Aetiology of ear infection and antimicrobial susceptibility pattern among patients attending otorhinolaryngology clinic at a tertiary hospital in Dar es Salaam, Tanzania: a hospital-based cross-sectional study

Abstract

ObjectivesTo determine the aetiological pathogens causing ear infections and their antimicrobial susceptibility patterns among patients with ear complaints at a tertiary hospital in Dar es Salaam.DesignHospital-based cross-sectional study.SettingsOtorhinolaryngology clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania.ParticipantsPatients presenting with signs and symptoms of ear infection.Main outcome measureBacteria and fungi isolated from ear swab specimens of patients presenting with signs and symptoms of ear infection; and antimicrobial susceptibility patterns of isolated bacteria.ResultsTwo hundred and fifty-five participants were enrolled, with a median age of 31 years and an IQR of 15–49. Otitis externa was the predominant type of ear infection, accounting for 45.1%. We observed positive bacteria culture in 53.3% of study participants, in which 41% of isolates were obtained from patients with chronic suppurative otitis media. Moreover,Staphylococcus aureus(27.3%) andPseudomonas aeruginosa(24.2%) were the most frequently isolated bacteria, whileCandidaspp, 12 (63.8%) andAspergillusspp, 9 (36.2%) were the only isolated fungi. Furthermore, we report that 93% of isolatedEnterobacteraleswere resistant to amoxicillin/clavulanic acid, and 73% were resistant to ceftazidime. In addition, we detected 34.4% extended-spectrum beta-lactamase-producingEnterobacterales(ESBL-PE) and 44.4% methicillin-resistanceS. aureus(MRSA). We also found that 22% of the bacteria isolates were resistant to ciprofloxacin, a primary topical antibiotic used in managing ear infections.ConclusionsThe findings from this study reveal that the leading aetiological agent of ear infection is bacteria. Furthermore, our findings show a significant proportion of ESBL-PE and MRSA-causing ear infections. Hence, detecting multidrug-resistant bacteria is crucial to improving ear infection management.