The Impact and Control of Emerging and Re-Emerging Viral Diseases in the Environment: An African Perspective

Emerging viral infections (EVI), and re-emergent variants of existing ones, are a growing threat to public health worldwide with outbreaks occurring sporadically especially in Africa associated with significant adverse ecological, socioeconomic and public health implications. These pathogens have devised evolved environmental adaptations, including the possession of genomic resistance mutations. Haemorrhagic fever viruses like Ebola, Marburg and Lassa fever viruses and respiratory pathogens like the avian and human influenza severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) viruses, most from zoonotic reservoirs, may significantly increase morbidity and mortality in the human population in the nearest future. Likewise, vector-borne zoonotic viral diseases including Rift Valley fever, yellow fever, dengue, chikungunya and West Nile, transmitted by arthropods from animal reservoirs, occur frequently in the tropics, exhibiting previously unseen patterns of infection and spread. These patterns are facilitated by many intrinsic factors like mutated sites in the viral genome, and external factors including urbanization, displacement, human migration and climate change. Emerging viruses can easily cross boundaries and pose severe threats to the human populations in new geographical areas. Here, we outline the features of common emergent viruses and factors facilitating their emergence, effects, control and sustained management in the environment.