It is a place both sublime and terrible, of Miltonian, or Tolkeinesque romance, even. In the core of Kenya, paradoxically humanity's purported first
home, and yet still among the most savagely primal places in the world, is Kitum cave.
Volcanic vents full of sulpherous exhalations. An ancient caldera. A vast elephant bone-yard at the bottom of a massive chasm. And all of this
penetrating into the core of Kenya's 2nd highest mountain- Mount Elgon.
Kitum cave is the cumulative result of several natural forces working in concert over millions of years. The volcanism that helped build the mountain
also left it penetrated by intricate tunnel lattices whose extents are both vast and unknown. More recently, the mountain has been excavated by
elephants, who sought the salt deposits left by mineral erosion and bat guano. The elephants have expanded what are thought to have been originally
very small entrances into vast caverns. The bones of many elephants unable to navigate the pitch-black depths are scattered over the bases of several
great drops. The large parts of the cave which humans have been able to explore extend around 200-300 meters into the mountain, however vast,
unknowable tube networks are believed to penetrate all through the mountain, and are likely home to bats and invertebrates living in a soup of
detritus and guano.
These caves have long been believed to be the incubation reservoir to many infectious diseases, most prominently the Marburg and Ebola Viruses, and
with good reason; Mount Elgon is at the middle of the greatest number of the recorded outbreaks in Kenya. Bats and monkeys in the area have been
anecdotally implicated in spread of the diseases nearly every time.
Just as the caves extend far beyond human knowledge, so too the life cycles of these two infectious agents. There are several candidates for the chain
of carriage, however. Bats are clearly believed to play a core role in any hypothetical chain. They are believed to possibly not suffer from these
diseases, but may be host transmitters that pass on the virus through biting other animals or humans, or in some cases being consumed by locals as
"bush meat".
Even though they are the probably a major intermediary, that bats are unlikely to be the primary reservoir. That is more likely to be the thousands of
species of arthropods that inhabit the cave. Mites, insects, small crab-like creatures, and many others living in and consuming the bat guano soup,
especially hematophagus (blood consuming) arthropods have kept the viruses in their stores from time immemorial, and will continue to do so for
millions of years, most likely. These viruses may even have started as breakaway chunks of plant DNA that entered the food chain at some unknown time
in geological history. How the viruses first got there is unknown, however Kitum cave and several places like it will hold the diseases in their
biological banks essentially forever.
Let us hope that this current outbreak can be contained well before it reaches the CDC's "worst case" 1.4 million infection scale projected for
January, because Ebola, or Marburg, whatever this actual strain turns out to be, will become a permanent part of the human ecosystem, just as it has
lived in the biological memory of places such as this. It is my belief that the outbreak will still be primarily be limited to Africa, not because of
the argument that lack of proper medical facilities has led to a more acute spread, but rather because the life cycle and propogation is probably
still intimately dependent on the chain of infection between the bats and the associated arthropods that serve as the reservoir. But as people say,
with the rate of mutation being what it is, this is not unfortunately a foregone conclusion.
Read more about the role of these caves in the outbreaks centered around them in the Oxford Journal of Medicine and Infectious Diseases:
jid.oxfordjournals.org...