Background: Chronic suppurative otitis media (CSOM) is a major health problem in developing countries causing serious local damage leading to conductive hearing loss and life threatening complications. Early and effective treatment based on the knowledge of causative micro-organism and their antimicrobial sensitivity is essential for prompt clinical management to prevent possible complications. Therefore, this study was performed to determine the etiological, susceptibility pattern and treatment outcome among patients with CSOM attending Bugando Medical Centre (BMC).
Methods: This was a prospective hospital based descriptive study of patients aged above one years, with CSOM attending Bugando Medical Centre (BMC) over six months period between October 2013 and March 2014. All eligible patients were consecutively enrolled in the study. Sample (pus) was obtained from each patient’s ear using sterile cotton swabs and cultured for microorganisms. Drug susceptibility testing for bacterial isolates was conducted using Kirby-Bauer disc diffusion method. Data were collected using a pre-tested, coded questionnaire and analyzed using SPSS version 17 and STATA version 11.0.
Results: A total of 301 patients with CSOM were studied, with mean age 33.7±17.9 years. The female to male ratio was 1.21:1. The prevalence of HIV among patients with CSOM was 4.3% and about 13.6% participants were smokers. The right ear was mostly affected (53.5%), and duration of otorrhoea ranged from 1-72 months, with median of 18 months and Inter Quarterly Range (IQR) of 8-24 months. All patients in this study presented with otorrhoea followed by otalgia (44.8%) and tinnitus (32.2%). Out of 301 patients, 187 (62.1%) had positive aerobic culture within 48 hours of incubation. Majority of isolated organisms were gram negative bacteria 116 (61%). Pseudomonas spp. 56 (29.5%) were predominant isolates, followed by Staphylococcus aureus 34 (17.9%). Fungal growth was detected in 3(4.2%) of ear swabs. Pseudomonas spp were 95%, 70%, 62%, 52%, 47%, 9% and 0% resistance to amoxicillin/clavulanic acid, sulphamethaxazole/trimethoprim, tetracycline, ceftriaxone, ceftazidime, gentamicin, and ciprofloxacin respectively. Resistance rates of Staphylococcus aureus were 74% to sulphamethaxazole/trimethoprim, 31% to erythromycin, 11% to gentamicin, 4% to ciprofloxacin and 0% vancomycin. Of 34 staphylococcus aureus, 14(41%) were found to be methicillin resistant Staphylococcus aureus (MRSA) while of 116 gram negative enteric bacteria, 49 (42%) were resistant to third generations cephalosporins. Most patients, 296 (98.3%) were treated conservatively using ototopical agents with the cure rate of 84.7% after 2 weeks treatments whereas only 5 (1.7%) patients underwent surgical intervention. Hearing loss was found in 114 (37.5%) patients hence being the commonest complication, of which conductive type being predominant 99 (86.8%). On multivariate logistic regression analysis only HIV positive was independently factor found to predict the outcome of CSOM in this study (p-value<0.001).
Conclusion: CSOM remain a major public health problem in this part of Tanzania. Pseudomonas spp. and S. aureus were found to be the commonest isolates with majority of them being sensitive to ciprofloxacin and gentamicin. Urgent preventive measures and laboratory guided early treatment of the disease are necessary to reduce the incidence of CSOM and its complications in this region.