title: Epidemiological Characteristics and Clinical Treatment Outcome of Typhoid Fever in Ningbo, China, 2005-2014: Pulsed-Field Gel Electorophoresis Results Revealing Great Proportion of Common Transmission Sources.
abstract: We aimed to describe the molecular epidemiological characteristics and clinical treatment outcome of typhoid fever in Ningbo, China during 2005-2014. Eighty-eight Salmonella Typhi isolates were obtained from 307 hospitalized patients. Three prevalent pulsed-field gel electrophoresis (PFGE) patterns of 54 isolates from 3 outbreaks were identified. Overall, there were 64 (72.7%) isolates from clustered cases and 24 (27.3%) isolates from sporadic cases. Resistance to nalidixic acid (NAL) (n = 47; 53.4%) and ampicillin (AMP) (n = 40; 45.4%) and rare resistance to tetracycline (TET) (n = 2; 2.3%) and gentamicin (GEN) (n = 2; 2.3%) were observed. No isolates resistant to cefotaxime (CTX), chloramphenicol (CL), ciprofloxacin (CIP), and trimethoprim-sulfamethoxazole (SXT) were found. The occurrence of reduced sensitivity to CIP was 52.3% (n = 46). The medians of fever clearance time in cases with and without complications were 7 (interquartile range (IQR): 4-10) and 5 (IQR: 3-7) days (P = 0.001), respectively, when patients were treated with CIP or levofloxacin (LEV) and/or third-generation cephalosporins (CEP). Rates of serious complications were at low levels: peritonitis (2.3%), intestinal hemorrhage (6.8%), and intestinal perforation (1.1%). The present study revealed a long-term clustering trend with respect to PFGE patterns, occasional outbreaks, and the rapid spread of AMP resistance and decreased CIP susceptibility among S. Typhi isolates in recent years.
authors.affiliation: Department of Microbiology, Ningbo Municipal Centre for Disease Control and Prevention.
authors.forename: Qifa
authors.initials: Q
authors.lastname: Song
authors.affiliation: Department of Microbiology, Ningbo Municipal Centre for Disease Control and Prevention.
authors.forename: Yuanbin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Microbiology, Ningbo Municipal Centre for Disease Control and Prevention.
authors.forename: Wenping
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Microbiology, Ningbo Municipal Centre for Disease Control and Prevention.
authors.forename: Bo
authors.initials: B
authors.lastname: Yi
authors.affiliation: Department of Microbiology, Ningbo Municipal Centre for Disease Control and Prevention.
authors.forename: Guozhang
authors.initials: G
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D012485:Salmonella typhi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016896:Treatment Outcome; D014435:Typhoid Fever / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Salmonella enterica serotype typhi; antimicrobial resistance; clinical treatment outcome; pulsed-field gel electrophoresis (PFGE)