[Association between Severity of Scrub Typhus and Serum Procalcitonin Level]

Objective To explore the association between the severity of scrub typhus (ST) and the serum procalcitonin (PCT) level. Methods The clinical data of 58 ST patients who were treated in the First Affiliated Hospital of Xiamen University and confirmed by Xiamen Municipal Center for Disease Prevention and Control (CDC) from January 2016 to October 2017,were retrospectively analyzed. According to clinical manifestations and related laboratory tests,these patients were divided into four grades:Ⅰ,Ⅱ,Ⅲ,and Ⅳ. These four grade groups were compared in terms of age,interval from symptom onset to hospital presentation,hospitalization days,and serum PCT level. Results These 58 patients were divided into four grade groups:grade Ⅰ group (n=17),grade Ⅱ group (n=17),grade Ⅲ group (n=11),and grade Ⅳ group (n=13). No significant difference was found among these four groups in terms of age (F=0.618,P=0.606),interval from symptom onset to hospital presentation (F=1.744,P=0.169),and hospitalization days (F=0.398,P=0.755).However,the median serum PCT level in the grade Ⅳ patients[2.60(1.33,61.08)ng/ml] was significantly higher than those in grade I[0.24(0.10,0.33)ng/ml;Z=-4.63,P=0.000], grade Ⅱ[0.29(0.21,0.51)ng/ml;Z=-4.63,P=0.000], and grade Ⅲ[1.33(0.89,2.41)ng/ml;Z=-2.09,P=0.040].The median serum PCT level in the grade Ⅲ patients was also significantly higher than grade Ⅰ (Z=-4.16,P=0.000)and grade Ⅱ(Z=-3.83,P=0.000).There was no significant difference between the grade Ⅰ patients and grade Ⅱ patients(Z=-1.37,P=0.170).There was significantly positive correlation between PCT level and the severity of ST (r=0.804,P=0.000).Conclusion There is positive correlation between serum PCT level and the severity of ST,and serum PCT level may be a biomarker in assessing the severity of ST.