Friday, September 29, 2023

What Are The Different Types Of Flu

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Lesson #: Influenza C Symptoms

Dr. Bob discusses the different types of flu

Ah, sweet, sweet influenza C. Influenza C is the mildest of all of the strains. In fact, it typically only causes minor respiratory symptoms. Far less is known about influenza C because it’s much rarer and not easily isolated, so scientists aren’t able to study it in depth.

Plus, influenza C isn’t capable of undergoing antigenic shift , so it’s not a significant concern for humans.

How The Flu Spreads

The flu spreads several ways: through airborne coughs or sneezes, through touching contaminated surfaces like doorknobs or keyboards, through contact like handshakes or hugs and from saliva shared through drinks or kissing. If you become sick, consider working or studying from home while recovering, as going to work or school can spread the disease to others.

How Flu Pandemics Arise

Influenza is a constantly evolving virus. It quickly goes through mutations that slightly alter the properties of its H and N antigens.

Due to these changes, acquiring immunity to an influenza subtype such as H1N1 one year will not necessarily mean a person is immune to a slightly different virus circulating in subsequent years.

But since the strain produced by this antigenic drift is still similar to older strains, the immune systems of some people will still recognize and properly respond to the virus.

In other cases, however, the virus can undergo major changes to the antigens such that most people dont have an immunity to the new virus, resulting in pandemics rather than epidemics.

This antigenic shift can occur if an influenza A subtype in an animal jumps directly into humans.

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The Influenza Virus And Its Genome

There are three basic types of influenza viruses: A, B, and C. Influenza B and C viruses only infect humans, so novel antigens are not introduced from other species. Only influenza A viruses infect nonhuman hosts, and a reassortment of genes can occur between those subtypes that typically infect animals and those that infect humans, resulting in antigenic shift and potential pandemics. Epidemics of seasonal influenza occur due to influenza A or B viruses.

Due to the segmented nature of the influenza genome, in which coding sequences are located on individual RNA strands, genomes are readily shuffled in host cells that are infected with more than one flu virus. For example, when a cell is infected with influenza viruses from different species, reassortment can result in progeny viruses that contain genes from strains that normally infect birds and genes from strains that normally infect humans, leading to the creation of new strains that have never been seen in most hosts. Moreover, because at least 16 different hemagglutinin subtypes and nine different neuraminidase subtypes have been characterized, many different combinations of capsid proteins are possible. Of these subtypes, three subtypes of hemagglutinin and two subtypes of neuraminidase have caused sustained epidemics in the human population. Birds are hosts for all influenza A subtypes and are the reservoir from which new HA subtypes are introduced into humans .

What Are The Different Types Of Influenza

Understanding Influenza Viruses

Influenza viruses are divided into three types designated as A, B, and C:

  • Influenza types A and B cause epidemics of respiratory illness that occur yearly during the winter. They often lead to increased rates of hospitalization and death. Public health efforts to control the impact of influenza focus on types A and B. One of the reasons the flu remains a problem is because the viruses actually change their structure regularly. This means that people are exposed to new types of the virus each year.
  • Influenza type C is more infrequent and causes either a very mild respiratory illness or no symptoms at all. It does not cause epidemics and does not have the severe public health impact of influenza types A and B.

Influenza viruses continually change , which helps the virus to evade the immune system of both children and adults. People can get the flu no matter what their age. The process works like this:

  • A person infected with an influenza virus develops antibodies against that specific virus.
  • The virus changes.
  • The “older” antibodies no longer recognize the “newer” mutated virus when the next flu season occurs.
  • The person becomes infected again.
  • The older antibodies can give some protection against recurrence of the flu. In addition, the flu vaccine given each year is produced from influenza virus strains expected to cause that year’s flu outbreak.

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    What Type Causes The Seasonal Flu

    Three types of flu virusesA, B, and Ccause seasonal influenza. Influenza D may also have the potential to do so if the potential for future transmission from animals to humans comes to fruition.

    Seasonal flu is the type of influenza that typically causes illness for just a few months out of the year. Flu season is different depending on where you are in the world. In the United States, it usually falls between October and April.

    The Intradermal Flu Shot

    Known as Fluzone Intradermal, it is used for people that are between the ages of 18 and 65 years old. As opposed to the typical flu vaccine being injected into the muscles of the arm, this vaccine makes use of smaller needles that are 90% smaller than the needle used for the regular flu shot and enter just under the skin.

    It works just as well as other vaccines, however, side effects are often more commonly experienced.

    The side effects at the site of the injection are:

    • Redness

    All of the above side effects should pass in about three days to a week.

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    What Is Type A Flu Virus

    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. The influenza A2 virus is spread by people who are already infected. The most common flu hot spots are those surfaces that an infected person has touched and rooms where they have been recently, especially areas where they have been sneezing.

    Influenza Virus: Epidemics And Pandemics

    Three types of flu | Infectious diseases | Health & Medicine | Khan Academy

    Influenza virus has caused serious respiratory illness and death over the past centuries. Epidemics and pandemics due to Influenza virus were known to cause morbidity and mortality in humans and other animals. Pandemics have been documented since the 16th century and in the last 400 years, at least 31 pandemics have been recorded . Influenza virus belongs to the family Orthomyxoviridae, which is characterized by a segmented, minus-stranded RNA genome. Influenza

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    When Should I Get Vaccinated

    The flu season ranges roughly from October-March. Because the flu vaccine takes about two weeks to fully protect you from viral antibodies, we recommend you try to get vaccinated by the end of October. However, if youve yet to get your vaccination this year, its not too late!

    We understand there are many questions about vaccines, especially the flu vaccine, and we always encourage our patients to ask any questions they may have. Call East Meadow Medical P.C. today to schedule your vaccination, or use the online booking tool. Its important not just for yourself, but also for those around you!

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    Types Of Viral Gastroenteritis

    There are four different viruses that cause gastroenteritis. The most common cause of stomach flu in kids and infants is rotavirus. Adults can get rotavirus too, but the condition tends to be milder. A virus called norovirus is the most common cause of viral gastroenteritis in adults. Adenovirus and astrovirus are less common causes of viral gastroenteritis that occur more often in kids than adults.

    The stomach virus incubation period ranges from 12 hours to 10 days depending on the type of virus. How long does stomach flu last? Again, that depends on the type of virus, but it ranges from 1 day to 2 weeks.

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    Symptoms Of Influenza B

    Flu B symptoms are often said to be milder than symptoms caused by influenza A. However, flu B can be just as dangerous as flu A, especially in high-risk populations including people over 65.

    Flu A and B cause the same types of symptoms, so its impossible to tell which variety you have from symptoms alone. Flu B symptoms often come on quickly and last for about a week. These are the most common flu symptoms:

    Subtypes Of Influenza A Viruses

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    Influenza A viruses are divided into subtypes on the basis of two proteins on the surface of the virus: hemagglutinin and neuraminidase . There are 18 known HA subtypes and 11 known NA subtypes. In birds, 16 HA and 9 NA subtypes have been identified. Many different combinations of HA and NA proteins are possible. For example, an A virus designates an influenza A virus subtype that has an HA 7 protein and an NA 2 protein. Similarly, an A virus has an HA 5 protein and an NA 1 protein.

    All known subtypes of influenza A viruses can infect birds, except subtypes A and A, which have only been found in bats. Only two influenza A virus subtypes Apdm09, and A, are currently circulating among people. Influenza A viruses have been detected and are known to circulate in seven different animal species or groups, including humans, wild water birds, domestic poultry, swine, horses, dogs and bats. In many other animal species, avian influenza A viruses have been reported to cause occasional infections, but do not regularly spread among them . Equine influenza A virus routinely circulates and can cause illness in horses, and canine influenza A virus routinely circulates and can cause illness in dogs.

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    What Are The Symptoms Of Influenza A

    If you have influenza A, you will have some or all of these symptoms:

    Children may also have abdominal pain, nausea and vomiting.

    Influenza A is a bit like a very bad cold, but a cold doesn’t usually cause aches and pains or a high fever.

    If your symptoms get worse instead of better, it’s best to see a doctor. You should also get help straight away if you feel chest pain, you are short of breath, dizzy or confused, or you are vomiting a lot.

    Why The Flu Vaccine Is Reformulated Every Year

    Welcome to National Influenza Vaccination Week, established in 2005 by the Centers for Disease Control and Prevention to promote vaccination awareness to the general public. In that spirit, Dr. Sebeen Razzaq-Ahmed and the team here at East Meadow Medical P.C. remind you to get your annual flu vaccine. You may be one of the many people we hear ask why they need to get vaccinated each year. Well, were here to answer that for you!

    Its no secret that influenza, commonly called the flu, is inconvenient, nasty, and downright deadly. The 2017-2018 flu season was among the worst on record, afflicting and killing more Americans about 80,000 than in any season dating back more than three decades. Because the flu is so common, not to mention so deadly, we always recommend that anyone whos able to gets an updated vaccine each year.

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    Can Flu B Be Prevented

    The best way to prevent the flu is by getting your annual flu vaccine. The flu vaccine protects against the most common flu strains. For the 2021-2022 flu season, the vaccine protects against two flu A, and two flu B strains.

    In addition to getting vaccinated, you can protect yourself from the flu by practicing good hygiene, including frequent hand washing. Since the pandemic started, flu cases have been lower, suggesting that COVID precautions such as social distancing and wearing masks might also help prevent flu.

    What Is Type B Flu

    What are the different types of flu vaccines?

    Type B influenza is only found in humans and people tend to see it as less severe than type A. This has been challenged in recent years however, and The Centers for Disease Control and Prevention reported that this could be equally as dangerous.

    B type flu viruses are divided into two lineages B/Yamagata and B/Victoria .

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    The Invaluable Contribution Of Nurses

    Across a variety of roles and specializations, nursing professionals fight viruses in numerous ways. Some of their methods are direct, such as preventing surgical infections. Others are legislative in nature, such as advocating for care equality by questioning imbalanced care delivery systems. Nurses also share their expertise with the public on a host of vital topics, such as care delivery models, infection prevention and the distribution of important resources.

    Public health nurses were involved in managing the severe acute respiratory syndrome outbreak in 2003. They did so by tracing contacts, educating the public regarding disease signs and symptoms and serving in research teams in related case control studies. Nursing researchers have also benefited HIV testing and prevention in Malawi via identifying the benefits of working with religious leaders to promote HIV testing and prevention behaviors. Additionally, nurses have developed family planning services in Kenya by providing childbearing families with the opportunity to space pregnancies to support the health of pregnant women. Finally, nurses have played a key role in West Africas Ebola outbreak by improving the protocols and levels of protection for health care workers.

    How Effective Is The Flu Shot

    The effectiveness of the flu shot is different each year. Between 2009 to 2020, the flu shot was, on average, around 40% effective in preventing the flu. The reason the flu shot does not have a high disease-prevention rate is because the influenza virus mutates, or changes over time. This is why people do not have lifelong immunity to the flu after getting sick with it. The bodys immune system may not be able to use antibodies made for a previous flu infection for a different flu virus strain.

    Since the flu virus changes each year, so does the vaccine. This is why you need a flu shot each year. Sometimes, the flu virus strains that are chosen dont completely match the virus strains that end up causing most infections during the flu season. This is why the vaccine isnt 100% effective. Even if you get sick with the flu, the flu vaccine can reduce how sick you get. Regardless, it is important to get vaccinated against the flu, since any decreased chance of infection is worth keeping you healthy.

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    Lesson #: Flu Strain Basics

    Okay, we know we’re not all biology majors, so we’re going to take this slow and start from the very beginning. One of the most important things for you to know is that there are four types of influenza viruses: A, B, C, and D. Influenza A and B viruses are the ones we know really well in fact, they’re the ones that cause those almost-annual seasonal epidemics in the United States. Influenza C typically causes a mild respiratory illness and doesn’t typically cause epidemics. Finally, influenza D mostly affects cattle and, at least for now, is not known to infect people. Anyway, more on the specifics strains later.

    The second most important thing for you to understand is how these viruses get their names. Influenza A viruses are all characterized based on two proteins on the outer shell of the virus: hemagglutinin and neuraminidase . Say those names ten times fast! These proteins both must be present in order for the virus to replicate, or reproduce. Hemagglutinin helps the virus attach to the cells in your body, and neuraminidase allows the virus to be released from the host cell once it has replicated ultimately spreading the infection.

    Phew still with us? Okay, good.

    What about those numbers, you ask? Well, they’re determined by the subtype, or secondary type, of hemagglutinin and neuraminidase proteins currently, there are 18 known hemagglutinin subtypes and 11 known neuraminidase subtypes , according to the CDC.2

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    The adjuvanted flu vaccine is sold under the names FLUAD and FLUAD Quadrivalent. Approved for use in the United States in 2015, the original form of FLUAD is a trivalent, but this flu season the FLUAD comes in a quadrivalent form as well. Because FLUAD Quadrivalent is new, supplies of the trivalent may be the only type of FLUAD available at certain locations.

    Either the high dose vaccine or the adjuvanted vaccine are both considered pretty equivalent at this point , says Conway. Its important that people in that older age group advocate for themselves and insist that they get one of those vaccines.

    For seniors worried that a stronger flu shot may be more painful, Dr. Winslow has some personal wisdom to share: I am 67 so I had the experience of getting the high dose vaccine myself just a couple of weeks ago, and Id like to reassure your readers that my arm was not particularly sore.

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    The Pandemic Of Influenza And Vaccination

    Every year, millions of people start talking about the influenza virus and getting their vaccines as the flu season approaches, which starts around the October-November period and reaches its peak between December and March. Therefore, public health officials around the world- and in the U.S in particular- are constantly challenged by properly preparing for the annual influenza dilemma, given that this viruses, and other respiratory viruses, are a serious health threat to the U.S population and the

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