During this meeting, the advisory committee reviewed and evaluated the surveillance data related to epidemiology and antigenic characteristics of recent influenza isolates, serological responses. Origins, ecology and epidemiology of pandemic and seasonal influenza a virus ecology, epidemiology and evolution of infectious disease research group. Epidemiology and past outbreaks of aivs in china the first h9n2 low-pathogenicity avian influenza virus (lpaiv) and h5n1 high-pathogenicity avian influenza virus (hpaiv) in asia were isolated from guangdong province, china, in 1994 and 1996, respectively (2, 4.
Canada geese (branta canadensis) are numerous, highly visible, and widely distributed in both migratory and resident populations in north america as a member of the order anseriformes, they are often suggested as a potential reservoir and source for avian influenza (ai) viruses to further examine. A novel influenza, influenza a 2009 h1n1 virus outbreak, emerged in mid-april 2009, and by december 2009, spread across the world this epidemiologic analysis uses the epidemiologic problem oriented approach to gather information for, and develop a quantitative risk assessment model that evaluates. To determine clinical and epidemiologic differences between influenza caused by different virus types and subtypes, we identified patients and tested specimens patients were children and adults.
The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity more additional information. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. Epidemiology of influenza a 2009 h1n1 virus pandemic in the us ehsan abdalla, tsegaye habtemariam, david nganwa, asseged b dibaba, gemechu.
Global epidemiology of interpandemic influenza global influenza surveillance indicates that influenza viruses are isolated every month from humans somewhere in the world. The nomenclature to describe the type of influenza virus is expressed in this order: 1) virus type, 2) geographic origin where it was first isolated, 3) strain number, 4) year of isolation, and 5) virus subtype. Flu is a top 10 killer in the united states, and it leads to approximately 200,000 hospitalizations every year due to complications of the influenza virus in addition to the 200,000 hospitalizations that we have every year in this country, approximately 20,000 to 40,000 people die every single year, 20,000 to 40,000 deaths on an annual basis. Influenza epidemiology download pdf copy influenza virus is transmitted among humans in three main ways: by direct contact with infected individuals, through contaminated objects (such as. Influenza remains a globally important cause of febrile respiratory illness influenza virus activity in the community results in significant mortality, morbidity and economic disruption.
The mode of transmission of influenza viruses includes direct transmission between an infected host and susceptible host, the airborne route through the aerosols produced by infected host or indirectly through contaminated surfaces (hall 2007 weber and stilianakis 2008. Ebola virus disease » describe critical features of influenza epidemiology including risk groups, transmission characteristics, and impact world health. Flu season is an annually recurring time period characterized by the prevalence of outbreaks of influenza (flu) the season occurs during the cold half of the year in each hemisphere. Global epidemiology of influenza 411 outbreaks and epidemics typically occur between november and march, whereas in the southern hemisphere, inﬂuenza activity occurs between april and septem. Attempts to confirm influenza diagnoses by testing for influenza virus have limitations, because many adults tested after 6-8 days of illness are no longer shedding virus and, hence, are likely to test negative.
Influenza (flu) in arizona information arizona department of health services health and wellness for all arizonans. Of influenza viruses is driven by the need to ensure the efficacy of seasonal influenza vaccines, and to monitor circulating strains for pandemic potential or resistance. We describe the epidemiology of highly pathogenic avian influenza (hpai) a(h7n9) based on poultry market environmental surveillance and laboratory-confirmed human cases (n = 9) in guangdong, china we also compare the epidemiology between human cases of high- and low-pathogenic avian influenza a. Epidemiology and emergence of schmallenberg virus part 1: origin, transmission and differential diagnosis by fernando esteves, joão rodrigo mesquita, cármen nóbrega, carla santos, antónio monteiro, rita cruz, helena vala and ana cláudia coelho.
As the behavior of influenza viruses in populations is examined, it is important to recognize whether cases are identified by virus identification or serology, or, as is most commonly the case, by epidemiologic means as was the case in fig 1. The epidemiology of influenza due to the ever-changing nature of the multiple strains of the virus, influenza cannot be cured and instead a battle is. Standard flu vaccines contain the types of influenza virus—either three or four strains—that researchers determine will be most common in the upcoming season other options this year include a high-dose vaccine and vaccine that contains an adjuvant to create a stronger immune response for use in adults over the age of 65.