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Zhou Y, Jiang S, Li KY, Lo ECM, Gao X. Association between oral health and upper respiratory tract infection among children. Int Dent J 2017; 68:122-128. [PMID: 28905361 DOI: 10.1111/idj.12335] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The oral cavity is a potential reservoir for respiratory pathogens. This longitudinal study investigated the association between upper respiratory tract infection (URI) and oral health among children. METHODS A total of 288 children aged 4 years were recruited. Their dental caries and oral hygiene status were clinically determined, using the dmft (decayed, missing and filled teeth) index and the Silness-Löe plaque index. Questionnaires were completed by parents to collect information on the child's socio-demographic background and URI episodes and symptoms in the following 12 months. Standard or zero-inflated negative binomial regressions were used to analyse the association between URI and both oral health indicators (dmft and plaque score). RESULTS Some 138 (47.9%) children had URI in 12 months, including 63 (21.9%) and 75 (26.0%) children with 1-2 episodes and ≥3 episodes, respectively. The reported URI episodes fell into two peaks, coinciding with the two influenza peaks in Hong Kong. Significantly a higher dmft was found among children without URI compared with children who had ≥3 URI episodes (1.32 vs. 0.49; P = 0.043). The number of URI episodes was inversely associated with dmft (IRR = 0.851; 95% CI: 0.766-0.945; P = 0.003). There was no significant association between the plaque score and URI (P > 0.05). CONCLUSIONS The children's caries experience was associated with reduced episodes of URI. Whether this inverse association is attributed to the immune response induced by dental caries is yet to be investigated.
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Affiliation(s)
- Ying Zhou
- Department of Preventive Medicine, Health Sciences Center, Shenzhen University, Shenzhen, China
| | - Shan Jiang
- Dental Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Kar Yan Li
- Centralized Research Laboratories, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Edward Chin Man Lo
- Dental Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Xiaoli Gao
- Dental Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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Lietz J, Westermann C, Nienhaus A, Schablon A. The Occupational Risk of Influenza A (H1N1) Infection among Healthcare Personnel during the 2009 Pandemic: A Systematic Review and Meta-Analysis of Observational Studies. PLoS One 2016; 11:e0162061. [PMID: 27579923 PMCID: PMC5006982 DOI: 10.1371/journal.pone.0162061] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/16/2016] [Indexed: 01/18/2023] Open
Abstract
Introduction The aim of this review was to record systematically and assess the published literature relating to the occupational risk of influenza A (H1N1) infection among healthcare personnel during the 2009 pandemic. Methods The literature search was performed in June 2015. An update was carried out in May 2016. It was applied to the electronic databases EMBASE, MEDLINE, PsycINFO, PubMed, CINAHL and Google Scholar. The quality assessment was conducted with a tool using eight criteria. A meta-analysis was carried out to compute pooled effect estimates for influenza A (H1N1) infection. Results A total of 26 studies were included in the review, 15 studies met the criteria for the meta-analysis. After a sensitivity analysis the pooled analysis showed a significantly increased odds for influenza A (H1N1) infection for healthcare personnel compared to controls/comparisons (OR = 2.08, 95% CI = 1.73 to 2.51). The pooled prevalence rate for healthcare personnel alone was 6.3%. Conclusions This review corroborates the assumption that healthcare personnel were particularly at risk of influenza A (H1N1) infection during the 2009 pandemic. Healthcare facilities should intensify their focus on strategies to prevent infections among healthcare personnel, especially during the first period of pandemics.
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Affiliation(s)
- Janna Lietz
- Institute for Biostatistics and Social Welfare Matters, Hamburg, Germany
| | - Claudia Westermann
- Competence Centre for Epidemiology and Health Service Research in Nursing, Institute for Health Service Research in Dermatology and Nursing, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- * E-mail:
| | - Albert Nienhaus
- Competence Centre for Epidemiology and Health Service Research in Nursing, Institute for Health Service Research in Dermatology and Nursing, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Department of Occupational Health Research, German Social Accident Insurance Institution for the Health and Welfare Services, Hamburg, Germany
| | - Anja Schablon
- Competence Centre for Epidemiology and Health Service Research in Nursing, Institute for Health Service Research in Dermatology and Nursing, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
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Nandhini G, Sujatha S. Seropositivity to influenza A(H1N1)pdm09 and influenza A (H3N2) and risk of infection in health care workers. CLINICAL EPIDEMIOLOGY AND GLOBAL HEALTH 2016. [DOI: 10.1016/j.cegh.2015.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Sandoval C, Barrera A, Ferrés M, Cerda J, Retamal J, García-Sastre A, Medina RA, Hirsch T. Infection in Health Personnel with High and Low Levels of Exposure in a Hospital Setting during the H1N1 2009 Influenza A Pandemic. PLoS One 2016; 11:e0147271. [PMID: 26799564 PMCID: PMC4723060 DOI: 10.1371/journal.pone.0147271] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 12/31/2015] [Indexed: 11/13/2022] Open
Abstract
A novel H1N1 influenza A virus caused the first pandemic of the 21st century in 2009. Hospitals had an increased demand of health consultations, that made it difficult to estimate the incidence of infection in hospital personnel due to asymptomatic presentations and the under notification of cases. To estimate and compare the rate of exposure of high versus low risk health personnel to 2009 pandemic H1N1 (H1N1pdm2009) influenza A virus in a University Hospital in Chile, we performed a comparative and prospective study. Serum samples were obtained from 117 individuals that worked in the emergency room (ER) and the operating room (OR) during the peak of the pandemic. Antibody titers were determined by the hemagglutination inhibition (HI) assay. Of the samples analyzed, 65% were workers at the ER and 35% at the OR. Of the total number of the subjects tested, 29.1% were seropositive. One out of 3 (36.8%) workers at the ER had positive HI titers, meanwhile only 1 out of 7 (14.6%) workers from the OR was seropositive to the virus. The possibility of being infected in the ER as compared to the OR was 3.4 times greater (OR 3.4; CI 95%, 1.27–9.1), and the individuals of the ER had almost twice as much antibody titers against H1N1pdm2009 than the personnel in the OR, suggesting the potential of more than one exposure to the virus. Of the 34 seropositive subjects, 12 (35.3%) did not develop influenza like illness, including 2 non-clinical personnel involved in direct contact with patients at the ER. Considering the estimated population attack rate in Chile of 13%, both groups presented a higher exposure and seropositive rate than the general population, with ER personnel showing greater risk of infection and a significantly higher level of antibodies. This data provide a strong rationale to design improved control measures aimed at all the hospital personnel, including those coming into contact with the patients prior to triage, to prevent the propagation and transmission of respiratory viruses, particularly during a pandemic outbreak.
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Affiliation(s)
- Carmen Sandoval
- Departmento de Enfermedades Infecciosas e Inmulogia Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Aldo Barrera
- Laboratory of Infectious Diseases and Molecular Virology, Centro de Investigaciones Médicas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Marcela Ferrés
- Departmento de Enfermedades Infecciosas e Inmulogia Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratory of Infectious Diseases and Molecular Virology, Centro de Investigaciones Médicas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jaime Cerda
- Departmento de Enfermedades Infecciosas e Inmulogia Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Public Health Department, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Javiera Retamal
- Departmento de Enfermedades Infecciosas e Inmulogia Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Adolfo García-Sastre
- Department of Microbiology and Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Rafael A. Medina
- Departmento de Enfermedades Infecciosas e Inmulogia Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratory of Infectious Diseases and Molecular Virology, Centro de Investigaciones Médicas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Microbiology and Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
- Instituto Milenio en Inmunología e Inmunoterapia, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail: ; (TH); (RAM)
| | - Tamara Hirsch
- Hospital Clínico, Emergency Room, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Pediatría, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail: ; (TH); (RAM)
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Pandemic influenza A(H1N1)pdm09: risk of infection in primary healthcare workers. Br J Gen Pract 2014; 63:e416-22. [PMID: 23735413 DOI: 10.3399/bjgp13x668212] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Healthcare workers in primary care are at risk of infection during an influenza pandemic. The 2009 influenza pandemic provided an opportunity to assess this risk. AIM To measure the prevalence of seropositivity to influenza A(H1N1)pdm09 among primary healthcare workers in Canterbury, New Zealand, following the 2009 influenza pandemic, and to examine associations between seropositivity and participants' sociodemographic characteristics, professional roles, work patterns, and seasonal influenza vaccination status. DESIGN AND SETTING An observational study involving a questionnaire and testing for influenza A(H1N1)pdm09 seropositivity in all primary healthcare workers in Canterbury, New Zealand between December 2009 and February 2010. Method Participants completed a questionnaire that recorded sociodemographic and professional data, symptoms of influenza-like illness, history of seasonal influenza vaccination, and work patterns. Serum samples were collected and haemagglutination inhibition antibody titres to influenza A(H1N1)pdm09 measured. RESULTS Questionnaires and serum samples were received from 1027 participants, from a workforce of 1476 (response rate 70%). Seropositivity was detected in 224 participants (22%). Receipt of seasonal influenza vaccine (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2 to 3.3), recall of influenza (OR = 1.9, 95% CI = 1.3 to 2.8), and age ≤45 years (OR = 1.4, 95% CI = 1.0 to 1.9) were associated with seropositivity. CONCLUSION A total of 22% of primary care healthcare workers were seropositive. Younger participants, those who recalled having influenza, and those who had been vaccinated against seasonal influenza were more likely to be seropositive. Working in a dedicated influenza centre was not associated with an increased risk of seropositivity.
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Alagappan K, Silverman RA, Hancock K, Ward MF, Akerman M, Dawood FS, Branch A, De Cicco S, Steward-Clark E, McCullough M, Tenner K, Katz JM. Seropositivity for influenza A(H1N1)pdm09 virus among frontline health care personnel. Emerg Infect Dis 2013; 19:140-3. [PMID: 23260627 PMCID: PMC3557970 DOI: 10.3201/eid1901.111640] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Seroprevalence of antibodies to influenza A(H1N1)pdm09 virus among 193 emergency department health care personnel was similar among 147 non–health care personnel (odds ratio 1.4, 95% CI 0.8–2.4). Working in an acute care setting did not substantially increase risk for virus infection above risk conferred by community-based exposures.
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Affiliation(s)
- Kumar Alagappan
- North Shore-Long Island Jewish Health System, New Hyde Park, New York 11040, USA
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Liu T, Li Z, Song S, Zhang S, Wang Y, Wang L, Xu A, Wang X, Bi Z. Seroepidemiological study of influenza A (H1N1) pdm09 virus following the 2009-2010 wave in Shandong Province, China. ACTA ACUST UNITED AC 2013; 45:552-6. [PMID: 23672510 DOI: 10.3109/00365548.2013.793818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION The aims of this study were to understand the geographic extent, risk factors, and attack rate of influenza A (H1N1) pdm09 virus (pH1N1) infection in Shandong Province China and to elucidate influencing factors. METHODS In January and March 2010, a cross-sectional seroprevalence survey of pH1N1 was carried out. Serum samples from 9022 participants in the survey were subjected to the hemagglutination inhibition assay. RESULTS Among the 9022 participants, the overall rate of seropositivity against pH1N1 was 22.6%. The weighted rate, adjusted for gender, age, and region, was estimated to be 18.7%. Among 8340 subjects who did not report previous vaccination, the rate was 16.7%, as compared to 50.9% among 682 subjects reporting previous vaccination (p < 0.001). Within the unvaccinated population, the rate of seropositivity among 16-24 and 6-15 y-old subjects was 31.8% and 29.9%, respectively, as compared to 9.6% among subjects aged ≥ 60 y (p < 0.001) and 23% in the 0-5 y age group (p < 0.001). Those aged 6-15 y and aged 16-24 y had higher odds of seropositivity than those aged 0-5 y (odds ratio 1.53 and 1.48, respectively). CONCLUSIONS These study findings help enhance our understanding of pH1N1 epidemiology and provide valuable information for the vaccination strategy for the influenza season.
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Affiliation(s)
- Ti Liu
- Shandong Center for Disease Control and Prevention, Shandong Provincial Key Laboratory of Infectious Diseases Control and Prevention, Shandong University Institute for Prevention Medicine, Jinan, Shandong, China
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Wu P, Cowling BJ, Wu JT, Lau EHY, Ip DKM, Nishiura H. The epidemiological and public health research response to 2009 pandemic influenza A(H1N1): experiences from Hong Kong. Influenza Other Respir Viruses 2012; 7:367-82. [PMID: 22883352 PMCID: PMC3705741 DOI: 10.1111/j.1750-2659.2012.00420.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In recent years, Hong Kong has invested in research infrastructure to appropriately respond to novel infectious disease epidemics. Research from Hong Kong made a strong contribution to the international response to the 2009 influenza A (H1N1) pandemic (pH1N1). Summarizing, describing, and reviewing Hong Kong’s response to the 2009 pandemic, this article aimed to identify key elements of a real‐time research response. A systematic search in PubMed and EMBASE for research into the infection dynamics and natural history, impact, or control of pH1N1 in Hong Kong. Eligible articles were analyzed according to their scope. Fifty‐five articles were included in the review. Transmissibility of pH1N1 was similar in Hong Kong to elsewhere, and only a small fraction of infections were associated with severe disease. School closures were effective in reducing pH1N1 transmission, oseltamivir was effective for treatment of severe cases while convalescent plasma therapy has the potential to mitigate future pandemics. There was a rapid and comprehensive research response to pH1N1 in Hong Kong, providing important information on the epidemiology of the novel virus with relevance internationally as well as locally. The scientific knowledge gained through these detailed studies of pH1N1 is now being used to revise and update pandemic plans. The experiences of the research response in Hong Kong could provide a template for the research response to future emerging and reemerging disease epidemics.
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Affiliation(s)
- Peng Wu
- School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
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Yen TY, Lu CY, Chang LY, Tsai YT, Huang LM. Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital. BMC Infect Dis 2012; 12:89. [PMID: 22498010 PMCID: PMC3364885 DOI: 10.1186/1471-2334-12-89] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 04/13/2012] [Indexed: 11/10/2022] Open
Abstract
Background To probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a children's hospital. Methods From August 2009 to March 2010, serum samples were drawn from 150 HCWs in a children's hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed. Results Among the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion. Conclusion The infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.
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Affiliation(s)
- Ting-Yu Yen
- Department of Pediatrics, National Taiwan University Hospital, No, 8, Chung-Shan South Road, 10016 Taipei, Taiwan
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Cheng VCC, To KKW, Tse H, Hung IFN, Yuen KY. Two years after pandemic influenza A/2009/H1N1: what have we learned? Clin Microbiol Rev 2012; 25:223-63. [PMID: 22491771 PMCID: PMC3346300 DOI: 10.1128/cmr.05012-11] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The world had been anticipating another influenza pandemic since the last one in 1968. The pandemic influenza A H1N1 2009 virus (A/2009/H1N1) finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Because of the persistent threat from the A/H5N1 virus since 1997 and the outbreak of the severe acute respiratory syndrome (SARS) coronavirus in 2003, medical and scientific communities have been more prepared in mindset and infrastructure. This preparedness has allowed for rapid and effective research on the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the disease, with impacts on its control. A PubMed search using the keywords "pandemic influenza virus H1N1 2009" yielded over 2,500 publications, which markedly exceeded the number published on previous pandemics. Only representative works with relevance to clinical microbiology and infectious diseases are reviewed in this article. A significant increase in the understanding of this virus and the disease within such a short amount of time has allowed for the timely development of diagnostic tests, treatments, and preventive measures. These findings could prove useful for future randomized controlled clinical trials and the epidemiological control of future pandemics.
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Affiliation(s)
- Vincent C C Cheng
- Department of Microbiology, Queen Mary Hospital, Hong Kong Special Administrative Region, China
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Nukui Y, Hatakeyama S, Kitazawa T, Mahira T, Shintani Y, Moriya K. Pandemic 2009 influenza A (H1N1) virus among Japanese healthcare workers: seroprevalence and risk factors. Infect Control Hosp Epidemiol 2011; 33:58-62. [PMID: 22173523 DOI: 10.1086/663208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To evaluate the seroprevalence and risk factors for 2009 influenza A (H1N1) virus infection among healthcare personnel. DESIGN Observational cross-sectional study. PATIENTS AND SETTING Healthcare workers (HCWs) in an acute care hospital. METHODS Between September 14 and October 4, 2009, before 2009 H1N1 vaccination, we collected serological samples from 461 healthy HCWs. Hemagglutination-inhibition antibody assays were conducted. To evaluate the risk factors of seropositivity for 2009 H1N1 virus, gender, age, profession, work department, usage of personal protective equipment, and seasonal influenza vaccination status data were gathered via questionnaires. RESULTS Our survey showed that doctors and nurses were at highest risk of seropositivity for the 2009 H1N1 virus (odds ratio [OR], 5.25 [95% confidence interval {CI}, 1.21-22.7]). An increased risk of seropositivity was observed among pediatric, emergency room, and internal medicine staff (adjusted OR, 1.98 [95% CI, 1.07-3.65]). Risk was also higher among HCWs who had high titers of antibodies against the seasonal H1N1 virus (adjusted OR, 1.59 [95% CI, 1.02-2.48]). CONCLUSIONS Seropositivity for the 2009 H1N1 virus was associated with occupational risk factors among HCWs.
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Affiliation(s)
- Yoko Nukui
- Department of Infection Control and Prevention, University of Tokyo Hospital, Tokyo, Japan
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12
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Zhou Y, Ng DMW, Seto WH, Ip DKM, Kwok HKH, Ma ESK, Ng S, Lau LLH, Peiris JSM, Cowling BJ. Seroprevalence of pandemic H1N1 antibody among health care workers in Hong Kong following receipt of monovalent 2009 H1N1 influenza vaccine. PLoS One 2011; 6:e27169. [PMID: 22102878 PMCID: PMC3213124 DOI: 10.1371/journal.pone.0027169] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 10/11/2011] [Indexed: 11/28/2022] Open
Abstract
Background Healthcare workers in many countries are recommended to receive influenza vaccine to protect themselves as well as patients. A monovalent H1N1 vaccine became available in Hong Kong in December 2009 and around 10% of local healthcare workers had received the vaccine by February 2010. Methods We conducted a cross-sectional study of the prevalence of antibody to pandemic (H1N1) 2009 among HCWs in Hong Kong in February–March 2010 following the first pandemic wave and the pH1N1 vaccination campaign. In this study we focus on the subset of healthcare workers who reported receipt of non-adjuvanted monovalent 2009 H1N1 vaccine (Panenza, Sanofi Pasteur). Sera collected from HCWs were tested for antibody against the pH1N1 virus by hemagglutination inhibition (HI) and viral neutralization (VN) assays. Results We enrolled 703 HCWs. Among 104 HCWs who reported receipt of pH1N1 vaccine, 54% (95% confidence interval (CI): 44%–63%) had antibody titer ≥1∶40 by HI and 42% (95% CI: 33%–52%) had antibody titer ≥1∶40 by VN. The proportion of HCWs with antibody titer ≥1∶40 by HI and VN significantly decreased with age, and the proportion with antibody titer ≥1∶40 by VN was marginally significantly lower among HCWs who reported prior receipt of 2007–08 seasonal influenza vaccine (odds ratio: 0.43; 95% CI: 0.19–1.00). After adjustment for age, the effect of prior seasonal vaccine receipt was not statistically significant. Conclusions Our findings suggest that monovalent H1N1 vaccine may have had suboptimal immunogenicity in HCWs in Hong Kong. Larger studies are required to confirm whether influenza vaccine maintains high efficacy and effectiveness in HCWs.
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Affiliation(s)
- Ying Zhou
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Diane M. W. Ng
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Wing-Hong Seto
- Hospital Authority, Hong Kong Special Administrative Region, China
| | - Dennis K. M. Ip
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Henry K. H. Kwok
- Hospital Authority, Hong Kong Special Administrative Region, China
| | - Edward S. K. Ma
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Sophia Ng
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Lincoln L. H. Lau
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - J. S. Malik Peiris
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, China
- HKU-Pasteur Research Centre, Hong Kong Special Administrative Region, China
| | - Benjamin J. Cowling
- Infectious Disease Epidemiology Group, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China
- * E-mail:
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Seto WH, Cowling BJ, Lam HS, Ching PTY, To ML, Pittet D. Clinical and nonclinical health care workers faced a similar risk of acquiring 2009 pandemic H1N1 infection. Clin Infect Dis 2011; 53:280-3. [PMID: 21765076 DOI: 10.1093/cid/cir375] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Reporting of confirmed pandemic influenza A virus (pH1N1) 2009 infection was mandatory among health care workers in Hong Kong. Among 1158 confirmed infections, there was no significant difference in incidence among clinical versus nonclinical staff (relative risk, 0.98; 95% confidence interval, 0.78-1.20). Reported community exposure to pH1N1 was common and was similar in both groups.
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Affiliation(s)
- Wing-Hong Seto
- Hospital Authority, The University of Hong Kong, Hong Kong Special Administrative Region, China
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High incidence of severe influenza among individuals over 50 years of age. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:1918-24. [PMID: 21900532 DOI: 10.1128/cvi.05357-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Age-specific epidemiological data on asymptomatic, symptomatic, and severe infections are essential for public health policies on combating influenza. In this study, we incorporated data on microbiologically confirmed infections and seroprevalence to comprehensively describe the epidemiology of pandemic H1N1 2009 influenza. Seroprevalence was determined from 1,795 random serum samples collected in our hospital in January 2007 (before the first wave of the pandemic) and March 2010 (after the second wave). Data on microbiologically confirmed infection and severe cases were obtained from the Centre for Health Protection in Hong Kong. Severe cases were most common in the 51- to 60-year-old age group. The microbiologically confirmed incidence rate was highest for children aged ≤10 years and dropped sharply for the adult population (ρ = -1.0; P < 0.01), but the incidence rate for severe disease was highest for the 51- to 60-year-old age group. For the 51- to 60-year-old age group, the seroprevalence was similar to that for the younger age groups, but the proportion of severe cases relative to seroprevalence was significantly higher than that for 11- to 50-year-old age groups. As judged from the percentage of specimens positive for other respiratory viruses compared with that for pandemic H1N1 virus, the impact of symptomatic disease due to pandemic H1N1 virus was higher than that for other respiratory viruses in people aged ≤50 years. In conclusion, the 51- to 60-year-old age group, which had the highest overall incidence and the highest rate of severe disease but is currently not considered by the World Health Organization to be an at-risk group, should be prioritized for influenza vaccination in areas where universal influenza vaccination is not practiced.
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An analysis of national target groups for monovalent 2009 pandemic influenza vaccine and trivalent seasonal influenza vaccines in 2009-10 and 2010-11. BMC Infect Dis 2011; 11:230. [PMID: 21871096 PMCID: PMC3175216 DOI: 10.1186/1471-2334-11-230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 08/26/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vaccination is generally considered to be the best primary prevention measure against influenza virus infection. Many countries encourage specific target groups of people to undertake vaccination, often with financial subsidies or a priority list. To understand differential patterns of national target groups for influenza vaccination before, during and after the 2009 influenza pandemic, we reviewed and analyzed the country-specific policies in the corresponding time periods. METHODS Information on prioritized groups targeted to receive seasonal and pandemic influenza vaccines was derived from a multi-step internet search of official health department websites, press releases, media sources and academic journal articles. We assessed the frequency and consistency of targeting 20 different groups within populations which are associated with age, underlying medical conditions, role or occupations among different countries and vaccines. Information on subsidies provided to specific target groups was also extracted. RESULTS We analyzed target groups for 33 (seasonal 2009 and 2009-10 vaccines), 72 (monovalent pandemic 2009-10 vaccine) and 34 (seasonal 2010 and 2010-11 vaccines) countries. In 2009-10, the elderly, those with chronic illness and health care workers were common targets for the seasonal vaccine. Comparatively, the elderly, care home residents and workers, animal contacts and close contacts were less frequently targeted to receive the pandemic vaccine. Pregnant women, obese persons, essential community workers and health care workers, however, were more commonly targeted. After the pandemic, pregnant women, obese persons, health care and care home workers, and close contacts were more commonly targeted to receive the seasonal vaccine compared to 2009-10, showing continued influence from the pandemic. Many of the countries provided free vaccines, partial subsidies, reimbursements or national health insurance coverage to specific target groups and over one-third of the countries offered universal subsidy regarding the pandemic vaccine. There was also some inconsistency between countries in target groups. CONCLUSIONS Differences in target groups between countries may reflect variable objectives as well as uncertainties regarding the transmission dynamics, severity and age-specific immunity against influenza viruses before and after vaccination. Clarification on these points is essential to elucidate optimal and object-oriented vaccination strategies.
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