Frequency of recovery of pathogens from the nasopharynx of children with acute maxillary sinusitis before and after the introduction of vaccination with the 7-valent pneumococcal vaccine.

OBJECTIVE: To compare the proportion of recovery of pathogens in the nasopharynx of children with acute maxillary sinusitis in the 5 years period before to the 5 years period following the introduction of vaccination with the 7-valent pneumococcal vaccine (PCV7).

METHODS: Nasopharyngeal cultures were obtained from 428 children with acute maxillary sinusitis, 208 between 1996 and 2000, and 220 between 2001 and 2005. The PCV7 was administered to 174 (79%) of the 220 children seen between 2001 and 2005.

RESULTS: One hundred and thirty eight potentially pathogenic organisms were isolated from 208 children between 1996 and 2000. Organisms were isolated in 114 patients (55%). The predominant organisms were Streptococcus pneumoniae (59 or 43% of all isolates), Haemophilus influenzae non-type b (46 or 33%), Moraxella catarrhalis (18 or 13%), Streptococcus pyogenes (9 or 7%), and Staphylococcus aureus (6 or 4%). One hundred and sixty five potentially pathogenic organisms were isolated from 220 patients between 2001 and 2005. Organisms were isolated in 121 patients (55%). The predominant organisms were H. influenzae non-type b (68 or 41% of all isolates), Streptococcus pneumoniae (41 or 25%), M. catarrhalis (23 or 14%), Streptococcus pyogenes (20 or 12%), and Staphylococcus aureus (13 or 8%). Significant statistical differences were noted in the rates of recovery of Streptococcus pneumoniae (p<0.05). A decrease occurred in the recovery of Streptococcus pneumoniae resistant to penicillin from 44% between 1997 and 2000 to 27% between 2000 and 2005. An increase was noted in the isolation of beta-lactamase producing H. influenzae from 37% between 1997 and 2000 to 44%. However, neither of these changes was statistically significant.

CONCLUSIONS: This data illustrates that a significant shift occurred in the causative pathogens of acute maxillary sinusitis in children in the 5 years after the introduction of vaccination of children with the PCV7 as compared to the previous 5 years. While the proportion of Streptococcus pneumoniae declined by 18%, the proportion of H. influenzae increased by 8%.