3.Nasopharyngeal Pneumococcal Carriage of Children Attending Day Care Centers in Korea: Comparison between Children Immunized with 7-valent Pneumococcal Conjugate Vaccine and Non-immunized.
Kyung Hyo KIM ; Jung Yun HONG ; Hyunju LEE ; Ga Young KWAK ; Chan Hee NAM ; Soo Young LEE ; Eunsang OH ; Jigui YU ; Moon H NAHM ; Jin Han KANG
Journal of Korean Medical Science 2011;26(2):184-190
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 (> or = 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.
Adult
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Carrier State/*immunology/prevention & control
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Child
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*Child Day Care Centers
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Child, Preschool
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Humans
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*Immunization
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Infant
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Male
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Microbial Sensitivity Tests
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Nasopharynx
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Pneumococcal Infections/*epidemiology/immunology/*prevention & control
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Pneumococcal Vaccines/*administration & dosage
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Prospective Studies
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Republic of Korea/epidemiology
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Serotyping
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Streptococcus pneumoniae/*isolation & purification