Seeking a Better Way for African Farmers to Fight a Fever

07 November 2011

This is the VOA Special English Agriculture Report.

East Coast fever kills hundreds of thousands of cattle in

eastern and central Africa every year. The animals become infected when they get bitten by ticks carrying the parasite that causes the disease. A parasite is an organism that feeds on other organisms.

Donald Knowles directs the animal disease research unit in the Agricultural Research Service, part of the United States Department of Agriculture. The service is working with the International Livestock Research Institute in Kenya to find better ways to prevent parasitic diseases in cattle. Dr. Knowles is also a professor at Washington State University.

He points out that East Coast fever is not a contagious disease, so animals cannot give it to each other.

DONALD KNOWLES: "You need a tick to transmit from one infected cow to the other. They won’t transmit just by standing next to each other. You need a tick to move it between them."

Farmers in parts of Africa use a vaccination method against East Coast fever known as infect and treat. First they infect animals with live parasites. Then they treat them with drugs to help them recover.

That way, explains Dr. Knowles, the animal becomes immunized or vaccinated against a full case of the deadly fever. But there are problems with this method of vaccination. Uninfected ticks that bite the vaccinated animal can still get infected and spread the parasite to other animals.