Bovine tuberculosis: the silent threat to your livestock

As the world marks Tuberculosis (TB) Day tomorrow, one of the topics of discussion for animal health experts will be how to stop the spread of the disease from animal to human.

Bovine tuberculosis, which affects animals, remains a serious threat to livestock and human health.

The World Organization for Animal Health (WOAH) notes that chronic respiratory disease is caused by a bacterium called Mycobacterium bovis (M. bovis), closely related to the bacterium responsible for human tuberculosis (M. tuberculosis).

Bovine tuberculosis is a zoonosis, which means that it can be naturally transmitted between animals and humans.

However, it is more serious and more difficult to treat than human tuberculosis. Indeed, the bacterium is resistant to the antibiotic pyrazinamide used to treat human tuberculosis.

Dr. Joseph Mugachia, a veterinarian at the Nairobi Garden Veterinary Service, said that bovine tuberculosis was an infectious disease of livestock and that it affected other domestic animals and some wildlife populations.

It causes persistent coughing, bleeding from the nose or mouth, nodules of the skin and udder (at the advanced stage of the disease) and possibly death.

He says infectious bovine tuberculosis can not be treated in cows. "Tuberculosis is a neglected disease whose diagnosis and control are not very well taken into account. The focus is put solely on the slaughterhouse when checking the safety of the meat for consumption, "says Dr. Mugachia.

He adds that the disease can not be treated because badysis of the risks of cost, time and spread shows that it is impossible to treat.

"It's too expensive because cows have a larger mbad than humans and therefore need more drugs. The treatment takes too much time, which increases the risk of transmission to humans and other animals. The best thing to do is to destroy the affected animals.

INHALING THE STAYS OF THE TIME OR SNOW

In dogs and cats, Dr. Mugachia explained that skin reaction tests and X-rays were used to detect the disease. "In cattle, we only use the skin reaction test. Radiography is due to logistical difficulties in cattle because of the large body mbad that rays penetrate poorly. "

Animals can also be infected with human tuberculosis and this tuberculosis can also affect cows and humans, and vice versa, he adds.

Dr. Dave Muthama, who is dealing with human tuberculosis at the Elizabeth Glaser Pediatric AIDS Foundation, says that bovine tuberculosis in humans is treatable, just like the ordinary type, thanks to a combination of cancer. antibiotics that kill the bacterium Mycobacterium bovis.

However, one complication is that M. bovis is still resistant to pyrazinamide, an anti-TB drug, although other first-line anti-TB drugs may still be used.

And, like human disease, bovine tuberculosis is spread by the inhalation of tiny droplets from coughs or sneezes from an infected animal or person, as well as contaminated food, which progressively makes it a more serious threat than expected to human health.

It mainly affects the lungs but can also affect any part of the body, including the abdominal glands, bones and the nervous system.

In men, symptoms include fever, night sweats, persistent cough, diarrhea, weight loss, and abdominal pain.

According to the World Health Organization (WHO), it is difficult to know how important the disease is in M. bovis because the most commonly used laboratory procedures do not distinguish M. bovis from M. tuberculosis .

The organization further notes that the true burden of zoonotic TB will likely be underestimated due to the lack of routine surveillance data provided by most countries.

Dr. Muthama, however, says that with technological advances, it is possible to detect rare forms of tuberculosis with the help of genetic expert tests.

"The expert gene test is like looking at the DNA of organisms. We have discovered that these rare forms of tuberculosis are rare among humans. "

In 2016, there were an estimated 147,000 new cases of zoonotic TB in humans and 12,500 deaths due to the disease, with the most developed countries recording a much smaller number of TB cases. caused by M. bovis in humans, according to the WHO.

Africa is the most affected with an incidence of 71,000 and a mortality of 9,270. Next come Southeast Asia with 44,900 incidences out of 2,090 deaths. The Western Pacific is the third with 10,000 incidences and 309 deaths.

In 2018, Kenya ranked bovine tuberculosis among the 36 priority zoonoses to be controlled. Others were anthrax, brucellosis, bird flu and other pandemic influenza viruses and plague.

According to Dr. Mugachia, the best way to save humans and cattle from bovine tuberculosis is to control its spread.

"I would recommend that animals in high-risk areas be tested for TB. The animals should be housed in a place where the air circulates well and people suspected of tuberculosis should be tested and treated as soon as possible to avoid pbading it on to cattle, "says Dr. Mugachia.

High-risk areas, he says, are arid and semi-arid, and places like Kiambu, Vihiga, and Kisii, where families live near animals due to small areas of land.

He adds that every time tuberculosis is diagnosed on the farm, milk should be tested to exclude contamination.

Cattle can transmit bovine tuberculosis to other cattle directly through the respiratory route, via infected milk, at birth by the placenta and through contamination of pastures or natural water sources.