Data from: Pneumococcal colonisation density: a new marker for disease severity in HIV-infected adults with pneumonia

Objective: High genomic load of pneumococcus from blood or cerebrospinal fluid has been associated with increased mortality. We aimed to analyse whether nasopharyngeal colonisation density in HIV-infected patients with community-acquired pneumonia (CAP) is associated with markers of disease severity or poor outcome. Methods: Quantitative lytA real-time PCR was performed on nasopharyngeal swabs in HIV-infected South African adults hospitalized for acute CAP at Chris Hani Baragwanath Hospital, Soweto,. Pneumonia aetiology was considered pneumococcal if any of sputum culture or Gram stain, urinary pneumococcal C-polysaccharide-based antigen, blood culture or whole blood lytA real-time PCR revealed pneumococci. Results: Among all-cause pneumonia patients, mean nasopharyngeal colonisation densities tended to increase with increasing CURB65 scores (Spearman correlation coefficient r=0.15, p=0.06). In patients with pneumococcal pneumonia, nasopharyngeal colonisation density was higher among non-survivors than survivors (7.7 vs. 6.1 log10 copies/mL, respectively, p=0.02) and among those who had pneumococci identified from blood cultures and/or by whole blood lytA real-time PCR than those with non-bacteraemic pneumococcal pneumonia (6.6 vs. 5.6 log10 copies/ml, p=0.03). Nasopharyngeal colonisation density correlated positively with the biomarkers procalcitonin (Spearman correlation coefficient r=0.37, p<0.0001), proadrenomedullin (r=0.39, p=0.008), copeptin (r=0.30, p=0.01). Conclusions: Nasopharyngeal colonisation density serves not only as a diagnostic but also as a severity marker for pneumococcal pneumonia in HIV-infected adults. It correlates with mortality and prognostic biomarkers.