Clinical Features of Actinomycosis: A 20-year Experience of A Single Institute in Southern China

Background: Actinomycosis is a rare indolent infectious disease with nonspecific clinical presentations that delay diagnosis. Although actinomycosis is thought to be more prevalent in developing countries, data from developing countries are scanty. This study was to reveal the current situation of actinomycosis in developing countries and the difference from that in developed countries. Methods Patients fulfilling the inclusion criteria for actinomycosis from Nanfang Hospital in southern China between January 2003 and December 2018 were retrospectively analyzed. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance. Results Thirty-one patients were included in this study. Disease was diagnosed predominately in the orocervicofacial (n=14), cardiothoracic (n=11), abdominopelvic (n=5), soft tissue (n=1). Diagnosis was obtained from either histopathology (n=29, 94%) or microbiology (n=2, 6%). Only one-thirds of patients presented with general symptoms such as fever, weight loss. Ten was lost to follow-up, and median duration of antibiotics was 93.5 days (interquartile range 28–300), whereas the median follow-up time was 34 months (interquartile range 9–132). Ten patients receiving complete resection of the lesion were cured without postoperative use of antibiotic. Only one patients relapsed during the follow-up period. Conclusions Actinomycosis is a rare disease even in developing countries, and both misdiagnosis and missed diagnosis are common. Diagnosis was often delayed and obtained from histopathology postoperatively in developing countries. Hence, clinicians should be aware of this disease in patients with high riks factors. In the future, specific molecular methods may help to improve early diagnosis and treatment.