West Africa's Ebola crises edging towards a human catastrophe, scientist warn

Andrew Fazekas
Geekquinox
West Africa's Ebola crises edging towards a human catastrophe, scientist warn

As the Ebola epidemic is about to reach 3,000 deaths and over 6,200 confirmed cases according to the World Health Agency, the frightening disease is now spreading exponentially and has scientists deeply worried as to how far this health crisis will spread.

“We are at this point well past the total number of human cases in all of human history,” said Brian Ward, a world expert on infectious diseases at McGill University.  

“This is the first real attempt of Ebola to enter the human population.”

According to the latest sobering statistical forecasts released this week by the U.S. Centers for Disease Control and Prevention (CDC), Ebola could spread out of control and claim hundreds of thousands of lives and infect more than 1.4 million people by the end of January.

If the computer models created by epidemiologists with the Virginia Bioinformatics Institute hold true - the models upon which the CDC is basing their own predictions - then the number of cases can be expected to drastically skyrocket beyond all previous expectations.

Up until these new figures were released this week health officials were publicly proclaiming that the epidemic could be brought under control in a matter of 9 months with case numbers topping out at 20,000. But now the new epidemic models show that this number could be reached in as little as a week’s time. And the world may be battling the virus for years if not decades to come.

Governments have been hoping like every other time Ebola will burn itself out. Concerns now however are that because its a virus that is spreading fast and can mutate easily - it may become more dangerous than ever.

“The huge fear is that Ebola will mutate in a way that will allow it to be spread by the respiratory route,” said Ward.

“Right now it spreads by direct contact, but its entirely within possibilities that it will mutate and spread by aerosol through the respiratory route.”

Viruses can replicate only when they have snuck into host cells. Viruses like Ebola - which include influenza, mumps and the common cold for instance, are classified as RNA viruses - meaning they have single stranded nucleic acids as their genetic material they use for reproduction.

Turns out when this genetic material replicates there are a certain level of mistakes that can be made. Viruses with double-stranded DNA have edit checks to make sure its correct and if it isn’t it tries to fix it. But RNA viruses, like Ebola, have no editing systems so they just make whatever they make and so when they make a mistake that virus is either a dead end because the mistake is fatal to the virus or its a successful mutation.

“Ebola appears to have a very well defined and fairly high rate of mutation,” said Ward.

“So now you have thousands of people, each [of them] an incubator producing a trillion Ebola viruses which means you have a lot of errors, a lot of mutations and that means its mutating really quickly compared to anytime in the past.”

Fears of airborne transmission of Ebola is nothing new. Back in the late 1990’s another species of the Ebola virus found in macaque monkeys from the Philillipines, showed signs of being passed through aerosol. Luckily they were not dangerous to humans.

However Ward and many other experts believe that it’s more likely that the the current African Ebola virus will mutate towards attaining a better transmission, like influenza, where it can be spread through casual close contact, but not necessarily physical contact.

“That I think is more likely and more feared, and if that happens in these huge African population centres it could become endemic,” he warned.

“If it mutates so that it’s more easily spread amongst humans it could simply become a disease that is always there at a low level.”

One possibility is that Ebola may sweep through west Africa and kill a very large proportion of its people, but the survivors and their offspring would become relatively resistant.

An example of this can be seen with the measles today.  It’s not really considered a dangerous virus now,  but when it first entered the Americas thanks to the Spanish Conquistadors centuries ago it had a 50 percent mortality rate, explains Ward.

So what we are seeing today are the descendants of those survivors of what was a 50 per cent die-off from the disease, he said.

“This may be a possible scenario we could see come around this time with Ebola - because clearly not everyone is dying from it and if you live it’s probably because you were genetically suited better to survive,” he added.

Ebola jumping out of Africa is the fear many have, but Ward believes that would really only happen if it mutates into a form that is more transmissible, which may never happen.

But this is a scary virus even to researchers since we know already that its Asian cousin can be spread by aerosol. 

“The wrong set of mutations in this virus and it could circle the world at which point our hesitancy and lack of action early on will surely haunt us,” said Ward.