Viruses are thought to cause up to 30 percent of adult pneumonia cases. The condition can be hard to diagnose because it may start out with similar symptoms as the common cold; typical symptoms include low-grade fever, cough, and trouble breathing. Antibiotics don't work for this type of pneumonia, but antiviral drugs may provide relief.
What Is Viral Pneumonia?Pneumonia is an infection in one or both lungs. It can be caused by a number of different germs, including bacteria, viruses, and fungi. When caused by viruses, it is known as viral pneumonia.
What Causes It?Up to 30 percent of pneumonia cases in adults are thought to be caused by viruses. These organisms are the most common cause of pneumonia in children under the age of 5. Up to 35 percent of all cases in children are thought to be due to viruses (see Pneumonia in Children).
Some of the viruses known to cause viral pneumonia in adults and children include:
- Influenza viruses
- Parainfluenza viruses (which can cause croup)
- Human metapneumovirus
- Respiratory syncytial virus (RSV)
- Severe acute respiratory syndrome (SARS)
- Herpes zoster virus.
Most people get viral pneumonia within the community (this is called community-acquired viral pneumonia). Viral cases are less likely to happen within the hospital.
- A cough (it may be dry, but can also produce green or yellow phlegm)
- A rapid heart rate and/or breathing rate
- Fever (often low-grade)
- Trouble breathing
- Chest pain when breathing or coughing
- Shortness of breath.
Often, symptoms of pneumonia will begin a couple of days after a person has developed upper respiratory symptoms, such as runny nose, congestion, and sore throat.
(Click Viral Pneumonia Symptoms for more information on possible signs or symptoms of this illness.)