Burkholderia pseudomallei serology: Worth the hassle?

Abstract

Background: Melioidosis is an infection caused by Burkholderia pseudomallei. Bacteraemia is the most common presentation occurring in 38-73% of patients, with a mortality rate up to 42%. There is limited published data regarding laboratory investigations associated with bacteraemia or mortality. This study assessed standard laboratory investigations and their association with patient outcomes. Methods: Retrospective cohort study in Townsville, Australia. Medical and laboratory records of 124 patients were reviewed from 1 January 1997 -31 December 2020. Results: 87 (70%) patients were bacteraemic and 27 (22%) died. Lymphopenia on admission (<1.5×10 9 cells/L) was the highest risk for bacteraemia [relative risk (RR) 2.2; 95% CI 1.3-3.7, p<0.001). Mortality was associated with lymphopenia, (RR 1.4; 95% CI 1.2-1.6, p= 0.004); uraemia (RR 1.7; 95% CI 1.1 -2.5, p=0.03); and an elevated international normalised ratio (INR) (RR 1.5; 95% CI 1.2-2.0, p=0.006). External validation of the Darwin predictive mortality scoring system demonstrated 85% sensitivity. Conclusion: Simple baseline investigations at time of presentation may be used to stratify patients at high risk for both bacteraemia and mortality. Clinicians may use this information as a decision tool for early intensive management.