An update on the prevention of influenza in children and adolescents

Influenza virus types A and B cause yearly outbreaks of respiratory tract infections in all age groups including children and adolescents. Complications, such as high fever, febrile convulsions, secondary bacterial infections and myositis frequently lead to hospitalisation. Safe and effective split, subunit and virosome vaccines are available from 6 months of age onwards. Most European countries do have guidelines for the use of influenza vaccines and current strategies primarily aim at decreasing the burden of influenza disease in certain, heterogeneously defined high risk groups. Conclusion:unfortunately, compliance of many physicians and patients with immunisation recommendations is rather poor and several barriers to immunisation have been identified. These deserve our specific attention in the future. Recently, neuraminidase inhibitors with curative and preventive efficacy against influenza virus types A and B have become available. They serve as second line weapons for influenza prophylaxis under specific circumstance

Protecting newborns from pertussis – the challenge of complete cocooning

BACKGROUND: An increase of pertussis cases, especially in young infants and adolescents, has been noted in various countries. Whooping cough is most serious in neonates and young infants in whom it may cause serious complications such as cyanosis, apnoea, pneumonia, encephalopathy and death. To protect newborns and infants too young to be fully immunized, immunization of close contact persons has been proposed (“cocoon strategy”) and implemented in several countries, including Switzerland in 2011. The goal of this study was to assess knowledge about pertussis among parents of newborns and acceptance, practicability and implementation of the recently recommended pertussis cocoon strategy in Switzerland. METHODS: We performed a cross sectional survey among all parents of newborns born between May and September 2012 and 2013 in Basel city and country. Regional statistical offices provided family addresses after approval by the ethical and data protection committees. A standardized questionnaire with detailed instructions was sent to all eligible families. For statistical analyses, independent proportions were compared by Pearson’s chi-squared test. RESULTS: Of 3546 eligible parents, 884 (25%) participated. All three questions exploring pertussis knowledge were answered correctly by 37% of parents; 25% gave two correct answers, 22% gave one correct answer and in the remaining 16% no answer was correct. Pertussis immunization as part of cocooning was recommended to 20% and 37% of mothers and 14% and 32% of fathers in the 2012 and 2013 study cohorts, respectively. Principal advisors for cocooning were pediatricians (66%) followed by gynecologists/obstetricians (12%) and general practitioners (5%). When recommended, 64% of mothers and 59% of fathers accepted pertussis immunization. The majority of vaccinations were administered in the perinatal period and within 2 months of the child’s birth. However, cocooning remained incomplete in 93% of families and in most families <50% of close contacts received pertussis vaccination. CONCLUSIONS: Implementation of cocooning for protecting newborns from pertussis is challenging and usually remains incomplete. Pertussis immunization rates among close contacts of newborns need to be improved. Ideally, all healthcare providers involved in family planning, pregnancy and child birth should recommend cocooning. Pertussis immunization of pregnant women is an additional measure for optimal protection of newborns and should be promoted

Immunization rates and timely administration in pre-school and school-aged children

Whereas immunization coverage has been repeatedly assessed in the Swiss population, little is known about the timely administration of universally recommended immunizations in Switzerland and elsewhere. The goal of this study was to determine compliance with official standard immunization recommendations in pre-school and school-aged children in Basel, Switzerland, focusing on coverage rates and timely administration. Of a cohort of children entering kindergarten and third-grade primary school in Basel in 2001, 310 and 310, respectively, were identified in proportion to the overall age-appropriate populations in the four city districts. Foreign-born children were excluded. The data were extracted from immunization records provided voluntarily by parents. Coverage for three doses of diphtheria, tetanus, and poliomyelitis vaccines was >95% and <90% for pertussis and Hib. The rates of age-appropriate booster doses were significantly lower, especially for pertussis and Hib (<60%). Cumulative coverage for measles, mumps, and rubella (MMR) was <90% for the first dose and 33% for the second dose by 10 years of age. All immunizations were administered with significant delays. Coverage for the first three doses of DTP combination vaccines did not reach 90% before 1 year of age and, for the first dose of MMR, a plateau just below 80% was not reached before 3 years of age. Delayed administration of immunizations in childhood, as well as complete lack of booster doses in a significant fraction of children, with important implications for public health have been discovered in this study. This may lead to fatal disease in individuals, epidemics in the community, and threatens national and international targets of disease elimination, such as measles and congenital rubella syndrom

No temporal association between influenza outbreaks and invasive pneumococcal infections

Objective: To assess whether the influenza peak in populations precedes the annual peak for invasive pneumococcal infections (IPI) in winter.Design: Ecological study. Active surveillance data on influenza A and IPI in children up to 16 years of age collected from 1997 to 2003 were analysed.Setting: Paediatric hospitals in Germany.Patients: Children under 16 years of age.Results: In all years under study, the influenza A season did not appear to affect the IPI season (p = 0.49). Specifically, the influenza peak never preceded the IPI peak.Conclusion: On a population level there was no indication that the annual influenza epidemic triggered the winter increase in the IPI rate or the peak of the IPI distribution in children

Comparison of clinical characteristics of influenza and respiratory syncytial virus infection in hospitalised children and adolescents

While significant morbidity due to respiratory syncytial virus (RSV) infection in the paediatric population has been well acknowledged, little is known about the burden of influenza in primarily healthy children in Europe. In our institution, a University Children's Hospital in Switzerland, medical staff were encouraged to take nasopharyngeal specimens for multiplex polymerase chain reaction assays for influenza A and B, RSV and several other pathogens from patients hospitalised with respiratory symptoms. We took advantage of this strategy and performed a retrospective study to compare specific characteristics of influenza virus infections with those of RSV during two consecutive winter seasons. Overall, 126 patients were positive for RSV and 60 patients were positive for influenza (type A: 45; type B: 15). The median age of children with RSV, influenza A, and influenza B infection was 4 months; 2 years and 4 months; and 6 years and 2 months, respectively (P<0.001). Fever and cough predominated in children with influenza infection whereas cough, rhinorrhoea, feeding difficulties and dyspnoea were the major symptoms in children with RSV infection. Of patients with influenza, 41% suffered from lower respiratory tract infection compared to 91% of those with RSV infection (P<0.001). Of 60 patients hospitalised with influenza, 12 (20%) experienced febrile convulsions. None of the patients with influenza had been immunised in the respective winter season, although 27% of them had at least one underlying medical condition that would have counted as an indication for immunisation in Switzerland. Conclusion: influenza virus infections, like respiratory syncytial virus infections, are a major cause of hospitalisation in children with respiratory illness during the winter season. Since it is impossible to make an aetiological diagnosis on clinical grounds, it is important to apply specific diagnostic tools in children hospitalised with respiratory illness in order to better characterise the relative burden of disease caused by the respective agent

Clinical findings and unusual epidemiologic characteristics of human metapneumovirus infections in children in the region of Basel, Switzerland

Human metapneumovirus (hMPV) worldwide causes respiratory tract infections with features similar to those of RSV infection. We describe features of hMPV infections in children and compare some of the characteristics with those of RSV infections. From October 2004 to February 2006, 75 patients, 34 hospitalized and 41 outpatients, were diagnosed with hMPV infections by multiplex PCR applied to nasopharyngeal specimens. While hMPV was found rarely in the early phase of the study, a significant increase occurred in the second winter of the study period. Patients with hMPV infections were older than those with RSV infection; clinical characteristics were similar as was the rate of serious disease among hospitalized patients (intensive care treatment: 18% versus 8%). In conclusion, hMPV leads to endemic and epidemic respiratory disease with features similar to those of RSV and should be considered in the differential diagnosis of upper and lower respiratory tract diseas

Compliance with antenatal screening for hepatitis B surface antigen carrier status in pregnant women and consecutive procedures in exposed newborns

The goal of this study was to determine compliance with official recommendations for prevention of perinatal hepatitis B virus transmission from hepatitis B surface antigen (HBsAg) positive mothers to their offspring. All infants born to HBsAg positive mothers at the University Women's Hospital in Basel, Switzerland, in 2001 were identified and post-exposure immunisations were analysed. In addition, detailed written information on subsequent hepatitis B immunisations was obtained from the infants' paediatricians. A total of 1513 women gave birth to 1554 children and screening for HBsAg had been performed in 1503 (99%) women, of whom 8% were screened during delivery. A group of 18 (1.2%) women were HBsAg positive and 17 (95%) of the 19 exposed infants promptly received active and passive immunisation. One exposed infant was lost to follow-up and in one, postnatal vaccination was missed. Of the remaining 17 exposed infants, 9 (53%) received the full course of three active immunisations, but only two (12%) were immunised within the recommended time frame. On follow-up, six children were still too young for serological testing for successful immunisation. Among the remaining 11 immunised infants, serological testing had been performed in 4 (36%). Conclusion:Compliance with recommendations for hepatitis B surface antigen screening was excellent in this study. The proportion of exposed infants receiving all three active immunisations was satisfactory, but more attention must be paid to complete and timely administration and serological testing in the future. This will require improved communication between neonatology units and care-providing paediatricians in private practice

Serologic Response and Antibody-Titer Decay in Adults with Pertussis

Pertussis is a frequent and significant illness in adults. Because acellular pertussis vaccines for use in adolescents and adults have now been developed, it is important to compare serologic responses in adults after infection with serologic responses in adults after vaccination. We measured IgG and IgA antibodies to 4 Bordetella pertussis antigens at ∼6-month intervals for 28 months in 11 adults with pertussis. After reaching peak levels, titers of antibody to pertussis toxin decreased more than did titers of antibodies to filamentous hemagglutinin, pertactin, and fimbriae type 1 and type 2. Although studies of adults who have been vaccinated with acellular pertussis vaccines have had shorter follow-up periods than studies of adults with pertussis infection, the antibody decay patterns are similar in both group

Human metapneumovirus infections—biannual epidemics and clinical findings in children in the region of Basel, Switzerland

Human metapneumovirus (hMPV) epidemics vary in time and severity. We report findings for PCR for hMPV and respiratory syncytial virus (RSV) performed on nasopharyngeal aspirates (NPA) of hospitalized and outpatient children with respiratory tract infections between October 2004 and April 2008. A total of 3,934 NPAs were tested for hMPV and 3,859 for RSV. Of these, 198 (5%) were hMPV positive and 869 (23%) were RSV-positive. Median age was 17months and 9months for hMPV and RSV, respectively. Fifty-nine percent of hMPV and 58% of RSV patients were hospitalized. Proportions of hMPV positive samples for the four winter seasons were 0.4%, 11%, 0.2%, and 14%. For RSV, they were 28%, 15%, 28%, and 28%. HMPV epidemics follow a biannual variation in our area. Major epidemics were observed in winter seasons starting in odd years (2005/06 and 2007/08), minor epidemics in those starting in even years (2004/05 and 2006/07). RSV epidemics usually follow a reciprocal biannual pattern, leading to annually alternating major RSV and hMPV epidemic