Diagnostic dilemma: A woman got a rare parasitic lung infection after eating raw frogs
The patient: A 32-year-old woman in Shanghai
The symptoms: The woman went to the hospital with a persistent cough accompanied by occasional bloody phlegm, which she coughed up two to three times a day. She said the cough started four months before her hospital visit. And about a month before the cough started, she had a fever it lasted several weeks and reached up to 100.8 degrees Fahrenheit (38.3 degrees Celsius).
The patient’s doctors gave her steroids to reduce inflammation in her lung tissue. However, his cough persisted even after two months of treatment. A CT scan of her lungs revealed recurrent lesions, or tissue damage, and she was later sent to another hospital for further examination.
The diagnosis: When doctors at the second hospital reviewed the woman’s medical history, they noted that her diet often included raw seafood, and she also reported “a preference for raw frogs and bullfrogs,” the doctors wrote in a report describing his case. The team performed a blood test to see if his blood contained antibody to all parasites, and they found antibodies for the larvae of mansoni spirometer, a kind of tapeworm.
The larvae, or sparganof S. mansoni cause a parasitic infection called sparganose. This infection is more common in East Asiaand people often contract the parasites by eating raw or undercooked snakes or frogs that are infected with the larvae, evidence suggests. After S. mansoni the larvae are swallowed, they migrate into various tissues and organs of the body. In the woman’s case, they accumulated in her lungs – a very rare destination for the parasite.
When the patient provided doctors with a frog from her Shanghai region, they dissected it and discovered that it carried S. mansoni.
Because the woman’s symptoms and CT scan results closely resembled signs of eosinophilic pneumonia, doctors who examined her during her first hospital visit misdiagnosed her, according to the report.
The treatment: Doctors treated the woman with praziquantel tabletsa medicine that works against various types of parasitic worms. After the woman took the tablets for five days, her cough subsided.
CT scans taken 20 days after his admission to the second hospital showed that the previously observed dark areas in his lungs – a sign of infection or physical trauma – were diminishing. At a follow-up visit a month later, her cough had completely disappeared. However, the patient’s blood tests showed that she was still producing antibodies against the parasite, suggesting that the infection persisted.
Doctors prescribed another course of praziquantel for five days and conducted a follow-up examination five months later. Traces of antibodies remained in the patient’s blood, but only in extremely small amounts. Her white blood cell count was normal and doctors determined no further treatment was needed.
What makes the case unique: Sparganosis infections usually appear in tissues just under the skin, near the surface of the body. They rarely migrate to internal organs. This is Shanghai’s first documented case of pulmonary sparganosis, the report’s authors wrote.
Eating raw animal flesh is a long-standing cultural tradition in parts of Asia and sometimes small animals may be eaten while alive. Live frogs are sometimes eaten as a folk remedy for various illnesses; an 82-year-old woman in Hangzhou was hospitalized with a parasitic infection after swallowing eight small live frogs to try to relieve her chronic back pain.
For more intriguing medical cases, check out our Diagnostic Dilemma Archives.
This article is for informational purposes only and is not intended to offer medical advice.
