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1.
Vaccine ; 38(19): 3582-3590, 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32229052

RESUMO

BACKGROUND: Concern about adverse events following immunization is frequently cited by both those who receive or decline vaccines. Neurological adverse events are especially concerning. OBJECTIVES: Our aim was to detect associations between seasonal influenza vaccination and the occurrence of severe anesthesia/paresthesia or severe headaches. METHODS: Data were analyzed from the Canadian National Vaccine Safety network. Events occuring on days 0-7 were self-reported and prevented daily activity, led to school or work absenteeism, or required medical attention. Controls were the previous year's vaccinees; events in controls were collected prior to the start of the influenza vaccination program of each year (2012/13 through 2016/17). Multivariable logistic regression was used to determine the association between seasonal influenza vaccination and the occurrence of anesthesia/paresthesia or severe headaches. RESULTS: The total sample was 107,565 for investigating anesthesia/paresthesia and 97,420 for investigating severe headaches. Anesthesia/paresthesia was reported by 104/107,565 (0.10%) participants; 63/69,129 (0.09%) vaccinees and 41/38,436 (0.11%) controls (adjusted odds ratio (aOR) = 0.89; 95% CI = 0.60, 1.32). Severe headaches were reported by 1361/97,420 (1.40%) participants; 907/61,463 (1.48%) vaccinees and 454/35,957 (1.26%) controls (aOR = 1.21; 95% CI = 1.08, 1.36). No specific vaccine product was associated with severe headaches. CONCLUSIONS: Our study found no association between severe anesthesia/paresthesia and seasonal influenza vaccination. While there was an association with severe headaches as an adverse event following influenza vaccination, the rates of these events are similar to rates reported from clinical trials and are not a cause for additional concern.

2.
J Infect Dis ; 221(1): 81-90, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504649

RESUMO

BACKGROUND: To understand real-world human papillomavirus (HPV) vaccine impact, continuous evaluation using population-based data is critical. We evaluated the early impact of the school-based HPV immunization program on cervical dysplasia in women in British Columbia, Canada. METHODS: Data linkage was performed using records from provincial cervical screening and immunization registries. Precancerous outcomes were compared between unvaccinated and HPV-vaccinated women born 1994-2005. Incidence rate, relative rate (RR), and vaccine effectiveness (VE), using unadjusted and adjusted Poisson regression of cytology (HSIL) and histopathology (CIN2, CIN3, and CIN2+) outcomes, were compared across vaccination status groups. RESULTS: Women who received a complete series of vaccine on schedule between age 9 and 14 years had an adjusted RR = 0.42 (95% confidence interval [CI], 0.31-0.57) for CIN2+ over 7 years of follow-up compared to unvaccinated women, resulting in a VE of 57.9% (95% CI, 43.2%-69.0%). Adjusted RR for HSIL was 0.53 (95% CI, .43-.64), resulting in a VE of 47.1% (95% CI, 35.6%-56.7%). CONCLUSION: Women vaccinated against HPV have a lower incidence of cervical dysplasia compared to unvaccinated women. Immunization between 9 and 14 years of age should be encouraged. Continued program evaluation is important for measuring long-term population impact.

3.
Clin Infect Dis ; 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31617568

RESUMO

BACKGROUND: Several countries have implemented a 2-dose (2D) human papillomavirus (HPV) vaccination schedule for adolescents based on immunobridging studies. We compared immunogenicity of 2D vs 3-dose (3D) schedules of the quadrivalent vaccine (4vHPV) up to 10 years after the first dose. METHODS: Girls aged 9-13 years were randomized to receive 2D or 3D and were compared with women aged 16-26 receiving 3D at day 1 and months 7, 24, and 120 after the first dose. Antibody levels for HPV6/11/16/18 were evaluated using the competitive Luminex immunoassay (cLIA) and total immunoglobulin G assay. Geometric mean titers (GMTs) and seropositivity rates were compared between the different groups at different time points. Noninferiority of GMT ratios was defined as the lower bound of the 2-sided 95% confidence interval (CI) being greater than 0.5. Kinetics of antibody titers over time among study groups were examined. RESULTS: At 120 months, data from 35 2D girls, 38 3D girls, and 30 3D women were used for analyses. cLIA seropositivity rates were above 95% for all HPV vaccine types and all schedules, except HPV18, with the lowest seropositivity observed among 3D women (60.0%; 95% CI, 40.6%-77.3%). GMT ratios (cLIA) for both 2D and 3D girls were noninferior to 3 doses in women for HPV6/11/16/18. Trends were comparable between assays. CONCLUSIONS: GMTs for HPV6/11/16/18 after 2D or 3D of 4vHPV in girls were noninferior to 3D in adult women up to 120 months postvaccination. This study demonstrates long-term immunogenicity of the 2D HPV vaccine schedule.

4.
Vaccine ; 37(30): 4001-4007, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31204156

RESUMO

OBJECTIVES: In 2012, British Columbia (BC) implemented a province-wide vaccinate-or-mask influenza prevention policy for healthcare workers (HCWs) with the aim of improving HCW coverage, and reducing illness in patients and staff. We assess post-policy impacts of HCW vaccination status on their absenteeism. METHODS: We matched individual HCW payroll data from December 1, 2012 to March 31, 2017 with annually self-reported vaccination status for BC health authority employees to assess sick rates (sick time as a proportion of sick time and productive time). We modelled adjusted odds ratios (OR) of taking any sick time, relative rates (RR) of sick time taken, and predicted mean sick rates by vaccination status in influenza (December 1-March 31) and non-influenza seasons (April 1 to November 30). We used two methods to assess changes in influenza season sick rates for HCWs who had a change in their vaccination status over the five years. RESULTS: HCWs who reported 'early' vaccination (before December 1 when the policy is in effect) were less likely to take sick time (OR 0.874, 95%CI: 0.866-0.881) and took less sick time (RR 0.907, 95%CI: 0.901-0.912) in influenza season compared to HCWs who did not report vaccination; whereas HCWs who reported 'late' (between December 1 and March 31, and subject to masking until vaccinated) had similar sick rates to HCWs who did not report vaccination. These trends were also observed in non-influenza season. Influenza season sick rates were similar for HCWs that had at least one year of 'early' vaccination and one year where vaccination was not reported over the five year period. CONCLUSIONS: Overall absenteeism is lower among HCWs who report vaccination versus those who do not report. However, absenteeism behaviours appear to be influenced by individual level factors other than vaccination status.

5.
Vaccine ; 37(30): 4008-4014, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31204158

RESUMO

OBJECTIVES: Vaccinate-or-mask (VOM) policies aim to improve influenza vaccine coverage among healthcare workers (HCW) and reduce influenza-related illness among patients and staff. In 2012, British Columbia (BC) implemented a province-wide VOM influenza prevention policy. This study describes an evaluation of policy impacts on HCW absenteeism rates from before to after policy implementation. METHODS: Using payroll data from regional and provincial Health Authorities (HA), we assessed all-cause sick rates (sick time as a proportion of sick time and productive time) before (2007-2011, excluding 2009-2010) and after (2012-2017) policy implementation, and during influenza season (December 1-March 31) and non-influenza season (April 1-November 30). We used a two-part negative binomial hurdle model to calculate odds ratios (OR) of taking any sick time, relative rates (RR) of sick time taken, and predicted mean sick rates, adjusting for age group, sex, job type, job classification, HA, year and vaccine effectiveness. RESULTS: During influenza season, HCWs in the post-policy period were less likely to take any sick time (OR 0.989, 95%CI: 0.979-0.999) but had higher rates of sick time (RR 1.038, 95%CI: 1.030-1.045). However, during non-influenza season, HCWs in the post-policy period were more likely to take any sick time (OR 1.015, 95%CI: 1.008-1.022) but had lower rates of sick time (RR 0.971, 95%CI: 0.966-0.976). There was an overall increase in predicted mean sick rate from pre to post-policy in influenza season (4.392% to 4.508%) and non-influenza season (3.815% to 3.901%). CONCLUSIONS: The observed year-round increase in sick rates from pre-to-post policy was likely influenced by other factors; however, opposite trends in how HCWs took sick time in the influenza and non-influenza seasons may reflect policy influences and need further research to explore reasons for these differences.

6.
CMAJ Open ; 7(2): E264-E271, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31018972

RESUMO

BACKGROUND: Motivated by concerns of inadequate vaccination coverage and the potential for outbreaks of vaccine-preventable diseases, Canadian provinces have been discussing, implementing and tightening policies requiring documentation of vaccination for school enrolment. We sought to understand the acceptability of 14 potential vaccination policy levers among parents and other adults in British Columbia. METHODS: A representative online panel of 1308 adults in BC was surveyed in April 2017. Respondents were representative of the BC population by sex, age, geographic residence and percentage of household with children younger than 19 years. We used Poisson regression to estimate predictors of policy endorsement. RESULTS: Most respondents (> 80%) held positive attitudes toward vaccination. Policies such as mandatory documentation of vaccination at school entry were supported by more than 75% of all respondents. Punitive policies, such as denial of child tax benefits for nonvaccination, were supported by less than 40% of respondents. In multivariable regression, respondents with positive attitudes toward vaccination were significantly more likely to strongly support all potential policies. Additionally, female respondents and respondents with postsecondary education were significantly more likely to strongly support policies involving additional requirements for parents. INTERPRETATION: Most adults in BC held favourable attitudes toward vaccination, and strong support existed for policies designed to support vaccination. This study provides evidence that most adults in BC are supportive of vaccination and, when presented with a wide range of options, would likely be supportive of information and requirement policy options designed to increase vaccination uptake.

7.
PLoS One ; 13(10): e0204799, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30332477

RESUMO

BACKGROUND & OBJECTIVES: Vaccine safety signals require investigation, which may be done rapidly at the population level using ecological studies, before embarking on hypothesis-testing studies. Incidence rates were used to assess a signal of narcolepsy following AS03-adjuvanted monovalent pandemic H1N1 (pH1N1) influenza vaccination among children and adolescents in Sweden and Finland in 2010. We explored the utility of ecological data to assess incidence of narcolepsy following exposure to pandemic H1N1 virus or vaccination in 10 sites that used different vaccines, adjuvants, and had varying vaccine coverage. METHODS: We calculated incidence rates of diagnosed narcolepsy for periods defined by influenza virus circulation and vaccination campaign dates, and used Poisson regression to estimate incidence rate ratios (IRRs) comparing the periods during which wild-type virus circulated and after the start of vaccination campaigns vs. the period prior to pH1N1 virus circulation. We used electronic health care data from Sweden, Denmark, the United Kingdom, Canada (3 provinces), Taiwan, Netherlands, and Spain (2 regions) from 2003 to 2013. We investigated interactions between age group and adjuvant in European sites and conducted a simulation study to investigate how vaccine coverage, age, and the interval from onset to diagnosis may impact the ability to detect safety signals. RESULTS: Incidence rates of narcolepsy varied by age, continent, and period. Only in Taiwan and Sweden were significant time-period-by-age-group interactions observed. Associations were found for children in Taiwan (following pH1N1 virus circulation) and Sweden (following vaccination). Simulations showed that the individual-level relative risk of narcolepsy was underestimated using ecological methods comparing post- vs. pre-vaccination periods; this effect was attenuated with higher vaccine coverage and a shorter interval from disease onset to diagnosis. CONCLUSIONS: Ecological methods can be useful for vaccine safety assessment but the results are influenced by diagnostic delay and vaccine coverage. Because ecological methods assess risk at the population level, these methods should be treated as signal-generating methods and drawing conclusions regarding individual-level risk should be avoided.


Assuntos
Narcolepsia/epidemiologia , Adjuvantes Imunológicos/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Canadá/epidemiologia , Criança , Pré-Escolar , Simulação por Computador , Europa (Continente)/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/efeitos adversos , Influenza Humana/complicações , Influenza Humana/imunologia , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Narcolepsia/diagnóstico , Narcolepsia/etiologia , Fatores de Risco , Segurança , Taiwan/epidemiologia , Vacinação/efeitos adversos , Adulto Jovem
8.
CMAJ ; 190(41): E1221-E1226, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30322986

RESUMO

BACKGROUND: The human papillomavirus (HPV) vaccine is delivered widely through school-based immunization programs. Some groups have expressed concern that HPV vaccination programs will result in an increase in sexual risk-taking behaviours among adolescents. We aimed to evaluate population-level changes in sexual behaviours before and after implementation of the school-based HPV vaccination program in British Columbia. METHODS: In 2008, a school-based HPV vaccination program for girls was introduced in British Columbia. Using data from the BC Adolescent Health Survey - a longitudinal provincial survey administered in schools to capture adolescent physical and emotional health indicators, we conducted a linear trend analysis on sexual health behaviours and risk factors in adolescent girls before and after the implementation of vaccination for HPV (2003, 2008 and 2013). RESULTS: We analyzed data for 298 265 girls who self-identified as heterosexual. The proportion of girls reporting ever having sexual intercourse decreased from 21.3% (2003) to 18.3% (2013; adjusted odds ratio [OR] 0.79). Self-report of sexual intercourse before the age of 14 years decreased significantly from 2008 to 2013 (adjusted OR 0.76), as did reported substance use before intercourse (adjusted OR for 2003-2013 0.69). There was no significant change in the number of sexual partners reported (2003-2013). Between 2003 and 2013, girls' reported use of contraception and condoms increased, while pregnancy rates decreased. INTERPRETATION: Since the implementation of school-based HPV vaccination program in BC, sexual risk behaviours reported by adolescent girls either reduced or stayed the same. These findings contribute evidence against any association between HPV vaccination and risky sexual behaviours.


Assuntos
Comportamento do Adolescente , Vacinas contra Papillomavirus/uso terapêutico , Comportamento Sexual/estatística & dados numéricos , Mulheres , Adolescente , Fatores Etários , Colúmbia Britânica , Coito , Preservativos/tendências , Comportamento Contraceptivo/tendências , Feminino , Humanos , Programas de Imunização , Razão de Chances , Crescimento Demográfico , Gravidez , Gravidez na Adolescência/estatística & dados numéricos , Assunção de Riscos , Serviços de Saúde Escolar , Autorrelato , Parceiros Sexuais
9.
Vaccine ; 36(41): 6202-6211, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30122647

RESUMO

BACKGROUND: In 2010, a safety signal was detected for narcolepsy following vaccination with Pandemrix, an AS03-adjuvanted monovalent pandemic H1N1 influenza (pH1N1) vaccine. To further assess a possible association and inform policy on future use of adjuvants, we conducted a multi-country study of narcolepsy and adjuvanted pH1N1 vaccines. METHODS: We used electronic health databases to conduct a dynamic retrospective cohort study to assess narcolepsy incidence rates (IR) before and during pH1N1 virus circulation, and after pH1N1 vaccination campaigns in Canada, Denmark, Spain, Sweden, Taiwan, the Netherlands, and the United Kingdom. Using a case-control study design, we evaluated the risk of narcolepsy following AS03- and MF59-adjuvanted pH1N1 vaccines in Argentina, Canada, Spain, Switzerland, Taiwan, and the Netherlands. In the Netherlands, we also conducted a case-coverage study in children born between 2004 and 2009. RESULTS: No changes in narcolepsy IRs were observed in any periods in single study sites except Sweden and Taiwan; in Taiwan incidence increased after wild-type pH1N1 virus circulation and in Sweden (a previously identified signaling country), incidence increased after the start of pH1N1 vaccination. No association was observed for Arepanrix-AS03 or Focetria-MF59 adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the case-control study nor for children born between 2004 and 2009 in the Netherlands case-coverage study for Pandemrix-AS03. CONCLUSIONS: Other than elevated narcolepsy IRs in the period after vaccination campaigns in Sweden, we did not find an association between AS03- or MF59-adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the sites studied, although power to evaluate the AS03-adjuvanted Pandemrix brand vaccine was limited in our study.


Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/prevenção & controle , Narcolepsia/prevenção & controle , Adjuvantes Imunológicos/uso terapêutico , Estudos de Casos e Controles , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/uso terapêutico , Influenza Humana/imunologia , Narcolepsia/imunologia , Estudos Retrospectivos , Vacinação
10.
J Clin Microbiol ; 56(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29491021

RESUMO

Mumps remains endemic in North America despite routine use of the measles, mumps, and rubella (MMR) vaccine. In 2016, an outbreak of mumps in British Columbia, Canada, provided an opportunity to determine the diagnostic utility of laboratory testing methods. Specimens from patients with clinical mumps were tested for infection using a commercial enzyme-linked immunosorbent assay (ELISA) for antibody detection and an in-house reverse transcriptase PCR (RT-PCR) targeting viral fusion and small hydrophobic (SH) genes. Viral genotyping was performed by SH gene sequencing. Laboratory data was linked with epidemiologic case data. Of the 139 confirmed cases, 94 (68%) had reported or documented history of MMR vaccination. Specimens were typically collected 1 day (for buccal and IgM tests) or 2 days (for urine tests) after symptom onset. Most confirmed cases (69%) were confirmed by buccal swab RT-PCR. Among cases tested by multiple methods, the percent positivity for buccal swab RT-PCR was 90% (96/107) compared to 43% (30/69) for both IgM ELISA and urine RT-PCR. Mumps IgM detection was higher in confirmed cases with no history of vaccination than in those with history (64% versus 34%, P = 0.02). The outbreak strain was identified as genotype G related to MuVi/Sheffield.GBR/1.05 but with conserved variations in five nucleotides within the SH gene that allowed linkage of geographically distinct cases. In conclusion, RT-PCR of buccal specimens had the highest diagnostic yield during a mumps outbreak in a partially vaccinated population. To optimize mumps diagnostic potential, clinicians should collect specimens depending on when the patient presents for care and their immunization history.


Assuntos
Surtos de Doenças , Vírus da Caxumba/genética , Caxumba/diagnóstico , Caxumba/epidemiologia , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Colúmbia Britânica/epidemiologia , Criança , Pré-Escolar , Feminino , Genes Virais/genética , Variação Genética , Genótipo , Humanos , Imunoglobulina M/sangue , Lactente , Masculino , Vacina contra Sarampo-Caxumba-Rubéola/genética , Vacina contra Sarampo-Caxumba-Rubéola/isolamento & purificação , Pessoa de Meia-Idade , Caxumba/virologia , Vírus da Caxumba/classificação , Vírus da Caxumba/imunologia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vacinação/estatística & dados numéricos , Adulto Jovem
11.
Vaccine ; 36(3): 395-399, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29223487

RESUMO

OBJECTIVES: In 2012, British Columbia (BC) became the first Canadian province to implement an influenza prevention policy requiring healthcare workers (HCW) to either be vaccinated annually against influenza or wear a mask in patient care areas during the influenza season. This study describes an evaluation of influenza policy implementation processes and identifies supports and challenges related to successful policy implementation at the level of healthcare facilities, during the second policy year (2013/14). METHODS: Implementation leaders from 262 long-term care (LTC) and acute care facilities, mostly in three of BC's five regional Health Authorities, were invited to participate in an online survey following the 2013/14 influenza season. Descriptive quantitative and qualitative analyses identified common and effective strategies for improving vaccination coverage and policy compliance. RESULTS: A total of 127 respondents completed the survey on behalf of 33 acute care and 99 LTC facilities, representing 36% of acute care and 27% of LTC facilities in BC. Respondents agreed that the policy was successfully implemented at 89% of facilities, and implementation was reported to be easy at 52% of facilities. The findings elaborate on communication and leadership strategies, campaign logistics and enforcement approaches involved in policy implementation. CONCLUSION: Implementation of a vaccinate-or-mask influenza policy is complex. This study provides insight for other jurisdictions considering implementing such a policy and offers practical recommendations for facilities and health authorities.


Assuntos
Infecção Hospitalar/prevenção & controle , Instalações de Saúde , Controle de Infecções/métodos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Máscaras , Política Organizacional , Colúmbia Britânica , Transmissão de Doença Infecciosa/prevenção & controle , Humanos , Inquéritos e Questionários
12.
Hum Vaccin Immunother ; 13(8): 1928-1936, 2017 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-28708945

RESUMO

Accurate and complete immunization data are necessary to assess vaccine coverage, safety and effectiveness. Across Canada, different methods and data sources are used to assess vaccine coverage, but these have not been systematically described. Our primary objective was to examine and describe the methods used to determine immunization coverage in Canada. The secondary objective was to compare routine infant and childhood coverage estimates derived from the Canadian 2013 Childhood National Immunization Coverage Survey (cNICS) with estimates collected from provinces and territories (P/Ts). We collected information from key informants regarding their provincial, territorial or federal methods for assessing immunization coverage. We also collected P/T coverage estimates for select antigens and birth cohorts to determine absolute differences between these and estimates from cNICS. Twenty-six individuals across 16 public health organizations participated between April and August 2015. Coverage surveys are conducted regularly for toddlers in Quebec and in one health authority in British Columbia. Across P/Ts, different methodologies for measuring coverage are used (e.g., valid doses, grace periods). Most P/Ts, except Ontario, measure up-to-date (UTD) coverage and 4 P/Ts also assess on-time coverage. The degree of concordance between P/T and cNICS coverage estimates varied by jurisdiction, antigen and age group. In addition to differences in the data sources and processes used for coverage assessment, there are also differences between Canadian P/Ts in the methods used for calculating immunization coverage. Comparisons between P/T and cNICS estimates leave remaining questions about the proportion of children fully vaccinated in Canada.


Assuntos
Programas de Imunização , Imunização/estatística & dados numéricos , Sistema de Registros , Cobertura Vacinal , Colúmbia Britânica , Canadá , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Ontário , Quebeque , Sistema de Registros/estatística & dados numéricos , Inquéritos e Questionários
13.
Can J Public Health ; 107(6): e575-e582, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28252378

RESUMO

OBJECTIVES: Canada does not have a national immunization registry. Diverse systems to record vaccine uptake exist, but these have not been systematically described. Our objective was to describe the immunization information systems (IISs) and non-IIS processes used to record childhood and adolescent vaccinations, and to outline the strengths and limitations of the systems and processes. METHODS: We collected information from key informants regarding their provincial, territorial or federal organization's surveillance systems for assessing immunization coverage. Information collection consisted of a self-administered questionnaire and a follow-up interview. We evaluated systems against attributes derived from the literature using content analysis. RESULTS: Twenty-six individuals across 16 public health organizations participated over the period of April to August 2015. Twelve of Canada's 13 provinces and territories (P/Ts) and two organizations involved in health service delivery for on-reserve First Nations people participated. Across systems, there were differences in data collection processes, reporting capabilities and advanced functionality. Commonly cited challenges included timeliness and data completeness of records, particularly for physician-administered immunizations. Privacy considerations and the need for data standards were stated as challenges to the goal of information sharing across P/T systems. Many P/Ts have recently implemented new systems and, in some cases, legislation to improve timeliness and/or completeness. CONCLUSION: Considerable variability exists among IISs and non-IIS processes used to assess immunization coverage in Canada. Although some P/Ts have already pursued legislative or policy initiatives to address the completeness and timeliness of information, many additional opportunities exist in the information technology realm.


Assuntos
Imunização/estatística & dados numéricos , Sistemas de Informação , Vigilância da População/métodos , Adolescente , Canadá , Criança , Pré-Escolar , Humanos , Lactente , Sistema de Registros
14.
Pediatr Infect Dis J ; 36(6): 609-615, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28134742

RESUMO

BACKGROUND: Hepatitis B virus (HBV) vaccination programs generally target infants to prevent chronic HBV infection and/or preadolescents to reduce transmission in adulthood. To assess whether infant HBV immunization can potentially accomplish both objectives, we measured residual immunity 10-16 years after vaccination in Canadian children. METHODS: A prospective, parallel group, single center study enrolled adolescents given HBV vaccine at 2, 4 and 6 months of age. Exclusion criteria included prior HBV infection and additional vaccinations. At follow-up anti-HBs testing, participants were 10-11 or 15-16 years old; those with <12 mIU/mL anti-HBs by the assay used were challenged with HBV vaccine to assess immune memory-based responsiveness. RESULTS: A total of 137 tested participants were 10-11 and 213 were 15-16 years old, respectively; none had evidence of prior HBV infection. At baseline, 78% of younger and 64% of older participants had <12 mIU/mL anti-HBs (P = 0.006) and were challenged with vaccine: 103/106 (97.2%) younger and 123/135 (91.1%) older participants developed ≥12 mIU/mL anti-HBs (P = 0.06), with geometric mean antibody concentration of 590 (95% confidence interval: 473-737) and 319 mIU/mL (95% confidence interval: 229-445; P = 0.004), respectively. Immune memory loss may have occurred in 3 younger (2.2%) and 12 older children (5.6%; P = 0.06) who were nonresponsive to first but not second vaccine challenge. CONCLUSIONS: After HBV vaccination at 2, 4 and 6 months of age, most adolescents had little or no residual antibody but nearly all responded to HBV challenge, confirming immune memory persistence. However, anamnestic responses were weaker in 15- to 16-year olds and lost in some. Booster responses in 10- to 11-year olds were vigorous in comparison. Extended evaluation of protection is warranted.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/imunologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Adolescente , Canadá , Criança , Anticorpos Anti-Hepatite B/imunologia , Vacinas contra Hepatite B/administração & dosagem , Humanos , Esquemas de Imunização , Estudos Prospectivos
15.
Hum Vaccin Immunother ; 13(3): 703-710, 2017 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-27835525

RESUMO

BACKGROUND: Intussusception has been identified as a rare adverse event following rotavirus immunization. We sought to determine the incidence of intussusception among infants in Canada both before and after introduction of rotavirus immunization programs. METHODS: We used Canadian Institute for Health Information (CIHI) Discharge Abstract Database (DAD) to identify infants under 1 y of age who were admitted to a Canadian hospital, which the exception of Quebec, which does not submit data to CIHI, with a diagnosis of intussusception (ICD-10 code K56.1, and ICD-9 code 560) between January 1st, 2003 and December 31, 2013. We compared rates of intussusception hospitalization before and after rotavirus vaccine program introduction. Rates were adjusted for calendar year, age (in months), sex and region using Poisson regression models. Denominator data for infants under 1 year, stratified by age in months, were obtained from Statistics Canada. RESULTS: Annual intussusception hospitalization rates ranged from 20-30 per 100,000 infants over the study period, with no evidence of a trend over time. Intussusception hospitalization rates were highest in infants 4 to <8 months and lowest in those under 2 months or between 10 and <12 months. Males had higher rates than females both overall and within each age group. The rate of intussusception hospitalization after rotavirus vaccine program introduction was 22.4 (95% CI: 18.3, 27.4) compared to 23.4 (95% CI: 21.5, 25.4) per 100,000 before program introduction. CONCLUSIONS: We have described baseline intussusception hospitalization rates for infants in Canada and have found no evidence of a change in rate after implementation of routine rotavirus immunization programs.


Assuntos
Intussuscepção/induzido quimicamente , Intussuscepção/epidemiologia , Vacinas contra Rotavirus/efeitos adversos , Canadá/epidemiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Estudos Retrospectivos , Medição de Risco , Vacinas contra Rotavirus/administração & dosagem
16.
J Infect Dis ; 212(10): 1574-8, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26153409

RESUMO

We used whole-genome sequencing to investigate a dual-genotype outbreak of measles occurring after the XXI Olympic Winter Games in Vancouver, Canada. By sequencing 27 complete genomes from H1 and D8 genotype measles viruses isolated from outbreak cases, we estimated the virus mutation rate, determined that person-to-person transmission is typically associated with 0 mutations between isolates, and established that a single introduction of H1 virus led to the expansion of the outbreak beyond Vancouver. This is the largest measles genomics project to date, revealing novel aspects of measles virus genetics and providing new insights into transmission of this reemerging viral pathogen.


Assuntos
Surtos de Doenças , Transmissão de Doença Infecciosa , Genoma Viral , Genótipo , Vírus do Sarampo/classificação , Sarampo/epidemiologia , Análise de Sequência de DNA , Canadá/epidemiologia , Aglomeração , Humanos , Sarampo/transmissão , Vírus do Sarampo/genética , Vírus do Sarampo/isolamento & purificação , Epidemiologia Molecular , Dados de Sequência Molecular
17.
Biomed Res Int ; 2015: 131623, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25918702

RESUMO

Soft ripened cheese (SRC) caused over 130 foodborne illnesses in British Columbia (BC), Canada, during two separate listeriosis outbreaks. Multiple agencies investigated the events that lead to cheese contamination with Listeria monocytogenes (L.m.), an environmentally ubiquitous foodborne pathogen. In both outbreaks pasteurized milk and the pasteurization process were ruled out as sources of contamination. In outbreak A, environmental transmission of L.m. likely occurred from farm animals to personnel to culture solutions used during cheese production. In outbreak B, birds were identified as likely contaminating the dairy plant's water supply and cheese during the curd-washing step. Issues noted during outbreak A included the risks of operating a dairy plant in a farm environment, potential for transfer of L.m. from the farm environment to the plant via shared toilet facilities, failure to clean and sanitize culture spray bottles, and cross-contamination during cheese aging. L.m. contamination in outbreak B was traced to wild swallows defecating in the plant's open cistern water reservoir and a multibarrier failure in the water disinfection system. These outbreaks led to enhanced inspection and surveillance of cheese plants, test and release programs for all SRC manufactured in BC, improvements in plant design and prevention programs, and reduced listeriosis incidence.


Assuntos
Queijo/microbiologia , Surtos de Doenças , Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/epidemiologia , Listeriose/epidemiologia , Listeriose/microbiologia , Animais , Colúmbia Britânica/epidemiologia , Indústria de Laticínios , Meio Ambiente , Manipulação de Alimentos , Microbiologia de Alimentos , Listeria monocytogenes , Leite , Pasteurização , Temperatura
18.
Int J Cancer ; 137(8): 1931-7, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25754686

RESUMO

We report on the rates of cervical intraepithelial neoplasia (CIN) in young women aged 15-22 years of age in British Columbia before and after the introduction of an HPV vaccine program. Rates of cervical intraepithelial neoplasia (CIN) 2+ for each age stratum (15-22) in the calendar years 2004-2012 for the province of British Columbia were obtained from the BC Cancer Agency's population-based cervical cancer program. Incidence rate ratios (IRR) of CIN2+ were described and compared before and after HPV vaccine program introduction in cohorts born in vaccine eligible years, and in non-vaccine eligible years using piece-wise Poisson regression analysis, and adjusted for age. Between 2004 and 2012, rates of CIN2 and CIN2+ in young women aged 15-22 years in the province of British Columbia have decreased overall. After the introduction of the HPV vaccine program, the age adjusted IRR for CIN2+ for young women aged 15-17 years decreased significantly from 0.91 (95% CI: 0.86-0.98 p < 0.01) to 0.36 (95% CI: 0.18-0.73 p < 0.01). During the same time period, no similar reduction was found in young women 18-22 years. After introduction of HPV vaccine program, IRR for CIN2+ in young women 15-17 was significantly reduced for CIN2+ (0.14; 95% CI: 0.04- 0.47; p < 0.01) and CIN2 (0.1; 95% CI: 0.02-0.54; p < 0.01). This ecological analysis shows a significant reduction in CIN2+ lesions in young women aged 15-17 years in British Columbia after the introduction of the HPV vaccine in young women despite vaccine uptake levels below 70%.


Assuntos
Neoplasia Intraepitelial Cervical/epidemiologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Neoplasias do Colo do Útero/epidemiologia , Adolescente , Adulto , Colúmbia Britânica/epidemiologia , Neoplasia Intraepitelial Cervical/prevenção & controle , Neoplasia Intraepitelial Cervical/virologia , Feminino , Humanos , Análise de Regressão , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/virologia , Adulto Jovem
19.
Influenza Other Respir Viruses ; 9(1): 32-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25382064

RESUMO

This case series describes morbilliform and other rash presentations among schoolchildren during a March 2014 outbreak of influenza-like illness (ILI) in British Columbia, Canada. Multiplex nucleic acid testing of nasopharyngeal specimens and paired serologic investigations identified that influenza B, characterized as B/Massachusetts/02/2012-like (Yamagata-lineage), was the only viral aetiology and most likely cause of ILI and rash. An association between influenza B and rash has been described infrequently elsewhere, and not previously in North America. Influenza B should be considered in the differential diagnosis of febrile exanthem. Evaluation of the nature, incidence and contributing agent-host-environment interactions, and immunologic mechanisms to possibly explain influenza-associated rash is warranted.


Assuntos
Exantema/etiologia , Vírus da Influenza B , Influenza Humana/fisiopatologia , Adolescente , Anticorpos Antivirais/sangue , Canadá/epidemiologia , Criança , Feminino , Humanos , Vírus da Influenza B/genética , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino
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