A 32-year-old woman in Shanghai, China, experienced a rare and misdiagnosed lung infection caused by a parasitic worm acquired through her diet, specifically her consumption of raw frogs. The case highlights the risks associated with eating undercooked or raw animals, particularly in regions where this practice is culturally ingrained.
Initial Misdiagnosis and Persistent Symptoms
The patient initially presented with a four-month-long persistent cough, occasionally producing bloody phlegm. She had also experienced a weeks-long fever reaching 100.8°F (38.3°C) prior to seeking medical attention. Doctors at the first hospital diagnosed her with eosinophilic pneumonia—a condition where white blood cells accumulate in the lungs, causing inflammation. Despite treatment with steroids, her cough persisted for two months, and follow-up CT scans revealed recurring lung lesions.
The True Cause: Sparganosis
A transfer to a second hospital led to a revised diagnosis. Medical history revealed that the patient consumed raw seafood and had “a preference for raw frogs and bullfrogs.” Blood tests detected antibodies for Spirometra mansoni larvae, the cause of sparganosis—a parasitic infection common in eastern Asia. The larvae, ingested from undercooked or raw infected animals, migrate through the body, though lung accumulation is extremely rare.
A dissected frog provided by the patient confirmed it carried the parasite, solidifying the diagnosis. The initial misdiagnosis occurred because the symptoms closely resembled eosinophilic pneumonia, masking the true parasitic cause.
Treatment and Recovery
Treatment with praziquantel tablets – an anti-parasitic drug – provided rapid improvement. Within five days, the patient’s cough subsided, and subsequent CT scans showed shrinking lesions. While initial follow-up tests still detected antibodies, indicating persistent infection, a second five-day course of praziquantel and a five-month checkup showed antibody levels reduced to negligible amounts, with normal white blood cell counts. The patient required no further treatment.
Why This Matters
This case is unique because sparganosis usually manifests in superficial tissues, not internal organs. It’s the first documented instance of lung-based sparganosis in Shanghai. The incident underscores the real health risks of consuming raw animal flesh—a long-held tradition in parts of Asia. As the case of an 82-year-old woman in Hangzhou demonstrates, some people even consume live animals for supposed medicinal benefits, often with devastating results. The prevalence of these practices raises concerns about public health and the need for increased awareness regarding parasitic infections.
