How Long Is Pneumonia Contagious?

Pneumonia is a common but serious lung infection that affects breathing capability in an individual. Pneumonia makes an individual weak because oxygen in the bloodstream decreases. In this infection, the air sacs in the lungs become swollen and fill up with fluid or pus. Pneumonia may be caused by bacteria, a virus, or fungi. The common symptoms of pneumonia include:

• Cough, usually with phlegm (a slimy substance from deep in the lungs)
• Fever
• Chills
• Shortness of breath
• Chest pain 
• Nausea and/or vomiting
• Diarrhea
• Weakness
• Generalized body aches and headaches

Usually, patients affected with pneumonia may cough or sneeze, which creates small respiratory droplets that contain the disease-causing organism. Other people may get infected if they breathe in those droplets. Most people who spend a short amount of time with someone who is sick may not get infected. However, the disease often spreads between people who live together because they spend a lot of time together such as schools, college residence halls, military barracks, nursing homes, and hospitals.

Bacteria are the most common cause. Several different types of bacteria can cause pneumonia, including:

• Streptococcus pneumoniae
• Legionella pneumophila (often called Legionnaires' disease)
• Mycoplasma pneumoniae
• Chlamydia pneumoniae
• Haemophilus influenzae

Viruses that infect the respiratory tract may cause pneumonia. Viral pneumonia is often mild and goes away on its own within a few weeks but sometimes may become serious and need immediate medical attention. An individual with viral pneumonia is usually also at risk of getting bacterial pneumonia. Different viruses that can cause pneumonia include:

• SARS-CoV-2, the virus that causes COVID-19
• Respiratory syncytial virus (RSV)
• Some common cold and flu viruses

Fungal pneumonia is more common in people who have chronic health problems or weakened immune systems. Some of the types include:

• Pneumocystis pneumonia (PCP)
• Coccidioidomycosis, which causes valley fever
• Histoplasmosis
• Cryptococcus

Pneumonia treatment depends on the type of disease-causing germ. It may take time to recover from pneumonia. Some people feel better within a week. For other people, it can take a month or more.

• Antibiotics are considered the treatment of choice for pneumonia because they can treat bacterial pneumonia and some types of fungal pneumonia. However, they may not work for viral pneumonia.
• Antiviral medicines such Tamiflu (oseltamivir) and Relenza (zanamivir) are prescribed for viral pneumonia.
• Antifungal medicines such as Diflucan (fluconazole), Sporanox (itraconazole), Ancobon (flucytosine), and Nizoral (ketoconazole) may be prescribed to treat other types of fungal pneumonia.
• Patients may be treated in a hospital if symptoms are severe or if they are at risk of complications such as a low blood oxygen level. Patients may need oxygen therapy in a few cases.