Study of azithromycin sensitivity in enteric fever in pediatric population

Abstract

Background: Enteric fever is a major human infectious disease in Southeast Asia. It is exacerbated by a high level of resistance some isolates display to the drugs routinely used in treatment. Azithromycin may be a treatment option for such isolates. Objective: The objective of this study was to analyze the azithromycin susceptibility in culture positive enteric fever and to evaluate the relationship between ciprofloxacin and azithromycin sensitivity and resistance patterns. Methods: This retrospective study was conducted at a tertiary care hospital, Bengaluru, India, between June 2012 and June 2016. Case records of 363 children in the age group of 0–18 years diagnosed with proven enteric fever were reviewed. Susceptibility to antimicrobial drugs was tested by the disc diffusion according to Kirby-Bauer method. They were interpreted based on Clinical and Laboratory Standards Institute guidelines 2016. Results: There were 280 Salmonella enterica serovar typhi (77.13%) and 83 serovar paratyphi A strains (22.86%) among the 363 enteric fever children. The susceptibility to azithromycin and third-generation cephalosporins has been 100% among these isolates. Azithromycin minimum inhibitory concentrations (MICs) were 0.064–12 ?g/ml among the 363 isolates, and there is no increase in resistance in the past 4 years. Only 5 (18.5%) of the isolates which were resistant to ciprofloxacin had MIC >4 to azithromycin, but none were resistant to azithromycin. Conclusion: Salmonella typhi continues to remain susceptible to azithromycin and third-generation cephalosporins. There is no increasing trend in resistance to azithromycin over the years in the area of study. Azithromycin can be used in the isolates resistant to ciprofloxacin as there is no correlation between their resistances, thus making it a safe alternative for oral therapy of enteric fever in children.