Co-infection with Salmonella typhi and Salmonella paratyphi A in a Young Female with Prolonged Febrile Illness: A Case Report

Abstract

Background: Co-infection with Salmonella enterica serovars Typhi and Paratyphi A has been reported very rarely. The overlapping clinical characteristics of this co-infection pose serious challenges for diagnosis and treatment. There is possibility of misidentification and inconsistent antimicrobial susceptibility patterns.  The increased incidence of antibiotic resistance exacerbates these problems in endemic areas. Case Presentation: A 29-year-old immunocompetent female presented with a prolonged febrile illness that did not respond to initial empirical antibiotics. Blood cultures showed mixed growth of S. Typhi and S. Paratyphi A, and susceptibility profiles were conflicting.  Coinfection was confirmed by molecular diagnostic testing and a thorough microbiological assessment. Discussion: This case highlights the complexity of managing Salmonella co-infections. Clinical improvements were delayed in patient due to the difference in culture-based susceptibility results for each isolate. This led to a treatment strategy based on molecular confirmation and close clinical monitoring. Missed or delayed identification of such co-infections can result in treatment failure and prolonged morbidity in endemic situations. Conclusion: Clinicians should maintain a high index of suspicion for Salmonella co-infections in patients with persistent febrile illness in endemic regions. Incorporating molecular diagnostics alongside traditional culture methods can improve diagnostic accuracy and guide effective treatment, especially in the face of emerging antimicrobial resistance.