The world’s staple food crops, and other food crops that optimize human nutrition, suffer from global virus disease pandemics and epidemics that greatly diminish their yields and/or produce quality. This situation is becoming increasingly serious because of the human population’s growing food requirements and increasing difficulties in managing virus diseases effectively arising from global warming. This review provides historical and recent information about virus disease pandemics and major epidemics that originated within different world regions, spread to other continents, and now have very wide distributions. Because they threaten food security, all are cause for considerable concern for humanity. The pandemic disease examples described are six (maize lethal necrosis, rice tungro, sweet potato virus, banana bunchy top, citrus tristeza, plum pox). The major epidemic disease examples described are seven (wheat yellow dwarf, wheat streak mosaic, potato tuber necrotic ringspot, faba bean necrotic yellows, pepino mosaic, tomato brown rugose fruit, and cucumber green mottle mosaic). Most examples involve long-distance virus dispersal, albeit inadvertent, by international trade in seed or planting material. With every example, the factors responsible for its development, geographical distribution and global importance are explained. Finally, an overall explanation is given of how to manage global virus disease pandemics and epidemics effectively.
Viral diseases provide a major challenge to twenty-first century agriculture worldwide. Climate change and human population pressures are driving rapid alterations in agricultural practices and cropping systems that favor destructive viral disease outbreaks. Such outbreaks are strikingly apparent in subsistence agriculture in food-insecure regions. Agricultural globalization and international trade are spreading viruses and their vectors to new geographical regions with unexpected consequences for food production and natural ecosystems. Due to the varying epidemiological characteristics of diverent viral pathosystems, there is no one-size-fits-all approach toward mitigating negative viral disease impacts on diverse agroecological production systems. Advances in scientific understanding of virus pathosystems, rapid technological innovation, innovative communication strategies, and global scientific networks provide opportunities to build epidemiologic intelligence of virus threats to crop production and global food security. A paradigm shift toward deploying integrated, smart, and eco-friendly strategies is required to advance virus disease management in diverse agricultural cropping systems.
Cucumber green mottle mosaic virus (CGMMV) was first described in 1935 infecting cucumber, making it one of the first plant viruses to be studied. Its initial distribution occurred out of England to other countries. This was followed by its distribution from England and these other countries to additional countries. This process increased slowly between 1935 and 1985, faster between 1986 and 2006, and rapidly between 2007 and 2016. The discovery that it diminished cucurbit fruit yields and quality, especially of watermelon, prompted a substantial research effort in worst-affected countries. These efforts included obtaining insight into its particle and genome characteristics, evolution, and epidemiology. CGMMV's particle stability, ease of contact transmission, and seed transmissibility, which are typical tobamovirus characteristics, explained its complex disease cycle and its ability to spread locally or over long distances without a vector. Knowledge of its disease etiology and epidemiology enabled development of integrated disease management approaches that rely heavily on diverse phytosanitary measures. Dispersal of seed-borne infection through the international seed trade following cucurbit seed crop production in tropical or subtropical countries explains its recent rapid dispersion worldwide.