Epidemiological, and Clinical Characteristics of International Travelers with Enteric Fever and Antibiotic Resistance Profiles of their Isolates: A GeoSentinel Analysis.

Background. Enteric fever, caused by Salmonella enterica serovar Typhi (S. Typhi) and Paratyphi (S. Paratyphi), is a common travel-related illness. Limited data are available on their antimicrobial resistance (AMR) patterns among travelers. Methods. Records with a culture-confirmed diagnosis seen during or after travel from January 2007 to December 2018 were obtained from GeoSentinel. Traveler demographics and antimicrobial susceptibility data were analyzed. Isolates were classified as 'non-susceptible' if intermediate or resistant, or 'susceptible' in accordance with participating site's national guidelines. Results. A total of 889 travelers (S. Typhi, n=474; S. Paratyphi, n=414; co-infection, n=1) were included; 114 (13%) were children <18 years. Most (41%) traveled to visit friends and relatives (VFRs) and acquired the infection in South Asia (71%). Child travelers with S. Typhi were most frequently VFRs (77%). The median trip duration was 31 days (interquartile range: 18-61 days) and 448 of 691 (65%) had no pre-travel consultation. Of 143 S. Typhi and 75 S. Paratyphi isolates with susceptibility data, non-susceptibility to antibiotics varied (fluoroquinolones: 65% vs 56% respectively; cotrimoxazole: 13% vs 0%; macrolides: 8% vs 16%). Two S. Typhi isolates (1.5%) from India were non-susceptible to 3rd-generation cephalosporins. S. Typhi fluoroquinolone non-susceptibility was highest when infection was acquired in South Asia (70 of 90; 78%) and sub-Saharan Africa (6 of 10; 60%). Conclusions. Enteric fever is an important travel-associated illness complicated by AMR. Our data contributes to a better understanding of region-specific AMR helping inform empirical treatment options. Prevention measures need to focus on high-risk travelers including VFRs and children.