Empyema caused by Streptococcus dysgalactiae subsp. equisimilis subsequently to bacteraemia

Streptococcus dysgalactiae subsp. equisimilis (SDSE) commonly causes a variety of infections in older individuals. However, respiratory infections are uncommon. We present the case of an older man with empyema due to SDSE subsequently to bacteraemia. He presented with a 1-day history of fever and laboratory findings revealed an increased white blood cell count and C- reactive protein (CRP) level. Chest CT revealed no infiltration and no pleural effusion. SDSE was detected in the blood cultures. Primary bacteraemia was suspected and antibiotic administration was initiated; however, 2 days later, his right breath sound diminished, and chest radiography revealed right pleural effusion. Thoracentesis yielded cloudy fluid with frank pus; thus, he was diagnosed with empyema due to SDSE, and a drainage tube was placed. Thereafter, his fever improved, and his CRP level decreased. Thus, SDSE can cause empyema probably by haemotological spread of SDSE to the pleura.