From the first reports of cassava brown streak disease (CBSD) in 1936 in East Africa, it took 65 years before the causal agent was identified as Cassava brown streak virus (CBSV) in 2001. The discovery, by researchers in the School of Biological Sciences at the University of Bristol, in collaboration with the Natural Resources Institute in Kent, was led by Professor Gary Foster and was one of a number of themes carried out within his group during his time as a BBSRC Advanced Research Fellow.

As the world's third most important staple crop, cassava feeds around 200M people in Africa. It is an excellent crop for poor farmers, providing carbohydrate when other staples are not available. Its ability to better withstand drought and grow in poorer soils is also contributing to cassava replacing maize as a primary food crop.

CBSD has become an extremely serious constraint to cassava production in East Africa as well as a threat to cassava production throughout Africa, It is listed as one of the seven most dangerous plant diseases in the world for the impact it can have on food and economic security and can cause losses of up to 100% in susceptible varieties.

Professor Foster's identification of Cassava brown streak virus as the causal agent of CBSD was instrumental in development of the diagnostic detection systems, vital in the fight to prevent spread and in developing resistant varieties.

Research to develop molecular tools to identify CBSV was highlighted as a major breakthrough in the UK Government report Perspectives on Pests: achievements of research under the UK Department for International Development's crop protection programme, 1996-2000. The group has hosted visiting fellows from Uganda working on variation of CBSV in the field and continues to research this serious disease.