Intestinal worms rare in the suburbs
On occasion, I find myself reassuring worried parents that their child's diarrhea is more likely due to a common stomach virus than to dreaded intestinal worms, which rarely cause gastrointestinal illness in American suburbia.
But one office day it was hard to argue with a college student when he declared that he had a tapeworm infestation and solemnly handed me a plastic bag with a long, flattened and segmented specimen.
His evidence sure did look like a tapeworm - not that I'd seen one up close since starting in private practice. The student's story was a pretty good one, too, as he recounted how he had gone on a wilderness adventure in Canada and eaten raw fish caught in a northwoods freshwater stream.
Sometime after the trip, the avid camper began experiencing monthly episodes of diarrhea mixed with wormlike objects. He was otherwise symptom-free without any abdominal cramping, pain, or fever.
The hospital microbiology lab quickly identified the zip-locked specimen as a tapeworm. After consultation with an infectious disease expert, I prescribed one dose of an oral anti-parasitic drug and warned my patient to expect an "expulsion" of multiple worms in the near future.
Final department of public health lab analysis classified the worm as Diphyllobothrium latum, a fish tapeworm consistent with the suspected route of infection.
Scientists at the Centers for Disease Control and Prevention describe D. latum as the largest human tapeworm. While life cycling from egg to adult tapeworm, D latum is passed around the food chain in stages, moving from water to crustaceans to small freshwater fish to larger predator fish and finally to humans and other mammals that consume raw or undercooked infected fish.
While most D. latum infections are asymptomatic, the CDC explains that patients can experience diarrhea, vomiting, abdominal discomfort and weight loss. Possible complications of fish tapeworm infections include Vitamin B12 deficiency and anemia, intestinal obstruction, and gall bladder disease.
The CDC reports that beef, pork and Asian tapeworms can also cause parasitic infections in humans who have eaten raw or undercooked infected meats. As with fish tapeworm infections, many individuals infected with meat tapeworms are asymptomatic. These intestinal infections are more commonly seen in geographic areas with poor sanitation.
Freezing, storing, and cooking fish properly and cooking beef and pork to safe temperatures can help prevent tapeworm infections. Visit http://www.fightbac.org/safe-food-handling for specific tips on safer food preparation. Careful hand washing and proper hygiene are, as always, additional "good health" practices.
Humans generally do not become infected with the same tapeworms that infect their pet cats and dogs. CDC experts find that while dogs and cats become infected by swallowing parasite-contaminated fleas, it is fortunate that their human owners rarely swallow fleas.
In his review in the online Medscape Reference, Dr. Lisandro Irizarry notes that oral medications used to treat human intestinal tapeworm infections are 85 to 98 percent effective. Patients can pass tapeworm segments and eggs for several days after treatment and stools should be retested one month after fish tapeworm infections and three months after meat tapeworm infections to verify treatment success.
• Dr. Helen Minciotti is a mother of five and a pediatrician with a practice in Schaumburg. She formerly chaired the Department of Pediatrics at Northwest Community Hospital in Arlington Heights