WASHINGTON – Scientists at the US Department of Agriculture and the International Livestock Research Institute (ILRI) in Kenya are developing a vaccine that protects cattle against East Coast fever, a destructive disease in eastern and central Africa, wrote Sandra Avant of the US Department of Agriculture’s Agricultural Research Service (ARS).

For more than five years, entomologist Glen Scoles, veterinary medical officer Massaro Uet, and research leader Don Knowles at the ARS Animal Disease Research Unit (ADRU) in Pullman, Wash., have been working on the collaborative project. Looking at combination vaccines for tick-borne diseases, this research supports USDA's priority of promoting international food security.

Scoles said scientists are focusing on the tick that transmits the parasite responsible for East Coast fever. Because the tick and parasite are similar to the tick and parasite that cause Texas cattle fever in the US, developing a vaccine for East Coast fever could lead to a vaccine for Texas cattle fever.

Scientists developed a polymerase chain reaction (PCR) test that detects parasite DNA in ticks in an initial study. They used tick populations that were produced at ILRI to have different susceptibilities. Two different strains of ticks – Muguga and Kiambu – were compared. The Muguga ticks had a low level of parasitic infection, while the Kiambu ticks were highly susceptible.

Understanding genetic differences between these two tick populations could lead to identifying proteins that might be good targets for a vaccine to help control East Coast fever, Scoles said.

East Coast fever isn't currently a problem in the US, but this collaborative research helps to keep it free of the disease and in reducing future risk in other countries. Results of this research may be also be applied to help control other similar parasitic diseases, Avant concluded.