Infectious Disease · Public Health · 2 h ago
US Enteric Fever Isolates Show High Ciprofloxacin Nonsusceptibility
A cross-sectional surveillance study examined 2,342 culture-confirmed enteric fever cases in the US from 2016 to 2020. Ciprofloxacin nonsusceptibility was common among tested Typhi and Paratyphi A isolates, while ceftriaxone resistance was found in a subset of Typhi isolates.
- Ciprofloxacin nonsusceptibility was common in Typhi and Paratyphi A.
- Ceftriaxone resistance occurred in 5.5% of tested Typhi isolates.
- Authors support susceptibility-guided treatment for enteric fever.
This cross-sectional, laboratory-based study linked US National Typhoid and Paratyphoid Fever Surveillance data with antimicrobial susceptibility results for culture-confirmed enteric fever diagnosed from 2016 through 2020. It included 2,342 cases: 1,784 typhoid and 558 paratyphoid infections. Most patients with available travel data had traveled or resided internationally within 30 days before illness onset (1,853/2,217; 81.9%). Susceptibility testing was available for 1,635 isolates.
Ciprofloxacin nonsusceptibility was reported in 78.4% of tested Typhi isolates (1,061/1,354) and 94.2% of Paratyphi A isolates (258/274). Among Typhi isolates, resistance exceeded 15% for ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 5.5% (74 isolates) were ceftriaxone-resistant. One Typhi isolate was azithromycin-resistant. Resistance to these agents was not observed among Paratyphi isolates.
The findings support avoiding ciprofloxacin as empiric therapy for most travel-associated enteric fever cases and tailoring treatment to susceptibility results. The study is based on US surveillance from 2016–2020, and the results may not reflect current resistance patterns or apply equally across settings; susceptibility testing was not available for every case.
In practice
For patients with suspected travel-associated enteric fever in the US, these surveillance findings argue against ciprofloxacin as empiric therapy: 78.4% of tested Typhi and 94.2% of tested Paratyphi A isolates were nonsusceptible. Ceftriaxone resistance was also documented in 5.5% of Typhi isolates. The study supports using susceptibility results to guide treatment, but it describes isolates collected in 2016–2020 and may not represent current patterns or resistance in other settings. It does not establish a specific treatment regimen.
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JAMA Network Open: Enteric Fever and Antimicrobial Resistance ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.