Pleural effusion due to Parvimonas micra. A case report and a literature review of 30 cases.

The clinical and microbiological characteristics of infections caused by Parvimonas micra is described, including 30 cases in the literature and a new case handled at the present centre. Out of the 31 patients, 18 were male; mean age at diagnosis was 65.1 ± 13.0 years. Infection site was the vertebral spine in 14 patients and joints and heart valves in 5 each one; pain was present in all patients with articular localization and in almost all patients with vertebral involvement. The diagnosis was obtained from fluid aspirate or drainage in 13 cases and blood cultures in 11. In 8 cases, molecular techniques were also applied. The most frequently used antimicrobials were clindamycin, penicillin, amoxicillin and ceftriaxone. The outcome was positive with the medical treatment in 28 patients. P. micra infections are uncommon and requires a high index of suspicion.