SARS-CoV-2 pneumonia more deadly than bacteraemic pneumococcal pneumonia

Bacteraemic pneumococcal community-acquired pneumonia (B-PCAP) is associated with higher disease severity and frequent intensive care unit (ICU) admission, as reported in a study. However, SARS-CoV-2-related pneumonia poses a greater mortality risk.

The study included 663 patients with B-PCAP and 1,561 patients with SARS-CoV-2 pneumonia. Compared with the latter, patients with B-PCAP were older, more likely to have comorbidities and more severe disease, but shorter symptom duration (median, 3 vs 7 days; p<0.001).

Moreover, B-PCAP was associated with worse laboratory findings than SARS-CoV-2 pneumonia, with B-CAP patients having higher C-reactive protein level and lower lymphocyte count (median, 710 vs 990; p<0.001) but less likely to have bilateral lung involvement on chest X-ray (16.9 percent vs 71.8 percent; p<0.001).

Patients with B-PCAP vs SARS-CoV-2 pneumonia were more likely to be classified in the higher risk classes according to CURB-65 (2–5) and Pneumonia Severity Index (4–5) scores (p<0.001) and were more frequently admitted to the ICU (27.9 percent vs 12.9 percent; p<0.001).

While there was no significant between-group difference in the rate of invasive mechanical ventilation (10.1 percent vs 9.1 percent; p=0.505), more patients with B-PCAP developed complications during hospitalization. In-hospital mortality occurred earlier in patients with B-PCAP.

In contrast, patients with SARS-CoV-2 pneumonia had a higher in-hospital mortality rate (10.8 percent vs 6.8 percent; p=0.004) and longer in-hospital stay. Among those admitted to the ICU, patients with SARS-CoV-2 pneumonia were more likely to require invasive mechanical ventilation (69.7 percent vs 36.2 percent; p<0.001) and had higher mortality.

In B-PCAP, mortality was associated with systemic complications (hyponatraemia, septic shock, and neurological complications), lower respiratory reserve, and tachypnoea. Meanwhile, chest pain and purulent sputum predicted lower mortality risk.

In SARS-CoV-2 pneumonia, mortality was associated with previous liver and cardiac disease, advanced age, altered mental status, tachypnoea, hypoxaemia, bilateral involvement, pleural effusion, septic shock, neutrophilia, and high blood urea nitrogen. On the other hand, ≥7 days of symptoms predicted lower mortality risk.