Antimicrobial Susceptibility Patterns and Associated Risk Factors In Enteric Fever: A Hospital-Based Study

Open Access

Abstract

Introduction: Enteric fever caused by Salmonella Typhi remains a significant public health challenge in Bangladesh, where dense urban populations, constrained sanitation infrastructure, and high antibiotic consumption have collectively driven a rapid and alarming deterioration in antimicrobial susceptibility profiles. The progressive failure of fluoroquinolones, the accelerating erosion of azithromycin efficacy, and emerging threats to third-generation cephalosporins have narrowed therapeutic options to a precarious few, making institution-level resistance surveillance an urgent clinical and public health priority. Aim of the Study: This study aimed to determine the antimicrobial susceptibility patterns and associated risk factors in enteric fever. Methods & Materials: This was a cross-sectional study conducted at the 300-bed General Hospital in Narayanganj, Bangladesh. The study duration lasted from November 2025 to April 2026, enrolling 55 consecutive patients with culture-confirmed enteric fever during this period.v Socio-demographic data were collected via a structured questionnaire, and associations between resistance and patient characteristics were analysed using Pearson Chi-Square and Fisher's Exact tests in SPSS v26.0, with statistical significance set at p < 0.05. Results: All 55 isolates were S. Typhi, with females (52.7%) and adults aged 18-40 years (58.2%) predominating; the mean patient age was 23.09 ± 10.25 years. Azithromycin demonstrated the highest resistance rate at 58.2%, which was significantly associated with age group (χ²=10.624, p=0.031), with paediatric patients accounting for 46.9% of resistant cases. Ciprofloxacin showed 23.1% outright resistance with a strikingly high intermediate susceptibility rate of 71.2%, rendering it clinically unreliable. Ceftriaxone and amoxicillin-clavulanate maintained the best susceptibility profiles, with resistance of only 1.8% and 2.0% respectively; resistance to both agents was confined exclusively to the elderly age group and was highly significant (ceftriaxone: χ²=12.986, p=0.002; amoxicillin-clavulanate: χ²=14.553, p=0.006). Meropenem resistance was similarly restricted to elderly patients (χ²=16.392, p=0.003). Cefixime and cotrimoxazole showed low resistance rates of 7.3% and 3.8% respectively, with significant associations with sanitation status (both p<0.001). No antibiotic resistance was significantly associated with patient sex (all p>0.05). Conclusion: This study confirms that azithromycin and ciprofloxacin are no longer reliable empirical choices for enteric fever management in this setting, given resistance rates of 58.2% and 23.1% respectively; ceftriaxone and cefixime remain the most defensible options pending culture results, though emerging plasmid-mediated cephalosporin resistance nationally demands vigilance, and elderly patients appear to carry a disproportionate burden of resistance to multiple drug classes, warranting age-tailored therapeutic strategies.