The epidemiology, economic impact and control of maize streak disease

Maize streak virus (MSV), the causal agent of maize streak disease (MSD), is one of the most significant biological threats to food security in sub-Saharan Africa. By reducing yields of Africa's most important food crop, it seriously undermines the already precarious social and economic wellbeing of subsistence farmers throughout the continent. Despite the availability of MSD control strategies-ranging from good farm management to the use of chemical insecticides, and the planting of MSD tolerant maize -MSD remains a problem. The main reason for this is the inherent unpredictability of MSD epidemics which makes it difficult for farmers to decide where and when to apply appropriate control strategies. Also, without better estimates of the economic impacts of the disease, there is unlikely to be any motivation for large scale efforts by scientists and national governments to refine and apply effective control measures. Besides reviewing the epidemiological factors that would need to be modeled to achieve predictive forecasting of epidemics, we approximate how much MSD costs national economies in sub-Saharan Africa and evaluate various possible approaches to minimizing the over-all economic impact of the disease.