Investigating reports of exposure to animals known to carry influenza viruses, such as pigs and birds. Monitoring responders to animal influenza outbreaks, such as people working in outbreaks among pigs and poultry. Below are examples of variant flu outbreaks: Multi-State Outbreak: From July to September , an outbreak of influenza A H3N2 variant virus or H3N2v infection involving 10 states resulted in infections reported among attendees of agricultural fairs where swine were present.
CDC worked closely with state and territorial health departments to investigate each human infection so that the risk of infection could be more fully understood and appropriate public health measures could be taken to minimize the chance that other people might get sick. CDC staff joined the state health department staff and others to support their efforts to: Determine the extent of the outbreak and the severity of illness among people infected; Identify any instances of person-to-person spread; and Examine possible risk factors for infection.
A team of CDC staff, including Epidemic Intelligence Service EIS officers , traveled to Michigan to look for additional variant flu infections among people exhibiting pigs at county fairs. TIM is a text-based illness monitoring system originally developed as a way to more easily remind outbreak responders and other potentially exposed people to report any signs and symptoms of illness to public health personnel.
The CDC team used this opportunity to evaluate the feasibility and acceptability of using TIM for future novel flu virus outbreaks. They used TIM to conduct active surveillance of people in 87 households for signs and symptoms of illness and potential variant virus infections. Of the people who signed up for active monitoring, 22 reported an illness to their health department through the TIM system.
Nine of those people sought medical care and five of them were tested. Of those tested, two tested positive for H3N2 v. Using a text-based system for active surveillance helped the team identify people with infections that may not have been identified otherwise.
Avian Flu Outbreaks: Every so often, avian influenza i. At the time, no human infections with these viruses were detected, however similar viruses were infecting people in other countries, causing serious illness and death in some cases.
While the risk of human infection among the public was low during this bird flu outbreak, it is still possible for these viruses to infect people. CDC provided recommendations and guidance to clinicians and public health professionals in the United States on appropriate follow-up, preventive treatment, testing, specimen collection and processing of samples from patients who may be infected with H5 viruses. Avian Influenza viruses have occasionally been detected in cats previously, although not in an outbreak situation.
During this investigation, nearly people who were exposed to the infected cats during the outbreak were screened or tested for H7N2 virus infection. This work took on renewed urgency when a veterinarian who worked closely with the sick cats tested positive for H7N2 virus infection on Dec. The vet experienced flu symptoms, including sore throat, cough, and fatigue. Most patients have experienced severe respiratory illness, with about one-third of the cases resulting in death.
Although the virus does not appear to pass easily from person to person, there is always the worry that it could mutate into a form that is more transmissible.
There are drugs that are effective against influenza, but the possibility that a virus could acquire resistance to the drugs is a serious issue. There are four different antiviral drugs, of two different classes, that are effective against influenza. However, influenza viruses can and do develop resistance to these drugs - as one of the main circulating seasonal viruses did during a recent flu season - so that the drugs can no longer be used to treat or prevent infections.
There is a need to develop additional drugs that can prevent or alleviate flu symptoms. Vaccines can be developed to protect humans from influenza viruses.
However, as was strikingly obvious during the H1N1 pandemic, vaccine production takes many months. By the time a vaccine was developed, tested, produced, and distributed, many individuals had already been infected. Clearly, a more rapid method of vaccine development is needed. The goal of developing a universal flu vaccine, one that would provide durable protection against multiple flu strains, remains a challenging feat.
The greatest fear is that a new pandemic influenza virus could emerge that could pass from person to person as easily as the H1N1 virus, but be as deadly as the H5N1 virus. Additional concerns are that an influenza virus could mutate into a form that would be resistant to anti-influenza drugs, such as Tamiflu, or that the virus could change so that a vaccine no longer afforded protection.
Even though the H1N1 pandemic was relatively mild, knowing how lethal and unpredictable influenza viruses can be, we must continue to remain alert and prepare for future pandemics. Investigators in the Department of Molecular Virology and Microbiology MVM have been studying influenza for several decades, with an Influenza Research Center first established in A major focus of the work is directed towards the development and testing of influenza vaccines to find the most effective vaccination dosages, methods, and strategies to protect the population against this deadly disease.
Other projects involve studying the structure and function of important influenza proteins. Research is ongoing on both epidemic influenza also referred to as seasonal or interpandemic influenza and pandemic influenza.
Epidemic influenza occurs annually and is attributable to minor changes in genes that encode proteins on the surface of circulating influenza viruses. Pandemic influenza occurs when more significant changes in the influenza A virus arise as a result of the acquisition of genes from influenza viruses of other animal species by a human virus strain, thus creating a novel virus.
The latter carries a greater risk for the human population. It was previously led by Dr. Wendy Keitel and is currently under the direction of Dr.
Hana El-Sahly. The VTEU network conducts clinical trials that evaluate vaccines and treatments for a wide array of infectious diseases. An important strength of this established network is that it is able to efficiently and safely test new vaccines within a rapid time frame. The VTEU research group in the department has been involved in important studies that led to the licensure of live attenuated and high dose inactivated influenza virus vaccines.
They have tested vaccines to seasonal influenza and they have performed many studies evaluating vaccines targeting pandemic influenza, including the swine-origin H1N1, and the H5N1, H9N2, and H7N9 viruses, among others. They have evaluated methods to improve vaccine immunogenicity, including delivery of vaccine by different routes of administration, different dosages, and with different adjuvant preparations.
Researchers involved in these studies include Drs. Their hope is that the results of these studies will identify the optimal and most effective dosages of vaccine to protect the public from seasonal influenza, as well as from a possible influenza pandemic. MVM investigators would like to better understand epidemic influenza seasonal flu infections, disease, and vaccines with the goal of developing ways to better control these epidemics.
Towards this goal, they are working on developing new improved vaccines against epidemic influenza strains and are trying to understand how the immune systems of different people respond to the influenza virus and influenza vaccines. In addition, MVM researchers with the VTEU have been evaluating the safety and immunogenicity of seasonal influenza vaccine in pregnant women.
Because pregnant women are at higher risk for serious complications from the flu, it is important to develop strategies to protect these women from seasonal and pandemic influenza. The clinical trial includes up to women recruited from nine sites across the nation and is headed by Dr. Shital Patel. It is one of the few studies that will evaluate antibody responses in pregnant women following vaccination. Evaluating the safety of seasonal inactivated influenza vaccine will yield vital information in anticipation of the need to test novel vaccines against possible future pandemic strains, in pregnant women.
Scientists are also conducting a study in collaboration with Kelsey-Seybold Clinics to determine the effectiveness of an inactivated influenza vaccine in protecting pregnant women and whether these immunized women can pass immunity against influenza to their infants, so that newborns would be protected from influenza during their first few months of life.
Another approach to protect against influenza epidemics is called herd immunity. The idea is to vaccinate a large percentage of school-age children to limit the spread of influenza without needing to vaccinate a larger percentage of the general population. The reasoning behind this idea is that school-age children are often the source of infection and pass the virus onto their friends, teachers, and family members.
This might be especially helpful to the elderly population who are at higher risk from influenza-related complications and whose immune systems may not mount as effective a response to influenza as younger individuals.
Another advantage to this approach is that it might be possible to achieve high community protection from influenza with a limiting amount of vaccine. Pedro Tony Piedra and colleagues are testing herd immunization in school-aged children in central Texas. In their initial study, they found that vaccination of 12 to 15 percent of children in selected communities resulted in an indirect protection to influenza infection in 8 to 18 percent of the adults in these communities.
They are currently conducting a larger, school-based vaccination program with the goal of immunizing 50 percent of the children, and they will determine how effective this level of immunization is in preventing infection in adults. Piedra and co-workers want to know how many children need to be vaccinated in order to protect the adult population from influenza infection, and they would like to use this approach to control the spread of epidemic influenza.
They also hope to use this approach as a model for combating pandemic influenza and bioterrorism. Piedra has also investigated the effects of oseltamivir commonly known as Tamiflu on influenza-related complications in children with chronic medical conditions.
Patients with underlying medical conditions are at higher risk of complications from both seasonal and pandemic flu. Piedra and his colleagues found that children with chronic medical conditions benefit from the use of Tamiflu if it is prescribed early in the disease process.
Children and adolescents between the ages of 1 and 17 who were at high risk of influenza complications showed significant reductions in the risks of respiratory illnesses other than pneumonia, reduced risk of otitis media a middle ear infection , and fewer hospitalizations in the 14 days after influenza diagnosis.
The most effective way to prevent the widespread infection and high mortality rate that a new influenza virus could inflict upon the human population would be to vaccinate people, so that the human immune system would be prepared to fight off an infection.
MVM investigators are trying to identify the best way to prime the human immune system to defend against flu strains that could cause a pandemic. Researchers have been testing vaccines against H1N1, H5N1, H7N9, and other potential pandemic flu strains and analyzing the immune responses of different people to the vaccines. Members of the Department were part of the national effort to prepare a vaccine against H1N1 influenza and test candidate vaccines.
Several different parameters were tested: the number of doses required one or two , different dosage amounts 15 or 30 micrograms , and different age groups 18 to 64 years old, age 65 and older, and healthy children. The goal was to determine the reactions and antibody protection responses following immunization with experimental influenza H1N1 vaccine when given with seasonal influenza vaccine.
The trial enrolled healthy adults, and a similar trial was conducted with children aged 6 months to 17 years. Study participants received a single strength of the H1N1 vaccine given in two doses along with the seasonal flu vaccine given either before, during, or after the time that they were inoculated with the H1N1 vaccine. Scientists in the department also examined ways to optimize the collection of samples and testing for infection, analyzing immune responses , and working on epidemiological, pathogenesis , and treatment studies of the virus.
They worked on developing a method to collect samples and isolate viruses so that they could assess the viruses and the immune responses against them. Researchers used these samples to isolate the virus for further characterization and study how the immune system responds.
These samples were banked and shared with researchers around the country. The goal of this study was to help guide the process of vaccine development and to give scientists an idea of the response to antiviral chemotherapy and changes of the virus over time. MVM researchers have been involved in preparing assays used to detect the virus and evaluate immune responses. The Respiratory Virus Diagnostic Research laboratory supports clinical trials on the epidemiology, immunology, pathogenesis, and vaccine prevention of important human respiratory pathogens and houses a cell culture lab for virus isolation and a polymerase chain reaction PCR lab for respiratory virus identification.
Under the direction of Dr. In addition, Dr. Robert Couch set up serologic assays for evaluation of immune responses. Studies conducted by MVM researchers helped guide public health officials in determining the best course of action in dealing with the H1N1 outbreak. They monitored vaccine recommendations made by the CDC and made suggestions. They kept the general public informed through local and national media outlets. The scientists continue to study the H1N1 virus to gain a deeper understanding of the virus itself, its interactions with the immune system, and responses to the H1N1 vaccine.
Additionally, researchers within the VTEU have been working on other new influenza strains that have pandemic potential including the new avian H7N9 virus and investigating vaccine strategies. This work will provide valuable information in responding to future influenza outbreaks.
In more recent work, Dr. Robert Atmar and his colleagues have been conducting a phase 2 clinical trial to test a candidate for a universal flu vaccine known as M Unlike other flu vaccines, which consist of a whole inactivated flu virus or an attenuated live virus, the M vaccine is comprised of nine epitopes, short stretches of viral protein, that are common to many different influenza strains. Because these regions are shared between different strains, it is hoped that the vaccine would trigger the immune system to respond to multiple strains.
Adult healthy volunteers will receive the experimental vaccine or a placebo and will be monitored over time to evaluate their immune responses. Andrew Rice and colleagues are studying an avian influenza virus protein called NS1 that has recently been shown to be associated with virulence.
Proteins like NS1 that are involved in pathogenesis are important targets for novel antiviral therapeutics. The goal of this project is to identify cellular proteins that interact with NS1 and play a role in the pathogenesis of avian influenza virus infection. The PBM is predicted to associate with a class of cellular proteins - termed PDZ proteins - that are typically involved in cell-cell contact, cellular polarity, and signaling pathways.
A long-term goal of this project is to derive small molecules that can inhibit the interaction between the NS1 protein and its cellular PDZ protein targets, as such small molecules may be the basis for the development of novel therapeutics to treat avian influenza virus infection. In a separate study, Dr. Venkataram Prasad and Zach Bornholdt, a graduate student in his laboratory, have determined the structure of a region of an important influenza protein called NS1.
Their work may explain, in part, why the H5N1 virus causes such a severe and often fatal illness. NS1, a protein essential for influenza infection, antagonizes the cellular immune response and is thought to play a role in virulence.
By knowing the structure of the NS1 protein, these investigators can surmise how variations in the H5N1 version of NS1 may alter its ability to interact with other molecules.
How do humans get influenza A? Infected birds shed avian influenza virus in their saliva, mucous and feces. Human infections with bird flu viruses can happen when enough virus gets into a person's eyes, nose or mouth, or is inhaled. Marbella Grimalt Professional. How did I get influenza A? Most experts think that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk.
Less often, a person might get flu by touching a surface or object that has flu virus on it and then touching their own mouth, nose, or possibly their eyes. Rahama Eckloff Professional. Can you get influenza A twice? Unfortunately, no. Experts say it is possible to catch the flu twice in one season. But a smaller portion of people around 10 to 15 percent are getting the H1N1 strain or the influenza B virus, according to data from the Centers for Disease Control and Prevention. H3N2 and H1N1 are both strains of influenza A.
Berena Long Explainer. What does flu type A mean? Type A flu or influenza A viruses are capable of infecting animals, although it is more common for people to suffer the ailments associated with this type of flu. Wild birds commonly act as the hosts for this flu virus. Type A flu virus is constantly changing and is generally responsible for the large flu epidemics.
Nedelcho Pobo Explainer. How does avian influenza spread to humans? The avian influenza virus is found in secretions from the nares nostrils , mouth, and eyes of infected birds and is also excreted in their droppings. H5N1 HPAI can be spread from birds to people as a result of direct contact with infected birds, such as during home slaughter and plucking of infected poultry. Teresa Naud Explainer. How long is influenza A contagious? About a week. Typically, you're contagious from 1 day before you have any symptoms.
You stay that way for 5 to 7 days after you start feeling sick. Kids and people may be able to spread the virus for even longer, until all of their symptoms fade. Sali Budi Pundit. How do you catch bird flu? Most of the people who get bird flu have had close contact with infected birds or with surfaces that have been contaminated by the birds ' saliva, mucous, or droppings. It is also possible to get it by breathing in droplets or dust that contain the virus.
Rarely, the virus has spread from one person to another.
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