tetano
Editor, Senior Moderator
Influenza Other Respi Viruses. 2012 Mar 2. doi: 10.1111/j.1750-2659.2012.00344.x. [Epub ahead of print]
Transmission dynamics and risk factors for pandemic H1N1-related illness: outbreak investigation in a rural community of British Columbia, Canada.
Janjua NZ, Skowronski DM, Hottes TS, Osei W, Adams E, Petric M, Lem M, Tang P, De Serres G, Patrick DM, Bowering D.
Source
BC Centre for Disease Control, Vancouver, BC, Canada School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada Northern Health Authority, Prince George, BC, Canada British Columbia Ministry of Health, Victoria, BC, Canada First Nations and Inuit Health, Health Canada, Vancouver, BC, Canada Institut National de sant? publique du Qu?bec, Qu?bec, QC, Canada.
Abstract
Please cite this paper as: Janjua et al. (2012) Transmission dynamics and risk factors for pandemic H1N1-related illness: outbreak investigation in a rural community of British Columbia, Canada. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2012.00344.x. Objective To characterize the first-wave epidemiologic features of influenza-like illness (ILI) associated with the novel pandemic A/H1N1 [A(H1N1)pdm09] virus. Methods We used generalized linear mixed models (GLMM) to assess risk factors and non-parametric and/or parametric distributions to estimate attack rates, secondary attack rates (SAR), duration of illness, and serial interval during a laboratory-confirmed community outbreak of A(H1N1)pdm09 clustered around on-reserve residents and households of an elementary school in rural British Columbia, Canada, in late April/early May 2009. ILI details were collected as part of outbreak investigation by community telephone survey in early June 2009. Results Overall, 92/408 (23%) of participants developed ILI and 36/408 (9%) experienced medically attended ILI (MAILI). The overall SAR in households was 22%: highest among participants 1-4 years of age (yoa) (50%) followed by <1 yoa (38%), 5-8 yoa (20%), 10-19 yoa (13%), 20-49 yoa (20%), and 50-64 yoa (0%). The median serial interval was estimated at 3?5 days (95% CI: 2?1-5?1). In multivariable GLMM analysis, having a chronic condition (OR: 2?58; 95% CI: 1?1-6?04), younger age [1-8 yoa: OR: 4?63; 95% CI: 2?25-9?52; 9-19 yoa: OR: 1?95; 95% CI: 0?97-3?9 (referent: ≥20 yoa)] and receipt of 2008-2009 influenza vaccine (OR: 2?68; 95% CI: 1?37-5?25) were associated with increased risk of ILI. Median duration of illness was 9 days, longer among those with chronic conditions (21 days). Median time to seeking care after developing illness was 4?5 days. On-reserve participants had higher chronic conditions, household density, ILI, MAILI, and SAR. Conclusions During a community outbreak of A(H1N1)pdm09-related illness, we identified substantial clinical ILI attack rates exceeding 20% with secondary household attack rates as high as 50% in young children. The serial interval was short suggesting a narrow period to prevent transmission.
? 2012 Blackwell Publishing Ltd.
PMID:
22385647
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22385647
Transmission dynamics and risk factors for pandemic H1N1-related illness: outbreak investigation in a rural community of British Columbia, Canada.
Janjua NZ, Skowronski DM, Hottes TS, Osei W, Adams E, Petric M, Lem M, Tang P, De Serres G, Patrick DM, Bowering D.
Source
BC Centre for Disease Control, Vancouver, BC, Canada School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada Northern Health Authority, Prince George, BC, Canada British Columbia Ministry of Health, Victoria, BC, Canada First Nations and Inuit Health, Health Canada, Vancouver, BC, Canada Institut National de sant? publique du Qu?bec, Qu?bec, QC, Canada.
Abstract
Please cite this paper as: Janjua et al. (2012) Transmission dynamics and risk factors for pandemic H1N1-related illness: outbreak investigation in a rural community of British Columbia, Canada. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2012.00344.x. Objective To characterize the first-wave epidemiologic features of influenza-like illness (ILI) associated with the novel pandemic A/H1N1 [A(H1N1)pdm09] virus. Methods We used generalized linear mixed models (GLMM) to assess risk factors and non-parametric and/or parametric distributions to estimate attack rates, secondary attack rates (SAR), duration of illness, and serial interval during a laboratory-confirmed community outbreak of A(H1N1)pdm09 clustered around on-reserve residents and households of an elementary school in rural British Columbia, Canada, in late April/early May 2009. ILI details were collected as part of outbreak investigation by community telephone survey in early June 2009. Results Overall, 92/408 (23%) of participants developed ILI and 36/408 (9%) experienced medically attended ILI (MAILI). The overall SAR in households was 22%: highest among participants 1-4 years of age (yoa) (50%) followed by <1 yoa (38%), 5-8 yoa (20%), 10-19 yoa (13%), 20-49 yoa (20%), and 50-64 yoa (0%). The median serial interval was estimated at 3?5 days (95% CI: 2?1-5?1). In multivariable GLMM analysis, having a chronic condition (OR: 2?58; 95% CI: 1?1-6?04), younger age [1-8 yoa: OR: 4?63; 95% CI: 2?25-9?52; 9-19 yoa: OR: 1?95; 95% CI: 0?97-3?9 (referent: ≥20 yoa)] and receipt of 2008-2009 influenza vaccine (OR: 2?68; 95% CI: 1?37-5?25) were associated with increased risk of ILI. Median duration of illness was 9 days, longer among those with chronic conditions (21 days). Median time to seeking care after developing illness was 4?5 days. On-reserve participants had higher chronic conditions, household density, ILI, MAILI, and SAR. Conclusions During a community outbreak of A(H1N1)pdm09-related illness, we identified substantial clinical ILI attack rates exceeding 20% with secondary household attack rates as high as 50% in young children. The serial interval was short suggesting a narrow period to prevent transmission.
? 2012 Blackwell Publishing Ltd.
PMID:
22385647
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22385647