BOB BROCKIE
Last updated 05:00, April 30 2018
Possums in Australia are spreading a hideous human disease called Buruli ulcer.
The
disease usually shows up as a tiny swelling on people's legs and arms,
growing to produce big edematous, pus-filled abscesses, devouring flesh
to the bone and, in the worst cases, leading to excisions, skin grafts
and amputated limbs. Youngsters are more at risk than older people.
Mycobacterium ulcerans – a bacterial cousin of human tuberculosis, bovine Tb, and leprosy – causes Buruli ulcer.
The
disease is commonest in Africa but infects thousands of people every
year in 30 other mainly tropical countries, including Indonesia and New
Guinea. There is no effective vaccine against the disease but
antibiotics are effective if it is diagnosed early enough.
Buruli
ulcer was first identified in the outskirts of Melbourne in the 1930s
and remained localised there until 2009, when it unexpectedly turned up
in North Queensland. The Australian Medical Journal now reports a worsening epidemic with 17 cases in 2009 but 275 cases last year.
In
its African homeland, the disease usually infects poor people living in
remote areas, and is often associated with swamps and wetlands,
flooding, new irrigation systems, and dam building. Throughout Africa
and elsewhere, the ulcer bacterium has been found in small aquatic
insects known as "creeping water bugs" and they may play a part
as spreaders of the disease. But nobody knows for sure.
In
Australia, scientists have struggled to understand how the disease
reached their country – from Africa, New Guinea, or elsewhere? How did
it spread from Melbourne to Queensland?
How did it infect possums,
koalas, and bandicoots and fill their guts and droppings with millions
of ulcer germs? How does it spread from marsupials to people?
The
germ has been found in the salivary glands of some Australian mosquitoes
so they are under suspicion as possible vectors. But, again, nobody
knows for sure.
Luckily, Buruli ulcer has not reached New Zealand,
but we must keep our eyes open for its appearance. If the disease can
jump more than 3000 kilometres from New Guinea to Melbourne it could
conceivably jump 4000km to NZ.
Source and painfully cute possum photo: https://www.stuff.co.nz/science/103386411/bob-brockie-possums-spreading-flesheating-disease-in-australia" rel="nofollow - https://www.stuff.co.nz/science/103386411/bob-brockie-possums-spreading-flesheating-disease-in-australia