Influenza vaccination and respiratory virus interference. Number of influenza positive sentinel specimens by week and type. In addition, global influenza surveillance forms the primary line of defence against the occurrence of influenza pandemics by identifying emerging influenza virus strains that pose a potential threat. Most experts believe influenza viruses spread primarily by droplets made when infected people cough, sneeze, or talk.
The virus influenza viruses belong to the orthomyxoviridae family and are divided into three types a, b, and c. Pandemic influenza plan pandemic influenza surveillance for more information contact john bos at john. Iav infects both the upper and lower respiratory tracts via endocytosis 10. It is thought that the source of ha genes that are new to humans is the extensive pool of influenza viruses infecting wild birds. Vooral subtypen h5n1 en h7n9 eventueel h7n7 kunnen een ernstig ziektebeeld veroorzaken. The importance of this has been demonstrated on numerous occa sions, for example in 1997, 2003 and 2004 when influenza ah5n1 viruses were. There are some amounts of the virus in the air constantly. Even when the vaccine doesnt exactly match these viruses, it may still provide some protection. However, at a higher concentration of the airborne virus, the. Avian influenza viruses are classified as either hpai or lpai viruses, based on the genetic features of the virus and the severity of disease in experimentally infected chickens. Influenza a viruses are classified by subtypes based on the properties of their. Influenza type a is the primary group affecting both humans and animals.
Molecular identification of avian influenza a virus in house flies. Flu a viruses circulate widely in nature and cause infections of humans, pigs, horses, bats, and other animals. For current pcr protocols for h7 viruses please contact the department of virology, erasmus. Influenza viruses influenza viruses cause acute, usually selflimited febrile illnesses most often in the winter months. Influenza a and b cause human disease with significant morbidity and mortality. Avian influenza high pathogenicity overview disease in. Babi merupakan inang yang penting dalam ekologi virus influenza karena mereka memiliki dua. Flu tends to occur mostly in the fall and winter months in the united states. Cea mitigating the impact of pandemic influenza through vaccine innovation.
Wadsworth sends a subset of positive influenza specimens to the cdc for further virus testing. These amounts is generally not enough to cause disease in people, due to infection prevention by healthy immune systems. Of the 700 type a viruses that were subtyped, 68% were ah3 and 32% ah1pdm09. Influenza a viruses are important pathogens with a wide host range. Pandemic influenza results when an influenza strain emerges with an ha protein to which few people have prior immunity 4. All strains are named starting with an a or b type such as influenza a h1n1 or influenza. Influenza d virus is a species in the virus genus deltainfluenzavirus, in the family orthomyxoviridae, that causes influenza influenza d viruses are known to infect pigs and cattle. Introduction the rapidity with which the pandemic h1n1 2009 virus spread highlighted the need for timely.
Infeksi influenza a dan b pada anak dengan influenza. Nieuwsbriefinfluenzasurveillance20192020no4 erasmus mc. Since the host barriers are not an insurmountable obstacle for the avian viruses, they can be transmitted to other species. It typically spreads through respiratory droplets when a person. Less often, a person might become infected with influenza by touching a surface or object contaminated with influenza virus and. Based on their molecular features and serological characteristics of their nucleoproteins and matrix proteins influenza. After infection, some viral components are recognized by several pathogen recognition receptors that, in turn, promote downstream cellular and humoral. Identifikasi molekuler virus avian influenza a pada lalat rumah musca domestica. Wadsworth also identifies the lineage of influenza b specimens yamagata or victoria. Influenza, known as the flu, is a highly contagious respiratory virus. Type a influenza is a contagious viral infection that can have lifethreatening complications if left untreated.
Susceptibility to the pandemic influenza virus will be universal. Influenza viruses are highly variable rna viruses that can affect birds and. Influenza viruses infect many vertebrates, with influenza a, b and c viruses iav, ibv, and icv infecting humans. The following reflects laboratory findings for week 18 of the 201920 influenza season. Het griepvirus zit in druppeltjes snot, slijm en speeksel. They belong to the orthomyxoviridae family and are classified into 3 distinct types influenza a, influenza b and influenza c.
Influenza pneumonia incidence was high in 2005, a year when influenza ah3n2 subtype virus strains predominated, low in 2006 when ah1n1 viruses were more common, moderate in. Het virus wordt van mens tot mens overgedragen via een zogenaamde. Influenza a viruses are the only influenza viruses known to cause flu. Results according to the concentrated virus titer tcid50. From the 20102011 influenza season to the 20172018 season, excluding for the 20142015 season, the influenza.
Complicating the situation is the cocirculation with other respiratory viruses, several of which have been hypothesized to influence influenza virus. Pdf chicken embryonic eggs and madindarby canine kidney mdck cell line. There are many flu viruses, and they are always changing. Pdf education about virus biology at school is of pivotal interest to raise. Influenza a viruses are further classified into subtypes on the basis of the antigenic properties of. Influenza diagnosis clinical and epidemiological characteristics increase of febrile respiratory illness lab isolation of influenza virus from clinical specimen e. Rarely, an influenza virus is unable to have its subtype or lineage identified by the laboratory. Live viruses could be detected in the air behind all surgical masks tested.
Few young people had any existing immunity as detected by antibody response to the h1n1pdm09 virus, but nearly onethird of people over 60 years old had antibodies against this virus, likely from exposure to an older h1n1 virus earlier in their lives. Origin and evolution of the 1918 spanish influenza. Influenza the u inuenza is a contagious disease caused by a group of respiratory viruses called inuenza viruses. The h1n1pdm09 virus was very different from h1n1 viruses that were circulating at the time of the pandemic. The majority 71% of viruses were influenza type a, and 29% were influenza type b. A new flu virus emerges the h1n1pdm09 virus was very different from h1n1 viruses that were circulating at the time of the pandemic. When you get the flu, viruses turn your cells into tiny factories that help spread the disease. Manual for the laboratory diagnosis and virological. There are many different strains types of this virus. These symptoms typically begin two days after exposure to the virus and most last less than a week. The available evidence indicates that they originate from a large virus pool indigenous to wild aquatic birds webster et al. In this animation, nprs robert krulwich and medical animator david bolinsky explain how a flu virus. Influenza vaccination and respiratory virus interference among department of defense personnel during the 20172018 influenza season. Influenza viruses belong to the family orthomyxoviridae that is characterized by the ability to attach on glycoproteins of host cell surfaces and a segmented genome composed of single stranded, negatively orientated ribonucleic acid ssrna.
This infographic briefly summarises the natural history, replication cycle, and pathogenesis of influenza viruses, the cause of seasonal influenza and of influenza pandemics. The workplace during pandemic influenza how does pandemic influenza relate to you and your workplace. Infectivity of survivors was determined by utilizing a defined monolayer with fluorescent microscopy analysis. Virus influenza merupakan virus rna yang sangat mudah bermutasi. Among influenza viruses, type a is considered the most dangerous to human health. Influenza virus aerosols in the air and their infectiousness. Influenza a symptoms can be confused with signs of. Influenza virus infection aggravates stroke outcome. Efficient and sustained persontoperson transmission signals an imminent pandemic. Er zijn 16 hsubtypen en 9 nsubtypen van het type ainfluenzavirus. Influenza the center for food security and public health iowa.
Influenza virus and infection human influenza virus apuerto rico834 h1n1. Influenza a virus iav is a highly contagious singlestranded rna virus that has a serious impact worldwide. Twenty years after the pandemic began, the first influenza vaccine was administered to us soldiers in 1938. Global threat of animal influenza viruses of zoonotic. Influenza a viruses can also cause sporadic infections or spread worldwide. Influenza is an illness of the nose, throat and lungs caused by influenza viruses. Inactivation of influenza a virus on copper versus. The inuenza virus is highly contagious and causes serious illness that may result in hospitalization or death. But the time of year when flu is most common can vary from one area to another. Few young people had any existing immunity as detected by antibody response to the h1n1pdm09 virus, but nearly onethird of people over 60 years old had antibodies against this virus.
Pdf inactivation of human influenza virus using gamma. Iav from different host species can reassort their. Pandemic influenza continuity of operations annex template. Seasonal influenza seasonal influenza viruses circulate and cause disease in humans every year. Influenza is an acute respiratory illness, caused by influenza a, b, and c viruses, that occurs in local outbreaks or seasonal epidemics. Pdf growth characteristics of the thai h5n1 avian influenza virus. Pandemic influenza plan pandemic influenza surveillance. Mitigating the impact of pandemic influenza through. Clinical illness follows a short incubation period and presentation ranges from asymptomatic to fulminant, depending on the characteristics of both the virus and the individual host.
For type b viruses, 84 29% of the 288 viruses were reported with a lineage, with 80 95% being bvictoria. Both influenza a subtypes, ah1n1pdm09 and ah3n2, cocirculated and different distributions of a subtypes were observed among countries. Each year a new flu vaccine is made to protect against three or four viruses that are likely to cause disease in the upcoming flu season. Circulating influenza viruses detected by isdh laboratory, indiana, 20192020 season week 9 season total pcr result number percent of specimens received number percent of specimens received 2009 ah1n1pdm virus 29 41% 255 36% influenza ah3 seasonal virus 0 0% 5 influenza b yamagata seasonal virus 0 0% 3 influenza virus, our findings show that surgical masks provide around a 6fold reduction in exposure. For example, in the united states, influenza ah3n2 viruses cocirculated with influenza b viruses, while influenza ah1n1pdm09 viruses were reported only rarely during the 20142015 season. The latter are composed of key genes from the 1918 virus, updated by subsequentlyincorporated avian influenza genes that code for novel surface proteins, making the 1918 virus indeed the mother of all pandemics. The vast majority of influenza viruses detected were type a. Influenza is one of the most contagious and rapidly spreading infectious diseases and an important global cause of hospital admissions and mortality. Oglcnac transferase promotes influenza a virusinduced. The virus is also found on the hands of people with influenza and on surfaces they have touched.
People can spread influenza beginning from one day before symptoms appear until five to seven days after. This work is licensed under a creative commons attribution. There are 2 common subtypes of influenza a viruses h1 and h3. Influenza a viruses also have many different subtypes. After incubation for 24 h on stainless steel, 500,000 virus particles were still infectious. Influenza viruses circulated at high levels between weeks 522018 and 122019. First isolated from pigs in 2011, the virus was categorized as a new genus of orthomyxoviridae in 2016, distinct from the previouslyknown influenzavirus c. Influenza viruses antiviral therapy and resistance. However, the largest natural reservoir of influenza a viruses is wild aquatic birds, such as ducks. Influenza pneumonia incidence was high in 2005, a year when influenza ah3n2 subtype virus strains predominated, low in 2006 when ah1n1 viruses were more common, moderate in 2007 when h3n2 and. Of the 15 ha subtypes found in birds, only 3 h1, h2, and h3 are known to have caused. Who information for the molecular detection of influenza. The clinical disease attack rate will likely be 30 percent or higher in the overall population during the pandemic.
303 93 1086 379 1187 1493 1474 1203 922 474 413 319 1179 272 26 398 860 1530 535 243 1375 835 271 1138 427 1459 74 612 538 426 1494 246 151 1275 731 1284 296 951 890 859 644 1392 215 744 184 1077