Background: Otitis media (OM) poses a high disease burden on Bangladeshi children, but little is known about its etiologies. We conducted a surveillance study in the largest pediatric hospital to characterize pathogens responsible for OM.
Methods: In the outpatient ear-nose-throat department of Dhaka Shishu Hospital, which serves 0 to 18-year-old children, we collected ear swabs from OM children with otorrhea from April 2014 to March 2015. We cultured all specimens for bacterial pathogens and assessed serotype and antimicrobial susceptibility of Streptococcus pneumoniae (Spn) and Haemophilus influenzae (Hi) isolates.
Results: We recorded 1111 OM episodes; 88% (981/1111) involved otorrhea, and we collected samples from 91% (891/981) of these children. Fifty-one percent (452/891) were culture positive (contaminants excluded), with Hi (21%, 187/891) and Spn (18%, 164/891) most commonly detected. Overall, 45 distinct single and mixed pathogens were revealed. Dominant pneumococcal serotypes were 19A, 19F, 3 and 14; 98% of Hi isolates were nontypeable. Pneumococcal conjugate vaccine (PCV)10 and PCV10 + 6A serotypes accounted for 8% and 9% of all OM and 46% and 49% of pneumococcus-positive cases, respectively, and were more likely to be nonsusceptible to at least 1 antibiotic (erythromycin and/or trimethoprim-sulfamethoxazole) than nonvaccine serotypes (91% vs. 77%). Staphylococcus aureus (9%, 83/891) and Pseudomonas aeruginosa (4%, 38/891) were also found.
Conclusions: Nontypeable Hi (NTHi) and Spn are predominant causes of OM in Bangladesh. PCV10, introduced in March 2015, is likely to reduce pneumococcal and overall OM burden. Data collected post-PCV10 will provide comprehensive insight into the effects of this vaccine on these pathogens.