# Aetiologies of Ear Infections Among Patients Who Visited King Fahad Hospital in Al-Baha, Saudi Arabia

## TL;DR

This study identifies the main causes of ear infections in Saudi Arabia, finding that bacteria like Staphylococcus aureus and Pseudomonas aeruginosa are common, with a notable presence of drug-resistant strains.

## Contribution

The study provides a detailed analysis of the aetiology of ear infections in a specific Saudi population over a four-and-a-half-year period.

## Key findings

- Bacterial pathogens were the most common cause of ear infections, followed by fungal infections.
- Staphylococcus aureus was the most frequently isolated pathogen, with 33% being methicillin-resistant.
- Otitis media was more common in children, while otitis externa had a higher proportion of fungal causes.

## Abstract

Background

Ear infections encompass otitis media (OM) which is a significant cause of hearing loss and otitis externa (OE) which may affect the surrounding tissues leading to serious complications. This study reports the common pathogens causing ear infections.

Methods

Microbiological, clinical, and demographic data of ear-infected patients who visited King Fahad Hospital in Al-Baha, Saudi Arabia, during the period from January 2019 to June 2023 were enrolled in this study.

Result

This study enrolled 307 patients aged 1-94 years, with a median age of 40 years (IQR=22-57). Overall, the detectable infection rate was 81.1% (n=249), while 18.9% (n=58) had no identified aetiology. Of all isolates, 178 (58%) were bacterial, while 71 (23.1%) were fungal. Staphylococcus aureus (S. aureus) followed by Pseudomonas aeruginosa (P. aeruginosa), Enterobacteriaceae, andcoagulase-negative Staphylococcus (CoNS) were the main bacterial isolates. Of the total 63 S. aureus isolates, 21 (33%) were methicillin-resistant (MRSA). A cohort of 227 subjects were diagnosed with either OM (n=178; 79.5%), OE (n=46; 20.5%), or both OM and OE (n=3; 1%). Of those with OM, children constituted 89.1% (41/46) as compared to 75.3% (134/178) of adults (p=0.041). The main isolates from OM patients were S. aureus followed by P. aeruginosa and fungi. Of 49 OE patients, 16 (32.7%) had no identified pathogen, while 15 (30.6%) had fungi, and 13 (29.5%) had P. aeruginosa.

Conclusions

Ear infections in general were mainly bacterial followed by fungal with a considerable proportion of unidentified aetiology. A significant proportion of S. aureus isolates were MRSA. S. aureus followed by P. aeruginosa and fungi were the main causes of OM, while fungi followed by P. aeruginosa were the main causes of OE.