FALL OR SPRING FOR PNEUMOCOCCUS? CHANGES IN INVASIVE PNEUMOCOCCAL DISEASE IN SPANISH CHILDREN
Mr. Fernando Moraga-Llop
6 slide(s) – English – 2011-06-07
The epidemiology of invasive pneumococcal disease (IPD) has changed since routine introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in the childhood vaccination calendar. Data from Spain and other European countries where PCV7 is not routinely included remain controversial. A retrospective-prospective study was performed in a single tertiary care paediatric hospital in Barcelona (Spain), in which data from all children aged <16 years with culture-proven IPD were compared in two different periods, before and after PCV7 introduction (prevaccine period, January 2000-December 2002; vaccine period, January 2007-December 2009). Twenty-seven and 84 cases of IPD were studied in the first and second period, respectively. The IPD rate increased from 19.65 to 50.84 episodes per 100,000 children-year between the two periods (p<0.05), due to an accumulation of respiratory forms. A dramatic decrease in PCV7 serotypes was observed (from 68.2% to 10.8%), and a consequent increase in non-PCV7 serotypes (from 31.8% to 89.2%) (p<0.05). Penicillin susceptibility rose in the second period from 58.3% to 83.9% (p<0.05). In the prevaccine period, bacteremia without focus and meningitis were the most common clinical forms of IPD (55.5%), whereas respiratory forms increased to 69% in the vaccine period (p<0.05), with pneumococcal empyema being the most frequent clinical presentation (39.3%).
Conclusions. Our study found statistically significant variations in IPD presentation in our area between the prevaccine and vaccine eras, including a higher incidence and predominance of non-PCV7 serotypes in the vaccine period, increased susceptibility to penicillin, and more cases of respiratory disease. These changes are likely associated with the introduction of PCV7, among other factors.