Effect of the introduction of the pneumococcal conjugate vaccine on invasive disease produced by Streptococcus pneumoniae

Abstract number: 1733_589

Cercenado E., Cuevas O., Fenoll A., Marin M., Vicioso D., Bouza E.

Objectives: The heptavalent pneumococcal conjugate vaccine (PCV7) reduces carriage of pneumococci and prevents the disease. The PCV7 was licensed in Spain in 2001. We evaluate the effect of PCV7 on invasive disease and the impact of non-PCV7 serotypes in the area cared for our institution.

Methods: We identified episodes of bacteraemia and meningitis due to pneumococci in patients admitted to our institution from 1999 to 2005. Serotype distribution and antibiotic resistance were compared.

Results: A total of 726 episodes of bacteraemia (9% children) and 46 cases of meningitis (22% children) were identified. Over the period of study, the most frequent serotypes were 14 (10.2%); 3 (9%); 19 (8.9%); 8 (8.5%); 1 (7.2%); 4 (6.6%); and 23F (3.5%). By comparing data from 1999–2001, with data from 2002–2005, the percentage of isolates non-susceptible to penicillin showed a slight decrease (from 31.47% to 30.2%) and isolates resistant to erythromycin increased (from 17% to 24.3%). The incidence of pneumococcal bacteraemia was unchanged (from 1.90 cases to 1.92 cases/1,000 admissions). Vaccine serotypes caused 38% of episodes of bacteraemia and meningitis in the first period, compared with 27.4% of episodes in the second period (p = 0.037). Infections due to vaccine serotypes 4, 9V, and 23F decreased significantly during the second period (p < 0.002) but not these caused by serotypes 6B, 14, 18C, and 19F. The percentage of episodes of invasive disease caused by vaccine-related serotypes (same serogroup but not the same serotype as PCV7) showed a tendency towards the increase from 10% of episodes in the first period to 14%of episodes in the second (p = 0.135). Episodes due to VRST 19A increased (p < 0.001). Infections caused by non-PCV7 serotypes 1 and 8 increased from 11% to 19% (p < 0.05). In 2005, all invasive infections in children were produced by non-vaccine serotypes, and the estimated coverage of the PCV7 in adults was 23.6%.

Conclusions: The overall incidence of invasive pneumococcal disease and the rate of antibiotic-resistant invasive infections has not decreased in our area after the introduction of the PCV7. There were significant decreases in the incidence of invasive infections caused by several vaccine serotypes, however, invasive infections due to vaccine-related serotype 19A, and to non-vaccine serotypes increased.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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