Influenza, also known as flu or flu, is an acute viral infection of the upper or lower respiratory tract. It is characterized by fever, chills, muscle weakness and pain throughout the body, and varying degrees of pain in the head and abdomen.

Influenza is caused by any of several closely related viruses in the Orthomyxoviridae (a group of RNA viruses). Influenza viruses are classified into type A, type B, type C and type D. These main types usually produce similar symptoms but have no antigenic relationship, so infection with one virus does not confer immunity to other viruses. Virus A causes a large-scale influenza epidemic, while virus B causes a smaller localized outbreak. Virus C only causes mild respiratory illness in humans. The influenza D virus is not known to infect humans, but it has only been observed in pigs and cattle.

Influenza can affect people of all ages, but the highest incidence of the disease occurs in children and young people. The flu tends to occur more often in the colder months of the year. The infection is transmitted from person to person through the respiratory tract, such as inhaling droplets of infection caused by coughing and sneezing. When virus particles enter the human body, they will selectively attack and destroy ciliated epithelial cells in the upper respiratory tract, bronchi, and trachea.

The incubation period for the disease is one to two days, after which symptoms appear suddenly, accompanied by sudden and obvious chills, fatigue, and muscle aches. The temperature rose rapidly to 38-40 ° C (101-104 ° F). Diffuse headaches and severe muscle aches throughout the body, usually accompanied by a sore throat or spasmodic sensation. After three or four days, the body temperature began to drop and the person began to recover. Symptoms associated with respiratory infections, such as a cough and runny nose, may become more prominent and may be accompanied by a persistent feeling of weakness. Death can occur, usually in older people who are already weakened by other debilitating illnesses, and in most cases caused by complications such as pneumonia or bronchitis.

The antiviral drugs amantadine and rimantadine have a beneficial effect in cases of influenza involving type A viruses. However, resistance of viruses to these drugs has been observed, reducing their effectiveness. In the late 1990s, a new class of drugs was introduced, the neuraminidase inhibitors, which included oseltamivir (Tamivir) and zanamivir (Relexa). These drugs inhibit influenza A and B viruses. In addition, standard treatment continues to be bed rest, fluid intake, and use of pain relievers to control fever. It is recommended that children and adolescents with the flu do not take aspirin, because the use of aspirin to treat viral infections is linked to Reye’s syndrome, which is a very serious illness.

The way to improve individual protection against influenza is by injecting vaccines that contain two or more epidemic influenza viruses. These viruses are produced in chicken embryos and become non-infectious. Standard commercial preparations generally include influenza B viruses and various subtypes A.

Protection from a single vaccine rarely lasts more than a year, and annual vaccination is recommended, especially for those who are extremely sensitive to influenza or who they are weak and can cause serious complications in the event of infection. However, routine immunization is also recommended for healthy people.

It’s advisable to take Covid 19 Vaccine.