By Victoria Lindrea
BBC News
A man in the US who complained of frequent migraines was found to have tapeworm eggs in his brain, likely linked to eating lightly-cooked bacon.
The 52-year-old visited his doctor after his usual migraines became worse and his regular pills stopped working.
Scans then found tapeworm eggs in his brain.
Doctors put the condition down to "improper handwashing". They believe the man, who had a tapeworm from eating undercooked pork, infected himself.
He was diagnosed with cysticercosis - a type of infection caused by the eggs or larvae of the parasite Taenia solium, or pork tapeworm, which can get into the brain.
Someone with a tapeworm can infect him-or herself with tapeworm eggs, a process known as autoinfection, which can pass out of the body as waste and can infect others in the same home. Eating undercooked pork cannot directly give a person cysticercosis.
Writing in the American Journal of Case Reports, doctors wrote that it "can only be speculated" the man's cysticercosis was transmitted through autoinfection after "improper handwashing".
Given his "predilection for undercooked pork" he contracted the tapeworm from his "eating habits", they also stated.
The patient responded to anti-parasitic and anti-inflammatory medication and has since made a full recovery.
'Poor handwashing'
According to the US Centres for Disease Control and Prevention (CDC), tapeworm eggs or larvae "get into tissues such as muscle and brain, and form cysts. When cysts are found in the brain, the condition is called neurocysticercosis".Tapeworm eggs are spread "through food, water, or surfaces contaminated with faeces".
"Humans swallow the eggs when they eat contaminated food or put contaminated fingers in their mouth".
"Someone with a tapeworm can infect him - or herself [autoinfection]" and other members of the family," it adds.
Experts say eating undercooked pork cannot give you cysticercosis - nor is the condition common in the US or UK.
The highest rates of the condition are found in parts of Latin America, Asia and Africa, and it is most common in rural areas where pigs - the carriers of pork tapeworm - are allowed to roam freely, and hygiene and food safety practices are poor.
People are most at risk from such infections through poor handwashing or by ingesting contaminated food or water.
The authors of the report concluded: "It is very rare for patients to contract neurocysticercosis outside of classic exposures or travel, and such cases in the United States were thought to be non-existent."
They say the case highlights the risk of "undercooked pork consumption" and subsequent autoinfection.
"It is historically very unusual to encounter infected pork in the United States, and our case may have public health implications," the report concludes.
