Community acquired pneumonia

Community-acquired pneumonia (CAP) is a type of pneumonia that is contracted by a person with little contact with the healthcare system. The chief difference between hospital-acquired pneumonia (HAP) and CAP is that patients with HAP have been recently hospitalized. CAP is common, affecting people of all ages, and its symptoms occur as a result of oxygen-absorbing areas of the lung (alveoli) filling with fluid. This inhibits lung function, causing shortness of breath, chest pain, and a variety of other symptoms.

Causes

CAP is typically caused by a bacterial infection, most commonly Streptococcus pneumoniae. Other bacteria that may cause CAP include Haemophilus influenzae, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. Viruses, such as the influenza virus, and fungi can also cause CAP.

Symptoms

Symptoms of CAP include fever, cough with or without sputum production, shortness of breath, chest pain, and fatigue. Other symptoms, such as confusion or delirium, may be present in older adults or those with a severe infection.

Diagnosis

Diagnosis of CAP involves a combination of clinical history, physical examination, and diagnostic testing. Chest X-ray is commonly used to confirm the diagnosis and determine the extent of the infection. Blood tests, sputum cultures, and other tests may also be used to identify the causative organism.

Treatment

Treatment for CAP depends on the severity of symptoms and the causative organism. Antibiotics are commonly used to treat bacterial CAP. Antiviral medications may be used for viral CAP, and antifungal medications for fungal CAP. Supportive care, including rest, hydration, and symptom management, is also important.

Prevention

Prevention of CAP includes vaccination against common causative organisms, such as the pneumococcal and influenza vaccines. Good hand hygiene and avoiding close contact with sick individuals can also help prevent the spread of CAP.

See also

• Hospital-acquired pneumonia
• Pneumonia
• Streptococcus pneumoniae
• Influenza