Understanding bacterial zoonotic disease infection and its severity on wildlife populations

Background/Question/Methods

Emerging infectious diseases have significantly increased in recent years; approximately 60% of these emerging diseases are of zoonotic origin, and of those, around 70% were identified to start with wild animals. Zoonotic diseases not only negatively impact humans but can have detrimental effects on wildlife populations as well. For example, the Zaire strain of Ebola virus was found responsible for the death of over 5000 gorillas in 2002 and 2003. Despite the detrimental effects zoonosis' can have on wildlife, most zoonotic disease control programs seek to mitigate the risk to humans, while wildlife conservation is a secondary concern if a concern at all. We sought to determine whether species of conservation concern more likely to be reservoirs of zoonotic diseases and the effect of these zoonoses on animal welfare. To comprehensively review the literature and construct a database of clinical symptoms associated with bacterial zoonotic infection for each species. To quantify animal welfare, we developed a severity index using ranked clinical symptoms scores. We then performed chi-square and ANOVA statistical tests to determine the relationships between conservation status and genera on stress and presence on bacterial zoonosis.

Results/Conclusions

Preliminary chi-square results found that the presence of bacterial zoonosis were significantly higher in species of least concern (X²=586, p < 0.001) than those carried by species of conservation concern. However, we did not find a significant difference (F(1278,1)= 1.199, p = 0.274) in pathogen load between species of conservation concern and least concern. Understanding the impacts of bacterial zoonosis on wildlife populations can help in planning for future wildlife management, particularly in species of conservation concern. Zoonosis’ are a threat to species of conservation concern (i.e., near threatened, vulnerable, endangered, critically endangered, or extinct in the wild). As travel of people and domesticated animals expands, there is a greater risk of zoonotic disease exposure to endangered populations, underscoring a need for zoonotic disease management in species of concern populations. To better understand the impacts of zoonotic diseases on wildlife, there is a need to identify the number of zoonotic pathogens that can infect wildlife and evaluate the subsequent severity of these pathogens to individual wildlife species.