Two people in Los Angeles have been infected with a raccoon-borne parasite that can burrow into the brain and cause blindness.
The individuals, who were not identified, live in the South Bay region and have been diagnosed with Baylisascaris procyonis — or raccoon roundworm.
Raccoon roundworm is a common parasitic infection among raccoons, where a worm infects their intestines and has its eggs expelled in their feces.
But the infection is rare in humans, with officials in the county saying the risk to the public is currently ‘low.’
However, they are warning the public of the raccoon-carried parasite following a spike in rabid raccoons earlier this year and because the animals are increasingly seen in neighborhoods where people have a higher risk of coming into contact with them.
Raccoons are increasingly appearing in neighborhoods, raising the risk that people could come into contact with them and get infected (stock)
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No further details were revealed about the patients, including their ages, genders and symptoms they had suffered.
However, symptoms of an infection with the parasite include a mild fever, fatigue or nausea but can quickly progress to neurological symptoms.
In severe cases, damage to organs can be so severe that patients die from the disease.
A spokesperson for the county said: ‘The confirmed cases of this rare infection are an important reminder for all in Los Angeles County to take precautions to prevent the spread of disease from animals to people.
‘While [raccoon roundworm] is rare in people… it is concerning because a large number of raccoons live near people, and the infection rate in raccoons is likely high.’
Only 23 cases of raccoon roundworm in humans have been recorded in medical literature to date, of which six patients — 26 percent — died from the disease, but doctors say the number of cases is likely a vast undercount because the infection is often misdiagnosed.
Other patients have been left with life-long disabilities including blindness and brain damage.
Previous cases in the US include a teen from Brooklyn, New York, WHO in 2009, was blinded in one eye, and an infant who suffered brain damage after catching the disease.
In 2021, a one-year-old boy in Canada became infected after eating raccoon feces from a garden flower pot. He was quickly treated and suffered from no long-term affects.
The above graph, from the CDC, shows the life-cycle of raccoon roundworm
Estimates suggest about 40 to 60 percent of raccoons are infected with the raccoon roundworm parasite.
It causes no symptoms to the animals, but they can pass it out in their feces — with humans then picking up the eggs if they come into contact with the droppings.
Rarely, dogs can serve as a host for Baylisascaris procyonis.
After a person accidentally ingests the eggs, the parasites hatch in their intestines and migrate to the bloodstream.
From there, they travel to organs including the liver, lungs, eyes and brain and tunnel into them — causing inflammation and damage to the surrounding area.
Symptoms can appear one week to one month after being infected.
Raccoon roundworm is diagnosed via tests to rule out other diseases. There is no specific test available for raccoon roundworm.
Treatment should be prompt and includes taking the anti-parasitic drug Albendazole. If administered rapidly, patients can suffer no ill effects.