‘a worm just crawled across my eye!’

Saw the webpage headline

First thought: ewwwwww.

Second thought: ooooh, I wonder what that's all about?

Answer: a little filiarid worm.

FIliarid worms are roundworms (nematodes). I knew about the one that causes the disfiguring disease known as elephantiasis, but hadn't heard about the 'eyeworm', or Loa loa. Elephantiasis is due to lymphatic filiariasis, where the nematodes congregate in lymphatic tissue; L.loa causes subcutaneous disease. Apparently it often presents as 'calabar swellings', typically on the hands & wrists, but can also travel across the eyeball. I can only think that this must be both painful and incredibly disconcerting.`

While L.loa infection isn't itself life-threatening, that changes if someone is also infected with other parasites. As the CDC notes

[r]ecognition of Loa loa infections has become more important in Africa because the presence of infection has limited programs to control or eliminate onchocerciasis and lymphatic filariasis.

Both these other parasites can be controlled by dosing patients with a drug like Ivermectin. Unfortunately the drugs can't be used in someone with a concurrent Loa loa infection, because where an individual has a high load of multiple parasites, the treatment can cause severe encephalitis, coma, or death

So it's really exciting to hear that health workers can now use a microscope attachment (& relevant app) for a smart phone to screen people for this particular parasite 🙂 And can get results in 2 minutes or less, out in the field, with no need for a diagnostic laboratory. The challenge now is to scale up production of the technology in order to meet burgeoning need in Africa: 

Fletcher admits that for the CellScope Loa to be applied to the many millions of people in Africa who need ivermectin treatments, his lab will first have to figure out how to scale up the technology; right now, they’re assembling each scope by hand in the lab. Getting industry help could also be a challenge, he says. “It’s hard to entice companies to make devices whose very goal is to eventually eliminate the need for the device.”

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