Woman's 'Highly Unusual' Pneumonia Caused by Parasite-Tainted Deer Meat
A Florida woman’s serious pneumonia that landed her in the hospital turned out to have a very strange culprit: deer meat tainted by the parasite Toxoplasma gondii. Though it took some time for the woman’s doctors to discover the true cause of her worsening illness, they were able to treat her in time once they did.
The bizarre case was detailed this week in the New England Journal of Medicine as part of a regular series on not-so-easily solved medical puzzles.
According to the report, the 32-year-old Florida resident visited an emergency room ten days into having shortness of breath, fever, and cough, along with sore throat and muscle aches. Her symptoms hadn’t improved after taking a five-day course of antibiotics and her initial medical history provided no clues as to what might be wrong with her. Early tests revealed that she had low oxygen and platelet levels, and doctors decided to admit her to the hospital under the suspicion that she had developed pneumonia.
The doctors started the woman on a broad spectrum antibiotic while they began testing for some common causes of pneumonia. These tests came negative and her condition only worsened over the next few days, however, with her eventually needing intubation and mechanical ventilation. On the third day of hospitalization, one of her friends remembered and told doctors that the woman had recently prepared a deer carcass collected from her boyfriend’s hunting trip in Alabama. The woman cooked, served, and ate the venison from the deer 20 days before her symptoms began.
Though no one else seemed to become sick after eating the deer meat, the potential clue prompted doctors to test for more exotic germs that could be caught from animals, including T. gondii. Five days into the woman’s hospitalization, antibody tests came back positive for T. gondii, and negative or unclear for the other suspected pathogens. The doctors conducted more tests to verify their findings, while adding a specific drug used against T. gondii to her treatment. On day 8, results showed that her blood was chock full of the parasite, confirming that she was experiencing an acute infection. The following day, she had improved enough to be taken off intubation.
T. gondii is a single-celled protozoan parasite with a notoriously complex life cycle. Its primary hosts are cats, but the parasite needs to hitch a ride onto other intermediate hosts to get there, usually rodents. To accomplish this, T. gondii will manipulate the behavior of rodents, making them reckless and more likely to get eaten by cats. The trouble is that T. gondii can infect many different hosts, even those not likely to get eaten by cats, such as deer and humans.
People can get a T. gondii infection by handling contaminated cat feces, but also through touching or eating contaminated meat that hasn’t been cooked well enough. And tainted venison has caused outbreaks of T. gondii before, but it was the severity and presentation of the woman’s infection that made this case “highly unusual,” the doctors wrote.
Most people don’t get sick at all from the acute infection (though chronic infections might still have subtle health effects),and severe illness typically only happens in very vulnerable groups, such as those with weakened immune systems or newborn children who catch the infection from their mothers in the womb. Even in those cases, pneumonia usually isn’t the primary symptom—more often, it’s neurological issues.
As far as the doctors know, this might be the first documented case of T. gondii-related pneumonia ever found in a healthy person, at least in the U.S. There have been some outbreaks of T. gondii caused by more virulent strains of the parasite in parts of South America, which made the doctors worry that these strains have made their way here, but genetic testing ruled out that possibility. So it’s still unclear whether the woman’s pneumonia was sparked by another unusual strain of the parasite, some missed vulnerability, or by her having gotten exposed to a massive dose of the germ.
Lingering mysteries aside, the doctors’ sleuthing did save the day and the woman was effectively treated.
“Although this syndrome is highly unusual, it underscores the importance of a comprehensive diagnostic approach guided by a detailed history taking, when standard treatment is ineffective and conventional testing fails to yield answers,” the doctors wrote.
