Seasonal Influenza (FLU)

Gude Himabindhu^*
*Correspondence: Gude Himabindhu, Department of Biotechnology, Osmania University, Hyderabad, Telangana, India, Tel: 8143389651, Email:

Flu (Influenza Virus)

Seasonal influenza is an acute respiratory infection caused by influenza virus which circulates globally. Seasonal influenza is characterized by a sudden fever, cough (usually dry), muscle and joint pain, runny nose, severe malaise (feeling unwell), headache, sore throat. The cough can be severe and it may last more than 2 weeks. Most of the people affected will recover from fever and other symptoms within a week without any medication. But influenza can cause severe illness or it may leads to death especially in people at high risk.

Seasonal influenza is caused by the virus Influenzavirus. It occurs mainly in winter, while in tropical regions, influenza may occur throughout the year, causing outbreaks more irregularly. It spreads the disease easily and rapidly transmitted in crowded areas including schools and nursing homes. When an infected individual coughs or sneezes, droplets containing viruses (infectious droplets) are dispersed into air and spread up to 1 meter, and infect persons in close proximity who breathe these droplets in. The virus can be contaminated by hands. To prevent the transmission of disease, people should cover their mouth and nose with a tissue when coughing, should wash their hands regularly.

Incubation period, of this influenza is about 2 days, but also ranges from one to four days. Diagnosis of Influenza can be done clinically. RIDTs (Rapid influenza diagnostic tests) are used in clinical settings, but they might have lower sensitivity when compared to RT-PCR methods & their reliability depends largely on conditions under which they are used.

Treatment is recommended for 5 days minimum, but can be extended until there is satisfactory clinical improvement. Currently, influenza viruses are resistant to the adamantane antiviral drugs (such as rimantadine and amantadine), and therefore these are not recommended for monotherapy.

Vaccination is the most effective way to prevent the disease. Safe and effective vaccines are available and have been used for more than 60 years.

WHO recommends annual vaccination for below categories

• Pregnant women at any stage of pregnancy
• Children aged between 6 months to 5 years
• Elderly individuals (aged more than 65 years)
• Individuals with chronic medical conditions
• Health-care workers.

Apart from the vaccination and antiviral treatment, public health management includes personal protective measures

• Regular hand washing with proper drying of the hands
• Good respiratory hygiene – covering mouth and nose when coughing or sneezing, using tissues and disposing them correctly
• Early self-isolation of those feeling unwell, feverish and having other symptoms of influenza
• Avoiding close contact with sick people
• Avoiding touching one’s eyes, nose or mouth