Listeria monocytogenes bacteremia one month after contact with raw venison: A case report

Listeria monocytogenes is a gram-positive bacillus that causes food poisoning. Listeriosis causes gastrointestinal infections and occasionally leads to fatal bacteremia in older adults. The symptoms of Listeria infections are non-specific and difficult to diagnose. We describe a case of Listeria bacteremia in an 82-year-old Japanese woman who had handled raw venison one month prior to becoming ill, but had not consumed any. No other possible sources of infection were identified. She presented with a fever without any focal symptoms. Computed tomography revealed enteritis with mucosal damage. Blood culture revealed bacteria with gram-positive rod morphology, that were confirmed as L. monocytogenes using mass spectrometry. The patient was treated with intravenous ampicillin and made a full recovery. This case illustrates the virulence of L. monocytogenes, which can cause bacteremia from handling contaminated food, even without consumption.