2007年以降に経験した急性乳様突起炎6症例の検討

抄録

We have previously reported that the number of children hospitalized due to intractable acute otitis media has recently shown a significant decrease. The introduction of pneumococcal vaccine seemed to be the most important factor. This study retrospectively reviewed the medical records of six children hospitalized due to acute mastoiditis at Chiba Children’s Hospital between 2007 and 2015. We also conducted comparisons with previously published data for children with intractable acute otitis media and acute mastoiditis from the same institution.

The six patients ranged in age from 11 to 39 months and were all boys. At the time of hospitalization, five patients presented with acute otitis media and acute mastoiditis in opposite ears. Administration of intravenous antibiotics and myringostomy were performed for all patients. Ventilation tube insertion was performed for one patient, and incisions for periosteal abscess were performed for two of the six patients. None required mastoidectomy. The period of hospitalization was seven to nine days. Streptococcus pneumoniae was isolated from three patients, with two showing penicillin intermediate-resistant S. pneumonia (PISP), and one showing penicillin-sensitive S. pneumonia (PSSP). Two of six patients had been vaccinated with pneumococcal conjugate vaccine. Serotype 7F (non-PCV-7) was isolated in one patient vaccinated with 7-valent pneumococcal conjugate vaccine (PCV-7), and non-PCV-13 serotype 35B was isolated in another patient vaccinated with PCV-13. The annual incidence of acute mastoiditis in our institution was 0.67 per year from 2007 to 2015, compared to 1.18 per year from 1990 to 2006. Significant changes were seen in the number of hospitalizations due to intractable acute otitis media, from 9.7 per year in 1990 to 2006 to 2.1 per year in 2007 to 2014. We found a smaller reduction in the number of children hospitalized due to acute mastoditis, compared to intractable acute otitis media cases. Although the introduction of PCV-13 could decrease the number of hospitalizations due to acute mastoiditis, continued surveillance is needed to monitor the changes of in pneumococcal susceptibility and serotype.