RESUMO
Differences in thermal regimes are of paramount importance in insect development. However, experiments that examine trait development under constant temperature conditions may yield less evolutionarily relevant results than those that take naturally occurring temperature fluctuations into account. We investigated the effect of different temperature regimes (constant 30 °C, constant 35 °C, fluctuating with a daily mean of 30 °C, or fluctuating with a daily mean of 35 °C) on sex-specific development time and body mass in Tribolium castaneum. Using a half-sib breeding design, we also examined whether there is any evidence for genotype-by-environment interactions (GEI) for the studied traits. In response to fluctuating temperature regimes, beetles demonstrated reaction norm patterns in which thermal fluctuations influenced traits negatively above the species' thermal optimum but had little to no effect close to the thermal optimum. Estimated heritabilities of development time were in general low and non-significant. In case of body mass of pupae and adults, despite significant genetic variance, we did not find any GEI due to crossing of reaction norms, both between temperatures and between variability treatments. We have observed a weak tendency towards higher heritabilities of adult and pupa body mass in optimal fluctuating thermal conditions. Thus, we have not found any biasing effect of stable thermal conditions as compared to fluctuating temperatures on the breeding values of heritable body-size traits. Contrary to this we have observed a strong population-wide effect of thermal fluctuations, indicated by the significant temperature-fluctuations interaction in both adult and pupa mass.
RESUMO
Temperature has profound effects on biological functions at all levels of organization. In ectotherms, body size is usually negatively correlated with ambient temperature during development, a phenomenon known as The Temperature-Size Rule (TSR). However, a growing number of studies have indicated that temperature fluctuations have a large influence on life history traits and the implications of such fluctuations for the TSR are unknown. Our study investigated the effect of different constant and fluctuating temperatures on the body mass and development time of red flour beetles (Tribolium castaneum Herbst, 1797); we also examined whether the sexes differed in their responses to thermal conditions. We exposed the progeny of half-sib families of a T. castaneum laboratory strain to one of four temperature regimes: constant 30°C, constant 25°C, fluctuating with a daily mean of 30°C, or fluctuating with a daily mean of 25°C. Sex-specific development time and body mass at emergence were determined. Beetles developed the fastest and had the greatest body mass upon emergence when they were exposed to a constant temperature of 30°C. This pattern was reversed when beetles experienced a constant temperature of 25°C: slowest development and lowest body mass upon emergence were observed. Fluctuations changed those effects significantly - impact of temperature on development time was smaller, while differences in body mass disappeared completely. Our results do not fit TSR predictions. Furthermore, regardless of the temperature regime, females acquired more mass, while there were no differences between sexes in development time to eclosion. This finding fails to support one of the explanations for smaller male size: that selection favors the early emergence of males. We found no evidence of genotype × environment interactions for selected set of traits.
Assuntos
Tamanho Corporal/fisiologia , Temperatura , Tribolium/crescimento & desenvolvimento , Animais , Feminino , MasculinoRESUMO
Setting priorities in the field of infectious diseases requires evidence-based and robust baseline estimates of disease burden. Therefore, the European Centre for Disease Prevention and Control initiated the Burden of Communicable Diseases in Europe (BCoDE) project. The project uses an incidence- and pathogen-based approach to measure the impact of both acute illness and sequelae of infectious diseases expressed in disability-adjusted life years (DALYs). This study presents first estimates of disease burden for four pathogens in Germany. The number of reported incident cases adjusted for underestimation served as model input. For the study period 2005-2007, the average disease burden was estimated at 33 116 DALYs/year for influenza virus, 19 115 DALYs/year for Salmonella spp., 8708 DALYs/year for hepatitis B virus and 740 DALYs/year for measles virus. This methodology highlights the importance of sequelae, particularly for hepatitis B and salmonellosis, because if omitted, the burden would have been underestimated by 98% and 56%, respectively.
Assuntos
Hepatite B/epidemiologia , Influenza Humana/epidemiologia , Sarampo/epidemiologia , Infecções por Salmonella/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etiologia , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Hepatite B/complicações , Hepatite B Crônica/complicações , Hepatite B Crônica/epidemiologia , Humanos , Incidência , Lactente , Influenza Humana/complicações , Falência Hepática Aguda/epidemiologia , Falência Hepática Aguda/etiologia , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/etiologia , Adulto JovemRESUMO
The role of the European Centre for Disease Prevention and Control (ECDC) is to strengthen the capacity of the European Union (EU) Member States to protect human health through the prevention and control of infectious diseases. The main objective of the programme on vaccine-preventable diseases and invasive bacterial infections (VPD) is to provide robust evidence and high-quality technical support to the EU Member States to help them in their efforts to prevent and control VPD. Since the establishment of ECDC, several existing VPD surveillance networks have been transferred to ECDC, namely EU-IBIS, DIPNET and EUVAC. In addition to surveillance of diseases, ECDC is collecting information and monitoring other parameters that are of crucial importance for a well-functioning immunization system, including vaccination coverage. The VPD programme also provides independent scientific opinions in the area of immunization and initiates and coordinates scientific studies in the area of vaccination to answer specific questions of public health importance, including risk perception and analysis of behaviour in different population groups. One of the overall ECDC priorities over recent years is the Centre's involvement in measles elimination. The 'Message' tool and the 'Measles Atlas' are examples of work aiming at supporting the efforts of Member States in the elimination phase.
Assuntos
Controle de Doenças Transmissíveis , Vacinação , Vacinas , União Europeia , Humanos , Saúde Pública , Sociedades MédicasRESUMO
Surveillance and studies in a pandemic is a complex topic including four distinct components: (1) early detection and investigation; (2) comprehensive early assessment; (3) monitoring; and (4) rapid investigation of the effectiveness and impact of countermeasures, including monitoring the safety of pharmaceutical countermeasures. In the 2009 pandemic, the prime early detection and investigation took place in the Americas, but Europe needed to undertake the other three components while remaining vigilant to new phenomenon such as the emergence of antiviral resistance and important viral mutation. Laboratory-based surveillance was essential and also integral to epidemiological and clinical surveillance. Early assessment was especially vital because of the many important strategic parameters of the pandemic that could not be anticipated (the 'known unknowns'). Such assessment did not need to be undertaken in every country, and was done by the earliest affected European countries, particularly those with stronger surveillance. This was more successful than requiring countries to forward primary data for central analysis. However, it sometimes proved difficult to get even those analyses from European counties, and information from Southern hemisphere countries and North America proved equally valuable. These analyses informed which public health and clinical measures were most likely to be successful, and were summarized in a European risk assessment that was updated repeatedly. The estimate of the severity of the pandemic by the World Health Organization (WHO), and more detailed description by the European Centre for Disease Prevention and Control in the risk assessment along with revised planning assumptions were essential, as most national European plans envisaged triggering more disruptive interventions in the event of a severe pandemic. Setting up new surveillance systems in the midst of the pandemic and getting information from them was generally less successful. All European countries needed to perform monitoring (Component 3) for the proper management of their own healthcare systems and other services. The information that central authorities might like to have for monitoring was legion, and some countries found it difficult to limit this to what was essential for decisions and key communications. Monitoring should have been tested for feasibility in influenza seasons, but also needed to consider what surveillance systems will change or cease to deliver during a pandemic. International monitoring (reporting upwards to WHO and European authorities) had to be kept simple as many countries found it difficult to provide routine information to international bodies as well as undertaking internal processes. Investigation of the effectiveness of countermeasures (and the safety of pharmaceutical countermeasures) (Component 4) is another process that only needs to be undertaken in some countries. Safety monitoring proved especially important because of concerns over the safety of vaccines and antivirals. It is unlikely that it will become clear whether and which public health measures have been successful during the pandemic itself. Piloting of methods of estimating influenza vaccine effectiveness (part of Component 4) in Europe was underway in 2008. It was concluded that for future pandemics, authorities should plan how they will undertake Components 2-4, resourcing them realistically and devising new ways of sharing analyses.
Assuntos
Surtos de Doenças/prevenção & controle , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/prevenção & controle , Vigilância da População/métodos , Medição de Risco/métodos , Europa (Continente)/epidemiologia , Saúde Global , Humanos , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Cooperação Internacional , Saúde Pública , PesquisaRESUMO
The field site network (FSN) plays a central role in conducting joint research within all Assessing Large-scale Risks for biodiversity with tested Methods (ALARM) modules and provides a mechanism for integrating research on different topics in ALARM on the same site for measuring multiple impacts on biodiversity. The network covers most European climates and biogeographic regions, from Mediterranean through central European and boreal to subarctic. The project links databases with the European-wide field site network FSN, including geographic information system (GIS)-based information to characterise the test location for ALARM researchers for joint on-site research. Maps are provided in a standardised way and merged with other site-specific information. The application of GIS for these field sites and the information management promotes the use of the FSN for research and to disseminate the results. We conclude that ALARM FSN sites together with other research sites in Europe jointly could be used as a future backbone for research proposals.
Assuntos
Biodiversidade , Europa (Continente) , Medição de RiscoRESUMO
During the 2007-08 influenza season, high levels of oseltamivir resistance were detected among influenza A(H1N1) viruses ina number of European countries. We used surveillance data to describe influenza A(H1N1) cases for whom antiviral resistance testing was performed. We pooled data from national studies to identify possible risk factors for infection with a resistant virus and to ascertain whether such infections led to influenza illness of different severity. Information on demographic and clinical variables was obtained from patients or their physicians. Odds ratios for infection with an oseltamivir resistant virus and relative risks for developing certain clinical outcomes were computed and adjusted through multivariable analysis. Overall, 727 (24.3%) of 2,992 tested influenza A(H1N1) viruses from 22 of 30 European countries were oseltamivir-resistant. Levels of resistance ranged from 1% in Italy to 67% in Norway. Five countries provided detailed case-based data on 373 oseltamivir resistant and 796 susceptible cases. By multivariable analysis, none of the analysed factors was significantly associated with an increased risk of infection with anoseltamivir-resistant virus. Similarly, infection with an oseltamivir-resistant virus was not significantly associated with a different risk of pneumonia, hospitalisation or any clinical complication. The large-scale emergence of oseltamivir-resistant viruses in Europe calls for a review of guidelines for influenza treatment.
Assuntos
Antivirais/farmacologia , Surtos de Doenças , Farmacorresistência Viral , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/virologia , Oseltamivir/farmacologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Farmacorresistência Viral/genética , Europa (Continente)/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Risco , Fatores de Risco , Estações do Ano , Inquéritos e Questionários , Resultado do Tratamento , Adulto JovemRESUMO
Pandemic vaccines from four manufacturers are now available for use within the European Union (EU). Use of these vaccines will protect individuals and reduce the impact on health services to more manageable levels. The majority of the severely ill will be from known risk groups and the best strategy will be to start vaccinating in line with the recommendation from the European Union Health Security Committee prioritizing adults and children with chronic conditions, pregnant women and healthcare workers. The composition of authorized vaccines is reviewed in this article. The vaccine strain in all authorized pandemic vaccines worldwide is based on the same initial isolate of influenza A/California/7/2009 (H1N1)v but the vaccines differ in conditions for virus propagation, antigen preparation, antigen content and whether they are adjuvanted or not. The vaccines are likely to be effective since no significant genetic or antigenic drift has occurred and there are already mechanisms for estimating clinical effectiveness. Influenza vaccines have good safety records and no safety concerns have so far been encountered with any of the vaccines developed. However, special mechanisms have been devised for the early detection and rigorous investigation of possible significant side effects in Europe through post-marketing surveillance and analysis. Delivery of the vaccines to the risk groups will pose difficulties where those with chronic illnesses are not readily identifiable to the healthcare services. There is considerable scope for European added value through Member States with excess vaccines making them available to other states.
Assuntos
Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza , Influenza Humana/prevenção & controle , União Europeia , Humanos , Vacinas contra Influenza/imunologia , RiscoRESUMO
Illness and death from diseases caused by unsafe food are a constant threat to public health security as well as socio-economic development throughout the world. The full extent of the burden and cost of foodborne diseases associated with pathogenic bacterial, viral and parasitic microorganisms, and food contaminated by chemicals is still unknown but is thought to be substantial. The World Health Organization (WHO) Initiative to estimate the global burden of foodborne diseases aims to fill the current data gap and respond to the increasing global interest in health information. Collaborative efforts are required to achieve the ambitious task of assessing the foodborne disease burden from all causes worldwide. Recognising the need to join forces, the WHO Initiative has assembled an alliance of stakeholders which share and support the Initiative's vision, intended objectives and outcomes. One important collaborator is the European Centre for Disease Prevention and Control (ECDC) which has embarked on a burden of disease study covering at least 18 foodborne diseases in nearly 30 countries.
Assuntos
Síndrome de Creutzfeldt-Jakob/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Doenças Transmitidas por Alimentos/epidemiologia , Cooperação Internacional , Vigilância da População/métodos , Organização Mundial da Saúde/organização & administração , Incidência , Medição de Risco/métodos , Fatores de RiscoRESUMO
Variable levels of oseltamivir resistance among seasonal influenza A(H1N1) isolates have been reported in Europe during the 2007-8 northern Hemisphere influenza season. It has been questioned whether oseltamivir use could have driven the emergence and predominance of resistant viruses. This study aimed at describing the levels of use of oseltamivir in 12 European Union (EU) Member States and European Economic Area (EEA)/European Free Trade Area (EFTA) countries. The data were converted into prescription rates and compared with the national proportions of resistant influenza A(H1N1) viruses through regression analysis. Overall use of oseltamivir in European countries between 2002 and 2007 was low compared to e.g. the use in Japan. High variability between the countries and over time was observed. In eight of the 12 countries, there was a peak of prescriptions in 2005, coinciding with concerns about a perceived threat from an influenza pandemic which might have lead to personal stockpiling. Ecological comparison between national levels of use of oseltamivir in 2007 and the proportions of A(H1N1) viruses that were resistant to oseltamivir showed no statistical association. In conclusion, our results do not support the hypothesis that the emergence and persistence of these viruses in 2007-8 was related to the levels of use of oseltamivir in Europe. Further investigation is needed to elucidate the reasons for different level of use between the countries.
Assuntos
Farmacorresistência Viral , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Oseltamivir/administração & dosagem , Prescrições/estatística & dados numéricos , Medição de Risco/métodos , Antivirais/administração & dosagem , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Europa (Continente) , Humanos , Incidência , Influenza Humana/virologia , Fatores de Risco , Estatística como AssuntoRESUMO
In this weeks issue of Eurosurveillance, Zambon and colleagues describe the first findings of the European Union-funded European Surveillance Network for Vigilance Against Viral Resistance (VIRGIL) of some seasonal influenza viral isolates resistant to the antiviral drug oseltamivir in Europe.
Assuntos
Antivirais/farmacologia , Farmacorresistência Viral , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Oseltamivir/farmacologia , Europa (Continente) , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/tratamento farmacológico , Influenza Humana/mortalidade , Influenza Humana/virologia , Estações do Ano , Virulência , Organização Mundial da SaúdeRESUMO
We investigated resistance to metals in carabid beetles inhabiting metal-polluted and reference areas. Chronic multigeneration exposure to toxic metal concentrations may potentially result in adaptation through decreased metal uptake rate and/or increased excretion rate. The cost of resistance to pollution could be associated with increased metabolic rate. To test these predictions, laboratory cultured F(1)-generation beetles originating from metal-polluted and reference sites were exposed to food contaminated with zinc and/or cadmium for 10 weeks. After that, uncontaminated food was offered to the animals for another 3 weeks. During the experiment, internal concentrations of Cd and Zn were measured as were respiration rates of the animals. The results obtained show no significant differences in metal accumulation and excretion patterns or respiration rates between the populations. This may suggest that adaptation has not occurred in the beetles chronically exposed to toxic metal concentrations. The possible explanations for the lack of differences between the populations are discussed.
Assuntos
Cádmio/metabolismo , Besouros/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo , Adaptação Fisiológica/genética , Animais , Cádmio/análise , Besouros/anatomia & histologia , Besouros/genética , Monitoramento Ambiental , Feminino , Masculino , Polônia , Respiração , Poluentes do Solo/análise , Fatores de Tempo , Zinco/análiseAssuntos
Besouros/efeitos dos fármacos , Metais Pesados/toxicidade , Animais , Cádmio/toxicidade , Besouros/crescimento & desenvolvimento , Cobre/toxicidade , Feminino , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Chumbo/toxicidade , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Reprodução/efeitos dos fármacos , Poluentes do Solo/análise , Zinco/toxicidadeRESUMO
We investigated the responses of invertebrates inhabiting polluted environments to multiple stressors. Carabid beetles (Pterostichus oblongopunctatus F.) were subjected to food deprivation and insecticide treatment (dimethoate) to resolve trends associated with a gradient of heavy metal pollution. Metal concentrations along the gradient of five sites ranged from approximately 150 to 10,500 mg/kg Zn, 136 to 2600 mg/kg Pb, and 0.84 to 81.9 mg/kg Cd. There was no difference in body mass along the pollution gradient. However, the beetles originating from the most contaminated sites were significantly less tolerant to food deprivation than beetles from the reference site. Median survival time was 120 h for the two most polluted sites, compared with 168 h at the reference site. Beetles from the two most polluted sites were also significantly more susceptible to dimethoate at 0.1 microgram active ingredient/beetle. Median survival times were 12 and 123 h for beetles from the two most polluted sites and 359 h for the reference site. Carabid beetles exposed to chronic pollution, therefore, exhibit elevated susceptibility to additional stressors.
Assuntos
Besouros/fisiologia , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Adaptação Fisiológica , Animais , Relação Dose-Resposta a Droga , Privação de Alimentos , Dose Letal Mediana , Mortalidade , Análise de Sobrevida , Fatores de TempoRESUMO
BACKGROUND: During the first year that the rhesus rotavirus tetravalent vaccine (RRV-TV) was licensed, the Vaccine Adverse Event Reporting System received several reports of intussusception after vaccination. To evaluate the risk of intussusception, we conducted a retrospective cohort study in ten managed care organizations. METHODS: Cases of intussusception were identified by searching electronic databases for diagnoses of intussusception (ICD-9 Code 560.0) in infants 1 to 11 months of age and confirmed by medical chart review. Vaccination and enrollment data were obtained from administrative databases. Incidence rate ratios (RR) of intussusception were computed by dividing incidence rates in prespecified risk intervals after vaccination by the background rate of intussusception and adjusted for age by Poisson regression. Cox proportional hazard regression was used to evaluate risk by vaccine dose. RESULTS: Of 463,277 children 56,253 had been vaccinated with a total of 91 371 doses of RRV-TV. The incidence rate of intussusception was 25/100,000 person years among unexposed infants and 340/100,000 person years 3 to 7 days postvaccination. In the interval 3 to 7 days after vaccination, the age-adjusted RR was 16.0 (95% confidence interval, 5.5 to 46.7) for all doses combined and 30.4 (95% confidence interval, 8.8 to 104.9) after the first dose. RRs for the 8- to 14- and 15- to 21-day risk intervals were >1.0, but the confidence intervals substantially overlapped 1.0. The attributable risk was one case of intussusception per 11 073 children vaccinated. CONCLUSIONS: RRV-TV is associated with an increased risk of intussusception. The risk is greatest 3 to 7 days after the first vaccination dose.
Assuntos
Intussuscepção/etiologia , Vacinas contra Rotavirus/efeitos adversos , Humanos , Lactente , Intussuscepção/epidemiologia , Distribuição de Poisson , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Risco , Vacinação/efeitos adversosRESUMO
No vaccine is perfectly safe or effective. As diseases such as diphtheria and polio fade, vaccine safety concerns, especially alleged links between vaccinations and several chronic illnesses, have become increasingly prominent in the media and to the public. This article reviews the current scientific evidence on several recent vaccine safety controversies. It also provides information on how various safety research is conducted, some of the concurrent challenges, and finally, some guidance on communicating with patients on vaccine risks.
Assuntos
Imunização , Segurança , Vacinas , Transtorno Autístico/etiologia , Doenças Autoimunes/etiologia , Coleta de Dados , Síndrome de Guillain-Barré/etiologia , Humanos , Intussuscepção/etiologia , Medição de Risco , Vacinas/administração & dosagem , Vacinas/efeitos adversos , Vacinas CombinadasRESUMO
CONTEXT: A link between measles virus-containing vaccines and inflammatory bowel disease (IBD) has been suggested by recent studies. OBJECTIVE: To address whether receipt or timing of measles-containing vaccine (MCV) increases risk for IBD. DESIGN: A case-control study. SETTING: Four large health maintenance organizations (HMOs) that are part of the Centers for Disease Control and Prevention's Vaccine Safety Datalink project. PATIENTS OR OTHER PARTICIPANTS: A total of 155 persons with codes from International Classification of Diseases, Ninth Revision specific for IBD, born between 1958 and 1989 and enrolled from birth to the onset of disease, were identified. Up to 5 controls were matched by sex, HMO, and birth year. INTERVENTION: None. MAIN OUTCOME MEASURES: Risk for IBD, Crohn's disease, and ulcerative colitis. RESULTS: Past vaccination was not associated with an increased risk for Crohn's disease (odds ratio [OR] for measles-mumps-rubella vaccine [MMR], 0.4; 95% confidence interval [CI], 0.08-2.0), ulcerative colitis (OR, 0.8; 95% CI, 0.18-3.56), or IBD (OR, 0.59; 95% CI, 0.21-1.68). Risk for IBD was not increased among children vaccinated who were younger than 12 months (OR for MMR, 0.61; 95% CI, 0.15-2.45) or aged 12 to 18 months (OR, 0.86; 95% CI, 0.28-2.59) relative to unvaccinated children. Children vaccinated with MMR who were older than 18 months were at significantly decreased risk for IBD (OR, 0.16; 95% CI, 0.04-0.68). Neither past vaccination nor age at vaccination with other MCV was associated with increased risk for Crohn's disease, ulcerative colitis, or IBD. Risk for Crohn's disease, ulcerative colitis, or IBD was not elevated in the time immediately following vaccination with either vaccine. CONCLUSIONS: Vaccination with MMR or other MCV, or the timing of vaccination early in life, did not increase the risk for IBD.
Assuntos
Doenças Inflamatórias Intestinais/induzido quimicamente , Vacina contra Sarampo-Caxumba-Rubéola/efeitos adversos , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Colite Ulcerativa/induzido quimicamente , Doença de Crohn/induzido quimicamente , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , Sistemas Computadorizados de Registros Médicos , Fatores de RiscoRESUMO
OBJECTIVE: Influenza can exacerbate asthma, particularly in children. The effectiveness of influenza vaccine in preventing influenza-related asthma exacerbations, however, is not known. We evaluated influenza vaccine effectiveness in protecting children against influenza-related asthma exacerbations. STUDY DESIGN: We conducted a population-based retrospective cohort study with medical and vaccination records in 4 large health maintenance organizations in the United States during the 1993-1994, 1994-1995, and 1995-1996 influenza seasons. We studied children with asthma who were 1 through 6 years of age and who were identified by search of computerized databases of medical encounters and pharmacy dispensings. Main outcome measures were exacerbations of asthma evaluated in the emergency department or hospital. RESULTS: Unadjusted rates of asthma exacerbations were higher after influenza vaccination than before vaccination. After adjustment was done for asthma severity by means of a self-control method, however, the incidence rate ratios of asthma exacerbations after vaccination were 0.78 (95% CI: 0.55 to 1.10), 0.59 (0.43 to 0.81), and 0.65 (0.52 to 0.80) compared with the period before vaccination during the 3 influenza seasons. CONCLUSIONS: After controlling for asthma severity, we found that influenza vaccination protects against acute asthma exacerbations in children.
Assuntos
Asma/prevenção & controle , Asma/virologia , Imunização , Influenza Humana/prevenção & controle , Doença Aguda , Asma/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Influenza Humana/complicações , Masculino , Análise de Regressão , Estudos Retrospectivos , Risco , Índice de Gravidade de Doença , Estados Unidos/epidemiologiaRESUMO
CONTEXT: Although influenza vaccination is recommended for children with asthma, only a minority are vaccinated. One reason for low influenza vaccine coverage among children with asthma may be concern that influenza vaccination may induce an exacerbation of asthma. OBJECTIVE: To evaluate the safety of influenza vaccination in children with asthma, we studied the incidence of hospitalizations and emergency department visits for asthma following influenza vaccination. DESIGN: Retrospective cohort study-analysis of population-based computerized medical and vaccination records. SETTING: : Four large health maintenance organizations on the West Coast of the United States. SUBJECTS: Children with asthma 1 through 6 years of age, identified by search of computerized databases of medical encounters and pharmacy prescriptions. MAIN OUTCOME MEASURES: Exacerbations of asthma. RESULTS: In unadjusted analyses vaccination was associated with high rates of asthma exacerbations. However, after adjusting for asthma severity using a self-control method, the incidence rate ratios of asthma exacerbations after vaccination were 0.58 (95% confidence interval, 0.36-0.95), 0.74 (95% confidence interval, 0.47-1.17), and 0.98 (95% confidence interval, 0.76-1.27) during the 3 influenza seasons. CONCLUSIONS: After controlling for asthma severity, we found that influenza vaccination does not result in acute asthma exacerbations in children. Concern about possible exacerbation of asthma is not a valid reason to not vaccinate children with asthma against influenza.
Assuntos
Asma/fisiopatologia , Vacinas contra Influenza/efeitos adversos , Asma/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Lactente , Masculino , Estudos RetrospectivosRESUMO
We assessed vaccination coverage and predictors of influenza vaccination in asthmatic children in four large Health Maintenance Organizations. We studied 68,839 children with asthma at four Health Maintenance Organizations (HMOs) in the 1995-1996 influenza season and 34,032 children at two HMOs in the 1996-1997 influenza season. In both seasons only 9-10% were vaccinated against influenza. Children who were hospitalized, had an emergency department visit for asthma or a prescription for a beta-agonist prior to the influenza season, were more likely to be vaccinated. Overall, 61% of the unvaccinated asthmatic children had made an outpatient clinic visit during months when influenza vaccination would have been appropriate. Vaccination coverage could be increased by taking advantage of all opportunities to vaccinate children with asthma whenever they make clinic visits in the fall and early winter.