Usefulness of Routine Antibacterial Susceptibility Testing Results for Resistance Surveillance in Lagos Metropolis

Abstract

The objective was to evaluate the usefulness and reliability of routine antibacterial susceptibility testing data in antibacterial resistance surveillance in Lagos Metropolis. The antibacterial susceptibility testing results of 3,961 clinical isolates of bacteria from four highly rated hospitals in Lagos metropolis were collated and evaluated. Sampling was systematically randomized over any four consecutive years between 2002-2009 for each hospital. The bacteria isolates and their respective degree of susceptibility/resistance profile among other parameters were collected using an appropriately designed and validated data collection form. Data were evaluated for conclusive identification of isolates and complete documentation of susceptibility/antibacterial resistance profile. Disk diffusion method of antibacterial susceptibility testing was used by the four hospitals. Apart from E. coli, only one hospital had a conclusive identification of all isolates. Reporting was similar but records were not as uniform with 4-graded and 3-graded reporting formats for susceptible and resistant isolates. None of the four hospitals has a comprehensive computerized data base of their antibacterial susceptibility results. Only one hospital; the oil company hospital, had a complete and consistent documentation in addition to a conclusive isolates identification. Documentation of resistant cases was incomplete in two hospitals and the fourth hospital had inconsistent graded reporting format. High degree of susceptibility of E coli isolates was exhibited to ciprofloxacin and ceftriaxone; 77.0% and 78.2% respectively. The isolates were highly resistant to amoxicillin (86.6%), tetracycline (91.0%), and cotrimoxazole (82.2%). Routine antibacterial susceptibility testing results as presently obtained in most of the hospitals are not reliable for surveillance purposes. Relevant policies and improvement in capacity building to enhance the reliability is of absolute necessity.

Keywords: Antibacterial Resistance, Infectious Diseases, Antibacterial Therapy, Antimicrobial resistance.