An empyema caused by Streptococcus constellatus in an older immunocompetent patient: Case report

Empyema caused by Streptococcus constellatus is rare in patients without underlying diseases. However, the importance of the Streptococcus anginosus group, which consists of S constellatus, S anginosus, and Streptococcus intermedius, as causative organisms of empyema has been increasing.

A 78-year-old man initially presented with dyspnea and chills for 4 days. He had no medical history.

Chest X-ray and chest computed tomography showed a large and multiloculated pleural effusion with an air bubble on the right side. Cultivation of the pleural effusion using clone library analysis of the 16S rRNA gene revealed S constellatus positivity.

The patient was treated by drainage of the pleural effusion and intravenous ceftriaxone and clindamycin for the possibility of anaerobes, followed by 10 weeks of oral antibiotics.

On the 11th day of admission, the thoracic drainage tube was removed. After 1 year of treatment, there were no sequelae of empyema.

Although S constellatus can cause serious infections in patients with underlying diseases and immunosuppression, physicians need to consider S constellatus infection in community-acquired empyema in elderly individuals. It should be treated with early pleural drainage and antibiotics to avoid surgical decortication and prolonged hospitalization.