Tracking antimicrobial resistance in typhoidal Salmonella, 2020-2024: Output from an antimicrobial resistance surveillance network in New Delhi, India

This surveillance study of over 10,000 Salmonella isolates in the Delhi NCR region (2020–2024) shows that while enteric fever remains a major public health burden—particularly among children—antimicrobial resistance patterns are shifting favorably for several first-line antibiotics. Resistance in S. Typhi declined for ampicillin and trimethoprim-sulfamethoxazole, chloramphenicol resistance remained low, and multidrug resistance dropped to just 1% by 2024. However, fluoroquinolone resistance remains persistently high (≈50–60% in S. Typhi and even higher in S. Paratyphi A), posing a continued challenge for treatment. Resistance to ceftriaxone, azithromycin, and carbapenems was rare or absent. Overall, the findings suggest a partial restoration of susceptibility to older antibiotics, but underscore the need for ongoing surveillance and careful antibiotic stewardship to preserve treatment options.