[Epidemiological features of invasive pneumococcal disease before and after the introduction of pneumococcal conjugate vaccine in Gran Canaria (Canary Islands)].
BACKGROUND
The introduction of pneumococcal conjugate vaccine (PCV-7) has modified the epidemiology of invasive pneumococcal disease (IPD). Our aim was to investigate the epidemiological features of IPD before and after implementing the use of PCV-7.


METHODS
All invasive Streptococcus pneumoniae strains isolated in our hospital from 2000 to 2006 were included. Serotypes were identified and antibiograms were performed in all cases. Data obtained before (2000-2001) and after (2004-2006) authorization of PCV-7 use in Spain were compared.


RESULTS
There were 241 cases of IPD. None of the patients with IPD aged 2 years or younger had received PCV-7. PCV-7 coverage in children aged 5 or younger was about 48%. There was a non-significant increase in the incidence of IPD in children (from 53.8 to 57.8 cases/100 000 population), with no change in adults. When IPD incidence was adjusted by the number of blood samples collected, there was a non-significant decrease in both children and adults. Since PCV-7 came on the market, there has been a decrease in vaccine serotypes and an increase in non-vaccine serotypes. The emergent serotypes since that time include 3, 6A, 15, and 19A. Penicillin resistance decreased significantly (p<0.001) from the pre-vaccine period (87.3%) to 2003 (13.8%), and later rose from 2003 through 2006 (41.7%). Erythromycin resistance showed no changes during the study.


CONCLUSIONS
The incidence of IPD in children aged 2 years and younger in Gran Canaria has not decreased despite the introduction of PCV-7. However, there has been a reduction in the number of cases related to vaccine serotypes and a significant decrease in penicillin resistance. In contrast, non-vaccine serotype IPD cases have increased. Universal vaccination and the use of new polyvalent vaccines may enhance these effects.
Artiles
Fernando
F
Servicio de Microbiología, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, España. fartcam@gobiernodecanarias.org
Horcajada
Iballa
I
Cañas
Ana María
AM
Alamo
Isabel
I
Bordes
Ana
A
González
Agustín
A
Santana
Milagrosa
M
Lafarga
Bernardo
B
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009017:Morbidity / Q000639:trends; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D022242:Pneumococcal Vaccines; D011159:Population Surveillance; D012189:Retrospective Studies; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects / Q000276:immunology / Q000302:isolation & purification*; D014611:Vaccination; D018074:Vaccines, Conjugate
D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate