It's time we talked about Ebola.

It's been in the news a lot, and for good reason - it's one of the deadliest diseases humanity faces (the second deadliest, technically) and it's making a stand in west Africa. Plus, for the first time, two US citizens with the disease have been flown home for treatment. But don't bar the doors and windows or get yourself whirled up into some kinda 2006 bird-flu hysteria because we've met Ebola before, and we're learning more about it than ever.

(Intro)

It used to be known as Ebola Hemorrhagic Fever, more recently the Ebola Virus Disease, but what the media have lately been referring to simply, and sometimes hysterically, as Ebola is really one of at least five known species of the Ebola virus. What they're referring to is the most dangerous species known as Zaire Ebola Virus or ZEBOV, named after the central African country where it was first discovered in 1976 along the banks of the Ebola River.

It's in the news because it has infected more people this year than it has any other year since that first outbreak. So far in 2014, it has infected 1,323 people, 729 of whom have died. And the virus has moved into some of West Africa's major population centers, including countries like Guinea, Liberia, Sierra Leone, and possibly the Nigerian capital of Lagos.

So, it's newsworthy for sure, and for plenty of reasons.

According to the World Health Organization ZEBOV has an average fatality rate of 83%, but in some outbreaks it has killed more than 90% of the people it infected.

Ebola is a type of hemorrhagic fever, which means that one of its most prominent symptoms is heavy bleeding, either internally or externally, but blood loss isn't what kills its hosts. After causing flu-like symptoms like vomiting and diarrhea, ZEBOV targets the entire circulatory system, causing blood vessels to fail, blood pressure to drop and, eventually, all of the major organs to shut down.

But let's check our heads for a minute.

For one thing, Ebola is definitely contagious, but it's not as easily transmitted as, like, the flu. It's not an airborne disease; it's only contagious by infected people that are exhibiting symptoms at the time, and even then it can only pass through close contact with body fluids. That's why most of the people getting infected are healthcare workers working in pretty austere conditions, or family members of patients who treat their loved ones at home and prepare the bodies for burial. Being on the same airplane or in the same hospital ward as an Ebola patient doesn't mean that you have automatically been exposed to the virus.

And, in another little glimmer of hope, it turns out that some people have developed a natural immunity to Ebola. A study in 2010 found that more than 15% of people in the West African country of Gabon carry antibodies for the ZEBOV virus, even though there is no record of an Ebola outbreak there. Researchers think that those people were exposed to the virus over decades, probably through fruit that had been contaminated by bats, which were the original carriers of the disease, but instead of getting sick, these people just developed natural defenses. We're not sure why, but as you might imagine there is a lot of scientific interest in the people of Gabon right now.

And of course, there is no vaccine for Ebola, but many prototypes are being developed. You may remember news we shared last year about a breakthrough in this effort (link 03:09). Biologists in Boston found that cells treated with a kind of compound called Indoline Alkaloids blocked the ability of the Ebola virus to replicate itself. These alkaloids are the same class of chemicals that give many plants their medicinal properties... the trouble is scientists haven't figured out why they work or how to turn them into an effective Ebola treatment.

But even beyond the short-term risks of the current outbreak, it's worth looking at the bigger picture.

The figures coming out of West Africa, while scary and tragic, pale in comparison to other public health crises in the region. Last week, I mentioned that the incidents of HIV in sub-Saharan Africa is still over 12% in some countries, and more than 1.2 million people die from AIDS there every year. Meanwhile, over 600,000 deaths occur every year due to malaria.

The more attention that all of these public health crises get, the better. So maybe the best outcome of this current scare might not be the better treatment of Ebola, but also more money, science and brainpower being devoted to conquering even bigger threats in West Africa and in other parts of the world.

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