Friends, don't eat slugs and snails you find on trails in Hawaii. And while you're at it, make sure to wash lettuce leaves thoroughly to get rid of slug and snail excretions. Failure to heed these warnings could result in rat lungworms that dig into your brain and cause "neurological problems, severe pain and long-term disability."

From Ars Technica:

The Centers for Disease Control and Prevention confirmed three new cases in unrelated adults visiting Hawaii Island from the US mainland, the health department announced. The latest known victims—who became infected at different times—bring the state’s 2018 case total to 10 and the 2019 total to five. While there were 17 confirmed cases in 2017, the state counted only two cases total in the prior decade. The new case counts indicate a sustained boom in the parasite’s population and spread.

The parasitic worm in these cases is the rat lungworm, aka Angiostrongylus cantonensis. As its common name suggests, the wandering worm primarily takes up residence in rats’ lungs, where female worms lay their eggs. Young worms leave the nest early to find their own windy homes, though. Larvae get coughed up into rats’ throats then swallowed. The hosting rat eventually poops out the young parasites, which then get gobbled up by feces-feasting snails and slugs (intermediate hosts). When other rodents come along and eat those infected mollusks, the prepubescent parasites migrate to the rats’ brains to mature before settling into the lungs and reproducing. The cycle then starts again.

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If you have young children, it's highly likely that at some point you will be sharing your home with lice. Best to know your enemy. From KQED:

Head lice can move only by crawling on hair. They glue their eggs to individual strands, nice and close to the scalp, where the heat helps them hatch. They feed on blood several times a day. And even though head lice can spread by laying their eggs in sports helmets and baseball caps, the main way they get around is by simply crawling from one head to another using scythe-shaped claws.

These claws, which are big relative to a louse’s body, work in unison with a small and spiky thumblike part called a spine. With the claw and spine at the end of each of its six legs, a louse grasps a hair strand to hold on tightly, or quickly crawl from hair to hair like a speedy acrobat.

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A fellow was recently busted at Toronto Pearson International Airport for allegedly attempting to "import" 5,000 live leeches in his luggage. Apparently an airport security beagles sniffed out the parasites. From National Geographic:

The man claimed that the leeches in his possession were for personal use and that their waste water would enrich his orchids, (says André Lupert, manager of intelligence for the Wildlife Enforcement Directorate at Environment and Climate Change Canada, Ontario Region.)

To Lupert, that seems shaky. “This sort of leech quantity would suggest it was for commercialization,” he says, adding that the man could have been trying to find buyers for leech uses such as treating frostbite and helping with recovery from face lifts. Some people want leeches for naturopathic home use, believing that they relieve pain or can cleanse the body of “bad” blood. Without prescribed antibiotics, however, any such use carries risk of infections...

When Canadian officials seized 5,000 leeches, they were immediately confronted with a problem: what to do with them? They didn’t want to kill the threatened animals—especially while the case remained under investigation. “Ultimately it’s up to the judge if he wants to view the leeches in person because they’re viewed as evidence,” Lupert says. Nor did the authorities want to be saddled with them long-term. These species aren’t endemic to Canada, so they shouldn’t be released into the wild, Lupert says...

The Royal Ontario Museum agreed to accept 50 of the leeches, a researcher at the American Museum of Natural History took 1,000, and authorities are still looking for homes for the rest.

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Over five days, a 32-year-old woman in Russia took selfies to document a strange lump on her face that moved from under her left eye to above it and then later to her lip. She finally visited a physician who reported a "superficial moving oblong nodule at the left upper eyelid." Turns out, she had a particular kind of parasitic worm, Dirofilaria repens, living under her skin. From Live Science:

Humans are "accidental" hosts — in other words, not where the worms want to end up — and once a worm gets into a human, it typically can't reproduce.

The worms are spread by mosquito bites, and human cases have been reported in parts of Europe, Asia and Africa, the 2011 report said. The Russian woman said she had recently traveled to a rural area outside Moscow and was frequently bitten by mosquitoes, according to the new report (in the New England Journal of Medicine)...

The Russian woman had the worm removed and made a full recovery, the report said.

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Did you know you can get worms in your eyes? According to National Geographic, it's a thing.

Back in 2016, 26-year-old Abby Beckley ended up with a bunch of the tiny, translucent critters living in and around the delicate flesh of the inside of her eyelids. Beckley described the sensation of the eye worms nesting in her as being similar to having an eyelash poking her. After much prodding and poking, Beckley managed to extract a worm from her eyelid... and then another. In total, she wound up pulling five worms out of herself before deciding that maybe checking in with a doctor might be a good idea. Beckley was in Alaska at the time that she discovered the infestation. After an initial consultation with the doctors there, she decided to head to Portland to hook up with an ophthalmologist who was able to snag yet another worm from her and send it to the CDC for analysis.

It turns out that the worms living in Beckley's head are called Thelazia gulosa – a parasite normally found in the eyes of livestock. The parasites are spread to a host when a face fly lands on an eyeball, like Beckley's, and begins drinking the sweet, delicious tears that keep it lubricated. The parasites, which gestate in the digestive tracts of the face fly, get passed on to the owner of said eye, where they mature until, finally, BOOM: eye worms. 

By the time Beckley was declared free of the parasite, she'd pulled 14 of the little buggers out of her eyelids. Read the rest

A Colombian HIV-positive man who'd gone off his meds died when a tapeworm in his body developed cancer and spread tumors to his lungs. It's the first known case of a person dying of a disease that had infected their parasite. Read the rest

The deadly infectious diseases that were eradicated in America during the 20th century are now roaring back, thanks to growing poverty, failing sanitation, and underinvestment in science and health research and regulation. Read the rest

Toxoplasma gondii is a single celled organism that lives in the guts of cats and is spread to humans through contact with cat crap. About a third of the human population is infected with it. It resides in the brain and muscles, and doesn't always cause symptoms. But a new study at the University of Iowa and Florida International University has linked Toxoplasma gondii to reading and memory difficulties in children. The study also suggests that vitamin E can reduce the effects.

Infected rats are already known to lose their fear of cats, making it more likely that they will be killed and eaten. This is advantageous to the parasite, since it reproduces inside the intestines of cats. The organism's egg-like oocysts are shed in cat faeces which may then contaminate food or infect other animals. Some studies have suggested that Toxoplasma gondii can alter the behaviour of humans too, making men more aggressive and even causing women to cheat on their husbands. Other research has pointed to a strong link between the parasite and schizophrenia.

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Researchers at Washington State University found that Aka people of the Congo basin who smoke cannabis have "significantly lower rate" of parasitic worm infection compared to non-cannabis users. Read the rest

A great, full-body-squick-inducing article in National Geographic provides an overview of the current research on parasites that use a combination of techniques to control their hosts' behavior, making them sacrifice themselves for the sake of the parasites and their offspring. Read the rest

Thermalstrike's heated luggage has plug-in elements that heat the contents of your bag to 140F before you unpack them, which should theoretically kill any bedbugs that hitched a ride home with you from the road (remember to take out your toiletries and electronics first!). Read the rest

The Kite Patch is the subject of a very successful Indiegogo fundraiser, and holds the promise of a lasting peace between mosquitoes and humans. It bears a compound designed by UC Riverside entomologist Anandasankar Ray that confuses mosquitoes' ability to track and follow concentration gradients of CO2, which is how they locate humans. However, the product couldn't be marketed in the USA without further testing, hence the crowdfunding campaign, which will send thousands of patches to Uganda, where they will be used as part of a wider trial in fighting malaria and other mosquito-borne diseases. The actual nature of the compound is confusing: the Wired article describes it as both "toxic" and "nontoxic" and the crowdfunding FAQ calls it "nontoxic." Read the rest

Tracy Miller, New York Daily News: "Toxoplasma gondii, the parasite that causes toxoplasmosis, can cause health problems in anyone, not just pregnant women and those with compromised immune systems, researchers warn in a newly published paper." Read the rest

The Last of Us is a new video game about the zombie apocalypse. But not just any zombie apocalypse. The Last of Us zombies are based heavily, and accurately, on a genus of parasitic fungus that really does take over the brains and bodies of non-human animals like tarantulas and ants. Kyle Hill has a lot of delightfully horrifying things to tell you about this fungus at the Overthinking It blog. Read the rest

So, the downside is that you are being eaten alive, from the inside out, by a wasp larva. On the plus side, though, at least it has the courtesy to disinfect you as it goes along. At Nature News you can watch a baby cockroach wasp burrows around through the insides of an American cockroach, leaving a trail of clear, liquid anti-microbials in its wake. Read the rest

"Everything you never wanted to know about the mites that eat, crawl, and have sex on your face". How can you say, "No", to that headline?

Ed Yong has a great post up today at Not Exactly Rocket Science about Demodex folliculorum and Demodex brevis, two species of mites which spend their entire lives on human skin. Humans aren't born with these mites. But by the time you are 40 years old, it's almost guaranteed that you are playing host to a few of them.

The bad news: They are having sex on your face.

Their favourite hook-up spots are the rims of your hair follicles. After sex, the female buries into the follicle (if it’s D.folliculorum), or into a nearby sebaceous gland (if it’s D.brevis). Half a day later, she lays her eggs. Two and a half days later, they hatch. The young mites take six days to reach adulthood, and they live for around five more. Their entire lives play out over the course of two weeks.

The good news: They don't poop—in fact, they don't even have an anus.

The bad news again: All that waste just builds up in their bodies. Demodex are, by nature, chronically constipated. Only after they die, and their bodies disintegrate, do they finally get to let it all go. All over your face.

Read the rest of Ed Yong's piece Read the rest

At the Thoughtomics blog, Lucas Brouwers has a really nifty post on a recent discovery about the biology of pentastomes. What's a pentastome? Oh, I am SO glad that you asked.

Every animal has its own parasites to worry about, but canivorous reptiles and amphibians have to deal with particularly gruesome ones. They can become infected with small, worm-like creatures called pentastomes that live inside their lungs, where they suck blood from ruptured blood vessels. Reptiles pick up the parasite when they eat infected prey.

Pentastomes are true escape artists. Once they realize they’ve entered a reptile stomach, they use their sharp hooks to claw themselves a way to the victim’s lungs. In an experiment where pentastomes were implanted in a gecko’s stomach, the parasites invaded the lungs in as little as four hours.

Fun!

BTW: The image above, of a pentastome called Kiricephalus coarctatus, comes from a student page on the life and pests of the Western Cottonmouth snake. It's worth poking around that site, too. Read the rest