Resistance and utilisation pattern of antibacterial agents in outpatient settings in two Teaching Hospitals in Colombo.

OBJECTIVES: Antibacterial resistance (ABR) is a public threat. Sri Lanka is a country with limited surveillance of ABR in the community. The WHO methodology was adapted to identify ABR in outpatient settings (nonhospitalised patients) and its link to consumption of antibiotics.

METHODS: It was a cross-sectional descriptive community based study to collect ABR data from Out Patient Department (OPD) of two leading Teaching Hospitals in Colombo district. The indicator organism Escherichia coli (E. coli) was obtained from the urine specimens of patients who were suspected to have urinary tract infections. Antibiotic susceptibility testing was performed for commonly used oral antibiotics using disc diffusion method. The antibiotic consumption aggregate data were collected from the OPD pharmacies of the said hospitals and expressed as Defined Daily Doses (DDD) per 1000 inhabitants per 1000 day.

RESULTS: Of the 2183 urine samples, pathogenic E. coli was isolated in 9.3% (204), and 8% (n=16) of them were Extended Spectrum Beta Lactamase (ESBL) producers. E.coli was most resistant to ampicillin (85%), followed by nalidixic acid (58.5%), trimethoprim/sulphamethoxazole (47.1%), ciprofloxacin (46.2%), norfloxacin (43.7%) amoxicillin /clavulanic acid (36.3%) and nitrofurantoin (15%). Multi-drug resistance was seen in 44%. Amoxicillin was the most frequently consumed antibacterial agent (2.65 DDD per 1000 inhabitants per day).

CONCLUSIONS: There is an alarmingly high antibiotic resistance in the non-hospitalised patients indicating high prevalence of E. coli resistance in the community.