tetano
Editor, Senior Moderator
Eurosurveillance, Volume 20, Issue 10, 12 March 2015
Research articles
Household transmissibility of avian influenza A (H7N9) virus, China, February to May 2013 and October 2013 to March 2014
Y Yang[SUP]1[/SUP], Y Zhang[SUP]2[/SUP], L Fang[SUP]3[/SUP], M E Halloran[SUP]4[/SUP], M Ma[SUP]3[/SUP], S Liang[SUP]5[/SUP], E Kenah[SUP]1[/SUP], T Britton[SUP]6[/SUP], E Chen[SUP]7[/SUP], J Hu[SUP]8[/SUP], F Tang[SUP]9[/SUP], W Cao[SUP]3[/SUP], Z Feng[SUP]2[/SUP], I M Longini Jr (
)[SUP]1[/SUP]
Citation style for this article: Yang Y, Zhang Y, Fang L, Halloran ME, Ma M, Liang S, Kenah E, Britton T, Chen E, Hu J, Tang F, Cao W, Feng Z, Longini Jr IM. Household transmissibility of avian influenza A (H7N9) virus, China, February to May 2013 and October 2013 to March 2014. Euro Surveill. 2015;20(10)
ii=21056. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=21056
Date of submission: 19 August 2014
[SIZE=+0]To study human-to-human transmissibility of the avian influenza A (H7N9) virus in China, household contact information was collected for 125 index cases during the spring wave (February to May 2013), and for 187 index cases during the winter wave (October 2013 to March 2014). Using a statistical model, we found evidence for human-to-human transmission, but such transmission is not sustainable. Under plausible assumptions about the natural history of disease and the relative transmission frequencies in settings other than household, we estimate the household secondary attack rate (SAR) among humans to be 1.4% (95% CI: 0.8 to 2.3), and the basic reproductive number R[SUB]0[/SUB] to be 0.08 (95% CI: 0.05 to 0.13). The estimates range from 1.3% to 2.2% for SAR and from 0.07 to 0.12 for R[SUB]0[/SUB] with reasonable changes in the assumptions. There was no significant change in the human-to-human transmissibility of the virus between the two waves, although a minor increase was observed in the winter wave. No sex or age difference in the risk of infection from a human source was found. Human-to-human transmissibility of H7N9 continues to be limited, but it needs to be closely monitored for potential increase via genetic reassortment or mutation.
full article[/SIZE]
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=21056
Research articles
Household transmissibility of avian influenza A (H7N9) virus, China, February to May 2013 and October 2013 to March 2014
Y Yang[SUP]1[/SUP], Y Zhang[SUP]2[/SUP], L Fang[SUP]3[/SUP], M E Halloran[SUP]4[/SUP], M Ma[SUP]3[/SUP], S Liang[SUP]5[/SUP], E Kenah[SUP]1[/SUP], T Britton[SUP]6[/SUP], E Chen[SUP]7[/SUP], J Hu[SUP]8[/SUP], F Tang[SUP]9[/SUP], W Cao[SUP]3[/SUP], Z Feng[SUP]2[/SUP], I M Longini Jr (
- Department of Biostatistics and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States
- Public Health Emergency Center, Chinese Center for Disease Prevention and Control, Beijing, China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States
- Department of Environmental and Global Health, University of Florida, Gainesville, Florida, United States
- Department of Mathematics, Stockholm University, Stockholm, Sweden
- Provincial Center for Disease Prevention and Control, Hangzhou, Zhejiang, China
- Municipal Center for Disease Prevention and Control, Shanghai, China
- Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu, China
Citation style for this article: Yang Y, Zhang Y, Fang L, Halloran ME, Ma M, Liang S, Kenah E, Britton T, Chen E, Hu J, Tang F, Cao W, Feng Z, Longini Jr IM. Household transmissibility of avian influenza A (H7N9) virus, China, February to May 2013 and October 2013 to March 2014. Euro Surveill. 2015;20(10)
ii=21056. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=21056Date of submission: 19 August 2014
[SIZE=+0]To study human-to-human transmissibility of the avian influenza A (H7N9) virus in China, household contact information was collected for 125 index cases during the spring wave (February to May 2013), and for 187 index cases during the winter wave (October 2013 to March 2014). Using a statistical model, we found evidence for human-to-human transmission, but such transmission is not sustainable. Under plausible assumptions about the natural history of disease and the relative transmission frequencies in settings other than household, we estimate the household secondary attack rate (SAR) among humans to be 1.4% (95% CI: 0.8 to 2.3), and the basic reproductive number R[SUB]0[/SUB] to be 0.08 (95% CI: 0.05 to 0.13). The estimates range from 1.3% to 2.2% for SAR and from 0.07 to 0.12 for R[SUB]0[/SUB] with reasonable changes in the assumptions. There was no significant change in the human-to-human transmissibility of the virus between the two waves, although a minor increase was observed in the winter wave. No sex or age difference in the risk of infection from a human source was found. Human-to-human transmissibility of H7N9 continues to be limited, but it needs to be closely monitored for potential increase via genetic reassortment or mutation.
full article[/SIZE]
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=21056