Is pneumonia contagious?

Pneumonia is a form of acute respiratory infection that affects the lungs. The lungs are made up of small sacs called alveoli, which fill with air when a healthy person breathes. When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake. Pneumonia can affect either one or both lungs.  It is called lobar pneumonia if it affects one or more sections (lobes) of the lungs; and bronchial pneumonia (bronchopneumonia) if it affects patches throughout both lungs.

According to the WHO, Pneumonia is the single largest infectious cause of death in children worldwide. Pneumonia killed 740 180 children under the age of 5 in 2019, accounting for 14% of all deaths of children under five years old but 22% of all deaths in children aged 1 to 5. Pneumonia affects children and families everywhere, but deaths are highest in South Asia and sub-Saharan Africa.

Approximately 1 million adults in the United States are hospitalized each year for pneumonia and 50,000 die from the disease. It is the second most common reason for being admitted to the hospital, with childbirth as number one. It is the most common reason children are admitted to the hospital in the United States. In terms of proportion, about 24.8 cases per 10,000 adults in the United States are diagnosed with pneumonia and it is the eighth leading cause of death and first among infectious causes of death. As many as 23% for patients admitted to the intensive care unit of hospitals with pneumonia die. All people with other disease conditions are at risk for pneumonia, but specific risk factors exist for children less than 2 years, children in daycare centers, people greater than 65 years, smokers, intake of some antibiotics in previous 90 days, alcohol use disorder, chronic medical conditions, and immune-suppression. The COVID-19 pandemic has also caused an increase in pneumonia cases especially in the older population.

What causes pneumonia?

Pneumonia can be caused by Viruses, bacteria, and fungi. In the United States, common causes of viral pneumonia are influenza, respiratory syncytial virus (RSV), and SARS-CoV-2 (the virus that causes COVID-19). A common cause of bacterial pneumonia is Streptococcus pneumoniae (pneumococcus). A special type of bacteria called mycoplasma also causes pneumonia. Apart from the bacteria, viruses, and fungi, there are many other causes of pneumonia and they are often named according to the organisms that cause them. However, practically, it is not always possible to able to find out which germ caused someone to get sick with pneumonia.

What are the types of Pneumonia?

Pneumonia can be classified based on how a person contacts it. It can be classified as the following:

  • Community-acquired pneumonia, which is when someone develops pneumonia in the community (not in a hospital). 
  • Healthcare-associated pneumonia, which is when someone develops pneumonia during or following a stay in a healthcare setting. Healthcare settings include hospitals, long-term care facilities, and dialysis centers. 
  • Ventilator-associated pneumonia, which is when someone gets pneumonia after being on a ventilator, a machine that supports breathing. The bacteria and viruses that most commonly cause pneumonia in the community are different from those in healthcare settings.

What are the symptoms of pneumonia?

The symptoms of pneumonia often depend on the organism responsible for the disease. These symptoms may vary but most often overlap with each other, making distinguishing between them difficult. Except in some cases. viral pneumonias usually show less symptoms and are less severe than bacterial pneumonias.

Bacterial pneumonia causes symptoms like:

  • Bluish color to lips and fingernails
  • Confused mental state or delirium, especially in older people
  • Cough that produces green, yellow, or bloody mucus
  • Fever
  • Heavy sweating
  • Loss of appetite
  • Low energy and extreme tiredness
  • Rapid breathing
  • Rapid pulse
  • Shaking chills
  • Sharp or stabbing chest pain that is worse with deep breathing or coughing
  • Shortness of breath that gets worse with activity

If the cause is from viral pneumonia, the early symptoms are the same as those of bacterial pneumonia, which may be followed by:

  • Headache
  • Increasing shortness of breath
  • Muscle pain
  • Weakness and
  • Worsening of the cough

Mycoplasma pneumonia has somewhat different symptoms, which include a severe cough that may produce mucus.

Is pneumonia contagious?

A disease is considered contagious when it can be spread from an infected individual to another who previously did not have the disease. Depending on the cause of pneumonia, it can be contagious. Pneumonia caused by bacteria or viruses can be contagious when the disease-carrying organisms are breathed into the lungs, while that caused by fungi, chemicals, and other causes are largely not contagious. Viral pneumonias are usually more contagious than bacterial pneumonias.

Usually, the organisms spread person to person by contact with an infected person’s mouth or when fluid containing the pneumonia bacteria or virus are launched in the air when someone coughs or sneezes and then inhaled by others. Touching an object previously touched by an infected person with pneumonia or a tissue used by the infected person and then touching the mouth or nose can also cause pneumonia to be breathed into the lungs and developed. The infection may spread to other lobes of the lung, or even to the other lung. In severe cases, the organisms causing pneumonia may spread to other organs of the body and cause damage or even death.

How long is a person with pneumonia contagious?

Just like the transmission of pneumonia from one person to another is based on the underlying organism causing it, the period a person is contagious also depends on the underlying cause. A person with bacterial pneumonia, is still considered contagious until about the second day after starting to take antibiotics and disappearance of a fever (if it was present). In the cases of a viral pneumonia, a person is still considered contagious until they feel better and have been free of fever for several days. In summary, a person with bacteria is contagious anytime from within 24 hours to up to 2 weeks or 14 days after infection.

How to reduce the chances of spreading pneumonia?

People with pneumonia, can reduce the spreading it to other people by adopting measures like:

Limiting of contact with family and friends even during recovery from illness

Covering of the mouth and nose during coughing, promptly dispose of tissues in a closed waste container and coughing or sneezing into the elbow when tissues are not available.

Frequent washing of hands and


If you or your loved one have been diagnosed with pneumonia or have symptoms of the disease, do visit your healthcare provider who will prescribe some medications and home remedies for you and you will recover in no time. Remember to keep your loved ones safe by adopting measures that will prevent you from spreading the disease.