title: Nasopharyngeal pneumococcal carriage of children attending day care centers in Korea: comparison between children immunized with 7-valent pneumococcal conjugate vaccine and non-immunized.
abstract: To confirm the effect of 7-valent pneumococcal conjugate vaccine (PCV7), pneumococcal nasopharyngeal (NP) carriage was compared between vaccinated (3 + 1 doses PCV7) and non-vaccinated children. Vaccinated subjects were recruited from highly vaccinated regions (≥ 60%), Seoul and Incheon whereas control subjects were recruited from Jeju Island where vaccination rates are low (< 15%). NP swabs were obtained from 400 children aged 18-59 months. Serotype and antibiotic susceptibility was analyzed. Pneumococcal carriage rate was 18.0% (36/200) and 31.5% (63/200) for the vaccinated and control group, respectively. Among those vaccinated, 41.7% (15/36) of the serotypes were vaccine-related type (VRT: 6A, 6C, 19A) with the most common serotype 6C. The next common type was non-typable/non-capsule 30.6% (11/36) followed by non-vaccine type 16.7% (6/36) and vaccine type (VT) serotypes were found in only 11.1% (4/36). In contrast, 52.4% (33/63) of the isolates in the control group were VT. Resistance rates for penicillin and erythromycin were lower in the vaccine group (vaccine vs control; penicillin 45.2% vs 71.4%, erythromycin 74.2% vs 90.5%, P < 0.05). Multi-drug resistance was also lower in vaccinated subjects (vaccine vs control; 45.2% vs 69.8%, P < 0.05). PCV7 reduces carriage in VT which leads to replacement of pneumococci by antibiotic susceptible VRT or non-vaccine type strains.
authors.affiliation: Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Hyo
authors.initials: KH
authors.lastname: Kim
authors.forename: Jung Yun
authors.initials: JY
authors.lastname: Hong
authors.forename: Hyunju
authors.initials: H
authors.lastname: Lee
authors.forename: Ga Young
authors.initials: GY
authors.lastname: Kwak
authors.forename: Chan Hee
authors.initials: CH
authors.lastname: Nam
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Eunsang
authors.initials: E
authors.lastname: Oh
authors.forename: Jigui
authors.initials: J
authors.lastname: Yu
authors.forename: Moon H
authors.initials: MH
authors.lastname: Nahm
authors.forename: Jin Han
authors.initials: JH
authors.lastname: Kang
mesh_terms: D000328:Adult; D002353:Carrier State / Q000276:immunology* / Q000517:prevention & control; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D006801:Humans; D007114:Immunization; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D009305:Nasopharynx; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
chemical_list: D022242:Pneumococcal Vaccines