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Streptococcus pneumoniae serotype 19A in children, South Korea.

Choi EH, Kim SH, Eun BW, Kim SJ, Kim NH, Lee J, Lee HJ - Emerging Infect. Dis. (2008)

Bottom Line: Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased.Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend).This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use.

View Article: PubMed Central - PubMed

Affiliation: Seoul National University College of Medicine, Seoul, South Korea.

ABSTRACT
Despite the concern of replacement disease, notably by serotype 19A after 7-valent conjugate vaccine (PCV7) use, serotype 19A was increasingly recognized in Korean children before the introduction of PCV7. To understand the dynamics of serogroup 19 prevalence from 1991-2006, we serotyped 538 pediatric pneumococcal isolates. Serogroup 19 isolates (n = 126) were characterized by antimicrobial drug susceptibility, presence of mefA/ermB, and multilocus sequence typing. Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased. Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend). This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use.

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Distribution of serotypes with regard to 7-valent conjugate vaccine (PCV7) among 538 isolates encountered during five 3-year periods from 1991 through 2006, South Korea. A) Invasive isolates. B) Noninvasive isolates.
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Figure 1: Distribution of serotypes with regard to 7-valent conjugate vaccine (PCV7) among 538 isolates encountered during five 3-year periods from 1991 through 2006, South Korea. A) Invasive isolates. B) Noninvasive isolates.

Mentions: The most common serotypes were 19F (113, 21%), 23F (96, 17.8%), 19A (58, 10.8%), 6B (50, 9.3%), 6A (43, 8%), 14 (40, 7.4%), and 9V (24, 4.5%); these 7 serotypes accounted for 79% of the total isolates. Overall, PCV7 serotypes accounted for 64.1% of total isolates and 62.7% of invasive isolates. Table 1 shows the serotype distributions of invasive and noninvasive isolates by age group. For invasive isolates, PCV7 serotype coverage was 67% among children <60 months of age and 47% among children >60 months (Table 1). During 2001–2003, just before PCV7 was introduced in South Korea, overall PCV7 coverage rates for PCV7 serotypes and PCV7-related serotypes were 54% and 10% among the 138 invasive isolates and 57% and 13% among the 380 noninvasive isolates. The proportion of serotype 19A isolates increased from 0% (0/40) during 1991–1994 to 18% (7/39) during 2001–2003 among the 138 invasive isolates. Similarly, from 1995–1997 to 1998–2000, the proportion of serotype 19A isolates increased from 3% (1/33) to 17% (14/81) among noninvasive isolates (Figure 1).


Streptococcus pneumoniae serotype 19A in children, South Korea.

Choi EH, Kim SH, Eun BW, Kim SJ, Kim NH, Lee J, Lee HJ - Emerging Infect. Dis. (2008)

Distribution of serotypes with regard to 7-valent conjugate vaccine (PCV7) among 538 isolates encountered during five 3-year periods from 1991 through 2006, South Korea. A) Invasive isolates. B) Noninvasive isolates.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2600206&req=5

Figure 1: Distribution of serotypes with regard to 7-valent conjugate vaccine (PCV7) among 538 isolates encountered during five 3-year periods from 1991 through 2006, South Korea. A) Invasive isolates. B) Noninvasive isolates.
Mentions: The most common serotypes were 19F (113, 21%), 23F (96, 17.8%), 19A (58, 10.8%), 6B (50, 9.3%), 6A (43, 8%), 14 (40, 7.4%), and 9V (24, 4.5%); these 7 serotypes accounted for 79% of the total isolates. Overall, PCV7 serotypes accounted for 64.1% of total isolates and 62.7% of invasive isolates. Table 1 shows the serotype distributions of invasive and noninvasive isolates by age group. For invasive isolates, PCV7 serotype coverage was 67% among children <60 months of age and 47% among children >60 months (Table 1). During 2001–2003, just before PCV7 was introduced in South Korea, overall PCV7 coverage rates for PCV7 serotypes and PCV7-related serotypes were 54% and 10% among the 138 invasive isolates and 57% and 13% among the 380 noninvasive isolates. The proportion of serotype 19A isolates increased from 0% (0/40) during 1991–1994 to 18% (7/39) during 2001–2003 among the 138 invasive isolates. Similarly, from 1995–1997 to 1998–2000, the proportion of serotype 19A isolates increased from 3% (1/33) to 17% (14/81) among noninvasive isolates (Figure 1).

Bottom Line: Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased.Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend).This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use.

View Article: PubMed Central - PubMed

Affiliation: Seoul National University College of Medicine, Seoul, South Korea.

ABSTRACT
Despite the concern of replacement disease, notably by serotype 19A after 7-valent conjugate vaccine (PCV7) use, serotype 19A was increasingly recognized in Korean children before the introduction of PCV7. To understand the dynamics of serogroup 19 prevalence from 1991-2006, we serotyped 538 pediatric pneumococcal isolates. Serogroup 19 isolates (n = 126) were characterized by antimicrobial drug susceptibility, presence of mefA/ermB, and multilocus sequence typing. Overall, the proportion of serotype 19A isolates increased but serotype 19F decreased. Among children <5 years of age, the proportion of serotype 19A isolates in invasive pneumococcal disease increased from 0% in 1991-1994 to 8%-10% in 1995-2000, reached 26% in 2001-2003, and remained at 20% in 2004-2006 when vaccine coverage did not exceed 25% (p = 0.005 for trend). This study demonstrates that the expansion of multidrug-resistant ST320 was responsible for the increase in serotype 19A before PCV7 use.

Show MeSH