Why We Need to Change How We Combat Rabies | Nat Geo Live

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Daniel: This is a bat that feeds exclusively on blood, as the name implies. And the way that that bat feeds is to make a razor sharp incision into the animal that it is feeding on and then it uses a specially grooved tongue to lap up blood.

That's not it, because these bats also have anti-coagulants in their saliva which keep that blood flowing. After they finish eating, they can just hop up into the air, which is really unusual for a bat; most have to climb up onto something. So, all of these traits make bats incredibly good transmitters of the rabies virus.

Rabies has been described in ancient Chinese and Arabic texts as an incurable wound resulting from the bite of a rabid animal. That incurable part of rabies is still true. We still don't have a treatment for people once they start to show signs of rabies.

Even by the most rudimentary standards that we have now, one person still dies of the disease every 15 minutes, and another 300 are exposed. We are talking about 50,000-60,000 people dying every year.

The natural response of the people that are affected by this is to kill bats. The state sanctioned way of killing bats is using a poison called vampiricide.

Where essentially a poison is mixed together with Vaseline and that's spread on the back of a bat. They release that one; it flies back to its roost. And the other ones groom it off, ingest the poison and die. Sounds straightforward enough.

Unfortunately, there's not really much evidence that it's doing anything to control rabies. One of the first questions that I wanted to ask was why is it that this conventional wisdom, that the only good bat is a dead bat, isn't actually doing its purpose.

So, one of the most, I think, innovative and exciting ideas we've had in the last, really, six months is whether we can replace the poison that's used in the vampiricide with an oral rabies vaccine.

In Peru, we're in a spectacular situation to be able to try this. We've recently detected that there are actually travelling waves of rabies moving down different valleys of the Andes. So, you can actually see this on the map; where the dark points are the old rabies cases, the light points are the new rabies cases.

And we see them in a very step-like manner moving through these valleys. That is powerful. That allows us to tell farmers, "Okay, you're going to have rabies. You don't have it now, but you will in a month; you will in six months; you will in a year."

That allows them to make an informed decision about vaccination. Second, this is a really powerful experimental opportunity. We can consider this valley, and there are several others like it; we can consider these as experimental replicates.

Can we try vaccinating at various stages in the valley or across different valleys and compare that with other types of interventions? And say what works, what doesn't... can we use science to figure this out?