Bacterial pneumonia is an infection that causes inflammation in the lungs due to bacteria. It can cause symptoms such as a cough with phlegm, fever, and difficulty breathing.
It may develop after a cold or the flu that does not go away or gets worse over time. Streptococcus pneumoniae is the main bacterium associated with this type of pneumonia, although several other bacteria can also cause the infection.
Bacterial pneumonia can spread through coughing and sneezing for up to two days after treatment begins. Treatment can often be done at home with antibiotics prescribed by a doctor, although hospitalization may be recommended in some cases, especially for babies, children, and older adults.
Symptoms of bacterial pneumonia
The main symptoms of bacterial pneumonia are:
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Dry cough or cough with phlegm containing mucus, pus, or blood;
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High fever above 102.2°F (39°C);
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Chills or excessive sweating;
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Difficulty breathing or shortness of breath;
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Chest pain when coughing or breathing;
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Nausea or vomiting;
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General feeling of being unwell;
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Excessive fatigue.
Other symptoms may include headache or muscle or joint pain. Confusion can also occur, especially in adults over 65.
See microbiologist Marcela Lemos explain how to recognize the symptoms of pneumonia:
How the diagnosis is confirmed
Bacterial pneumonia is diagnosed by a pulmonologist or primary care doctor based on symptoms, medical history, and a physical exam. During the exam, the doctor may ask the person to breathe in and out while listening to the lungs with a stethoscope to check for abnormal breathing sounds.
To confirm the diagnosis, the doctor may order a chest X-ray or CT scan to evaluate the lungs and determine which areas are affected.
Other tests may include blood tests, such as a complete blood count or blood cultures, as well as a sputum test, bronchoscopy, or pleural fluid culture to identify the infection and determine which bacterium is causing the pneumonia.
Causes of bacterial pneumonia
The main bacteria associated with bacterial pneumonia are:
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Streptococcus pneumoniae;
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Klebsiella pneumoniae;
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Staphylococcus aureus;
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Haemophilus influenzae;
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Legionella pneumophila;
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Mycoplasma pneumoniae.
Identifying the bacterium responsible for the infection is important so that treatment can be appropriately targeted to the infectious organism.
Is bacterial pneumonia contagious?
Bacterial pneumonia can be contagious because some bacteria can spread from one person to another through respiratory droplets released when an infected person coughs, sneezes, or talks. However, not everyone exposed to these bacteria develops pneumonia.
How bacterial pneumonia spreads
One of the main ways bacterial pneumonia develops is when bacteria accidentally enter the lungs. This can occur through the mouth, from an infection in another part of the body, after choking on food, or when a cold or the flu gets worse.
Reduced immune function due to older age, chronic illnesses, or the use of certain medications can make it easier for bacteria in the respiratory tract to multiply. This can lead to infection and inflammation in the lungs, resulting in pneumonia.
In addition, some bacteria, such as Streptococcus pneumoniae and Mycoplasma pneumoniae, can spread through respiratory droplets released into the air when an infected person coughs, sneezes, or talks. However, the risk of transmission varies depending on the type of bacteria and is generally lower than with viral pneumonia.
This type of pneumonia is more common in children and older adults because their immune systems may be more vulnerable. It is also more common in people with lung conditions such as asthma, emphysema, and COPD.
How bacterial pneumonia is treated
Bacterial pneumonia should be treated under the guidance of a pulmonologist or primary care doctor. Treatment can often be done at home with rest and antibiotics for 7 to 14 days, as prescribed by the doctor.
In some cases, the doctor may recommend daily respiratory physical therapy to help clear secretions from the lungs and make breathing easier.
In more severe cases, when pneumonia is more advanced or affects babies or older adults, hospitalization may be necessary. Antibiotics may then be given directly into a vein, along with supplemental oxygen.