Serotype distribution and antimicrobial susceptibilities of nasopharyngeal isolates of Streptococcus pneumoniae from healthy children in the 13-valent pneumococcal conjugate vaccine era.

Few epidemiological data are available since the introduction of 13-valent pneumococcal vaccine (PCV13) in 2010. We conducted a cross-sectional study to estimate the prevalence of Streptococcus pneumoniae (SP) nasopharyngeal carriage in healthy Italian infants and young children and to evaluate the impact of PCV13 on pneumococcal colonization. In the trimester September-December 2011 nasopharyngeal swabs were collected from healthy children aged 3-59 months presenting for routine well careat 16 primary care pediatricians in Milan. SP carriage isolates were serotyped and tested for antimicrobial resistance using EUCAST breakpoints. Among 1250 enrolled children, 618 had received at least 1 dose of PCV13, 292 at least 1 dose of PCV7, 94 a combination of the two vaccines and 246 were not vaccinated. The prevalence of SP carriage was 27% (95% confidence interval [CI] 25-30). At multivariable analysis, age≥25 months (prevalence ratio [PR]=0.74) and use of antibiotics in the previous 3 months (PR=0.67) were associated with lower SP carriage prevalence. Having siblings (PR=1.79 for 1 sibling and PR=2.23 for ≥2 siblings), day-care attendance (PR=2.27) and respiratory tract infections in the previous 3 months (PR=1.39) were associated with higher SP carriage prevalence. The immunization status for SP was not associated with SP carriage at univariable or at multivariable analysis. The most common carriage isolates were 6C, 19A and 23A. The prevalence of the six additional PCV13 serotypes carriage in children appropriately vaccinated with PCV13 was lower than in children appropriately vaccinated with PCV7 (0 vs. 0.060); the greater reduction in prevalence of carriage was observed for serotype 19A (0 vs. 0.041). Serotype 6C was the most common drug-resistant serotype (17.2%). Further epidemiological studies are needed to assess changes in circulating SP serotypes following the large-scale introduction of PCV13.

Low adherence to influenza vaccination campaigns: is the H1N1 virus pandemic to be blamed?

BACKGROUND: Over the last few months, debates about the handling of the influenza virus A (H1N1) pandemic took place, in particular regarding the change of the WHO pandemic definition, economic interests, the dramatic communication style of mass media. The activation of plans to reduce the virus diffusion resulted in an important investment of resources. Were those investments proportionate to the risk? Was the pandemic overrated? The workload of the Pediatric Emergency Room (P.E.R.) at a teaching hospital in Varese (Northern Italy) was investigated in order to evaluate the local diffusion and severity of the new H1N1 influenza epidemic. DISCUSSION: A 100% increase of the number of P.E.R. visits, particularly for influenza-like illness, was recorded during weeks 42-46 of 2009 (October, 17 to November, 2); the low rate of hospitalization and the mild presentation of the infection gave rise to the conclusion that the pandemic risk was overrated. Mass media communications concerning the new virus created a disproportionate fear in the population that significantly enhanced the burden of cares at the hospital. In the absence of generally implemented measures for etiological diagnosis, the actual incidence of the H1N1 infection could not be estimated. Virus identification, in fact, was limited to children showing severe symptoms after consultancy with an infectious disease specialist. The alarming nature of the communication campaign and the choice to limit etiologic diagnosis to severe cases created a climate of uncertainty which significantly contributed to the massive admissions to the P.E.R.. SUMMARY: The communication strategy adopted by the mass media was an important element during the pandemic: the absence of clarity contributed to the spread of a pandemic phobia that appeared to result more from the sensationalism of the campaign than from infection with the novel influenza A variant of human, avian, swine origin virus. One relevant effect of the media coverage was the extremely low adherence rate to the vaccination campaign for the 2009-2010 and 2010-2011, especially among the high-risk population and health care workers. One positive consequence was, however, the spread of preventive hygiene measures, such as hand washing.