The importance of long‐term studies on wildlife diseases and their interfaces with humans and domestic animals: A review

Long‐term wildlife disease research (LTWDR) and its interfaces with humans and domestic animals provide perspective to understand the diseases’ main drivers and how they operate. In a systematic review, we analysed the temporal trend of the studies on LTWDR, their aims, and the hosts, pathogens and geographic areas studied. We also evaluated the added value that such studies provide. For analysis, we selected a total of 538 articles from 1993 to 2017 with a study period greater than or equal to 4 consecutive years. A marked increase in the number of studies published during the last 20 years was observed that reflects a growing awareness of the outstanding role of wildlife as a reservoir of diseases. The most studied pathogen agents were viruses (39.2%), bacteria (38.5%) and protozoans (15.8%). Concerning the hosts, mammals (84.9%), particularly ungulates (40%) and carnivores (30.9%), and birds (12.5%) were the most represented in these long‐term studies. Most articles reached conclusions concerning the effect of the disease on the infection/host dynamics (98.7%) and over 40% considered the economic consequences or proposed management and control measures. The research was mainly located in the Northern Hemisphere. While the definition of LTWDR is not only determined by the duration of the monitoring, the study must be long enough to: (a) address ecological and epidemiological questions that cannot be resolved with short‐term observations or experiments, and (b) clarify the effects of different drivers. This review demonstrates that LTWDR has provided information about the causes and consequences of disease change that otherwise could not have been obtained. It may be used to inform decisions related to the emergence of disease and might help to design early warning systems of disease based on retrospective investigations.