Elevated procalcitonin is associated with increased mortality in patients with scrub typhus infection needing intensive care admission

Abstract

Context:Procalcitonin is a biomarker of bacterial sepsis. It is unclear if scrub typhus, a rickettsial illness, is associated with elevated procalcitonin levels.Aim:To assess if scrub typhus infection is associated with high procalcitonin levels and whether high levels portend a poorer prognosis.Setting and Design:Retrospective study of patients with severe scrub typhus infection, admitted to the medical intensive care unit of a tertiary care university affiliated teaching hospital.Materials and Methods:Eighty-four patients with severe scrub typhus infection that also had procalcitonin levels were assessed.Statistical Analysis:Relationship between procalcitonin and mortality explored using univariate and multivariate analyses.Results:The mean (±standard deviation) age was 40.0 ± 15.5 years. Patients were symptomatic for 8.3 ± 4.3 days prior to presentation. The median admission procalcitonin level was 4.0 (interquartile range 1.8 to 8.5) ng/ml; 59 (70.2%) patients had levels >2 ng/ml. Invasive mechanical ventilation was required in 65 patients; 20 patients died. On univariate analysis, admission procalcitonin was associated with increased odds of death [odds ratio (OR) 1.09, 95% confidence interval (CI) 1.03 to 1.18]. On multivariate logistic regression analysis including procalcitonin and APACHE-II score, the APACHE-II score was significantly associated with mortality (OR 1.16, 95% CI 1.06 to 1.30, P = 0.004) while a trend was observed with procalcitonin (OR 1.05, 95%CI 1.01 to 1.13, P = 0.09). The area under the receiver operating characteristic (ROC) curve, AUC, for mortality was 0.77 for procalcitonin and 0.78 for APACHE-II.Conclusions:Procalcitonin is elevated in severe scrub typhus infection and may be associated with higher mortality.

Predictors of Mortality in Scrub Typhus Infection Requiring Intensive Care Admission in Tertiary Healthcare Centre of Nepal

“…On multivariate analysis, age was observed to be a statistically significant predictor of mortality in our study, suggesting that increase in one year of age increases the odds of mortality by 1.063. Outcome was not associated with the sex of the patients in this study, and this finding is consistent with other studies [ 16 , 20 , 22 , 24 ].…”

“…However, this difference was not statistically significant in bivariate analysis. Similar results were observed in other studies [ 16 , 17 , 22 ], while some studies have indicated that increasing age is associated with death [ 20 , 23 , 24 ]. On multivariate analysis, age was observed to be a statistically significant predictor of mortality in our study, suggesting that increase in one year of age increases the odds of mortality by 1.063.…”

Severe scrub typhus infection: Clinical features, diagnostic challenges and management

“…The duration of treatment is 7 d. In critically ill patients, particularly those in shock, the absorption of enterally administered doxycycline may be problematic. In such situations, intravenous doxycycline should be used; where unavailable, intravenous azithromycin may be used in isolation or combined with enteral doxycycline [20,74] . Azithromycin is also the recommended drug for treatment of scrub typhus in pregnancy [77] .…”

“…In addition it is not inhibited by heme as is the case with PCR [73] . In the clinical setting, a diagnosis of scrub typhus is considered when a patient with an AFI has an eschar and a positive IgM ELISA for scrub typhus and other causes of fever excluded [74] . In the absence of an eschar, a positive IgM ELISA in the appropriate clinical setting with defervescence within 48-h of initiation of associated with significantly shorter median time to clearance of fever and lower adverse events when compared with azithromycin [75] .…”

Procalcitonin: present and future

“…Thus, the absence of an increase in serum PCT levels in patients with viral respiratory tract infection may be due to inhibition of PCT synthesis by IFN-c [10]. Although the PCT levels are also elevated in other microbial infections [45][46][47][48], three questions need consideration: first, the reports came from small-scale studies; second, the studies showed no evidences of an ability to exclude the possibility of co-infection with bacteria; third, the cut-off values for nonbacterial infections are unknown. We look forward to large-scale studies of PCT about other microbial infections in future.…”