Chuck Norris: Beware what gets inside your head

Chuck, I learned a lot from your series on Lyme disease and the dangers of tick bites. Speaking of infectious diseases, I had a science-buff friend tell me tapeworms can tap the inside of our brain, leading to all sorts of maladies. Ever heard of that? – "Squirming in Spokane"

This issue is not for the faint at heart, yet it should be read by everyone everywhere. MSNBC reported that this health problem is a "hidden" epidemic.

The network's report was based upon a May 2012 Discover magazine scientific investigation that was subtitled "Parasitic worms leave millions of victims paralyzed, epileptic, or worse. So why isn't anyone mobilizing to eradicate them?"

Dr. Theodore Nash, who is the chief of the Gastrointestinal Parasites Section at the National Institutes of Health, sees patients (or victims) of this freeloading worm in his clinic. Their symptoms include excess fluid in the brain, seizures, partial blindness, loss of speech, the inability to walk a straight line, partial body paralysis, coma and even death.

At the root of these symptoms are tapeworms, the notorious parasitic worms often regarded as residents in human intestines. They can grow up to 50 feet in length and live within a host for up to 20 years. Nash says their cranial counterparts are whitish blobs in the brain that often are misdiagnosed as tumors.

Discover magazine noted: "Before they become adults, tapeworms spend time as larvae in large cysts. And those cysts can end up in people's brains, causing a disease known as neurocysticercosis."

Though the cranial crawlers also are found in Africa and Asia, Nash estimates that 11 million to 29 million people have neurocysticercosis in Latin America alone. The disease most often is found in poor areas lacking good and sanitary health systems.

And in the U.S.?

Nash says, "Nobody knows exactly how many people there are with it in the United States," though he estimates the number to be between 1,500 and 2,000.

That may not be enough to cause alarm, but Americans would be wise to consider how global transport, travel and traffic (including food exporting and importing and improper handling and cooking) might increase that number (if you haven't squirmed yet, hold on to your seat).

Pigs are generally the source of neurocysticercosis, and the disease hits home when tapeworm larvae meander from swine to the human body.

Pigs are infected when they eat raw food or feces carrying microscopic tapeworm eggs. The larvae linger in their muscles and meat, and they pass them into soil through their waste – which, in turn, affects humans' food and water.

When humans eat food or drink water contaminated with tapeworms – for example, when we eat raw or undercooked meat from an infected animal – we ingest the eggs or microscopic larvae, too (pork has to be undercooked for the tapeworms' infection to come into complete fruition).

The Mayo Clinic reports, "If they migrate out of your intestines, they form cysts in other tissues, such as your lungs, central nervous system or liver."

As a tapeworm cyst grows in the body or the brain, it may impede the proper operation of one or several bodily functions.

Discover magazine explains: Our body's "immune system's attack on the cyst can cause the surrounding brain tissue to swell with inflammation. For reasons unknown, a calcified cyst can keep triggering these immune reactions for years after the parasite's death."

According to Nash, the first drug to terminate tapeworms in the brain was praziquantel, but it also triggered an immune reaction that caused brain swelling. Newer treatments combine praziquantel with other drugs less likely to cause bodily backlash or side effects. But no treatments are foolproof.

Nash is somewhat frustrated by the medical community's putting its head into the hole of avoidance. He concludes: "I see this as a disease that can be treated and prevented. All of this seems to be very feasible, but nobody wants to do anything about it."

Of course, prevention is always the best medicine. Being mindful of food and water conditions when you travel to other countries is paramount. Avoiding undercooked meats (particularly pork) is also a critical step to protect your body from foreign invaders.

As I mentioned in my series on Lyme disease, we would be wise not to overlook or ignore the potentially infectious diseases caused by the microbes and parasites of this world. Whether we face it or not, the fact remains that millions of people worldwide are running around with tapeworms living in their brains.

This could be a very timely warning at the start of this busy global travel season.