Incidence survey of acute otitis media in children in Sado Island, Japan--Sado Otitis Media Study (SADOMS)

• Published in: PloS one Vol. 8; no. 7; p. e68711
• Main Authors: Otsuka, Taketo, Kitami, Osamu, Kondo, Kouji, Ota, Hisayuki, Oshima, Shinsuke, Tsuchiya, Akio, Shirai, Takatoshi, Fujii, Koyata, Nakamure, Michihide, Shoji, Yasuhiro, Nakamura, Hisano, Masuda, Yasuko, Komiyama, Kenichi, Yoshida, Kazunaga, Ishikawa, Yukio, Iwaya, Atsushi, Takahashi, Sugata, Okazaki, Minoru, Hotomi, Muneki, Yamanaka, Noboru
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02.07.2013; Public Library of Science (PLoS)
• Subjects: Acute Disease; Adolescent; Age; Ampicillin; Antibiotics; Bacteria; Bacterial infections; Biology; Child; Child, Preschool; Children; Chronic illnesses; Clinical medicine; Comorbidity; Ear diseases; Epidemiology; Female; Genetic markers; Haemophilus Infections - diagnosis; Haemophilus Infections - epidemiology; Haemophilus influenzae; Haemophilus influenzae - classification; Haemophilus influenzae - isolation & purification; Health aspects; Hospitals; Humans; Immunization; Incidence; Infant; Infant, Newborn; Japan - epidemiology; Laboratories; Larynx; Male; Medicine; Middle ear; Nasopharynx; Otitis media; Otitis Media - diagnosis; Otitis Media - epidemiology; Otolaryngology; Otolaryngology - methods; Otolaryngology - statistics & numerical data; Outpatients - statistics & numerical data; Patients; Pediatrics; Pediatrics - methods; Pediatrics - statistics & numerical data; Penicillin; Physicians; Pneumococcal Infections - diagnosis; Pneumococcal Infections - epidemiology; Population Surveillance - methods; Risk factors; Sentinel surveillance; Serologic tests; Serotypes; Serotyping; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - classification; Streptococcus pneumoniae - isolation & purification; Surveillance; Surveys; Time Factors; Tympanic membrane; Typing; Vaccines; β Lactamase; Japan; Sado Island
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0068711

Acute otitis media (AOM) is one of the most common forms of bacterial infection and cause for clinic visits in children. The incidence of AOM was 0.9-1.2 episodes per person-year during the first 2 years of life in previous reports conducted before 2000. The aim of this study was to 1) evaluate the latest AOM incidence in pediatric outpatients and 2) identify the bacterial pathogens from these patients and ascertain their serotypes and resistance. The study was conducted in a closed population, involving all pediatricians and otolaryngologists in Sado Island allowing accurate determination of AOM incidence. In each month, one week was assigned as "surveillance week", and all outpatients with acute illness aged 0-18 years examined during the surveillance weeks were enrolled. AOM was diagnosed on the basis of otoscopic findings and clinical symptoms were recorded. Specimens were collected from the nasopharynx or middle ear cavity of AOM patients and examined for bacteria. Antimicrobial susceptibilities, serotypes, and molecular typing for resistance were determined among Streptococcus pneumoniae and Haemophilus influenzae. In total, 8,283 clinic visits were conducted, and 354 episodes (4.3%, 95% CI: 3.9-4.7%) among 312 children were diagnosed as AOM. The incidence of AOM was highest in children of 1 year of age (0.54 episodes/child/year, 95% CI: 0.44-0.64). Serotype coverage of 7- and 13-valent pneumococcal conjugate vaccines in this study were 38.0% (95% CI: 29.3-47.3) and 62.8% (95% CI: 53.6-71.4), respectively. Of 122 H.influenzae isolates available for typing, 120 were nontypeable and 2 were type b. A high proportion of S. pneumoniae isolates (46%) showed resistance to penicillin. Approximately half of H. influenzae isolates had genetic markers for beta-lactamase-negative ampicillin-resistance. Approximately 4-5% of pediatric outpatients, even without AOM-related symptoms, had AOM in our study. Pediatricians as well as otolaryngologists should check the tympanic membrane findings of all pediatric outpatients.