From the Guidelines
Bilateral pneumonia is most commonly caused by infectious agents, particularly bacteria like Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus, as well as viral pathogens such as influenza, respiratory syncytial virus (RSV), and SARS-CoV-2 (COVID-19) 1. The causes of bilateral pneumonia can be multifaceted, involving various infectious and non-infectious agents.
- Infectious causes include:
- Bacterial pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Klebsiella pneumoniae are common causes of community-acquired pneumonia (CAP) 1.
- Viral pathogens: Influenza, respiratory syncytial virus (RSV), and SARS-CoV-2 (COVID-19) can also cause bilateral pneumonia 1.
- Non-infectious causes include:
- Aspiration of stomach contents or foreign materials, which can lead to bilateral pneumonia, especially in patients with impaired consciousness or swallowing difficulties.
- Fungal infections, particularly in immunocompromised individuals.
- Chemical inhalation injuries and systemic inflammatory conditions. The bilateral nature of the infection indicates that both lungs are affected simultaneously, which often suggests either a more severe infection, a systemic condition, or inhalation of infectious particles that have reached multiple areas of the lungs 1. Risk factors that increase susceptibility to bilateral pneumonia include:
- Advanced age
- Smoking
- Chronic lung diseases
- Immunosuppression
- Recent hospitalization
- Mechanical ventilation It is essential to consider these risk factors and the potential causes of bilateral pneumonia when developing a treatment plan, as the bilateral involvement typically results in more significant respiratory compromise than unilateral pneumonia and may require more aggressive treatment approaches 1.
From the Research
Causes of Bilateral Pneumonia
The causes of bilateral pneumonia can be attributed to various pathogens, including:
- Bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus 2, 3, 4
- Viruses, with recent PCR-based studies identifying a respiratory virus in about 30% of cases of community-acquired pneumonia 3
- Other microorganisms, including Moraxella catarrhalis and Enterobacteriaceae 4
Bacterial Causes
Bacterial causes of bilateral pneumonia include:
- Streptococcus pneumoniae, which remains the most common cause of community-acquired pneumonia 3, 4
- Haemophilus influenzae, which is the second most common cause of community-acquired pneumonia 3, 4
- Staphylococcus aureus, which can cause severe pneumonia, including empyema 2
Viral Causes
Viral causes of bilateral pneumonia include:
- Influenza B virus, which can lead to pneumonia, as seen in a case report of a 32-year-old female with a history of mild persistent asthma 2
- Other respiratory viruses, which can cause pneumonia and may be identified through nucleic acid amplification technology 4
Other Factors
Other factors that may contribute to the development of bilateral pneumonia include: