Update on Extensively Drug-Resistant Salmonella Serotype Typhi Infections Among Travelers to or from Pakistan and Report of Ceftriaxone-Resistant Salmonella Serotype Typhi Infections Among Travelers to Iraq - United States, 2018-2019.

Louise Francois Watkins ,Jessica C Chen,Faris Lami,Aamer Ikram,Vickneswaran Sabaratnam,Cindy R Friedman,Gauri Godbole,Alison Winstead,Kaitlin A Tagg,Abdinasir Abubakar,Molly Leeper,Asaad M Asaad,Perrine Marcenac,Felicita Medalla,Kristina M Angelo,Grace D Appiah,Ashley E Wiggington,Zachary Schneider ,Elizabeth H Meservey ,Kelly Walblay ,Simon Hanna ,Allison Taylor Walker ,Meseret Birhane ,Michael Hughes ,Eric D Mintz

doi:10.15585/mmwr.mm6920a2

Abstract

Ceftriaxone-resistant Salmonella enterica serotype Typhi (Typhi), the bacterium that causes typhoid fever, is a growing public health threat. Extensively drug-resistant (XDR) Typhi is resistant to ceftriaxone and other antibiotics used for treatment, including ampicillin, chloramphenicol, ciprofloxacin, and trimethoprim-sulfamethoxazole (1). In March 2018, CDC began enhanced surveillance for ceftriaxone-resistant Typhi in response to an ongoing outbreak of XDR typhoid fever in Pakistan. CDC had previously reported the first five cases of XDR Typhi in the United States among patients who had spent time in Pakistan (2). These illnesses represented the first cases of ceftriaxone-resistant Typhi documented in the United States (3). This report provides an update on U.S. cases of XDR typhoid fever linked to Pakistan and describes a new, unrelated cluster of ceftriaxone-resistant Typhi infections linked to Iraq. Travelers to areas with endemic Typhi should receive typhoid vaccination before traveling and adhere to safe food and water precautions (4). Treatment of patients with typhoid fever should be guided by antimicrobial susceptibility testing whenever possible (5), and clinicians should consider travel history when selecting empiric therapy.

Highlights

Committee of Medical Journal Editors form for disclosure of potential conflicts of interest
Clinicians and public health officials should remain vigilant for ceftriaxone-resistant Typhi in patients who have traveled to Pakistan, Iraq, or neighboring countries
Public health officials and clinicians should remain vigilant for cases of ceftriaxone-resistant Typhi in patients who have traveled to countries neighboring Iraq and Pakistan and of strains of Typhi with more extensive resistance, to azithromycin, because this has been reported from some parts of South Asia (9)

Summary

Morbidity and Mortality Weekly Report

Update on Extensively Drug-Resistant Salmonella Serotype Typhi Infections Among Travelers to or from Pakistan and Report of Ceftriaxone-Resistant Salmonella Serotype Typhi Infections Among Travelers to Iraq — United States, 2018–2019. MD11; Vickneswaran Sabaratnam, MPH12; Aamer Ikram, PhD13; Kristina M. CDC had previously reported the first five cases of XDR Typhi in the United States among patients who had spent time in Pakistan (2). This report provides an update on U.S cases of XDR typhoid fever linked to Pakistan and describes a new, unrelated cluster of ceftriaxone-resistant Typhi infections linked to Iraq. Local and state public health departments send epidemiologic information from culture-confirmed cases to CDC’s National Typhoid and Paratyphoid Fever Surveillance system and submit isolates to CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory for antimicrobial susceptibility testing. 30 (31%) isolates were identified as XDR by antimicrobial susceptibility testing (28) or WGS (two); isolates were resistant to ceftriaxone, ampicillin, chloramphenicol, ciprofloxacin, nalidixic acid, streptomycin, sulfisoxazole, and trimethoprim-sulfamethoxazole (Figure 2).

Date of rst positive Salmonella Typhi culture by month and year

Intermediate susceptibility

Discussion

What are the implications for public health practice?