Household transmissibility of avian influenza A (H7N9) virus, China, February to May 2013 and October 2013 to March 2014
Autor: | W. Cao, J. Hu, E. Chen, S. Liang, Ye Zhang, Yang Yang, M. E. Halloran, Eben Kenah, Tom Britton, Fenyang Tang, Li Qun Fang, Zijian Feng, Ira M. Longini, M. Ma |
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Jazyk: | angličtina |
Rok vydání: | 2015 |
Předmět: |
Male
China Epidemiology Reassortment Genome Viral medicine.disease_cause Influenza A Virus H7N9 Subtype Natural history of disease Models Biological Article Poultry law.invention Disease Outbreaks law Virology Zoonoses Influenza Human medicine Animals Humans Transmission risks and rates Family Characteristics Reverse Transcriptase Polymerase Chain Reaction Zoonosis Public Health Environmental and Occupational Health Middle Aged medicine.disease Transmissibility (vibration) Influenza A virus subtype H5N1 Transmission (mechanics) Influenza in Birds Population Surveillance Female Basic reproduction number Demography |
Popis: | 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 R0 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 R0 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. |
Databáze: | OpenAIRE |
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