Last week, a story circulated the world wide web about a Chinese man, whose love of sashimi and the quantity he consumed, left his body riddled with parasites. The story was presented on the Chinese news source, ON TV; however, the English-language story that took the internet by storm was the one published in the Daily Mail.
The story, accompanied by a plethora of X-rays or related scans, tells of a man who body was overtaken with what appears to be the spargana of a Cestode, or tapeworm parasite.
The Daily Mail story says, Doctors believe some of the uncooked Japanese delicacy of raw meat or fish must have become contaminated. A couple of paragraphs later it states, Tapeworm infections occur after ingesting the larvae of Diphyllobothrium, found in freshwater fish such as salmon, although marinated and smoked fish can also transmit the worm.
I looked at these photos and the accompanying text of his symptoms and based I what I could ascertain from this little information, I can’t say that this was caused by Diphyllobothrium, as the article notes (unless, of course the author meant the larval stages of diphyllobothriid tapeworms).
While Diphyllobothrium latum (the fish or broad tapeworm), or Diphyllobothrium nihonkaiense (an Asian cousin) is contracted in humans after consumption of undercooked or raw freshwater fish (as would be used in sashimi), the clinical presentation didn’t line up to me.
The manifestations of Diphyllobothrium may include abdominal discomfort, diarrhea, vomiting, and weight loss. Vitamin B12 deficiency with pernicious anemia may occur. Massive infections may result in intestinal obstruction. Migration of proglottids can cause cholecystitis or cholangitis, according to the Centers for Disease Control and Prevention (CDC).
To me, the food consumed, the vague symptoms described in the article and the pictures of the scans resemble a cestode in the genus Spirometra, including Sparganum proliferum. Humans acquire sparganosis by either drinking water contaminated with infected copepods or consuming the flesh of an under-cooked second intermediate or paratenic host such as undercooked fish or amphibians.
The CDC describes the clinical presentation as follows:
Migrating spargana cause various symptoms depending on the final location in the host. Spargana may locate anywhere, including subcutaneous tissue, breast, orbit, urinary tract, pleural cavity, lungs, abdominal viscera and the central nervous system. The migration in subcutaneous tissues is usually painless, but when spargana settle in the brain or spine a variety of neurological symptoms may occur, including weakness, headache, seizure, and abnormal skin sensations, such as numbness or tingling. If the inner ear is involved, the patient may experience vertigo or deafness. Occasionally, Sparganum proliferumcan cause proliferative lesions in the infected tissue, with multiple plerocercoids present in a single site.
In the article published in Clinical Infectious Diseases (2005), Sushi Delights and Parasites: The Risk of Fishborne and Foodborne Parasitic Zoonoses in Asia, the authors write:
In the human body, larvae usually appear in the subcutaneous tissues of the anterior chest, the abdominal wall, or the inguinal region and form slow-growing migratory nodular lesions without causing pain or redness. Larvae may occasionally migrate into unexpected parts of the body, such as the pleural cavity or the CNS, causing unusual or even fatal manifestations. A total of 11 cases of cerebral sparganosis have been reported in Japan.
Obviously, I’m not sure of this and I’d love reader’s input on this particular case that hit the internet by storm last week.
Related: Sushi, sashimi and worms, oh my!