Etiological Analysis Of Typhoid Fever In Children And Risk Factors For Its Complications

Objective:To investigate the characteristics and complications of typhoid fever?TF?in children in Chongqing area in recent 10 years.Methods:The clinical data of TF children diagnosed in our hospital from 2008 to 2018 were analyzed retrospectively.The complications and related data of hospitalized TF children from 1998 to 2018 were also reviewed.Results:TF was sporadic in children and occurred all year round.The mean time from onset to diagnosis was 12.0±8.3 days.The average hospitalization time was 10.2±6.8 days,and the average time for abatement of fever was 5.4±4.8 days.The symptoms of typhoid fever in children were atypical,and apathetic expression,roseola and relative bradycardia were only found in 10 cases aged more than 3 years.The time from onset to diagnosis of typhoid fever was relatively long?12.0±8.3 days?.Only16.1%cases?9/56?were suspected for typhoid fever or confirmed when admission.Almost all the children with TF had febrile symptoms,and the rest were mainly characterized by diarrhea and respiratory tract infection.The mean duration of fever and diarrhea was 12.7±7.9 days and 5.8±4.6days,respectively.In most children with diarrhea,the diarrhea often occurred within 1-5 days after fever.The positive rates of bacterial culture were 63.8%in blood culture,41.7%in bone marrow culture and 39.0%in fecal culture.However,the positive rate of Widal test was only 8.8%.Peripheral blood leukopenia was found in 26.8%cases?15/56?.82.1%?46/56?has anemia,with mild anemia in 58.9%?33/56?.Thrombopenia was present in 67.9%?38/56?,and eosinophil count decreased in 73.8%and disappeared in 40.5%.Children with typhoid were prone to electrolyte disorders?hyponatremia,hypokalemia and hypocalcaemia?,especially in children aged less than 3 years.12.2%of the positive cases showed multidrug resistance.The sensitivity of clinical isolates to ceftazidime,cefepime,ceftriaxone,cefotaxime,ciprofloxacin and levofloxacin showed no significant change compared with that in 1993-2008^[1].Stratified by age group,cases aged more than 3 years infected with Salmonella typhimurium were more sensitive to cefotaxime,tianone and piperazone than infants aged less than 3 years.Complications occurred in 78.9%?71.7%-86.1%?of children with TF.Using multivariate regression analysis,we found that thrombocytopenia?OR:1.146;95%CI:1.040-1.264;p<0.05?and the age of the child were significantly associated with TF complications?OR:2.639;95%CI:1.107-6.292;p<0.05?.Of note,the degree of thrombocytopenia,age was also related to the number of complications.There was no correlation between sex,leukocyte,hemoglobin,eosinophil and multidrug resistance.Conclusion:TF in children in Chongqing,Sichuan,Guizhou area is sporadic and can occur all year round,with more morbidity in summer.TF is more common in children aged over 6 years.Clinical manifestations are not typical and often misdiagnosed.The time from onset to diagnosis of typhoid fever was relatively long.Febrile symptoms and diarrhea are still the main characteristics of the children with TF.In most children with diarrhea,the diarrhea often occurred within 1-5 days after fever.The positive rate of blood culture was the highest.For culture-negative individuals,Widal test and eosinophil counts may be useful in the diagnosis of IF.There was no significant change in the sensitivity of clinical isolates in the last 25 years in the three generation of cephalosporin and quinolones.Children with TF are prone to complications,and children with thrombocytopenia or older age are more prone to these complications and also more prone to multiple complications.