya that ugonjwa wa maziwa, or brucellosis is transmitted through the consumption of unboiled or unpasteurised milk.

Thus, most people heat-treat their milk by boiling it before drinking, thus making it safe. As a contradiction, however, among most people there is exceedingly low awareness that brucellosis can be transmitted from their livestock to them through open wounds, cuts or scratches on the skin. This is especially so if the cut is on the hands or feet.

Furthermore, awareness is also poor on the fact that brucellosis can be transmitted through the splashing of discharges from animals into your eyes, nose or mouth.

It is noteworthy that according to the Centre for Disease Control, about 75 per cent of all new human infectious diseases originate from animals. The same body also reports that about 60 per cent of all human diseases are zoonotic in nature — meaning they can spread between an animal and a human, and ugonjwa wa maziwa is one of them.

Brucellosis is mainly a disease of livestock, and its occurrence in human beings is generally accidental. It is the world’s most common zoonosis (disease spread between animals and people). Brucellosis is caused by bacteria and affects cattle, sheep, goats, pigs and camels.

People in close contact with livestock, such as farmers, pastoralists, veterinary professionals and slaughterhouse workers are at a high risk of contracting the disease.

They are at a higher risk because their chance of coming into contact with the disease is greater during the course of their work in either slaughter or assisting in livestock birth processes. The brucella bacteria occur in large numbers in the reproductive tract of the livestock.

Hence attending to livestock without protecting your hands using gloves increases the risk of getting the disease. This is more so, if you have a cut or a wound on your hands.

For the general public, the risk of getting the disease is through drinking of unboiled or unpasteurised milk or milk products including maziwa mala, mursik, yoghurt, ice-cream or cheese.

In humans, brucellosis causes symptoms such as fever, sweating, headaches, back pains and joint pains. In severe infections, the brain and heart may be affected.


Currently, there is no vaccine for humans, but the disease may be treated through the use of a combination of antibiotics for an extended period. Recovery can take several weeks or even months.

Spread of the disease between livestock happens when the animal eats contaminated feed or drink contaminated water.

The bacteria may also be spread during artificial insemination if the equipment is contaminated. In livestock, the symptoms include abortion, weak calves, lambs, kids or piglets, reduced milk production and joint infections.

To control the disease in livestock, efforts are directed at identifying sick animals and removing them from the herd or flock. Unfortunately, no practical treatment against the disease in livestock exists, but vaccines are there.

A scientific research undertaken in Kajiado County and cited in the Online Journal of Public Health revealed that on average, 14 in every 100 people in Kajiado tested positive for incubating the disease.

Furthermore, three in every 100 livestock in Kajiado tested positive for incubating the disease. A second study in the same area showed that the people were well aware that they should boil milk always before drinking it to make it safe.

All those who were interviewed, said that they always boiled milk before drinking.

This demonstrated that information on milk safety practices from the local health authorities is passed on to the people, who in turn put it into practice.

On the spread of the disease directly from livestock, nearly all those interviewed said that they were involved in the assistance of livestock delivery, and none of them used any form of covering such as gloves to protect their hands.

An animal health assistant said, “We always tell them to inform us when there is a difficult livestock birth, but they don’t do so because sometimes such cases occur when they are far away in the rangelands grazing their animals.”

These discussions show that there is room for improvement on the message on the use of protective wear to enable people associate the spread of the disease from livestock and the presence of wounds or cuts on their skin.

Each individual is responsible for what she eats. Thus, as we drink our glass of maziwa mala or mursik, we must remember that if our milk is not well boiled, we put ourselves at risk of ugonjwa wa maziwa.

A step further is that collaborative efforts ought to be put in place by both the animal health and public health authorities to sensitise the general public on ugonjwa wa maziwa.

Dr Maina is a senior veterinary officer, Division of Veterinary Public Health in the Ministry of Agriculture, Livestock and Fisheries.