| Objective To understand the detection and distribution characteristics of typhoid and paratyphoid fever with fever syndrome in Guangxi from 2010 to 2019,and to reveal the composition and epidemiology of pathogens,so as to provide reference for monitoring,early warning and prevention and control of typhoid and paratyphoid fever in Guangxi.To explore the drug resistance and molecular typing characteristics of Salmonella typhi and Salmonella paratyphoid based on fever with rush syndrome surveillance,and to establish the etiological database of typhoid and paratyphoid fever,so as to provide scientific basis for the selection of clinical antibiotics and the traceability of infectious diseases in Guangxi.Methods Epidemiological data of fever with rash syndrome in Nanning,Guilin,Guigang and Wuzhou sentinel hospital from 2010 to 2019 were collected by surveillance method,and corresponding blood and pharyngeal swabs were collected for isolation,culture and serological detection of pathogens(Streptococcus type A,Salmonella typhi,Salmonella paratyphoid,Borrelia burgdorferi,Rickettsia).Antimicrobial susceptibility test and molecular typing of isolated typhoid and paratyphoid strains were carried out by Microbroth dilution(MIC)and pulsed field gel electrophoresis(PFGE)respectively.Excel2016 and SPSS.26.0 were used to describe and analyze the distribution characteristics of typhoid and Paratyphoid accompanied by fever with rash syndrome.Chi-square test,Fisher exact probability method or Kruskal-Wallis Test were used to compare the differences,and the significance levelα=0.05.The results of PFGE typing were analyzed by Bio Numerics analysis system.The clustering method was unweighted pair group average method(UPGMA),and the clustering similarity coefficient(distance)was Dice based on strip comparison.Results 1.Basic information:A total of 973 cases of fever with rash syndrome were monitored from 2010 to 2019,and 973 blood and throat swab samples were collected and tested,and 218 strains of pathogens were detected,with a detection rate of 22.40%(218/973).Among them,there were 17 strains of Streptococcus type A,52 strains of Salmonella typhi and 149 strains of Salmonella Paratyphoid A,with pathogen positive rates of 1.75%,5.34%and 15.31%respectively.The monitoring cases of fever with rash syndrome were composed of 548 males(56.01%),428 women(43.99%);314 cases(32.17%)were under10 years old,followed by 175 cases(17.99%)in 10～years old group.The gender distribution among different age groups was significant difference(H=888.792,P<0.001).The occupational distribution of monitored cases is mainly farmers and students,with 358 cases(36.79%)and 280 cases(28.78%)respectively.2.Population distribution characteristics of typhoid and paratyphoid:Among the 973 monitoring cases of fever with rash syndrome,there were 201 positive cases of typhoid and paratyphoid,among which 100 were male(the positive rate was 18.35%)and 101 were female(the positive rate was 23.60%).There was no significant difference in the positive detection rate of typhoid and paratyphoid between male and female(?~2=4.032,P=0.133).The positive rates of Salmonella typhi and Salmonella Paratyphoid A in women were higher than those in men(6.07%vs4.77%,17.52%vs13.58%),and there was no significant difference in the detection rates of typhoid and Paratyphoid A between different genders(?~2=0.806,P=0.369;?~2=2.878,P=0.090).Among typhoid fever and paratyphoid fever A of different ages,the positive rate of pathogens in 10～years old group was the highest,and the positive rate was 57.71%.Followed by the 20～years old group,the positive rate was 33.33%;There are differences in the positive rate of typhoid and Paratyphoid A pathogens among different ages(H=210.160,P<0.001).The positive rate of Salmonella typhi in 20～years old group is the highest,with a positive rate of 12.00%.Followed by the positive rate of 10.29%in 10～years old group.The highest positive rate of Salmonella Paratyphoid A was 10～years old,with a positive rate of 47.43%,followed by 20～years old,with a positive rate of21.33%.There were significant differences in the positive rates of Salmonella typhi and Salmonella Paratyphoid A among different age groups(H=28.443,P<0.001;?~2=185.503,P<0.001).The age distribution of typhoid and Paratyphoid A positive cases is mainly 10～years old,followed by under 10 years old,followed by 20～years old,and the outbreak positive cases are mainly teenagers and children.Sporadic cases are mainly young and middle-aged people.The main cases of typhoid and Paratyphoid A are student cases(57.62%);followed by farmers(10.45%),and the difference of occupational distribution between typhoid and paratyphoid is statistically significant(Fisher exact probability method:P<0.001).3.Temporal characteristics of typhoid and paratyphoid:the highest pathogen positive rate was 100%in 2018 and 2017,followed by 2013,with a pathogen positive rate of 50.00%;In 2010,the pathogen positive rate was 44.05%.The positive rate of typhoid fever and paratyphoid fever was significantly different from year to year(H=508.996,P<0.001).The positive rate of typhoid and paratyphoid pathogens showed a downward trend in all years,There were significant differences in pathogen positive rates between typhoid fever and paratyphoid fever A in each year(H=211.782,P<0.001;H=571.905,P<0.001respectively);the highest positive rate of typhoid and paratyphoid pathogen in fever with rash syndrome was in October(69.50%),followed by July(29.29%),and there was a significant difference in the positive rate of typhoid and paratyphoid pathogen in each month(H=639.338,P<0.001).The positive rate of typhoid fever is the highest in summer,followed by winter;The positive rate of Paratyphoid A was the highest in autumn,followed by summer.There are differences in the positive rate of typhoid and Paratyphoid A pathogens in different seasons(?~2=27.958,P<0.001;?~2=315.396,P<0.001 respectively).4.Regional distribution characteristics of typhoid and paratyphoid:Typhoid and Paratyphoid A were the highest detection rate in Nanning,with 5.41%and13.51%respectively.There was no significant difference in the detection rate of typhoid in different regions((Fisher exact probability method:P=0.657),but there was significant difference in the detection rate of Paratyphoid A in different regions((Fisher exact probability method P=0.002).5.Drug resistance characteristics of Salmonella typhi and Salmonella Paratyphoid A:147 strains of typhoid and paratyphoid in Guangxi have the highest drug resistance rate of nalidixic acid,which is 95.24%;The MIC distribution of Salmonella Paratyphoid A to azithromycin,chloramphenicol and cefoxitin was higher than that of Salmonella typhi.The main drug resistance spectrum of typhoid and paratyphoid bacteria is sulfisoxazole-nalidixic acid(SUL-NAL),The multidrug resistance rates of typhoid and paratyphoid bacteria were 8.57%and 7.34%,respectively.The analysis of the change trend of drug resistance rate showed that the resistance rate of Salmonella Paratyphoid A to ciprofloxacin increased,while the resistance rate to nalidixic acid and sulfa isoxazole decreased.6.PFGE molecular typing characteristics of Salmonella typhi and Salmonella Paratyphoid A:52 Salmonella typhi strains were subjected to pulsed field gel electrophoresis,and 31 bands were obtained,with JPPX01.CN0720 as the main band,accounting for 21.15%,followed by JPPX01.CN0200 and JPPX01.CN0721,accounting for 7.69%each;A total of 22 PFGE bands were obtained from 111strains of salmonella Paratyphoid A,with JKPS18.CN0140 as the main band,accounting for 54.05%,followed by JKPS18.CN0173,accounting for 10.81%.Conclusion 1.Salmonella Paratyphoid A and Salmonella typhi are the main pathogens of fever with rash syndrome in Guangxi.Children and adolescents are the key populations of typhoid and paratyphoid infection.The occupational distribution of typhoid and paratyphoid is mainly among students and farmers.Summer and autumn are the peak of typhoid and paratyphoid epidemic,which suggests that we should strengthen the monitoring of key populations in routine monitoring.Strengthen school hygiene and student health education;Improve rural living and drinking water conditions,promote rural health education,and raise people’s awareness of typhoid and paratyphoid fever prevention;Strengthen the management of water and food during the epidemic period to prevent outbreaks.2.The pathogen of typhoid and paratyphoid fever in Guangxi has the highest drug resistance rate to nalidixic acid,followed by sulfisoxazole.The drug susceptibility to ciprofloxacin decreases and resistance rate gradually increases,and it is sensitive to the third generation cephalosporins,?-lactams and macrolides.It is suggested that the third generation cephalosporins、?-lactams and macrolides can be used for typhoid and paratyphoid fever clinical treatment,with caution use of sulfonamides and quinolones.3.Sulfisoxazole-Nalidixic acid(SUL-NAL)is the main drug resistance spectrum of typhoid and paratyphoid strains,the drug resistance spectrum of Salmonella typhi and Paratyphoid Ain Guangxi is widely distributed is widely distributed and there are multi-drug resistant strains.It is suggested that the use of antibiotics for typhoid and paratyphoid in Guangxi should be strengthened to prevent the further development of multi-drug resistance.4.The diversity of molecular types of Salmonella typhi in Guangxi is high,but the diversity of molecular types of Salmonella paratyphoid Ais low.Both of them have dominant clonal strains.The typing consistency of Salmonella Paratyphoid and Salmonella typhi A in outbreak is high,PFGE plays an important role in epidemic surveillance and outbreak identification. |
