The story behind the river blindness story: itching, weeding, snipping

When the Nobel for Medicine goes to two scientists who discovered a drug used to fight a variety of neglected diseases, how do you tell the story? NPR's Jason Beaubien decided the best way was to go to one country where the drug – ivermectin — has made a major difference in people's lives. That's what took him to Ghana, where yearly doses of ivermectin have dramatically reduced the scourge of river blindness, a disease caused by parasitic worms that can rob people of their sight. So ivermectin is a versatile drug?

It works on a bunch of different diseases. In addition to river blindness, the other main neglected tropical disease it's used on is elephantiasis, that awful swelling of the legs. And my wife even uses it to rid our horses of worms. It's effective against a large number of roundworm parasites.

And why Ghana?

I didn't want to go somewhere where river blindness was almost entirely wiped out, which is the case in most of Latin America and some places in Africa. And I also didn't want to go someplace like the Democratic Republic of Congo, where there hasn't been very much progress. I wanted to go somewhere where this drug was having an impact right now.

Does river blindness always cause people to lose their sight?

It does not. You can get a more mild form. Some people's bodies do a better job of suppressing it.

And more people end up with horrific itching all over their body and disfigured skin than full-on blindness.

How awful is the itching?

People say it's just completely obsessive, they are seeking some way to tear their skin off. Some people would take a red hot poker out of the fire and push it onto their skin and just scratch to the point where their skin was completely raw.

Does ivermectin help with the itching?

Ivermectin does help, but in an awful twist of fate, it makes the itching incredibly worse right after you take the tablets. The itching comes from the baby worms dying underneath the skin. Ivermectin kills them, so someone who has a lot of parasites will go through a terrible phase of being incredibly itchy. But after a few days, the itching will go away.

That initial increase in itchiness must have made people reluctant to take ivermectin.

The drug initially had this reputation of being something of a problem, but people soon realized it made them feel a lot better.

You interviewed Emmanuel Kwame, who lost his sight to river blindness when he was a young man and today, in his 60s, lives an independent life as a farmer and fisherman. He seems like an amazing individual. And not bitter.

He has figured out how to live with this disability. And he still has things he wants to do. He wants to get some pigs, he thinks raising pigs would be good, he'd started building what's going to be a pig pen.

And he grows vegetables. How does he manage?

I like to garden, and I asked him, "How do you know what is a weed and what isn't?" He said he puts little pegs in the ground in straight lines right next to where he puts the seeds. And anything that grows next to those pegs, he knows is the plant he wants. He weeds everything else.

Do you tell your kids about the lives of people like Kwame?

My kids have gotten a little sick of me telling them of how much better they have it than a lot of people in the world. But I'll tell other people about this guy, especially his ability to fish without any eyesight.

Any other details about river blindness you'd like to share?

It's been incredibly difficult to get accurate data about cases because the test for whether or not you're infected has been this thing called the skin snip.

Snip?

Yeah, snip. To see whether people really have the parasites, the only test available has been this process where you cut off a sliver of skin in several parts of the body, usually someplace where the bone is close to the surface like the hip or the shoulder blade, and you throw that bit of flesh into salt water and you can see the parasites come out if they're present. That has been the way to test for river blindness.

I can only say: Oh my! Any new tests in the pipeline? Some people at PATH in Seattle — they develop new diagnostics — have come up with a single prick blood test. It's not yet been rolled out in Ghana but people there are incredibly excited to have a simple test.

So in this final push toward eradication, they'll be able to monitor whether the village has gotten rid of river blindness or not. Because the skin snip is not practical – it's too invasive, too difficult, too painful.

Join Us For A Twitter Chat On River Blindness

Want to know more about river blindness? Dr. Neeraj Mistry, the managing director of the Global Network for Neglected Tropical Diseases, will be taking your questions on Twitter on Friday, Jan. 22, from 11 a.m. to 12 p.m. ET. Leave your questions in a comment below, or tweet them to @NPRGoatsandSoda with the hashtag #RiverBlindness. Copyright 2019 NPR. To see more, visit https://www.npr.org.