2009 Influenza A(H1N1) Seroconversion Rates and Risk Factors Among Distinct Adult Cohorts in Singapore

Chen, Mark; Lee, Vernon J. M.; Lim, Wei‐Yen; Barr, Ian G.; Lin, Raymond T. P.; Koh, Gerald Choon-Huat; Yap, Jonathan; Cui, Lin; Cook, Alex R.; Laurie, Karen; Tan, Linda; Tan, Boon Huan; Loh, Jimmy; Shaw, Robert C.; Durrant, Chris; Chow, Vincent T. K.; Kelso, Anne; Chia, Kee Seng; Leo, Yee Sin

doi:10.1001/jama.2010.404

Cited by 148 publications

(211 citation statements)

References 23 publications

(22 reference statements)

Supporting

Mentioning

173

Contrasting

Order By: Relevance

“…This may be because our study includes a number of additional middle and low countries who conducted serologic studies because this analysis was published and because we excluded studies which focused on specialized populations17). Additionally, the age‐specific trends we found in our cumulative incidence results are consistent with studies which measured cumulative incidence as a fourfold increase in titers among paired sera36, 42, 57 and similar to studies which measured age‐specific secondary attack rates using RT‐PCR 58, 59…”

Section: Discussionsupporting

confidence: 90%

Estimating age‐specific cumulative incidence for the 2009 influenza pandemic: a meta‐analysis of A(H1N1)pdm09 serological studies from 19 countries

Kerkhove¹,

Hirve

Koukounari

et al. 2013

Influenza Resp Viruses

164

139

View full text Add to dashboard Cite

BackgroundThe global impact of the 2009 influenza A(H1N1) pandemic (H1N1pdm) is not well understood.ObjectivesWe estimate overall and age‐specific prevalence of cross‐reactive antibodies to H1N1pdm virus and rates of H1N1pdm infection during the first year of the pandemic using data from published and unpublished H1N1pdm seroepidemiological studies.MethodsPrimary aggregate H1N1pdm serologic data from each study were stratified in standardized age groups and evaluated based on when sera were collected in relation to national or subnational peak H1N1pdm activity. Seropositivity was assessed using well‐described and standardized hemagglutination inhibition (HI titers ≥32 or ≥40) and microneutralization (MN ≥ 40) laboratory assays. The prevalence of cross‐reactive antibodies to the H1N1pdm virus was estimated for studies using sera collected prior to the start of the pandemic (between 2004 and April 2009); H1N1pdm cumulative incidence was estimated for studies in which collected both pre‐ and post‐pandemic sera; and H1N1pdm seropositivity was calculated from studies with post‐pandemic sera only (collected between December 2009–June 2010).ResultsData from 27 published/unpublished studies from 19 countries/administrative regions – Australia, Canada, China, Finland, France, Germany, Hong Kong SAR, India, Iran, Italy, Japan, Netherlands, New Zealand, Norway, Reunion Island, Singapore, United Kingdom, United States, and Vietnam – were eligible for inclusion. The overall age‐standardized pre‐pandemic prevalence of cross‐reactive antibodies was 5% (95%CI 3–7%) and varied significantly by age with the highest rates among persons ≥65 years old (14% 95%CI 8–24%). Overall age‐standardized H1N1pdm cumulative incidence was 24% (95%CI 20–27%) and varied significantly by age with the highest in children 5–19 (47% 95%CI 39–55%) and 0–4 years old (36% 95%CI 30–43%).ConclusionsOur results offer unique insight into the global impact of the H1N1 pandemic and highlight the need for standardization of seroepidemiological studies and for their inclusion in pre‐pandemic preparedness plans. Our results taken together with recent global pandemic respiratory‐associated mortality estimates suggest that the case fatality ratio of the pandemic virus was approximately 0·02%.

show abstract

Section: Discussionsupporting

confidence: 90%

Estimating age‐specific cumulative incidence for the 2009 influenza pandemic: a meta‐analysis of A(H1N1)pdm09 serological studies from 19 countries

Kerkhove¹,

Hirve

Koukounari

et al. 2013

Influenza Resp Viruses

164

139

View full text Add to dashboard Cite

show abstract

“…A Singapore study found that staff in an acute hospital had post-pandemic seroprevalence of 7% (95% CI = 5% to 9%). 34 Other estimates of post-pandemic seroprevalence among the general population range from 11% to 15% among English 25-64-year-olds, 29 to 14% to 33% among those aged >25 years in Taiwan. 35 The effect of receipt of seasonal influenza vaccine on the risk of pandemic influenza infection remains uncertain, and studies examining this effect have produced conflicting results.…”

Section: Comparison With Existing Literaturementioning

confidence: 99%

Pandemic influenza A(H1N1)pdm09: risk of infection in primary healthcare workers

Hudson¹,

Toop²,

Mangin³

et al. 2013

Br J Gen Pract

View full text Add to dashboard Cite

show abstract

“…In this study the lower seroprevalence in HCWs compared to household contacts could be due to the HCW reduced time of exposure, and to the use of personal protective equipment [21]. In a medical centre in Taiwan, 20% of HCWs had seroprotective titres compared to 3% of the control group (p < 0.001) [22].…”

Section: Discussionmentioning

confidence: 66%

Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico

Novales

Arriaga-Pizano

Herrera-Castillo

et al. 2015

J Infect Dev Ctries

View full text Add to dashboard Cite

Introduction: On April 2009, the Mexican Ministry of Health received notification of cases of severe pneumonia mostly affecting young healthy people; this was the beginning of the first influenza pandemic of the 21st century. The nature of the immune response to the influenza A(H1N1)2009 pandemic strain in Mexico at the beginning of the pandemic outbreak has not been completely defined. We describe the serological response to the 2009 pandemic influenza virus in paediatric patients with influenza-like illness, their household contacts (HHCs), and exposed health-care workers (HCWs) at the beginning of the pandemic outbreak in Mexico City. Methodology: thirty pre-epidemic and 129 epidemic samples were collected and serum antibodies were measured against A(H1N1)2009 pandemic virus and two non-pandemic swine influenza viruses by an haemagglutination inhibition assay . Results: 91% (29/32) of the convalescence samples from confirmed patients had an antibody titre ≥ 10 (GMT 25), 63% (41/65) of the HHCs (GMT 12), 41% of HCWs (GMT 6) and 13% (4/30) of pre-epidemic samples (GMT 6) for the pandemic influenza virus. Of the 32 confirmed cases, 60% had an antibody titre ≥ 40 for the pandemic strain, 53% for the A/swine/Iowa(H1N1) virus (GMT 62) and 43% for the A/swine/Texas(H3N2) virus (GMT 66). Conclusion: The antibody response to 2009 pandemic influenza virus was widespread in convalescence samples from patients with confirmed pandemic influenza infection but the GMT was below the protective titre. There was no evidence that antibodies to the swine influenza viruses had cross-protective effect against the 2009 pandemic influenza virus.

show abstract

2009 Influenza A(H1N1) Seroconversion Rates and Risk Factors Among Distinct Adult Cohorts in Singapore

Abstract: Following the June-September 2009 wave of 2009 influenza A(H1N1), 13% of the community participants seroconverted, and most of the adult population likely remained susceptible.

Cited by 148 publications

References 23 publications

Estimating age‐specific cumulative incidence for the 2009 influenza pandemic: a meta‐analysis of A(H1N1)pdm09 serological studies from 19 countries

Estimating age‐specific cumulative incidence for the 2009 influenza pandemic: a meta‐analysis of A(H1N1)pdm09 serological studies from 19 countries

Pandemic influenza A(H1N1)pdm09: risk of infection in primary healthcare workers

Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico

Contact Info

Product

Resources

About