Endovascular listeriosis, an infection with Listeria monocytogenes that manifests mainly as vascular infection and endocarditis, occurred mostly in older patients with vascular or cardiac valve prosthetic devices and those with comorbidities, according study results published in the Journal of Infection.1

Endovascular listeriosis is a rare but severe infection. As such, researchers used surveillance data from the National Reference for Listeria in France, which has an estimated capture-recapture of at least 87% for L monocytogenes strains, during a 25-year period to characterize L monocytogenes-associated endovascular infections.

Among the 7294 strains retrieved from non-maternal-neonatal infections between 1993 and 2018, 71 cases were identified: 42 patients had vascular aneurysms/prosthetic infections, 27 patients had endocarditis, and 2 patients had both. Patients were mostly men (82%) and older than age 65 years (85%), with 93% reporting at least 1 comorbidity.

Vascular infections consisted of infected aneurysms in 68% of patients and prosthetic graft infections in 32% of patients; vascular rupture was reported in 60% of patients.

The 29 endocarditis infections involved prosthetic valves in 62%, native valves in 28%, and intracardiac devices in 10%. Valves infected were more likely to be the aortic valve (16 of 26), mitral valve (8 of 26), or both (2 of 26). Concomitant neurolisteriosis was diagnosed in 5 patients (5 of 29).

All infections were culture-proven, and with the exception of 1 patient, all others provided samples that were positive for L monocytogenes. The biodiversity of clinical isolates was similar in patients with vascular infections and endocarditis.

All patients with vascular infections benefited from surgery, along with 38% of patients with endocarditis. The most frequent combination antimicrobial therapy used was amoxicillin plus aminoglycoside.

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Mortality was significantly higher for endocarditis than for vascular infections (41% vs 12%; P =.009). Further, compared with other pathogens, mortality was twice as high with L monocytogenese-associated endocarditis.2

Because there are no specific therapeutic guidelines for L monocytogenes-associated endocarditis and aneurysmal and prosthetic tubes infections, clinicians should carefully evaluate “for possible [L monocytogenes]-associated endovascular infections, so that active combined antimicrobial therapy and surgical management can be prescribed timely and appropriately,” concluded the researchers.

References

1. Shoai-Tehrani M, Pilmis B, Maury MM, et al; Listeria endovascular infections study group. Listeria monocytogenes-associated endovascular infections: a study of 71 consecutive cases [published online July 31, 2019]. J Infect. doi:10.1016/j.jinf.2019.07.0132.

2. Murdoch DR, Corey GR, Hoen B, et al; International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS) Investigators. Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: the International Collaboration on Endocarditis-Prospective Cohort Study. Arch Intern Med. 2009;169(5):463-473.