Difference Between Viral and Bacterial Pneumonia

Viral vs Bacterial Pneumonia

Pneumonia is an acute respiratory illness associated with recently developed radiological pulmonary shadowing, which may be segmental, lobar, or multilobar. It can occur both as a primary disease or, more commonly, as a complication that affects many seriously ill hospitalized patients. It can be resulted from different pathogenic organisms including bacteria, viruses, fungi etc.

Since all pneumonias share common characteristics, this article points out some of the differences between bacterial pneumonia and viral pneumonia with regard to their prevalence, pathogenic organisms, clinical symptoms and signs, investigations, complications and the management.

Bacterial Pneumonia

It usually causes acute air space pneumonia which results from infection by bacteria that multiply extracellularly in the alveoli. The commonest pathogen is streptococcus pneumoniae which accounts for 60% – 70% of the cases while the other bacteria includes legionella pneumophilia (2-5%), mycoplasma (1-2%), staphylococcus aureus (1-2%), etc.

The clinical symptoms and signs vary depending on the organism. For example, streptococcus pneumoniae shows rapid onset symptoms and produces rusty colour sputum while mycoplasma pneumonia has much more complications than the above. Rare complications of mycoplasma pneumoniae include haemolytic anaemia, erythema nodosum, myocarditis, pericarditis, meningoenchephalitis etc.

Diagnosis is made by clinical symptoms along with investigations including sputum examination, blood cultures, serology, and chest x ray findings.

Bacterial pneumonias are usually treated with antibiotics depending on the sensitivity of the particular organism.

Viral Pneumonia

Viral pneumonias can occur as a simple viral infection, or it can be commonly complicated by super added bacterial infection.

The common pathogens causing viral pneumonias are influenza, parainfluenza, and measles. RSV infections are commonly seen among infants. Varicella infections can cause severe pneumonia, if complicated.

Again the diagnosis is made by the clinical features and investigations.

Viral pneumonias can resolve spontaneously unless complicated. Usually antibiotics are added to the management to prevent supper added bacterial infections.

What is the difference between Bacterial Pneumonia and Viral Pneumonia?

• Bacterial pneumonias are more common than viral pneumonias.

• Bacterial pneumonias usually cause air space and interstitial pneumonia.

• Complications are much more common with bacterial pneumonia.

• Viral pneumonias are commonly complicated by bacterial infections.

• Bacterial pneumonias usually treated with antibiotics depending on the sensitivity of the organism while viral pneumonias can resolve spontaneously, unless complicated.