Every time we think we've nailed rainforests, having gained a good understanding their make-up, their function, their flora and fauna, some news comes along to show we really only know the tip of the iceberg.
As reported by Science magazine, it looks like the deadly disease Anthrax, rightfully feared across the world, is playing out its dreadful game in the beautiful Taï National Park in Ivory Coast. Anthrax is killing chimps, and Ph.D. student Fabian Leendertz and his team have been observing it happening. But this is no ordinary Anthrax. It's different, and it means an unexpected killer is on the rampage in the rainforest.
Chimps under threat from Anthrax
In a research paper published recently in the magazine ‘Nature', the team reveals how the Anthrax microbe, AKA Bacillus cereus, plays a vital but grim role in the rainforest's ecology. It causes a high percentage of mammal deaths and is thought to be threatening the chimpanzees in Taï to such an extent that they might actually go extinct.
All this is happening against a background where hunting and deforestation have already brought the local chimpanzee population to the very edge of extinction. Diseases like Anthrax and Ebola, as well as respiratory diseases introduced by humans, might tip them over the edge.
The B. anthracis microbe we know and fear usually kills wild animals in dry areas, not rainforests. The research team investigated, and soon linked the chimp deaths to the closely related B. cereus microbe, which is usually relatively benign. But the strain found in the Taï forest has morphed into something a lot more sinister, making it a formidable foe.
All 15 of the infected carcasses the team was able to study revealed the signs of a lethal Anthrax infection, including heavy bleeding and swollen lymph glands. But it also looks like some animals may merely act as carriers for the strain, with no symptoms developing.
Can the chimps of Tai survive?
Having simulated the new microbe's progress using a computer programme, the team showed that Anthrax has the potential to totally wipe out the Taï forest’s population of around 400 chimps within the next century and a half. Why it hasn’t already killed the animals off remains a mystery, but it looks like B. cereus has lived in the forest soils for a very long time.
While the standard anthrax vaccine protects against the Taï strain, there are signs that the vaccine might only be effective for a year, meaning that regular vaccinations would be needed. And nobody knows, yet, whether humans are immune, or how far the new pathogen has spread.