Epidemiological characteristics and clinical treatment outcome of typhoid fever in Ningbo China, 2005-2014, PFGE results revealing great proportion of common transmission sources

AUTHORS

Song Q, Yang Y, Lin W, Yi B, Xu G

ABSTRACT

We aimed to describe the molecular epidemiological characteristics and clinical treatment outcome of typhoid fever in Ningbo, China, 2005-2014. Eighty-eight Salmonella Typhi isolates were obtained from 307 admitted patients. Three prevalent pulsed-field gel electrophoresis (PFGE) patterns of 54 isolates in 3 outbreaks were identified. Overall, there were 64 (72.7%) isolates from cases in clusters and 24 (27.3%) isolates from sporadic cases. Resistance to nalidixic acid (n=47; 53.4%) and ampicillin (n=40; 45.4%) and rare resistance to tetracycline (n=2; 2.3%) and gentamicin (n=2; 2.3%) were observed. Isolates resistant to cefotaxime, chloramphenicol, ciprofloxacin and trimethoprim-sulfamethoxazole (SXT) were not found. The occurrence of reduced sensitivity to ciprofloxacin was 52.2% (n=46). The medians of fever clearance time in cases with complications and cases without complications were 7 (IQR: 4-10) and 5 (IQR: 3-7) days (P=0.001), respectively, when cases were treated with ciprofloxacin or levofloxacin and/or third-generation cephalosporins. The rates of serious complications were at low levels: i.e., peritonitis (2.3%), intestinal hemorrhage (6.8%), and intestinal perforation (1.1%). Present study exhibits clustering trend over long-term periods in terms of clustering PFGE patterns, occasional outbreaks and rapid spread of ampicillin resistance and decreased ciprofloxacin susceptibility among S. Typhi isolates in recent years.

Click here to view the article, published in Japanese Journal of Infectious Diseases