Bacterial and Fungal Pathogens in Chronic Suppurative Otitis Media and Otitis Externa With Persistent Otorrhea: A...

This study aimed to determine the prevalence and distribution of bacterial and fungal pathogens in cases of chronic suppurative otitis media (CSOM) and otitis externa presenting with persistent otorrhea and to compare associated pathogen profiles between these two conditions in a low-middle-income country setting (Pakistan). Design, setting, and duration: This cross-sectional study was conducted at Creek General Hospital and United Hospital in Karachi, Pakistan, over a three-month period from 1 December 2024 till 28 February 2025.

A total of 384 patients aged 11-65 years diagnosed with CSOM or otitis externa and exhibiting persistent otorrhea were recruited through convenient sampling. Demographic and microbiological data, including pathogen identification and characterization, were collected using a structured evaluation form. Data analysis employed Statistical Product and Service Solutions (SPSS, version 27; IBM SPSS Statistics for Windows, Armonk, NY), with the chi-square test to assess variable associations and significant variations between the groups (p < 0.05 considered significant).  Primary outcome: To identify the frequency of common pathogen types isolated from patients with CSOM and otitis externa.

The comparative distribution of bacterial and fungal pathogens isolated from patients diagnosed with CSOM and otitis externa presenting with persistent otorrhea.

Of 384 participants, 50.8% were male, and 49.2% were female, predominantly aged 21-30 years and from urban areas. CSOM was the most prevalent diagnosis (46.6%), followed by otitis externa (42.7%), with co-infections in 10.7%. Bacterial pathogens (50%) were more common than fungal (28.6%) or mixed infections (21.4%). The most frequently identified bacterial pathogen was Pseudomonas aeruginosa (34.6%), while Aspergillus spp. (49.7%) predominated among fungi. Pathogen-type distribution showed no significant variation between CSOM and otitis externa (p > 0.05).

This study highlights the high prevalence of P. aeruginosa and Aspergillus spp. as the most common pathogens in CSOM and otitis externa in Karachi, Pakistan. The findings underscore the importance of pathogen-specific treatment protocols tailored to local microbial patterns. Given the region's environmental factors, such as poor sanitation and humidity, integrating these microbial profiles into local healthcare strategies is crucial for effective antimicrobial stewardship. There was no significant variation between pathogen distribution across CSOM and otitis externa (p > 0.05), indicating that the choice of pathogen was not strongly linked to clinical condition. While this study did not explore the links between pathogen type and clinical severity or treatment outcomes, these results provide valuable insights for guiding clinicians in optimizing treatment regimens. Ultimately, such strategies could improve patient outcomes and reduce the burden of these infections in similar low-resource settings.