Drivers of Emerging Viral Zoonoses

Ghatak, Sandeep; Milton, Arockisamy Arun Prince; Das, Samir

Zoonotic viral diseases continue to inflict human mortality and morbidity worldwide. While efforts are on for containment of these diseases, many new viral diseases, especially those of zoonotic origin, were discovered in humans, often in newer geographical areas where diseases were not reported previously. It is now an established fact that with changes in society, demography, climatic patterns, global economy and trade, viral zoonoses have made a comeback. Many factors are responsible for the emergence of viral pathogens worldwide. These factors, known as ‘drivers’, are numerous and are complexly interlinked. Major drivers of the emergence include ecological perturbations caused by changes in agricultural practices, livestock husbandry, and developmental activities; global warming and changes in climatic patterns, various forces of globalization such as international travel, trade and commerce; human demographic changes augmented by rising population and urbanization, population mobility; human behavioural changes; microbial adaptation and evolution; changing technology and industrial practices; and deficiencies in public health infrastructure. Emergence of many new viral zoonoses, e.g. Nipah virus infection, severe acute respiratory syndrome, Middle East respiratory syndrome, highly pathogenic avian influenza, Crimean–Congo hemorrhagic fever, Alkhurma hemorrhagic fever, and others is testimony to role of complex set of drivers in predisposing emergence. Though detailed discussions of these drivers of emerging zoonotic infections are beyond the scope of the current discourse, in this chapter an attempt shall be made to discuss the most important causes of emergence of viral zoonoses so that these complex linkages are recognized and acted upon for attaining sustainable health.