All over the world, millions of people get paralyzed, epileptic, or worse due to parasitic tapeworms that found their way inside their brains. Prevention strategies seem to be very feasible. However, there’s little recognition of the problem.
Parasitic tapeworms are best known in their adult stage, when they live in people’s intestines and their ribbon-shaped bodies can grow as long as 6 meters. But apparently, that’s just one stage in the animal’s life cycle. 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 neurocysticerosis.
The alarming illness occurs when someone eats food contaminated with human feces, which contain tapeworm eggs. When the eggs hatch in the stomach, the larvae burrow their way into the person’s bloodstream and get swept through the body. Often those parasites end up in the brain, where they form whitish blobs (cysts).
When the cyst grows, it can push against a region of the brain and disrupt its function. Or it can get stuck in a passageway, hampering the flow of brain fluid. This impasse can cause dangerously high pressure, resulting in stupor, coma, or death. Overall, any cyst in a susceptible area of the brain can cause seizures. But especially those situated near regions that issue commands to muscles can trigger violent convulsions.
A cyst that doesn’t cause big troubles can persist for years, but when it can’t move it will die. This signals the immune system to attack the cyst, what often leads to inflammation in the brain.
Apparently, this illness is not something unusual. To the contrary, millions of people are infected worldwide, especially in developing countries that lack good public-health systems. In Latin America alone, somewhere between 11 million and 29 million people have neurocysticercosis. In the U.S., the number of victims is estimated 1,500 to 2,000.
Currently, the illness is treated with a drug able to kill tapeworms in the brain (praziquantel) in combination with other drugs that tamp down the immune system. But it is far from a perfect solution and researchers are trying hard to find a better cure.
Neurocysticercosis is a growing global health problem, but nevertheless, little is being done. Even though prevention – in contrast to treatment – seems to be no rocket science. According to Discover Magazine, “a favored strategy is identifying people who have adult tapeworms in their bodies and giving them drugs to kill the parasites. It is also possible to vaccinate pigs so that they destroy tapeworm eggs as soon as they ingest them.”
Theodore Nash, chief of the Gastrointestinal Parasites Section at the National Institute of Health in Maryland, U.S. says: “I see this as a disease that can be treated and prevented. All of this [strategies] seems to be very feasible, but nobody wants to do anything about it.”
Source: Discover Magazine
Photo credit: Theodore E. Nash , M.D.
Nash, T., & Garcia, H. (2011). Diagnosis and treatment of neurocysticercosis Nature Reviews Neurology, 7 (10), 584-594 DOI: 10.1038/nrneurol.2011.135