Viral pneumonia

Causes and Risks:
Pneumonia is a common serious illness that affects 1 out of 100 people annually. Viral pneumonia can range in seriousness from a mild illness to moderately severe ( respiratory syncytial virus) or sometimes fatal (Hantavirus pulmonary disease ). Influenza, parainfluenza, adenovirus, rhinovirus, herpes simplex , and cytomegalovirus may cause pneumonia. Viral infections are usually diagnosed when there are no bacterial organisms in a sputum culture (because it is difficult to isolate viruses in culture). Respiratory syncytial virus (RSV) and influenza are two of the more common viral infections that can cause pneumonia. Annual epidemics of both viruses occur with incubation periods between 1 and 4 days. The infections affect young children and the elderly more severely. Infants with congenital heart disease are at risk for severe or fatal RSV infection. The incidence is 2 out of 10,000 people.

Prevention:
Prophylactic vaccine for influenza A and B is available for high-risk people. No prevention is available for other viruses.

Symptoms:

Additional symptoms that may be associated with this disease:



Signs and Tests:



Treatment:
The objective of treatment is to provide supportive therapy, because viral infections will not respond to antibiotics. Supportive treatment includes humidified air, increased fluids, and supplemental oxygen, if indicated. Hospitalization may be necessary to prevent dehydration in young children and the elderly.

Occasionally, antiviral medications such as Ribavirin or Amantadine (for influenza A viruses) may be prescribed, especially for infants and young children.

Prognosis:
The outcome varies. Some infections will clear in 2 weeks with no residual damage while a life-threatening condition may exist in the elderly, in an immunosuppressed person, or in an infant with congenital heart defect.

Complications:
Acute respiratory failure is the main complication.

Call Your Healthcare Provider:
Call your health care provider if symptoms of viral pneumonia develop.


This is an illustration of the major features of the lungs and bronchial tree. The inset is of the alveoli. They are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.