Avian, swine and other zoonotic influenza virus infections in humans may cause disease ranging from mild upper respiratory tract infection fever and cough, early sputum production and rapid progression to severe pneumonia, sepsis with shock, acute respiratory distress syndrome and even death. A virus is defined as hpai or lpai by its ability to cause severe disease in intravenously inoculated young chickens in the laboratory, or by its. Avian influenza viruses are classified as either low pathogenic also called low pathogenicity avian influenza viruses or highly pathogenic high pathogenicity avian influenza viruses. Remote sensing based modeling of avian influenza transmission in indonesia, in an invited avian influenza symposium in. Colorized transmission electron micrograph of avian. The virus can live for a long time in the environment and can also be spread by objects or fomites e. It includes frequently asked questions and links to web sites. Human infections are primarily acquired through direct contact with infected animals or contaminated environments, these viruses have not acquired the ability of sustained transmission among humans.
Avian influenza background for information on how this type of transmission might occur. The emergence of new virus subtypes and their interspecies transmission is of great concern. Avian influenza it is caused by those influenza viruses that mainly affect birds and poultry, such as chickens or ducks, e. Lowpathogenic avian influenza lpai h7n8 was also identified. National science advisory board for biosecurity findings. Using a modified delphi method and a 4step elicitation process, 11 experts were asked to give initial individual estimates for the various pathways and practices in the presented. Influenza a viruses have infected many different animals, including ducks, chickens, pigs, whales, horses, and seals. However, certain subtypes of influenza a virus are specific to certain species, except for birds, which are hosts to all known subtypes of influenza a viruses. Introduction a disease capable of causing extremely high up to 100% mortality in poultry was first distinguished from bacterial diseases, such as fowl cholera, by perroncito in 1878. How infected backyard poultry could spread bird flu to people. Avian influenza ai is an infectious viral disease of birds, commonly known as bird flu.
Influenza a virus highly pathogenic avian influenzah5n1 aabb. We used network analysis to explore the devastating epidemic of hpai ah5n8 among poultry, in particular ducks, in france during 20162017 and to estimate the likely contribution of liveduck movements. Avian influenza a virus infection in people cannot be diagnosed by clinical signs and symptoms alone. Year one report avian influenza risk predictions in.
No human cases of infection with the avian influenza virus have been reported in either of these outbreaks. Influenza causes significant loss of workdays, human suffering, and m. Infections with low pathogenicity and highly pathogenic avian influenza ah7n9 viruses affected poultry in 4 states in the southeastern united states in 2017. Faqs on avian influenza and bird flu for georgians october 21, 2005. Current data for avian influenza a h5n1 infection indicate an incubation period ranging from 2 8 days and possibly as long as 17 days. However, bird flu is very contagious among birds and sometimes can make chickens, ducks, and turkeys very sick. Live bird markets in the spread of avian influenza 14 6128. Transmission of avian influenza a viruses between animals. Infected birds have virus in their saliva, mucous and droppings feces.
Role of liveduck movement networks in transmission of. Sars casepatient, emerging infectious diseases, vol. This is the first time h7n8 viruses have been found in birds in the. Seasonal influenza is an annual occurrence, but it is the threat of pandemics that produces universal concern. In january 2016, a highly pathogenic avian influenza hpai virus, h7n8, was identified on a commercial poultry farm in dubois county, indiana. Bird flu is a nonscientific term that refers to a specific virus h5n1 that has been present in domestic birds in asia since 1997. Influenza, one of the most common infectious diseases, is a highly contagious airborne disease that occurs in seasonal epidemics and manifests as an acute febrile illness with variable degrees of systemic symptoms, ranging from mild fatigue to respiratory failure and death. Avian influenza weekly update number 737 human infection with. Avian diseases transmissible to humans 2 avian influenza have been in areas where there is constant close contact between birds and humans or in cases where the humans were exposed to infected bird secretions. Wild birds worldwide carry the virus in their intestines, but usually do not get sick from them. Wild water birds like ducks and geese can be infected with bird flu viruses, but usually do not get sick.
Department of health and human services, office of the assistant secretary for preparedness and response. Between 10 and 16 april 2020, no new cases of human infection with avian influenza ah5n1 virus were reported to who in the western. Since the states avian influenza outbreak in 2002, virginias poultry industry has been vigilant in prevention techniques and anticipated response. Bird flu viruses do not usually infect humans, but several cases of human infection with bird flu viruses have occurred since 1997. We detected infectious droplets and aerosols during laboratorysimulated processing of asymptomatic chickens infected with human clades 1 and 2. Native north american strains of avian influenza naturally occur in wild birds and can spread to domestic birds. There have been four influenza pandemics since the early 20 th century, and each has been caused by the emergence of a novel virus. Avian influenza a viruses do not usually infect humans. Exposure to infected poultry is a suspected cause of avian influenza h5n1 virus infections in humans. Generally, influenza viruses are highly speciesspecific, meaning that viruses that infect an individual species humans, certain species of birds, pigs, horses, and seals stay true to that species, and only rarely spill over to cause infection in other species. Followup investigations by chinese health officials of more than 2,000 close contacts of people infected with h7n9 indicate that there is no sustained ongoing spread of. A crucial feature in the ecology and epidemiology of influenza virus is interspecies transmission.
Aspr tracie avian influenza resources at your fingertips. Should this virus, or another zoonotic influenza virus, gain the ability of sustained humantohuman transmission, an influenza pandemic could result. Avian influenza viruses avian influenza ai viruses primarily infect birds and occasionally cause illness in humans in close contact with infected birds and in predatory animals, including eagles, tigers, dogs, and cats that consume sick or dead birds. In most cases it causes no signs of infection or only. The relative roles that movement and proximity networks play in the spread of highly pathogenic avian influenza hpai viruses are often unknown during an epidemic, preventing effective control. Avian influenza virus isolated from a woman with conjunctivitis. An influenza pandemic planning guide for homeless and. The current avian influenza epidemic, which is affecting birds in eurasia and africa, has heightened world awareness about the possibility of a human influenza pandemic resulting from either antigenic drift or avian viral reassortment with a human strain. Avian influenza in humans national health portal of india.
We evaluated pathogenicity and transmission of representative viruses in mouse and ferret models and examined replication kinetics in. Nasa data, models, and analysis techniques are used to enhance the decision capabilities concerning avian influenza ai and pandemic influenza risks. Avian influenza h5n1 transmission in households, indonesia article pdf available in plos one 71. H5n1, h5n6, h6n1, h7n4, h7n9, h9n2 and h10n8 since they do not commonly infect humans, there is little or no immune. Most models of hpai h5n1 created up to date are autonomous and average out the seasonality but see 23. Scientific analysis of avian influenza spread from noneueea countries to poultry in. Influenza a virus, a member of the genus orthomyxovirus, is an economically important virus that causes disease in humans, pigs, horses, and fowl. What infection control actions should healthcare providers take to prevent. Assessing the probability of introduction and spread of. What are the signs of illnes s of birds infected with avian influenza. If this new influenza a virus causes illness in people and is transmitted easily from person to person in a sustained manner, an influenza pandemic can occur. Influenza ah7n9 virus in china implications for public. Highly pathogenic avian influenza a hpai subtype h5n1 has caused family case clusters, mostly in southeast asia, that could be due to humantohuman transmission. Colorized transmission electron micrograph of avian influenza a h5n1 viruses seen in gold grown in mdck cells seen in green.
In the 1957 and 1968 pandemics, the new viruses contained components of previous human, as well as avian, influenza viruses. Airborne transmission results from inhalation of smaller infected droplets that spread through the air, for example when an infected person coughs forcefully, and may occur over short distances three six feet. How infected backyard poultry could spread bird flu to people human infections with bird flu viruses rare but possible 1direct contact most common bird flu virus touching virus and then touching the eyes, nose or mouth infection can occur without touching poultry. Frequently asked questions for h7n8 avian influenza. How is human infection with avian influenza a virus treated. The disease also can be easily spread by people and equipment contaminated with avian influenza virus. It is possible that the process of genetic reassortment could occur in a person who is coinfected with an avian influenza a virus and a human influenza a virus. These outbreaks mark the first cases of avian influenza in the republic of korea, and the first cases in japan since 1925. The study of the influence of sialic acid receptors on virus infection may contribute to a better understanding of the cross. This fact sheet has information about bird flu and bird flu infections in people. This document provides healthcare system and public health preparedness professionals, emergency managers, and other stakeholders with resources and information to consider. No cases of hpai virus infection were reported in wild birds from asian key areas such as mongolia, western china or siberia.
Pdf avian influenza h5n1 transmission in households. Page 3 of 14 date member state main event action by the european commission, member states authorities and stakeholders tu 3010 bg hpai h5 confirmed in poultry infonote 62 to cvos informing about from the bulgarian authorities on further outbreaks of highly pathogenic avian influenza of subtype h5 confirmed on xxxxxx in a small rural holding keeping poultry of mixed species. Transfer of eggs is a potential means of transmission. Transmission and infection of h5n1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of h5n1 that constitutes a pandemic threat infected birds pass on h5n1 through their saliva, nasal secretions, and feces. Avian influenza a virus infections in humans avian influenza flu. Recurring reports of avian influenza viruses severely affecting humans have served as constant reminders of the potential for another pandemic. Avian influenza viruses can be transmitted on contaminated shoes, clothing, crates, egg flats, egg cases, vehicles, and other equipment. Also known as the bird flu, a strain of influenza that naturally occurs among wild birds. Ai viruses are called highly or lowly pathogenic depending on the response of poultry to infection. Poultry birds are also susceptible to ai infection that can cause large outbreaks and epidemics in poultry. Avian influenza refers to the disease caused by infection with avian bird influenza flu type a viruses. Avian influenza ai is an infectious viral disease of birds.
Transmission of influenza a in human beings sciencedirect. In two independent studies conducted in two leading influenza laboratories at the university of wisconsinmadison and erasmus mc in rotterdam, the netherlands, investigators have proved that viruses possessing a hemagglutinin ha protein from highly pathogenic avian h5n1 influenza viruses can become transmissible in ferrets. Avian influenza bird flu is an infection caused by avian bird influenza flu viruses. Potential transmission of avian influenza a h5n1 virus. The risk of zoonotic transmission of ai viruses to the general public in europe remains very low. Ai is an infection caused by avian influenza viruses.
Scientists and animal and public health officials closely monitor avian influenza a virus outbreaks for indications that the virus can infect humans or spread from person to person. Wild water fowl such as ducks and geese are mostly affected by ai, but often show no apparent signs of illness. A highly pathogenic avian influenza of the h5n1 type. Interspecies barriers to transmission of influenza viruses are generally. Transmission of avian influenza a viruses between animals and people. Destruction of h5n1 avian influenza virus in meat and. Other birds may pick up the virus through direct contact with these excretions or when they have. Highly pathogenic avian influenza such as h5n1 has crossed the species barrier to infect humans, but persontoperson spread has thus far been rare, if it has occurred at all, according to some authorities. If a novel avian influenza a virus acquires the ability to spread from person to person in a. The world health organization currently recommends that an incubation period of 7 days be used for field investigations and the monitoring of patient contacts for avian influenza a.
This disease is now termed highly pathogenic avian influenza hpai, but was known as fowl plague until 1981. Avian influenza a h7n8 selfobservation instructions information is being provided to you because of your participation in a response to highly pathogenic avian influenza hpai andor low pathogenic avian influenza lpai a h7n8 outbreak in poultry. Airborne transmission of highly pathogenic influenza virus. Transmission to humans is inefficient, and human disease is rare after 10 years of potential exposures. Who regards every case of transmission of an avian influenza virus to humans as a cause for heightened vigilance. The objective of this study was to elicit experts opinions and gather estimates on the perceived probability of introduction and spread of avian influenza ai virus in the australian broiler and layer industry. The first human case due to avian influenza ah7n4 was notified in china underlining the threat that newly emerging avian influenza viruses pose for transmission to humans.
Avian influenza virus avi this information is published for commissary patrons who want to know more about the avian influenza virus. Rapid risk assessment human infection with a novel avian influenza ah7n9 virus, china 3 july 2017 2 the continued transmission of ah7n9 to humans in china poses the risk that sporadic travelrelated cases returning from china may be detected in europe. Although usually transmitted from wild birds as a virus of low pathogenicity, it may mutate during replication in domestic poultry and highly pathogenic avian influenza hpai strains may arise. Avian influenza a h7n9 key points june 7, 20 in this. Avian influenza also can be found on the outer surfaces of egg shells.
We detected fewer airborne infectious particles in simulated processing of. Lessons from influenza pandemics of the last 100 years. Avian influenza in poultry 3 through improper disposal of infected carcasses, manure, or poultry byproducts. Examining environmental effects on influenza transmission in warm climate using neural network, in astmh annual meeting, washington, dc, november 1822, 2009.