Tracking virus gives insight into lion life
Johannesburg - How do the lion prides of the Kruger National Park interact with each other? A mysterious disease is offering clues: cat HIV.
A team of researchers at Stellenbosch University and SANParks is using the Feline Immunodeficiency Virus (FIV) to understand how widespread the disease is among lion populations in the Kruger, and how it affects various lion prides.
FIV resembles HIV so closely that both diseases have similar symptoms: wasting, immune depletion, oral lesions caused by opportunistic infections, renal disease and chronic inflammation.
Numerous strains are found among members of the cat family including cheetahs, pumas and leopards, and these strains seem to be host specific. But little is as yet known about its presence and effects in wild populations such as lions.
“The work now being done will extend our knowledge about how widespread the disease is among southern Africa’s lion population, and in the process how different prides interact,” said Dr Danny Govender of scientific services at SANParks, who approached Stellenbosch University to conduct the research over a year ago.
She is fascinated how FIV, so like the HIV virus, has a different transmission rate. “It looks like the predominant route of transmission is bites and scratches among lions, unlike HIV, which is mainly sexually transmitted in humans.”
Researcher Tanya Kerr said the social behaviour of lions suggested that if one member of the pride was infected with the virus, “most, if not all, adult members will be infected regardless of pride size”.
Kerr is a conservation ecology masters student at the university who is studying the spread and rate by which various subtypes of this virus occur among the prides in the Kruger.
FIV is transmitted by fighting or other aggressive encounters between members of the same cat species through saliva and blood. It is not harmful to humans.
“We still don’t know whether the mother-to-cub route of infection plays a role in the virus transmission, which is recognised as an important transmission route with HIV, but prevalence patterns seem to suggest otherwise in lions,” said Kerr.
“Provided that their home ranges overlap, it is expected that prides in close proximity will also share similar viral subtypes through inter-pride contact. Prides that are in contact with more than one other population might even be infected with multiple viral subtypes,” Kerr explained. “We therefore expect that with increasing distance between prides, the viral subtypes which they carry will become more and more dissimilar.”
Sonja Matthee, of the conservation ecology department, added: “We’ve all seen how lions lick a carcass before they eat. What often happens is that a lion is pushed out by another individual.
“The second one is feeding where the first one was and potentially has the virus. So, within the pride, while they are feeding, there is transmission. That is going to be more than compared to lions mixing with each other. Within a pride, there is lots of sharing.”
The virus is expected to be more prevalent in the south of Kruger because of the higher density and smaller home-range sizes of lions, which increases the chances of viral transmission. The chances are also higher that the prides will infect each other.
“We also expect the virus to be more prevalent in adult males because viral prevalence increases with age,” Kerr said. “Males tend to spend more time away from their prides either as territorial males or nomads, and thus have more chances of being in contact with other lions.”
Matthee added that the virus could be used as an indicator of how the lions in the Kruger were moving. “You are using the virus because it is mutating much faster than a lion would produce offspring… to track the movement of the host and see which prides are interacting. You can probably also use this research as a model for controlling and managing diseases within our large nature reserves.” - Saturday Star