Herpes in Marsupials
In 1975 a group of captive Parma Wallabies started to seemingly die for no reason and the remaining population appeared to all come down with an unknown disease.
So, in 1976 Doctors Finnie, Littlejohns and Acland studied the remains of this population and this led to the discovery of MaHV-1 or Macropodid Herpesvirus 1.
The affected wallabies exhibited abnormalities, including rhinitis, conjunctivitis, pneumonia, cloacal ulceration, and variable splenic, pulmonic and hepatic necrosis.
Since then, multiple types of herpes virus have been discovered from further outbreaks in mostly captive but some wild populations:
- Macropodid herpesvirus 2 (MaHV-2)
- Macropodid herpesvirus 3 (MaHV-3)
- Macropodid herpesvirus 4 (MaHV-4)
Those viruses have been found in several marsupial species to date.
Most marsupials are now considered vulnerable due to habitat loss from fire/ urbanisation/ climate change, introduced predators like cats, inbreeding from the populations being isolated and disease spread.
MaHV-3 and MaHV-4 have recently been found in wild populations Eastern Grey Kangaroos which may impact free living populations due to the respiratory disease associated with the disease.
Which led to the 2010 - 2015 study Prevalence and Clinical Significance of Herpesvirus Infection in Populations of Australian Marsupials. Quite the name.
For this study they studied 99 Koalas, 96 Eastern Grey Kangaroo, 50 Tasmanian Devils and the 33 Wombat all got tested. Some were free range, but most were captive animals.
Cotton swabs were used to take samples from the eyelids, nose cavity, mouth and some blood samples were taken.
What did they find:
3 novel herpesviruses in wombats. The wombats have a 17 times higher chance of having one of the herpesviruses. This could be from urbanisation making wombats co-habitat more often.
The Tassie Devils didn’t fair too bad for herpes; on the facial tumour front they aren’t doing too well though. Herpes was detected in only 34% of the evaluated animals, this was the first time that it had been found in the species. It also found that captivity was a major factor in the disease spread for them. It could be from the increased stress or shared eating arrangements; but they did confirm more research was needed.
Now we get to the poor kangaroos. They found a high prevalence of one or more of the herpesviruses in both captive and non-captive kangaroos. This could be due to many factors: being herd animals, sharing feeding spots and environmental destruction causing them to group together.
Now what was the point of this study. Because there is a point.
It was to do with disease spread in marsupials in captive environments. Zoos for example have a lot of different species of animals and some diseases can easily jump in between species and destroy a population. These types of environments allow for increased rates of transmission and potentially higher stress levels in the captive animals. And as we know stress is a main cause of cold sores for us, so for them as well.