Association between Pre-Hospital Antibiotic Exposure and Level of Bacterial Resistance (PHAE Study): A Matched Case Control Study at the Medical and Paediatric wards of Mbarara Regional Referral Hospital-South Western Uganda

Abstract

Background: This study aimed to determine the association between pre-hospital antibiotic exposure and level of bacterial resistance among adult and paediatric patients. Methods: In the study, 79 antibiotic pre-exposed patients (cases) were compared with 79 non-pre-exposed patients (controls) hospitalized at medical and paediatric wards at Mbarara Regional Referral Hospital (MRRH) for various bacterial diagnoses. Data collected included participant demographics, previous medications and bacterial culture and sensitivity results. Data was analysed to determine the odds ratios for the occurrence of bacterial resistance between the cases and controls. Results: Results from the study showed that there was no statistically significant difference in terms of antibiotic resistance between pre-exposed and non-pre-exposed participants (OR: 0.5, 95%CI: 0.045 - 5.51, P = 0.571), whereby “no resistance” was defined as zero antibiotics resisted and “resistance” defined as 1 or more antibiotics resisted. However, when we adjusted the definition of “no resistance” and “resistance” to mean “one or less antibiotics resisted” and “two or more antibiotics resisted” respectively, there was a statistically significant more resistance in pre-exposed participants (cases) compared to non-pre-exposed participants (OR: 7, 95% CI: 1.59 - 30.8; p = 0.010). When the definition of resistance was further adjusted upwards to “three or more antibiotics resisted”, the resistance in cases was still significantly higher compared to controls (OR: 5.4, 95%CI: 2.42 - 12.2, p = 0.000) and when the definition of resistance was further adjusted to “four or more antibiotics resisted”, the OR increased even further (OR: 7.14, 95%CI: 3.24 - 15.8, p = 0.000). Ceftriaxone (17.6%) and amoxicillin (14.1%) were the commonest antibiotics to which participants were pre-exposed. Conclusion: The study showed that pre-hospital antibiotic exposure is strongly associated with resistance to one or more antibiotics. Strategies should be sought to reduce the level of such exposures and to enforce proper screening of patients during admission to facilitate rational prescription of antibiotics, improve quality of care, and slow the emergence of antimicrobial resistance in the management of infections. Registration: This study was approved and registered by Mbarara University Research Ethics Committee (MUREC) and its number is 53/03-20