Emergence of vector-borne diseases during war and conflict

Throughout history, the deadly comrades of war and disease have accounted for a major proportion of human suffering and death. During conflict, human populations are often suddenly displaced, associated with crude mortality rates over 60-times higher than baseline rates. Promoting factors like mass movement of populations, overcrowding, no access to clean water, poor sanitation, lack of shelter, and poor nutritional status directly result in rapid increase of infectious diseases, especially measles, respiratory tract infections as well as diarrhoeal and vector-borne diseases.
In 26 out of 53 retrospectively analysed wars from 480 B.C. to 2002 A.D., vector-borne diseases like plague, louse-borne typhus, malaria, yellow fever, relapsing fever, scrub typhus and visceral leishmaniasis prevailed, or essentially contributed to, overall mortality. During the last decades, devastating war-related outbreaks of malaria, louse-borne typhus, trench fever, African sleeping sickness, visceral and cutaneous leishmaniasis and dengue fever have been reported. According to the humanitarian imperative to protect, or to re-establish, the health of the affected population, essential medical entomological expertise has been involved increasingly in complex emergencies in order to analyse transmission modes as well as the epidemiological impact. Adequate countermeasures, such as entomo-epidemiological near-real-time surveillance, personal protection against arthropod vectors and vector control efforts have to be initiated and implemented subsequently, aiming at rapid as well as efficient identification and interruption of transmission cycles. Recent experiences made during deployments and emergency situations reveal that more medical entomological expertise and involvement is necessary to successfully react on future disease threats.