Influenza A Virus Infection

What is Influenza A Virus Infection?

Influenza A virus infection is an infectious respiratory illness caused by influenza A virus, which belongs to the family of Orthomyxoviridae. Influenza A virus is responsible for the majority of human flu epidemics, which cause moderate to severe illness and can sometimes lead to deaths.

Infection by influenza A virus is typically spread from person to person via respiratory droplets when an infected person coughs or sneezes. It takes about 1-4 days for a person to develop symptoms after being exposed to the influenza A virus, and symptoms include fever, cough, sore throat, chills, muscle aches, and fatigue. Severe illnesses associated with influenza A virus infection can include pneumonia, bronchitis, and sinus and ear infections.

Treatment and Prevention of Influenza A Virus Infection

Antiviral drugs such as tamiflu can be used to treat influenza A virus infection, but they must be taken within 48 hours of symptom onset. Vaccines are the best method of prevention of influenza A virus infection. The Centers for Disease Control and Prevention (CDC) recommends that everyone aged 6 months and older receive the influenza vaccine each year.

Complications of Influenza A Virus Infection

Complications of influenza A virus infection can include bacterial pneumonia, ear and sinus infections, dehydration, and worsening of chronic medical conditions. People at high risk of serious flu complications include pregnant women, young children, and people with certain chronic health conditions, like asthma, diabetes, and heart and lung disease. Severe complications and death from influenza A virus infection can occur, although these cases are rare.

Signs and Symptoms of Influenza A Virus Infection

  • Fever
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Chills
  • Fatigue
  • Vomiting and diarrhea (more common in children)