Influenza a is a common infectious disease that causes severe illness, especially in the very young and the elderly.influenza a In some cases, flu symptoms can lead to serious complications like pneumonia or heart attacks.influenza a It can also cause social disruptions and economic losses. Influenza viruses are constantly changing, and new strains emerge regularly. When a new strain of the virus appears that can be easily passed from person to person, it may cause a global outbreak of disease called a pandemic.
The flu virus spreads easily, from one infected person to another through droplets that contain the virus.influenza a These droplets are released into the air when a sick person coughs, sneezes or talks. They can then be inhaled by people nearby. The flu is very contagious and can spread to healthy people as well as those with weakened immune systems. Symptoms usually start within a day or two of contact with the virus and last about 7 days.
There are three types of influenza virus that can affect humans – A, B and C.influenza a Type A is the most common cause of influenza pandemics. It normally infects wild birds, but it can also infect domesticated poultry and other mammals such as pigs and horses. Type B and type C normally only affect humans.
Vaccines can help prevent the flu, which is why it’s important to get one each year.influenza a Vaccines protect against the most common strains of the virus that are expected to circulate that season. Vaccines are made by injecting dead or weakened versions of the virus into a person. The body’s natural defences then recognise the virus and fight it off.
Scientists study the genome of influenza viruses to track their changes over time.influenza a They can then use this information to predict what kind of vaccines are needed for each season. They can also identify new strains of the virus quickly.
Influenza A viruses are divided into subtypes and sub-clades based on the way that they share parts of their hemagglutinin (HA) protein.influenza a HA proteins are the main surface proteins on the influenza virus particle and they help it to attach to cells. Influenza clades and sub-clades are shown on phylogenetic trees.
There are several medications that can be used to treat the flu.influenza a These drugs include oseltamivir and zanamivir. They are both neuraminidase inhibitors and work by blocking the action of neuraminidase, which allows the influenza virus to spread from cell to cell. These drugs can be bought with a prescription and are recommended for those at high risk of developing more serious complications if they become infected. This includes the elderly and those living with underlying conditions such as asthma or heart disease. The drugs can be taken orally or as injections and can be effective when started early in the illness, ideally within 48 hours of the onset of symptoms. However, they are not suitable for children and should never be given to those who are breastfeeding or pregnant.