Viral respiratory infections - including symptoms, treatment and prevention

There are many different types of viruses that can affect the breathing passages and cause respiratory illnesses such as a cold or flu-like illness.

Some of the common respiratory viruses include:

  • influenza virus
  • respiratory syncytial virus
  • parainfluenza virus
  • adenovirus
  • rhinovirus
  • human metapneumovirus
  • enterovirus.

Influenza virus infection and respiratory syncytial virus infection are not included here as they are covered elsewhere.

How viral respiratory infections spread

Viral respiratory infections are spread when an infected person talks, coughs or sneezes small droplets containing infectious agents into the air. The droplets in the air may be breathed in by those nearby. The viruses are also spread by direct contact with a sick person or indirect contact with hands, tissues or other articles soiled by nose and throat discharges.

Enterovirus and adenovirus infections are also spread through contamination of hands or objects with infected faeces.

Signs and symptoms

Signs and symptoms vary depending on the particular virus causing the illness. Most respiratory viruses cause cold-like symptoms or flu-like illnesses.

 Common signs and symptoms include:

  • fever
  • cough
  • runny nose
  • sneezing
  • sore throat
  • headache
  • muscle aches
  • fatigue
  • malaise (feeling unwell).

Most people improve within a few days.

Sometimes illness can result in complications. Types of complications depend on the particular virus but may include:

  • pneumonia (lung infection or inflammation)
  • bronchiolitis (inflammation of small air passages in the lungs)
  • croup
  • sinusitis
  • meningitis (inflammation of the lining of the brain and spinal cord)
  • encephalitis (inflammation of the brain).


Laboratory tests are not always necessary; however, the infection can be confirmed by laboratory testing of mucus from the back of the nose or throat.

Incubation period

(time between becoming infected and developing symptoms)

Usually 1 to 10 days, varies with the specific virus

Infectious period

(time during which an infected person can infect others)

The infectious period varies widely and depends on the specific virus. However, usually viral respiratory infections are usually most contagious during the first few days of symptoms. In some cases, people with an infection can shed (or release) the virus (and so remain infectious) for some time after they have recovered from the infection.


No specific treatment is required for mild viral respiratory infections. Most people recover with rest and drinking plenty of fluids. Paracetamol may be used for relief of symptoms but must be used according to the manufacturer’s instructions. Aspirin should not be given to children under 12 years of age unless specifically recommended by a doctor.

Antiviral medication may be used for severe or prolonged viral respiratory infections such as influenza virus infection. Antibiotics do not help even though they are often prescribed.

When to seek medical advice

Seek medical advice if you are concerned about your symptoms or have any of the following:

  • worsening symptoms
  • shortness of breath
  • difficulty breathing
  • confusion
  • inability to keep liquids down because of vomiting
  • symptoms of dehydration (such as being dizzy when standing or passing much less urine than normal).


Viral respiratory infections can be prevented by the following measures:

  • If unwell with a viral respiratory infection, try to stay away from childcare, preschool, school and work until well.
  • Wash hands as soon as possible after sneezing or coughing and after contact with nose and throat discharges or articles soiled by these. Use soap and water or an alcohol-based hand rub.
  • Cover a cough or sneeze with tissue or arm. Dispose of used tissues immediately and wash hands afterwards.
  • Wipe down all frequently touched surfaces regularly with a cleaning cloth dampened with detergent, or with a large alcohol wipe.
  • Avoid sharing cups, glasses and eating utensils with people who have respiratory infections.

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