ILRI seeks lasting solution for the tsetse fly menace


A researcher works at a laboratory. The International Livestock Research Institute in Kenya is developing cattle species resistant to animal trypanosomiasis caused by the tsetse fly. AFP

Plans are under way to develop a cow that is resistant to trypanosomiasis at the International Livestock Research Institute (ILRI).

The disease is known as nagana in animals and sleeping sickness in human beings.

“Since animals carry parasites that cause trypanosomiasis, a resistant cow will thus improve animal and human health in Kenya,” says Dr Steve Kemp, a scientist at ILRI.

In the first step of the project, ILRI scientists have successfully developed a cloned Boran calf named Tumaini. The project leader, Dr Kemp, says that it is healthy and is being raised at Kenya’s ILRI’s research facility.

In the second phase of the project, the researchers will develop a new cloned Boran cow, with a gene that will make it resistant to trypanosomiasis.

The gene originates from baboons that are naturally resistant to trypanosomiasis. And as such, these primates do not harbour parasites that cause sleeping sickness in humans and nagana in cattle.

Dr Kemp notes that the project is timely as it will offer a sustainable solution for the trypanosomiasis problem in the country.

Nagana is a major impediment to livestock keeping in Kenya. “It is rampant all over the country and affects about 70 per cent of our farmers,” says Ochieng’ Gamba, an entomologist at the Kenya Tsetse and Trypanosomiasis Eradication Council.

He notes that Nagana causes heavy economic losses as it reduces milk and meat production in cattle. Most Kenyans rely on oxen to plough their land and this can’t happen if the animal is sick. Affected animals could also lose their fertility and suffer from abortions.

Gamba adds that the government also incurs millions of shillings to buy insecticides to control the disease. Symptoms of the disease in cattle include weight loss, increase in body temperatures, swelling of glands and discharge from the eyes and nose.

Death may occur if the animal is not properly and timely treated. Gamba says that drugs to prevent and treat the disease are available. But researchers warn that some of them are no longer effective as unscrupulous middlemen often dilute the drugs before selling them to farmers.

To control nagana, he adds that farmers could also spray cattle with insecticides to rid them of tsetse flies that spread the disease form one infected animal to the other. But some of these insecticides also pollute the environment.

According to Dr. Kemp, efforts aimed at developing a vaccine against trypanosomiasis in the last 40 years have not borne fruit.

“So the development of the trypanosomiasis resistant cattle is the best option,” he says.