Actinomycosis: An infrequent disease in renal transplant recipients?

Actinomycosis is a rare and heterogeneous infection involving Gram-positive anaerobic bacteria, which are commensals in the oral cavity and digestive tract. Only four cases of actinomycosis in renal transplant recipients have been reported to date. We performed a retrospective study in French renal transplantation centers to collect data about actinomycosis, patients, and transplantation. Seven cases were reported between 2000 and 2017; mean age was 55.7 years, and prevalence of actinomycosis was 0.02%. Median time between transplantation and infection was 104 months (4-204 months). Locations of actinomycosis were cervicofacial (n = 2), pulmonary (n = 2), abdominopelvic (n = 2), or cutaneous (n = 1). Two patients (28.5%) had acute kidney injury. Diagnosis was made possible by microbiology (71%) or histopathology (filaments and sulfur granules) (14%) of the infection site. The suspected gate of entry for the infection was dental (57%), abdominal (28.5%) or through the sinuses (14%). All patients were treated with amoxicillin for 30-200 days (median duration of 115 days), and clavulanic acid was added for 28.5% of cases. Three patients (43%) required surgery. All patients, except one, recovered completely after a few months. Actinomycosis is a rare, slow, progressive disease in French renal transplant recipients. The location and clinical features of this infection are miscellaneous. Global and renal outcomes do not seem to be affected by actinomycosis.