Migratory Wave due to Conflicts: Risk of Increased Infection From Zoonotic Diseases

Wars have devastating effects on all the components of the One Health approach: humans, animals, and ecosystems. Wars and the resulting migratory waves massively disrupt normal animal health services and surveillance. Among other consequences, they adversely impact the early detection, prevention, and control of animal diseases. Uncontrolled movement of animals or their undisposed carcasses, the destruction of wildlife habitats, and the increased interface between humans, wildlife, and domestic animals contribute to uncontrolled transmission and spread of zoonotic pathogens from animals to humans. In the last millennium, zoonotic diseases such as the "Black Death" were triggered by devastating wars and led to the deaths of a large fraction of the human population. However, also recent and ongoing wars carry the risk of an uncontrollable increase in zoonotic diseases. The most significant zoonotic diseases reported during the recent wars are African swine fever, highly pathogenic avian influenza, rabies, leptospirosis, and brucellosis, as well as foodborne and waterborne zoonotic diseases. Indeed, alarming rates of infections by antimicrobial-resistant pathogens such as Mycobacterium tuberculosis go along with wars, as seen in the current Ukraine-Russia conflict. Considering human migration, foodborne and waterborne zoonotic diseases are key health threats for refugees due to the consumption of unsafe food, lack of safe water, and disruption of the water supply and sanitation system. This review summarizes the potential factors and some data associated with the increased risk of zoonotic disease emergence and transmission during recent and ongoing conflicts.