Increasing incidents of pork tapeworm, or cysticercosis, are a growing health concern among Latin American immigrants in Southern California and other areas of the United States adjacent to the Mexican border.
However, the problem is unlikely to diminish even though researchers discovered a means of controlling cysticerci, or the tapeworm larvae, according to a recent report in the Journal of the American Medical Assn.
Scientists at Mexico City's National Institute of Neurology found that the parasite was destroyed by subjecting infected pork to freezing temperatures for several days. But the authors conceded that implementing their findings will be difficult in Mexico because of the "educational, economic, nutritional and cultural factors that pose obstacles."
The study found that simple refrigeration was not enough to destroy the parasites, which have become common in Mexico and several other Latin American countries. Only temperatures considerably below freezing will eliminate the larvae. (American pork supplies have not been known to host the tapeworm.)
Once ingested, cysticerci affect the central nervous system with symptoms that include seizures, headaches, abnormal behavior and other neurological deficiencies. Drugs are used to treat the condition, but surgery has also been conducted to remove the infection.
Contributing to the problem is that humans suffering from the parasite become carriers of the infection, according to previous reports on the condition. Transmission occurs through contact with feces as a result of poor sanitation or inadequate sewerage.
A 1985 study by California health officials found 250 cases of cysticercosis locally during a five-year period beginning in 1979. A similar study by the Centers for Disease Control in Atlanta found about 500 cases between 1973 and 1983, primarily in Latin American immigrants. All of the cases documented in the CDC study were found in four Los Angeles-area hospitals.
The report recommends that countries where cysticercosis is a problem require that all pork be held at minus 15 degrees Celsius (about 7 degrees Fahrenheit) for three days.
Leningrad Sickness--Travelers returning from the Soviet Union have also encountered an illness believed to have originated from either water or food supplies, according to a recent report in California Morbidity, a newsletter from the state's Health Services Department.
First signs of the parasitic infection, giardiasis, were spotted in 1969. But subsequent surveys have found that a significant number of Americans who visited Leningrad developed the symptoms, which include diarrhea, abdominal cramps, fatigue, weight loss, anorexia and nausea, upon their return to this country. The sickness has been known to last as long as several months, and physicians have had difficulty diagnosing it in the past, according to the report.
Evidence of giardiasis became more common in the early 1970s. A survey of 47 tour groups that visited the area in question between 1972 and 1973 found that 23% of those examined had the infection. In one case, a group bound for Leningrad was tested before its departure and found free of the illness. The same test was conducted upon return, and as many as 80% showed signs of giardiasis.
Health officials have speculated that tap water is the likely source of the infection, which has an incubation period of one to 14 weeks. Recommendations for avoiding the problem while traveling in the Soviet Union involve eating only foods that can be peeled or have been cooked. Drinks should consist only of boiled water or bottled carbonated water, bottled soft drinks, beer or wine.
The newsletter also recommends that travelers who develop a diarrheal illness after returning from the Soviet Union should be checked by a physician for the parasitic infection.
Bad Bones--The threat of contamination is not limited exclusively to human food as judged by a recent incident in Northern California. Federal health officials in San Francisco were alerted recently to a number of reports from pet owners that their dogs were showing severe side effects to a rawhide chew shaped like a bone, according to an account in FDA Consumer magazine.
Some of the dogs' reactions included hysterical barking, fearfulness and involuntary urination. Veterinarians treating the problems discovered that the symptoms reported were similar to those found in a 1982 incident that was attributed to Mister Max rawhide chews manufactured in Korea by the Ssang Yong Corp.
The Amigo-brand product linked to the most recent episode of bizarre pet behavior was also made in Korea, but the manufacturer's identity was unknown, according to the article. The Amigo chews were recalled by the Food and Drug Administration.
In both cases the agency conducted extensive laboratory tests and failed to reveal the material that caused the reactions. As a result, the FDA attributed the problem to "an unidentified poisonous and deleterious substance."