Group C Beta Haemolytic Streptococcus Causing Necrotising Pneumonia Complicated With a Pyopneumothorax

Group C Beta Haemolytic Streptococcus (GCBHS) rarely causes invasive infection but is associated with high mortality. Pneumonia is common; however, severe necrotising pneumonia is very rare, and no previous cases complicated by pyopneumothorax have been described. Associations with male gender and animal exposure have been previously reported in the literature.

A 20-year-old male agriculture student with no past medical history presented with 6 days of productive cough and fever and 2 days of shortness of breath, chest pain, and confusion. He presented with clinical signs of sepsis, developed acute kidney injury (AKI), disseminated intravascular coagulation (DIC), and acute respiratory distress syndrome (ARDS) requiring intubation and ventilation. Initial computed tomography (CT) of the thorax showed right pyopneumothorax, left small pyopneumothorax, bilateral large pulmonary nodules of varying size, some cavitating with progression on serial imaging. Blood cultures grew GCBHS, later showing Streptococcus dysgalactiae subsp. equisimilis (SDSE). Bilateral chest drains were required, with eventual bilateral video-assisted thoracic surgery (VATS) with washout due to nonresolution. After a prolonged intensive care stay and a community course of antibiotics, his follow-up CT of the thorax is improving, and he is planning to return to his studies at agricultural college.

Invasive infection with GCBHS is associated with higher mortality and prolonged hospital admission and may be zoonotic. Of the four reported cases of GCBHS necrotising pneumonia, all were young men with minimal or no past medical history. Half had documented exposure to unwell animals, and half required thoracoscopic intervention.