Does influenza B cause pandemics?
Human influenza A and B viruses cause seasonal epidemics of disease (known as the flu season) almost every winter in the United States. Influenza A viruses are the only influenza viruses known to cause flu pandemics, i.e., global epidemics of flu disease.
Can influenza A cause pandemics?
Any novel influenza A virus, such as those of avian or swine origin, has the potential to cause an influenza pandemic.
Why can influenza cause pandemics?
When were the last flu pandemics? Pandemic influenzas are caused by a new strain of the influenza virus. Because the virus is new, humans do not have an immunity to it and the illness is usually more severe.
Which type of influenza can cause a pandemic?
Only type A influenza virus can cause a pandemic, because it is the only type that is found in both animals (pigs, birds, horses) and humans. Type A influenza is less genetically stable than type B.
Is flu A or B worse?
Type A influenza is generally considered worse than type B influenza. This is because the symptoms are often more severe in type A influenza than in type B influenza. Type A influenza is more common than type B influenza.
How long does flu B last?
The first symptoms of influenza (flu) virus B, including fever, chills, headache and body aches, often begin to go away after about 2 or 3 days. In some cases, these symptoms will last 5 days or longer.
Do pandemics last forever?
The truth of the matter is that pandemics always end. And to date vaccines have never played a significant role in ending them. (That doesn’t mean vaccines aren’t playing a critical role this time. Far fewer people will die from Covid-19 because of them.)
What has been the longest pandemic?
The H1N1 influenza A pandemic of 1918–1920 (colloquially, but likely inaccurately, known as the Spanish flu) remains the deadliest pandemic of the modern age, with estimates of mortality ranging from 17 million to 100 million from an estimated 500 million infections globally (approximately a third of the global …
When does the WHO declare a pandemic influenza?
The Pandemic will be declared when the new virus sub-type has been shown to cause several outbreaks in at least one country, and to have spread to other countries, with consistent disease patterns indicating that serious morbidity and mortality is likely in at least one segment of the population.
Why does influenza B not cause pandemics?
Influenza B viruses cause the same spectrum of disease as influenza A. However, influenza B viruses do not cause pandemics. This property may be a consequence of the limited host range of the virus – humans and seals – which limits the generation of new strains by reassortment.
What is the difference between a pandemic and an epidemic?
According to the Center for Disease Control and Prevention (CDC), the difference between an epidemic and a pandemic is that: Epidemic is a sudden outbreak of a disease in a certain geographical area. Pandemic is an outbreak of a disease that has spread across several countries or continents.