Disease invasion, multi-parasite interactions and conservation: Rift Valley fever and bovine tuberculosis in African buffalo in Kruger National Park, South Africa

Background/Question/Methods

The unprecedented increase of emerging infectious diseases in conjunction with anthropogenically induced range shifts of endemic pathogens exposes hosts to novel parasite combinations, lending urgency to research on disease dynamics in wildlife systems . Most ecological studies focus on single infections and fail to consider that most free-living populations are exposed to and are infected with multiple pathogens at one time.   Fundamental theory in ecology and immunology suggests that pathogens sharing a host should interact strongly – begging the question of how they mediate one another’s dynamics.We are investigating interactions between the bacterial disease bovine tuberculosis (BTB) and the native viral disease Rift Valley fever (RVF) in a competent reservoir host, African buffalo at Kruger National Park (KNP), South Africa.

Results/Conclusions

.  African Buffalo previously infected with BTB are more likely to subsequently acquire RVF; both in a captive population and a wild population.  In addition coinfected buffalo are twice as likely to exhibit the clinical signs of RVF (abortion) than buffalo singly infected with only BTB.  Therefore, invasion of a non-native infection such as BTB may thus secondarily alter the dynamics of native infectious diseases in free-ranging wildlife populations.