Critical pertussis: A multicentric analysis of risk factors and outcomes in Oman.

Abstract

OBJECTIVES\nTo identify risk factors and outcomes of patients with critical pertussis.\n\n\nDESIGN\nA retrospective observational cohort study.\n\n\nSETTING\nSultan Qaboos University Hospital and The Royal Hospital, Muscat, Oman.\n\n\nSUBJECTS\nChildren <13 years presenting to the Emergency Departments and diagnosed with laboratory-confirmed pertussis by PCR, between January 2013 and December 2018.\n\n\nMEASUREMENTS AND MAIN RESULTS\nThere were a total of 157 patients with pertussis, of which 12% (n\u2009=\u200919) had critical pertussis. Those with critical pertussis had higher counts of white blood cell (WBC) (adjusted odds ratio (aOR), 1.05; 95% confidence interval (CI): 1.02-1.08; p\u2009=\u20090.003), absolute lymphocyte count (ALC) (aOR, 1.08; 95% CI: 1.03-1.15; p\u2009=\u20090.004) and absolute neutrophil count (ALC) (aOR, 1.05; 95% CI: 1.01-1.10; p\u2009=\u20090.032) even after multivariate adjustment. The area under the curve (AUC) for discriminatory accuracy of laboratory variables were 0.75 (95% CI: 0.65-0.85), 0.74 (95% CI: 0.64-0.84) and 0.72 (95% CI: 0.60-0.83), for maximum WBC, ALC and ANC, with the Youden s cut-off values of 31.5 x109/L, 19.9\u2009×\u2009109/L and 5.0\u2009×\u2009109/L, respectively.\n\n\nCONCLUSIONS\nIn children, higher counts of WBC, ALC and ANC were significant predictors of critical pertussis. A 31.5\u2009×\u2009109/L WBC cut-off was also associated with critical pertussis.