Age Distribution of Cases of 2009 (H1N1) Pandemic Influenza in Comparison with Seasonal Influenza

INTRODUCTION: Several aspects of the epidemiology of 2009 (H1N1) pandemic influenza have not been accurately determined. We sought to study whether the age distribution of cases differs in comparison with seasonal influenza. METHODS: We searched for official, publicly available data through the internet from different countries worldwide on the age distribution of cases of influenza during the 2009 (H1N1) pandemic influenza period and most recent seasonal influenza periods. Data had to be recorded through the same surveillance system for both compared periods. RESULTS: For 2009 pandemic influenza versus recent influenza seasons, in USA, visits for influenza-like illness to sentinel providers were more likely to involve the age groups of 5-24, 25-64 and 0-4 years compared with the reference group of >64 years [odds ratio (OR) (95% confidence interval (CI)): 2.43 (2.39-2.47), 1.66 (1.64-1.69), and 1.51 (1.48-1.54), respectively]. Pediatric deaths were less likely in the age groups of 2-4 and <2 years than the reference group of 5-17 years [OR (95% CI): 0.46 (0.25-0.85) and 0.49 (0.30-0.81), respectively]. In Australia, notifications for laboratory-confirmed influenza were more likely in the age groups of 10-19, 5-9, 20-44, 45-64 and 0-4 years than the reference group of >65 years [OR (95% CI): 7.19 (6.67-7.75), 5.33 (4.90-5.79), 5.04 (4.70-5.41), 3.12 (2.89-3.36) and 1.89 (1.75-2.05), respectively]. In New Zealand, consultations for influenza-like illness by sentinel providers were more likely in the age groups of <1, 1-4, 35-49, 5-19, 20-34 and 50-64 years than the reference group of >65 years [OR (95% CI): 2.38 (1.74-3.26), 1.99 (1.62-2.45), 1.57 (1.30-1.89), 1.57 (1.30-1.88), 1.40 (1.17-1.69) and 1.39 (1.14-1.70), respectively]. CONCLUSIONS: The greatest increase in influenza cases during 2009 (H1N1) pandemic influenza period, in comparison with most recent seasonal influenza periods, was seen for school-aged children, adolescents, and younger adults

Characterisation of macrolide-non-susceptible Streptococcus pneumoniae colonising children attending day-care centres in Athens, Greece during 2000 and 2003

Nasopharyngeal Streptococcus pneumoniae isolates colonising young children are representative of isolates causing clinical disease. This study determined the frequency of macrolide-non-susceptible pneumococci, as well as their phenotypic and genotypic characteristics, among pneumococci collected during two cross-sectional surveillance studies of the nasopharynx of 2847 children attending day-care centres in the Athens metropolitan area during 2000 and 2003. In total, 227 macrolide-non-susceptible pneumococcal isolates were studied. Increases in macrolide non-susceptibility, from 23% to 30.3% (p &lt; 0.05), and in macrolide and penicillin co-resistance, from 3.4% to 48.6% (p &lt; 0.001), were identified during the study period. The M resistance phenotype, associated with the presence of the mef(A)/(E) gene, predominated in both surveys, and isolates carrying both mef(A)/(E) and erm(AM) were identified, for the first time in Greece, among the isolates from the 2003 survey. Pulsed-field gel electrophoresis analysis of the isolates from the 2000 survey indicated the spread of a macrolide- and penicillin-resistant clone among day-care centres. The serogroups identified most commonly in the study were 19F, 6A, 6B, 14 and 23F, suggesting that the theoretical protection of the seven-valent conjugate vaccine against macrolide-non-susceptible isolates was c. 85% during both study periods