Prolonged fever in ESBL-producing Salmonella Typhi in Lebanon: Diagnostic challenges and the possible role of occult low-level carbapenemase activity

Salmonella Typhi remains a global health concern, particularly in travelers returning from endemic regions. We report a 32-year-old male with persistent fever after travel to Iraq. Initial investigations were inconclusive, but cultures later identified ESBL-producing S. Typhi resistant to ceftriaxone, fluoroquinolones, and TMP-SMX, but susceptible to meropenem. Fever persisted despite meropenem and resolved only after azithromycin was added. Standard testing showed no carbapenem resistance, suggesting possible undetected low-level carbapenemase activity. This case highlights the need for heightened clinical suspicion, use of advanced diagnostics, and consideration of combination therapy in prolonged typhoid fever, especially in returning travelers from high-resistance regions.