Analysis Of Clinical Features And Laboratory Predictors Of Severity In 315 Cases Pediatric Scrub Typhus

Objective(s):To explore the prevalence,clinical features and laboratory predictors of severe cases of scrub typhus in children,so as to provide a theoretical basis for the intervention and treatment of scrub typhus in children.Methods:Using the method of current situation research,the clinical data,laboratory and auxiliary examination data,treatment and outcome of 315 children with scrub typhus admitted to Kunming Children’s Hospital from January 2014 to December 2021 were collected in Excel.The research objects were divided into mild group and severe group according to the severity of the disease.SPSS 25.0 statistical software was used to conduct statistical analysis on the data,and to analyze the relevant laboratory predictors of children with severe scrub typhus.Results:1.Epidemiological characteristics1.1 Time and geographical distribution:Onset occurs throughout the year,and the highest peak occurs in July and August,showing a single-peak distribution.The province and rural cases each accounted for 93.0%;the out-of-province and urban cases each accounted for 7.0%.1.2 Population distribution:186 males and 129 females,male to female ratio 1.44:1.The age range was 10 days to 15 years old,with an average of(5.57±3.65)years old.Among children under 5 years old,the proportion of scrub typhus among children aged 2 to 3 was the highest,accounting for 15.2%.2.Clinical features2.1 Clinical manifestations2.1.1 Main symptoms:fever 100%,eschar or ulcer 91.8%,hepatomegaly 62.9%,cough 60.0%,splenomegaly 58.4%,superficial lymphadenopathy 50.5%,abdominal pain 39.4%,nausea and vomiting 36.8%,Edema 34.4%.2.1.2 Other symptoms:drowsiness 14.6%,shortness of breath 14%,diarrhea 6.4%,convulsions,coma,lower limb pain,unsteady standing,fatigue,jaundice,and gastrointestinal bleeding accounted for less than 5%.2.2 Laboratory examination2.2.1 Blood routine:WBC increased by 53.3%,anemia by 55.2%,thrombocytopenia by 61.6%,and EOS%by 88.9%.2.2.2 Inflammation indicators:PCT increased by 93.8%,SF increased by 89.5%,CRP increased by 87.9%,IL-10 increased by 60.7%,IL-6 increased,and ESR increased by 52.1%.2.2.3 Organ function damage indicatorsLiver function:ALT increased by 85.9%,AST increased by 86.5%,TP decreased by 75.5%,ALB decreased by 94.8%,hypoalbuminemia by 51.3%,and TBA increased by 44.4%.Myocardial enzymes:LDH increased by 88.0%,α-HBDH increased by 55.5%,LDH1,CK,and CKMB increased in 16.6%,9.7%,and 2.6%,respectively.Renal function:Elevated UA,Urea,and SCr accounted for 22.6%,18.0%,and 10.5%,respectively.Cerebrospinal fluid(CSF):WBC increased>10×106/L accounted for 66.5%,protein increased 12.5%.Electrolyte disorders:low Ca2+,low Na+,low K+,low Cl+ accounted for 62.8%,53.7%,47.5%,32.3%respectively,and high Mg2+accounted for 31.1%.Immune function:C3 in humoral immunity decreased by 48.2%,IgM increased by 44.5%;CD4/CD8 in lymphocyte subsets decreased by 56.0%.Fibrinogen(FIB):FIB decreased by 53.0%.Thyroid function:80.0%of the patients had abnormal thyroid function.2.2.4 Etiology detection:Orientia tsutsugamushi polymerase chain reaction(PCR)molecular detection was positive in 23 cases(92%);There were 54 cases(43.6%)OXK≥1:160 in Weil-Felix test.2.3 Auxiliary examination:Imaging examination showed interstitial pneumonia in 44.3%;brain sulci deepened and widened in 50.5%;Hepatomegaly and splenomegaly accounted for 52.1%and 51.1%respectively;pericardial effusion,peritoneal effusion and pleural effusion accounted for 40.6%,36.8%and 28.6%respectively;74.7%had abnormal ECG;74.5%had increased slow wave activity in EEG.3.Complications:digestive system involvement 92.7%;blood system involvement 88.3%;respiratory system involvement 73.0%;cardiovascular system involvement 65.1%;encephalitis or meningitis 53.7%;kidney damage 31.1%;multiple organ dysfunction syndrome(MODS)16.2%.4.Comparison between the severe group and the mild group4.1 There were significant differences in age,hepatomegaly,splenomegaly,serous cavity effusion,heat course,antipyretic time after treatment and hospitalization time between the severe group and the mild group(P<0.05).4.2 WBC,NEUT%,CRP,PCT,ESR,SF,LI-6,ALT,AST,TBA,ALB,LDH,CK,CK-MB,α-HBDH,Urea,UA,IgM in the severe group were significantly higher than those in the mild group.RBC,Hb,PLT,EOS%,FIB,TP,ALB,Na+,K+,Cl-,Ca2+,C3,CD4/CD8 in the severe group were significantly lower than those in the mild group.There were statistically significant differences between the two groups(P<0.05).4.3 After statistical regression analysis,it was found that the significant decrease of Hb,PLT,FIB and the significant increase of AST were laboratory predictors of severe scrub typhus in children(P<0.05).The combined use of Hb<93g/L,PLT<69×109/L,FIB<1.36g/L,and AST>145U/L can further improve the predictive value of severe scrub typhus in children.5.Treatment and outcomeAmong the 239 febrile patients admitted to the hospital,doxycycline was used,of which 88.3%had fever within 48 hours,and 8.8%had body temperature returned to normal within 72 hours.26.0%were given oxygen therapy,and 5.4%of them required mechanical ventilation.5 cases died,and 98.4%were discharged after being cured or improved.Conclusion(s):1.This study found that among children under 5 years old,the proportion of scrub typhus in children aged 2 to 3 was the highest.Fever with eschar and hepatosplenomegaly were the main clinical features of scrub typhus.2.This study found that Hb,PLT,FIB significantly decreased and AST increased significantly are laboratory of severe scrub typhus in children.Hb<93g/L,PLT<69×109/L,FIB<1.36g/L,AST>145U/L are laboratory predictors for severe scrub typhus in children.