The bacterium Streptococcus pneumoniae (S. pneumoniae), which is also known as pneumococcus, causes pneumococcal disease.
Invasive pneumococcal disease is a life-threatening condition that is fatal in 10 percent of cases. Older people and those with underlying medical conditions have a higher risk than others of serious complications.
Regular vaccinations can prevent many types of pneumococcal disease and the potential complications that may arise.
There are two main types of pneumococcal disease: noninvasive and invasive with noninvasive being the less serious.
Noninvasive pneumococcal diseases
Pneumococcal disease can cause a mild infection, bronchitis, or a more serious illness.
These occur outside the major organs or the blood.
S. pneumoniae can spread from the nose and throat to the upper and lower respiratory tract.
The bacteria can cause:
- Otitis media: This causes inflammation of the middle ear. Symptoms usually include fluid in the middle ear, swelling of the eardrum, and earache. If the eardrum becomes perforated, pus may drain into the ear canal.
- Bronchitis: Acute bronchitis is an inflammation of the airways, resulting in a cough with the production of mucus. It usually lasts up to 3 weeks and often affects children below the age of 5 years.
- Sinusitis: This is a common condition causing inflammation of the sinuses in a person's skull. Its symptoms include pain, swelling, and tenderness around the cheeks, eyes, and forehead.
Invasive pneumococcal diseases
Invasive pneumococcal diseases (IPDs) are more serious than the noninvasive type and occur inside a major organ or in a person's blood.
- Bacteremia: A bacterial infection of the blood causes this condition and can be fatal. It often progresses rapidly to sepsis. Symptoms include fever, chills, and reduced alertness.
- Sepsis: This is a potentially life-threatening infection response by the body. Symptoms include fever, chills, clammy skin, confusion, a rapid heart rate, difficulty breathing, and severe pain.
- Meningitis: This is an inflammation of the meninges, the three membranes that cover the brain and the spinal cord. Symptoms include a stiff neck, a headache, confusion, sensitivity to light, and a fever.
- Pneumonia: This is a serious lung disease. Symptoms include chest pain, difficulty breathing, a cough, a fever, and chills.
Other infections that may occur are:
All IPDs need urgent medical treatment.
When diagnosing pneumococcal diseases, a doctor will ask about the symptoms and carry out a physical examination.
Depending on how serious the symptoms are, and which part of the body they affect, the doctor may also recommend some tests.
Tests may include:
A chest X-ray: The image produced by an X-ray may reveal a "shadow" that indicates pneumonia, or fluid in the pleural cavity, also a sign of pockets of pus called empyema.
Lab tests: A cerebrospinal fluid test (CSF) by lumbar puncture can detect meningitis. The doctor may also want to test the person's sputum, plus fluid from the lungs, joints, bones, around the heart, or fluid from an abscess.
If the infection could be serious, doctors are likely to begin treatment and prescribe a course of antibiotics before they receive the results of these tests.
Anybody can get pneumococcal disease, but some people have a higher risk of the infection or its complications than others.
Those at higher risk include:
- anyone under 2 years old or more than 65 years old
- anyone with an underlying medical condition
- people with a weakened immune system
- those with chronic diseases, such as diabetes, heart disease, kidney disease, alcohol use disorder, spleen dysfunction
- people who live in long-term care facilities
- anyone who smokes tobacco
- people with a hearing aid known as a cochlear implant
How does it spread?
Coughing and sneezing in public places can spread the infection.
S. pneumoniae bacteria are common in the throats and noses of children.
Bacteria can spread through droplets in the air, for example, when a person with the infection coughs or sneezes. The bacteria do not spread through contaminated food or water.
Most people who become exposed to the bacteria have no symptoms because their immune system stops the germs from moving to another part of the body.
However, if a person has a weak immune system, the bacteria can move from the throat to the lungs, blood, sinuses, middle ear, or the brain. This can lead to a potentially severe infection.
A weak immune system can happen if a person:
- has a condition that affects the immune system, such as HIV or AIDS
- is taking medication to suppress the immune system, for example, after a transplant or for an autoimmune condition
- is undergoing certain medical treatments, such as chemotherapy
- contracts another serious infection, such as influenza
Vaccination may be appropriate for older people, children, and those with a weakened immune system.
There are at least 90 strains of S. pneumoniae, and no vaccine can protect against them all. However, vaccines can help prevent infection by the most common strains of the bacteria.
Two vaccines are known as:
- pneumococcal conjugate vaccine (PCV13)
- pneumococcal polysaccharide vaccine (PPSV23)
Doctors recommend certain routine vaccinations to protect children and older adults from pneumococcal disease.
Who needs immunization?
The Centers for Disease Control and Prevention (CDC) recommend the following vaccinations:
- PCV13 for all children under 2 years of age.
- PCV13 and PPSV23 for all adults aged 65 years and over.
- PCV13 and PPSV23 for those aged from 2 to 64 years old with certain medical conditions.
- PPSV23 for people aged 19 to 64 year old who smoke cigarettes or have asthma.
After the injection, people may see some redness and swelling at the injection site and experience a mild fever. These symptoms usually go away quickly and are not usually serious.
A doctor can give more advice about who should have a vaccination and how often.
Who should not have the vaccine?
Anybody who has had a severe allergic reaction to PPSV23, PCV13, or PCV7, which is an older version of the conjugated vaccine, from one dose should not have another one. Severe allergic reactions are rare, however.
People who are severely or moderately ill with another infection should receive the vaccine when their condition improves.
The vaccines cannot cause pneumococcal disease as they are composed of bacterial capsule components.
The treatment will depend on how the bacteria affect the individual.
Noninvasive pneumococcal infections
Often, a person will recover from a mild pneumococcal infection without any treatment. In some cases, however, a doctor will recommend antibiotics to prevent complications from occurring.
Invasive pneumococcal infections
Antibiotics are necessary to treat and possibly to prevent invasive pneumococcal disease.
A doctor will prescribe antibiotics for an IPD.
They may prescribe broad-spectrum antibiotics immediately, before finding out exactly which bacteria are involved, as waiting may be dangerous.
If tests show what bacteria are causing the problem, the doctor may then change the antibiotics to target the specific microbe.
Depending on how severe the infection is, a person must take these either by mouth or intravenously (IV).
Growing antibiotic resistance means that some antibiotics no longer work for some people and some conditions, and so a doctor may prescribe a combination of antibiotics.
Some people who have a more severe illness will need to spend time in the hospital.
If a person's symptoms are severe, they may need supplemental oxygen and other forms of treatment, depending on what type of infection they have.
There are different types of pneumococcal disease. The impact of these diseases depends on their type and the health of the person it affects.
Some of these diseases can be mild and pass without treatment, or they may become serious and life-threatening.
Treatment is with antibiotics, but vaccination is essential for preventing many types of pneumococcal diseases in children, older people, and those with weakened immune systems.