Learn about influenza A

chinacdc.cn | Updated: 2023-03-14

What is influenza A?

Influenza viruses are divided into four types: A, B, C, and D. Influenza A is an acute respiratory infectious disease caused by the type A virus. The population is generally susceptible to the virus, which is highly contagious. Compared with influenza B, influenza A virus has many hosts in nature and is more prone to mutation. Many large-scale outbreaks of influenza (flu) in history are related to influenza A.

How does influenza spread?

Influenza is mainly transmitted through air droplets, and can also be transmitted via the mouth, nose and eyes. Contact with items contaminated by the virus may also cause infection.

In crowded, closed or poorly ventilated rooms, it can also be transmitted in the form of aerosols.

Symptoms of influenza A

Influenza A often causes symptoms more severe than the common cold. The infected are likely to experience a high fever — with body temperatures reaching 39°C or higher, chills and shivering. They may also experience muscle aches, fatigue and a loss of appetite.

Mild influenza and the common cold have similar symptoms, but the fever and general malaise caused by the former are more obvious. Severe flu cases may have serious associated complications, such as viral pneumonia, secondary bacterial pneumonia, acute respiratory distress syndrome, shock, and cardiovascular and nervous system conditions, and may even result in death.

How to treat influenza?

Patients are advised to rest at home and keep the room ventilated. Try to reduce contact with others to prevent infection.

The focus of treatment is to deal with the symptoms, such as fever and cough. In case of continuous high fever, accompanied by a severe cough, vomiting, and/or diarrhea, the patient should seek medical help.

Children under five years of age, the elderly, patients with chronic diseases, pregnant women or obese people are more likely to experience serious complications. They should seek medical help and use antiviral medicines under the guidance of doctors once infected.

How to prevent influenza A?

1.Pay attention to self-protection

Wear masks and maintain good hand hygiene. Refrain from going to crowded places during the flu season. Avoid close contact with people who have symptoms of respiratory illnesses as much as possible.

When sneezing or coughing, cover your mouth and nose with a handkerchief to prevent droplets from spreading to others. When going to the hospital for treatment, patients and companions need to wear masks.

2.Maintain environmental hygiene

Open windows to make sure indoor facilities are well ventilated. Regularly clean and disinfect frequently touched surfaces such as door handles and handrails.

3.Strengthen health monitoring in schools

Schools and kindergartens should strengthen monitoring. If any suspected influenza case appears, the sufferer should rest at home to reduce spread of the disease.

4.Receive influenza vaccines

The best time for vaccination is before the flu season. Receive influenza vaccines to reduce the probability of catching flu and developing severe and critical conditions. For pregnant women, the elderly, patients with chronic diseases, young children and other high-risk groups, they should get vaccination as soon as possible.