Anyhow, this week's lovely parasite is worth the wait.
Meet the Loa Loa worm.
Loa Loa worms ( Loa Loa filaria) are a kind of filarial nematode which is spread by fly bite. Filarial nematodes are a lovely bunch of parasites, resposible for wonderful diseases like Elephantiasis - but I'll get into that one another day. They all have similar life cycles: first, as a lovely adult in the host of choice (like us), the male and female nematodes mate and produce lots of adorable little larvae called microfilariae. These take up residence in the fluids of the body, usually the blood, but they can be found in spinal fluid, lymph, urine, and just about anything that flows. From there the micro worms are picked up by the transmitting host, usually a blood sucking insect. In the fly they wiggle a bit, go through a few larval forms, and finally end up ready to infect the next person. They wait for the bug's next meal, and when opportunity knocks, they swim on in to the new host and migrate to wherever they live to find more nematodes to make more little microfilariae.
Now, in the case of other filarial nematodes, its those darned babies swimming around that cause most of the problems. But in the Loa Loa worm, the more noticable pest is the adults. See for yourself:
Yeah, I probably should have mentioned that the Loa Loa is also called the "African Eye Worm".
The adult worms live in the subcutaneous tissues, where they move about quite a bit, often crossing areas like the eyeballs and nose.
12-13 million people are infected with Loa loa larvae. There is a treatment, a drug called diethylcarbamazine, but it isn't a nice one. It comes with a whole host of its own possible complications, especially in patients who have high parasite loads, and the only other treatment options are chemotherapy and surgery. For that matter, the little larvae cause quite a bit of trouble themselves. They get all around the body, causing immune reactions simiar to allergies, and can even get in the brain and cause fatal swelling there.
So, as you can see, they're a lovely little parasite - if you like sick, twisted, sci-fi creatures. They fit right in among the worst mental creations ever imagined.