STORY BY

Natalie Wong Camarata

Recent scares of bacteria and parasites in foods like spinach are reminders of how important it is to wash our hands, foods and cooking surfaces.

Juan José Dimas knows all too well the consequences of consuming a meal prepared by someone who didn’t practice good hygiene. In fact, it may be a long time till he trusts any kitchen but his own.

Dimas’ typical workday at the construction site was interrupted by a splitting headache, chills, nausea and vomiting. An MRI later revealed Dimas had neurocysticercosis, or a parasitic worm infection of the brain.

Cysticercosis is an infection caused by the pork tapeworm, Taenia solium, from the consumption of contaminated food, such as unwashed vegetables or undercooked pork. It is most prevalent in developing countries and in immigrant populations in the United States.

Dimas moved to the United States three years ago from San Luis Potosí, Mexico, where, like in many countries, vendors sell food on the street. Dimas believes one of these food carts harbored the contaminated food that made him sick.

In Dimas’ case, a neurosurgeon at The University of Texas Medical School at Houston diagnosed him and performed a minimally invasive endoscopic surgery at Memorial Hermann-Texas Medical Center to remove the parasitic cysts from his brain.

“I have a small scar on the upper right side of my head, but it’s only about two inches long, and my hairline covers it now,” says Dimas.

In the procedure, the surgeon makes a small burr hole in the skull and passes an endoscope through the brain cortex, where magnified images of the cysts guide the neurosurgeon to their location for removal.

Dimas was suffering from hydrocephalus (an abnormal accumulation of cerebrospinal fluid or CSF) due to a number of cysts obstructing the CSF pathways inside the brain, explains Aaron Mohanty, M.D., assistant professor in the Department of Neurosurgery at UT Medical School.

“We removed 15 to 20 cysts, some of which were as large as 3 - 4 centimeters in diameter, all next to the ventricles. Conventionally, these have been treated with an open microsurgical approach (craniotomy) with relatively higher morbidity and a longer hospital stay. Neuroendoscopic techniques are minimally-invasive and can be extremely useful in such a situation.” he explains.

Five days after brain surgery, Dimas returned to work and now comes in for follow-up MRIs. He no longer buys food from street vendors and he now brings his lunch from home every day.

Misdiagnosed

Francisco Escalante has not fared as well as Juan Dimas. Escalante moved to the United States from Mexico City more than 11 years ago, and also was diagnosed with neurocysticercosis at Memorial Hermann Hospital. He has been enduring complications for four years.

With similar symptoms, Escalante first sought help at a hospital in Ohio, where he was misdiagnosed numerous times and at one point was given chemotherapy. He continued to suffer from severe headaches and seizures.

“After coming to Houston, they tested me for everything you can think of. I was finally diagnosed with this and was told that I needed surgery,” says Escalante.

Mohanty also treated Escalante by using the endoscopic procedure to remove the parasitic cysts.

“He had several cysts and they had also gone into the meninges (a three-layered cover that envelops the brain) causing him to suffer from meningitis,” Mohanty says. In other cases the cysticercus larvae can lodge themselves in the brain parenchyma (the functional part of the brain) mimicking a brain tumor.

Escalante’s family questions whether the outcome would have been different if the disease had come any quicker, since he is still recovering and suffers from nausea and occasional shakes.

“The fact that they could have found these cysts with an MRI from the beginning is mind-blowing,” says Jean Escalante, his wife.

After the surgery, both patients were given anti-parasitic medications to cleanse the rest of the body of the parasites.

Taenia solium

The infection occurs when the tapeworm larvae enter the body and form cysts. When the cysts are found in the brain, the condition is called neurocysticercosis. The tapeworm that causes this is found worldwide. Infection occurs most often in rural, developing countries with poor hygiene where pigs are allowed to roam freely and consume human feces.

How we get infected

The tapeworm and the cyst of the tapeworm create two different problems.

“A person eats pork infected with tapeworm cysts. These cysts evolve into a tapeworm in his intestine and he will eventually shed the tapeworm eggs in his bowel movements and into the environment. This person, however, may still have a tapeworm, says infectious disease expert Luis Ostrosky-Zeichner, M.D., associate professor of medicine and epidemiology at the UT Medical School.

“If he does not properly wash his hands and then handles food or a food preparation area, another person who then eats the contaminated food can unknowingly swallow the tapeworm eggs. These eggs then cross through the intestine into the blood circulation and evolve into cysts. The cysts get "stuck" in tissues such as muscle or the brain and eventually may cause severe infection in humans,” says Ostrosky-Zeichner, who also serves as medical director for epidemiology with the Memorial Hermann Healthcare System.

“Neurocysticercosis is the most common cause of adult onset seizures in some developing countries like Mexico,” he adds.

Cysticercosis can take several years to manifest inside the human body, making it difficult to pinpoint when the person ate the contaminated food.

Dimas warns that “People need to know that they should wash their hands well and should completely cook their meat. I also advise that they go to the doctor for check-ups regularly. I was in perfect health before this, so you never know,” says Dimas.

With more people traveling to some of these countries, an increase in incidence may be seen in the future, Mohanty says.

Avoiding cysticercosis while traveling

• Avoid eating raw or undercooked pork and other meats.
• Don’t eat the meat from pigs that are likely to be infected by tapeworm.
• Wash hands with soap and water after using the toilet and before handing food.
• Wash and peel all raw vegetable and fruits before eating.
• Drink bottled water, and avoid fountain drinks or any drinks with ice cubes.

Information from CDC.gov

Last Updated: 10-25-2006

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