A case of Extensively Drug Resistant (XDR) Extended Spectrum Beta-Lactamase (ESBL) Typhoid Fever in the Ambulatory Emergency Care (AEC) Unit

Abstract Background An outbreak of extensively drug resistant (XDR) Salmonella Typhi (S. Typhi) has recently emerged from Pakistan. The strain is resistant to most first-line antibiotics, including cephalosporins, and has become a significant public health threat due to limited treatment options. We report one such case of S.Typhi in a 48-year-old female presenting to our West London ambulatory emergency care department. Case Report The patient, who had recently travelled to Pakistan, presented with symptoms of a dry cough, fever, maculopapular rash, and dysuria. Blood cultures initially isolated Salmonella spp, serotype Typhi and empirical ceftriaxone was commenced. Antibiotic sensitivity testing (AST) identified Salmonella spp. ESBL (Extended Spectrum Beta Lactamase-producing) subspecies I (ST1 EBG:13), with cephalosporin and fluoroquinolone resistance (ciprofloxacin MIC 2mg/L), hence labelling it XDR. It retained susceptibility to meropenem and azithromycin (azithromycin MIC 12mg/L). An ESBL Escherichia coli was concurrently grown in urine cultures. Once antibiotic sensitivities were available, the patient was converted from ceftriaxone to a course of azithromycin orally and ertapenem intravenously. The patient defervesced promptly, demonstrated blood and urine clearance on follow up and was successful treated. Conclusions This case report highlights the limitations of ceftriaxone in our empirical management of suspected typhoid fever, especially in those returning from high-risk regions. Increased prevalence of these resistant salmonella will lead to failures of the current treatment practices and continuous surveillance and improving infection control measures are required to mitigate the spread of these XDR S. Typhi. Azithromycin and carbapenems retain in vitro activity and play an important role in treatment of XDR S. Typhi; loss of the organism’s sensitivity to these agents presents a serious public health threat. Further studies are warranted to confirm in vivo efficacy of ertapenem particularly when used as monotherapy.