Pneumococcal infections are caused by the Streptococcus pneumoniae (S. pneumoniae) bacterium. They can be mild or severe. There are more than 90 different strains of S. pneumoniae bacteria, which are known as serotypes.
S. pneumoniae enters the human body through the nose and mouth.
The symptoms of a pneumococcal infection can vary depending on the type of infection you have. Common symptoms include a high temperature (fever) of 38°C (100.4°F) or above, aches and pains, and a headache.
Pneumococcal infections usually fall into one of two categories:
These are described in more detail below.
Non-invasive pneumococcal infections include:
Invasive pneumococcal infections include:
People with a weakened immune system are most at risk of catching a pneumococcal infection. This may be because:
Other at-risk groups include:
Read more about the causes of pneumococcal infections.
Cases of invasive pneumococcal infection usually peak in the winter during December and January.
Non-invasive pneumococcal infections are usually mild and go away without the need for treatment.
More invasive types of pneumococcal infections can be treated with antibiotics, either at home or in hospital.
Read more about how pneumococcal infections are treated.
There are two different types of pneumococcal vaccine used:
The PCV protects against 13 types of S. pneumoniae bacteria and the PPV protects against 23 types. It is thought that the PPV is around 50-70% effective at preventing more serious types of invasive pneumococcal infection.
Read about pneumococcal vaccination and when pneumococcal vaccination is used.
The outlook for pneumonia in people who are otherwise healthy is good, but the infection can lead to serious complications in people who are very young, very old or have another serious health condition.
However, due to the introduction of the PCV in 2002, the number of people dying from complications that arise from pneumonia has fallen to around 7%.
The outlook for other types of invasive pneumococcal infections such as bacteraemia is generally good, although there is about a one in 20 chance that bacteraemia will trigger meningitis as a secondary infection.
If you have a pneumococcal infection, your symptoms will vary depending on the type of infection you have.
Some common symptoms include:
You should contact your doctor as soon as possible if you:
You should also contact your doctor as soon as possible if your child is:
You should also see your doctor if you have any of the risk factors that make you more vulnerable to developing a pneumococcal infection.
Read about causes of pneumococcal infections for more information about these risk factors.
The most serious type of pneumococcal infection is bacterial meningitis, which requires immediate admission to hospital for emergency treatment.
Bacterial meningitis has a number of early warning signs that can occur earlier than the other symptoms.
As the condition gets worse it may cause:
The symptoms of bacterial meningitis are different in babies and young children. Possible symptoms include:
You should immediately request an ambulance if you suspect that you or someone you know has bacterial meningitis.
Pneumococcal infections are caused by bacteria called **Streptococcus pneumoniae (S. pneumoniae).
There are more than 90 different strains of S. pneumoniae and some are much more likely to cause serious infection (virulent) than others.
Some strains can be easily killed by infection-fighting white blood cells, while others are resistant and likely to cause a more serious infection.
It is thought that between eight and 10 strains are responsible for two-thirds of cases of serious infections in adults, and most cases in children.
S. pneumoniae enter the human body through the nose and mouth, and an infection can be spread in the same way as a cold](https://www.your.md/condition/cold-common) or [the flu. This can be through:
It is important to emphasise that pneumococcal infections are far less contagious than a cold or flu. This is because most people's immune systems are able to kill the bacteria before they have the opportunity to cause an infection.
Outbreaks of pneumococcal infections can sometimes occur in environments where there are many people who have poorly functioning immune systems, such as in children's nurseries, care homes for the elderly and shelters for people who are homeless.
People with a weakened immune system, either due to their age or general health, are particularly at risk of developing a pneumococcal infection.
The bacteria can move from their throat to other parts of their body, such as the lungs, the blood or the brain. If this occurs, a more serious infection can develop.
People at higher risk include:
Several different tests can be used to diagnose pneumococcal infections. The tests you have will depend on your symptoms.
Some of the tests used are outlined below.
If a pneumococcal infection is suspected, your doctor will listen to your chest with a stethoscope. The fluids produced during an invasive pneumococcal infection often cause a distinctive crackling sound.
You may have a blood test to check for the presence of bacteria. A high number of infection-fighting white blood cells may indicate the presence of an infection. The blood sample can be sent to a laboratory so the bacteria that caused the infection can be identified.
Several different types of imaging tests may be used depending on your symptoms.
X-rays may be able to highlight the presence of fluid in the lung, which would indicate a lung infection. An X-ray uses radiation to produce images of the inside of the body.
Other imaging tests that may be used to investigate a potential pneumococcal infection include:
You may have a blood pressure test as a serious infection can often lead to a decrease in blood pressure.
A lumbar puncture test involves taking a sample of cerebrospinal fluid (the fluid that surrounds the brain and spine) from the base of your spine and checking it for the presence of bacteria. If the sample contains infection-fighting white blood cells and/or bacteria, it may indicate you have meningitis.
A urinary antigen test is a relatively new type of test used to help diagnose a pneumococcal infection.
It involves taking a urine sample and then carrying out a technique known as an immunochromatographic assay. This is able to detect the distinctive protein molecules that make up the outer shell of the S. pneumoniae bacteria.
The treatment you receive depends on whether you have an invasive or non-invasive pneumococcal infection. Antibiotics are often used to treat a serious infection.
Non-invasive pneumococcal infections, such as sinusitis or bronchitis, will usually clear up within a week without the need for treatment.
Drinking plenty of fluids, getting plenty of rest and taking over-the-counter painkillers, such as paracetamol, should help relieve your symptoms.
Read more information about treatment for specific types of pneumococcal infections:
If you have an invasive pneumococcal infection, such as pneumonia, a decision will be made about whether you are well enough to be treated at home or need to be admitted to hospital.
Most doctors use a scoring system, known as the CRB-65 score, to assess the potential seriousness of a case of pneumonia.
Each of the above criteria is given a score of either 0 or 1 depending on whether or not it is applicable. This scoring system is explained below.
Hospital admission is also recommended for:
If you are being treated at home, you will usually be prescribed a seven-day course of antibiotics. An antibiotic called amoxicillin is the preferred choice. If you are allergic to amoxicillin, alternative antibiotics such as doxycycline can be used.
The most common side effects of the antibiotics used to treat pneumonia are:
These side effects are usually mild.
Sometimes, doxycycline can make your skin more sensitive to the effects of sunlight. Therefore, you should minimise your exposure to direct sunlight and avoid using sun lamps and sun beds when taking doxycycline.
It is very important to finish your course of antibiotics, even if you start to feel better. Not completing the full course of antibiotics could cause the pneumonia to return.
If your symptoms are moderate, you can usually be treated with antibiotic tablets.
If your symptoms are severe, you will usually be given antibiotics through a drip into your arm. You may also be given fluids to stop you becoming dehydrated, and oxygen to help you breathe.
Depending on how well you respond to treatment, it may be possible to switch from a drip to antibiotic tablets after a few days.
Most people who are treated in hospital require a seven to ten-day course of antibiotics. The length of time it will take before you are well enough to return home will depend on your general state of health and whether you experience a more serious type of pneumococcal infection, such as meningitis.
It is usually recommended that you attend a follow-up examination six weeks after the start of your symptoms. This is to check the infection has not caused any serious or permanent damage to the affected parts of your body, such as your lungs.
The follow-up examination usually involves taking a chest X-ray so the state of your lungs can be assessed.
You can help prevent the spread of a pneumococcal infection by taking some simple hygiene precautions.
Pneumococcal vaccination - also known as the 'pneumo jab' is very effective at preventing pneumococcal infections.
There are two types of pneumococcal vaccination - one for children, known as the pneumococcal conjugate vaccine (PCV) and one for adults, known as pneumococcal polysaccharide vaccine (PPV).
All children are offered pneumococcal vaccination as part of their NHS childhood immunisation schedule.
It involves three injections - at two, four and 13-13 months old.
The pneumococcal vaccination for children is entirely safe, although about one child in 10 will experience some redness and swelling at the site of the injection and symptoms of a mild fever. However, these side effects will pass quickly.
Speak to your doctor or health visitor if you are not sure whether your child has received their pneumococcal vaccination.
Adults can have the pneumococcal vaccine or 'pneumo' jab on the NHS if they are in a high-risk group for developing a pneumococcal infection. Find out more about who should have the pneumococcal vaccine.
If you are eligible, your doctor surgery will contact you to arrange a vaccination. If they do not, contact your doctor to arrange an appointment.
Healthy adults usually only need one dose of the pneumo jab. However, if you have a weakened immune system or spleen disorder may need additional booster doses. Your doctor will be able to advise you about this.
After you've had the pneumo jab you may experience some pain and inflammation at the site of the injection. This should only last for one to three days. Less commonly, some people report the symptoms of a mild fever. Again, this should pass quickly.
Read more information about side effects of the pneumococcal vaccine.
There is an increasing body of evidence that suggests that people who drink an excessive amount of alcohol are at a greater risk of developing invasive pneumococcal infections.
Alcohol is known to suppress the immune system, the body's natural defence system that will attempt to prevent an invasive pneumococcal infection.
Therefore, the best way to lower your risk of developing a pneumococcal infection is to ensure that you stick to the recommended daily amounts of alcohol.
For men, the recommended daily amount of alcohol consumption is three to four units, and for women it is two to three units. A unit of alcohol is equal to about half a pint of normal-strength lager, a small glass of wine or a pub measure (25ml) of spirits.
Speak to your doctor if you are finding it difficult to moderate your alcohol consumption. Counselling and medication are available for people with an alcohol misuse problem.
Smoking is the single biggest risk factor for developing an invasive pneumococcal infection in otherwise healthy adults.
Research has found that almost 60% of previously healthy people who develop an invasive pneumococcal infection are smokers.
It is not known exactly why smoking makes a person more vulnerable to an invasive pneumococcal infection. One theory is that the chemicals contained in tobacco smoke disrupt the normal workings of the immune system and make it less efficient.
As well as reducing your risk of developing an invasive pneumococcal infection, giving up smoking will help reduce your risk of developing other serious health conditions, such as cancer, heart disease and stroke.
If you want to give up smoking, a good first step is to see your doctor. They will be able to provide help and advice about quitting.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.