What Are The Types Of Influenza A
As well as infecting people, the influenza A virus can infect animals, including birds and pigs . In some cases, these types of influenza can be passed on to humans.
Bird flu: Avian influenza also known as ‘bird flu’ is a subtype of influenza virus A that mainly affects birds. The virus has caused serious infections in humans and deaths but has not been found in Australia.
Swine flu: This is a type of influenza A virus found in pigs. In 2009, a strain of flu virus known as H1N1 caused the respiratory infection in humans that was commonly referred to as swine flu. It spread rapidly around the world and became a pandemic. The 1918 flu pandemic was also caused by an influenza A H1N1 virus.
Difference Between Influenza A And B
Influenza A vs B
Influenza is the common viral infection, which is commonly called the flu. This infection is common to mammals as well as birds. The viruses are all belong to the group orthomyxoviridae. There are three types of influenza viruses. They are type A, B and C. Even though the virology may differ from one infection to the other, general features, symptoms, investigations and diagnosis, treatment, prevention and prognosis go along similar principles.
Full blood count may show a response to infection. Viral cultures may be used to confirm the diagnosis if doubts are there. Drinking a lot of fluids, bed rest, and good nutrition are very important to aid recovery. Antivirals are needed only in severe disease. Neuraminidase inhibitors and M2 inhibitors are the most commonly used antiviral drug classes. Prevention of influenza is difficult because of it can spread along many pathways. Good hygiene, hand washing, using separate utensils, and wearing masks may go a long way towards limiting spread. There is a flu vaccine available. It is recommended to healthcare workers, children, elderly, and people with long standing diseases. This vaccine can even be given to HIV/AIDS patients, post-transplant patients, and those who are on immuno-suppressive drugs. Because influenza viruses mutate and change rapidly, vaccination does not confer lifelong immunity. The protection lasts for about two to three years.
Influenza A is commoner than B.
Influenza Comes In A B And C Antigenic Virus Types
Influenza virus type A is further subdivided into subtypes pertaining to its variations. The variations of the virus are called the serotypes, while Influenza B and C have only one serotype. Serotypes are classified depending on the specific antibody-antigen reactions of the virus. The basis is the presence of proteins on the surface of the virus. HA-haemagglutinin and NA- neuraminidase) are glycoproteins, which composed the external structure of a virus. The number followed by the letter H and N represents the number of protein contents in each virus subtypes.
Aquatic birds are the favorite reservoir of most Influenza A virus known to cause Avian Influenza which can either be low or highly pathogenic based on the viral activity and its ability to cause diseases.
Influenza A virus subtypes posses a very unique characteristic with various genetic and antigenic differences. It means that some influenza virus can only infect birds and animals , some can infect humans, such as H1N1 and H3N2 which are the common cause of influenza that is currently in general circulation among humans and some can infect both. Mutation of influenza A viruses that are highly pathogenic imposes a constant threat of pandemic outbreaks.
Influenza type B virus only infects humans . The virus is known to evolve slower is less common than Influenza A. There are no identified cases of pandemics caused by an influenza B virus.
Recommended Reading: Do You Have To Get A Flu Shot
Treatments For Influenza A Or B
These two main types of flu viruses can also differ in their response to certain treatments. The antiviral medications zanamivir , oseltamivir , peramivir and baloxavir marboxil are active against and approved by the U.S. Food and Drug Administration for the treatment of influenza types A and B infections.
The antiviral medications rimantadine and amantadine are FDA approved only for treatment of influenza type A infections because they are not active against type B viruses.
The CDC does not, however, recommend amantadine or rimantadine as first-line treatment for type A influenza because of high levels of resistance to these drugs among circulating strains.
- These two main types of flu viruses can also differ in their response to certain treatments.
- The antiviral medications rimantadine and amantadine are FDA approved only for treatment of influenza type A infections because they are not active against type B viruses.
Which Type Of Bird Flu Is In The News
Health care professionals had been very vocal about the strain of avian influenza known as H5N1.
The reason H5N1 has caused so much alarm is its ability to pass from wild birds to poultry and then on to people. While wild birds are commonly immune to the devastating and possibly deadly effects of H5N1, the virus has killed more than half of the people infected with it. The risk of avian flu is generally low in most people because the virus does not typically infect humans. Infections have occurred as a result of contact with infected birds. Spread of this infection from human to human has been reported to be extremely rare.
Read Also: Where To Get Flu Shot With Medicare
What Is The Flu In Children
Influenza is a very contagious viral infection that affects the air passages of the lungs. It causes a high fever, body aches, a cough, and other symptoms. It is one of the most severe and common viral illnesses of the winter season. Most children are ill with the flu for less than a week. But some children have a more serious illness and may need to be treated in the hospital. The flu may also lead to lung infection or death.
What Causes The Flu In A Child
The flu is caused by flu viruses. Flu viruses are divided into 3 types:
Influenza types A and B. These 2 types of viruses cause widespread illness almost every winter. They often lead to more people needing to go to the hospital, and more people dying from the flu. Public health officials focus on stopping the spread of types A and B. One of the reasons the flu remains a problem is because the viruses change often. This means that people are exposed to new types of the viruses each year.
Influenza type C. This type of virus causes a very mild respiratory illness or no symptoms at all. It does not cause epidemics. It does not have the severe public health impact that influenza types A and B do.
A flu virus is often passed from child to child through sneezing or coughing. The virus can also live for a short time on surfaces. This includes doorknobs, toys, pens or pencils, keyboards, phones and tablets, and countertops. It can also be passed through shared eating utensils and drinking. Your child can get a flu virus by touching something that was touched by an infected with person, and then touching his or her mouth, nose, or eyes.
Also Check: How To Treat A Toddler With The Flu
A Vs B: Severity And Recovery
An uncomplicated infection with either influenza A or influenza B can cause symptoms that last around one week. Some people may still have a cough or feel fatigued after two weeks.
Some influenza A subtypes can cause more severe disease than others. For example, in the recent past influenza A viruses have been associated with more hospitalizations and deaths in children and the elderly than in other age groups, according to the CDC.
In the past, it was thought that infection with influenza A was more severe than infection with influenza B. However, a 2015 study in adults with influenza A and influenza B found they both resulted in similar rates of illness and death.
Additionally, in a Canadian study looking at children 16 years old and younger, influenza B infection was associated with a higher risk for mortality than influenza A.
Influenza C is regarded as the least serious of the three types that humans can get. It typically produces a mild respiratory illness in adults. But theres some evidence that it can cause serious respiratory illness in children under age 2.
The CDC estimates that each year, from 2010 to 2018, influenza infection resulted in between 9.3 and 49 million illnesses, 140,000 to 960,000 hospitalizations, and 12,000 to 79,000 deaths.
What Is Influenza A
Influenza A is a type of virus that causes influenza , a highly contagious respiratory illness. If you get it, you will need to rest at home and avoid infecting others. Vaccination can protect you against influenza A.
Although coronavirus , is a viral illness that has developed into a pandemic, the virus that causes COVID-19 is different from the one that causes influenza.
Both the influenza A and influenza B viruses circulate in the community and change continually, with new strains coming out each winter. This is why yearly vaccination is recommended.
Read Also: Cvs Pharmacy Flu Shot Records
Who Contracts Influenza A Or B
Another difference between influenza A and B is the range of animal hosts they infect in addition to people.
Wild and domestic birds are the natural hosts for nearly all influenza type A subtypes. Various A subtypes can also infect a variety of mammals including pigs, ferrets, horses, bats and humans, of course.
Influenza type B viruses infect humans almost exclusively, though they have been rarely found in other mammals such as seals. Influenza type B viruses do not infect birds.
- Another difference between influenza A and B is the range of animal hosts they infect in addition to people.
- Influenza type B viruses infect humans almost exclusively, though they have been rarely found in other mammals such as seals.
There Is No Difference Between Flu And Influenza
Influenza virus causes flu. It is an infectious respiratory disease that can be transmitted through airborne and droplets due to unethical coughing and sneezing from an infected individual or inhaling air infected with the virus.
Common signs of influenza include runny nose, cough, sore throat, headache, muscle pain, vomiting and diarrhea and fever . Most of the influenza viruses are quite aggressive and it can be deadly. It can lead to serious life-threatening complications when a persons immune system is sabotaged. People who are immunocompromised and with chronic ailments such as lung diseases, Cancer and HIV infection are at greatest risk for flu infection.
Flu virus invasion usually starts on the upper respiratory tract and can penetrate deeper into the lungs. Bronchitis and pneumonia are among serious complication from flu infection that may require hospitalization. In addition to this, there are some studies proved that antiviral medication had potency in combating flu virus in the first 24 to 48 hours of clinical symptom appearance.
For protection, flu vaccine is widely recommended to lessen disease-related casualties from specific strains of flu virus. It is administered through injection or via a nasal spray. However, the vaccine does not give a person lifetime immunity against influenza virus. It is given annually to keep away from the flu virus.
Also Check: Cvs Hanover Nh Flu Shot
The Difference Between Influenza A And B
- Influenza A is usually the more common form of the virus and tends to circulate early in the season, while influenza B is normally less common and shows up late in the season.
- This season, influenza B has been more common and is circulating earlier than in previous seasons.
- Influenza B in recent years has been disproportionately fatal in children, according to the CDC.
- Because influenza A can spread from animals to humans, it can cause pandemics. Influenza B is also very contagious, but only spreads between humans.
- Influenza B can be more common and more severe than influenza A in children. In the population as a whole, influenza A tends to be milder.
- Both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person.
There Are Actually Three Of Them
Aside from type A flu and type B flu, there is also type C flu. However, health authorities say that type C flu is something that causes only very mild flu symptoms. More importantly, its not responsible for flu epidemics and pandemics, and thats why we will focus on only the most notorious of the bunch, and they are type A flu and type B flu.
Yes, the flu virus is the one to blame for some of the moments in the history of mankind where so many human beings have died. For instance, back in 1918 theres the so-called Spanish Flu. In 1957 theres Asian Flu. Then theres Hong Kong flu in 1968. Not too long ago in 2004, theres whats known as Bird Flu.
In all of the above-mentioned cases of the flu, it is type A flu thats responsible. Needless to say, its far more dangerous than type B flu.
Recommended Reading: When Is Flu Season In Arkansas
What Does Treatment For Influenza B Typically Involve
The treatments for influenza B and A are also pretty similar. You can use prescription meds to help shorten the duration of your illness, as well as other medication and lifestyle changes to lessen the intensity of your symptoms.
- Antiviral medication: “These help to lower the duration of symptoms, and can help prevent serious complications,” says Dr. Shanker-Patel. There are currently 4 FDA-approved flu antivirals.
- Over-the-counter fever reducers: “These are for fever control, and other symptoms,” says Dr. Shanker-Patel, and include nonsteroidal anti-inflammatory drugs like NSAIDs and acetaminophen .
- Lots of rest and hydration
- Staying home
Difference Between Flu A And B
July 30, 2018 Posted by Ranidu
The key difference between Flu A and B is that the causative of Flu A is the Influenza A viral strain while that of Flu B is the influenza B viral strain.
Influenza viruses are a group of orthomyxoviruses that cause respiratory tract diseases. There are four main strains of these viruses as A, B, C and D. Influenza A and B are the commonest viral strains and cause flu A and flu B respectively. Therefore, the difference between these two conditions is in the infectious agent is the main difference between the two forms of flu.
Also Check: Flu And Pneumonia Vaccine Same Day
Classification Of Influenza Viruses
Influenza is caused by any of several closely related viruses in the family Orthomyxoviridae . Influenza viruses are categorized as types A, B, C, and D. These major types generally produce similar symptoms but are completely unrelated antigenically, so that infection with one type confers no immunity against the others. The A viruses cause the great influenza epidemics, and the B viruses cause smaller localized outbreaks. The C viruses cause only mild respiratory illness in humans. Influenza D viruses are not known to infect humans and have been observed only in pigs and cattle.
Influenza A viruses are classified into subtypes, and both influenza B and subtypes of influenza A are further divided into strains. Subtypes of influenza A are differentiated mainly on the basis of two surface antigens hemagglutinin and neuraminidase . Examples of influenza A subtypes include H1N1, H5N1, and H3N2. Influenza B viruses are subdivided into two major lineages, B/Yamagata and B/Victoria. Strains of influenza B and strains of influenza A subtypes are further distinguished by variations in genetic sequence.
A Vs B: Vaccine Coverage
The seasonal flu vaccine is developed many months in advance of flu season. The viruses selected for the vaccine are based on research into which strains will likely be most common.
Sometimes the circulating influenza viruses can mutate from one season to the next. Since experts must select the viruses to include in the vaccine months before flu season, there may not be a good match between the vaccine and the circulating viruses.
This can lead to a decrease in the effectiveness of the vaccine. But even when this happens, the vaccine still offers some protection.
Flu vaccines can be either trivalent or quadrivalent.
A trivalent vaccine protects against three flu viruses:
- H1N1 influenza A virus
- H3N2 influenza A virus
- influenza B virus
A quadrivalent vaccine protects against the same three viruses as the trivalent vaccine plus protection against an additional influenza B virus.
Influenza C virus isnt included in influenza vaccines.
Don’t Miss: Alka Seltzer Plus Cold And Flu Night While Breastfeeding
What Is Pandemic Influenza Preparedness
When an influenza pandemic emerges, WHO adheres to its six-phase preparedness plan. Phases 13 are the early stages in pandemic preparedness designed to prevent or contain small outbreaks. The 4th and 5th phases are characterized by urgency in implementation of mitigation procedures. Phase 6 is characterized by widespread disease and sustained transmission of the virus between humans.
Type A Influenza And Its Subtypes
Type A influenza viruses are divided into subtypes, based on the presence of two glycoproteins on the surface of the virus. These glycoproteins are called hemagglutinin and neuraminidase . About 18 hemagglutinins have been identified, although generally, only H1, H2, and H3 are found in human influenza viruses. There are more than 100 types of neuraminidase, but only N1 and N2 have been positively linked to influenza epidemics in humans.
The above image shows the features of an influenza virus, including the surface proteins hemagglutinin and neuraminidase . Following influenza infection or receipt of the influenza vaccine, the bodys immune system develops antibodies that recognize and bind to antigenic sites, which are regions found on an influenza viruss surface proteins. By binding to these antigenic sites, antibodies neutralize flu viruses and prevent them from causing further infection. Source: CDC.
Hemagglutinin and neuraminidase are also called antigens, substances that, when introduced into the body, stimulate the production of an antibody. Currently, there are two subtypes of influenza A viruses found circulating among human populations: influenza A and influenza A .
Wild Birds Provide the Usual Reservoirs
Zhejiang province, China . Shanghai, a city with a population of 24 million, is located on the northern tip of Zhejiang province. Source: Uwe Dedering, Wikipedia Commons.
Genetic Evolution of H7N9 Virus in China, 2013
Recommended Reading: Best Flu Vaccine For Over 65