Pneumococcal disease is an illness caused by infection with the bacterium (‘germ’) Streptococcus pneumoniae.
These germs often live harmlessly in the throats of healthy people, particularly children, without causing illness. However, if they spread to other areas of the body, they may cause potentially deadly illnesses.
Pneumococcal disease is a leading cause of serious illness among Australian children under two years of age and persons over 70 years of age. It is a frequent cause of death in the elderly. The rates are higher among Aboriginal and Torres Strait Islander children, especially in central Australia.
Pneumococcal infection is an important and common cause of middle ear infection, but may also cause pneumonia, meningitis (infection of the lining of the brain), and septicaemia (‘blood poisoning’).
Pneumococcal meningitis and pneumococcal septicaemia are both forms of ‘Invasive Pneumococcal Disease’ (IPD).
There are at least 90 different strains of Streptococcus pneumoniae. Some of these are regular causes of IPD in Australia. Immunisation against these strains greatly reduces the risk of disease. Vaccines are available to help protect against the strains that cause most disease.
Invasive pneumococcal disease – particularly septicaemia and meningitis – is a very serious illness.
Almost all people with IPD (children and adults) will be obviously sick, and in need of urgent medical care.
Streptococcus pneumoniae can cause a range of illnesses, depending on which part of the body is infected. These include:
The Pneumococcus bacteria usually lives harmlessly in the nose and throat of healthy people, especially young children (up to half of young children in winter). In some people (particularly those at increased risk), the Pneumococcus bacteria invades the body or blood stream causing pneumococcal disease.
The pneumococcal germ passes from one person to another in droplets from the upper throat or nose. These get spread directly when someone with the germ in their throat sneezes or coughs close to someone else. It may also be possible to spread it by kissing and from contaminated objects, such as toys.
Most of the time, this doesn’t cause any illness. However, vulnerable people may develop pneumococcal disease. The immune system is unable to keep the bacteria in check, which then multiply out of control and spread to other areas of the body.
Pneumococcal disease occurs most commonly in the colder months in Australia. Young children who have higher rates of carriage and don’t always cover their mouth when sneezing or coughing are more likely to pass the bacteria on to the elderly or those with specific risk factors.
When people do get sick with pneumococcal disease, it is rarely possible to be sure where or how they caught their infection.
The World Health Organization (WHO) states that pneumococcal disease is the world’s number 1 vaccine-preventable cause of death among infants and children younger than 5 years of age.
Pneumococcal disease is a leading cause of serious illness among Australian children under two years of age and persons over 70 years of age. The rates are higher among Aboriginal and Torres Strait Islander children, especially in central Australia.
Immunisation can reduce the risk of infection, especially in young children, where it is on the routine vaccine schedule.
Pneumococcal disease is also an important cause of pneumonia in adults 70 years of age or over. Older people are especially at risk of death from this disease. It is estimated to kill around one million people worldwide every year.
While pneumococcal disease can occur at any time, infections seem to be more common during winter and spring. Young children, older people and people with impaired immune systems and chronic diseases are among the most susceptible.
Immunisation can reduce the risk of infection, especially in young children, where it is on the routine vaccine schedule.
There are at least 90 different strains of Streptococcus pneumoniae. Only some these are regular causes of IPD in Australia. Immunisation against these strains greatly reduces the risk of disease. Vaccines are available to help protect against the strains that cause most disease.
Treatment is urgent, and involves an antibiotic, usually given intravenously, and hospital care, sometimes intensive care.
Treatment options for pneumococcal disease include:
Pneumococcal disease is caused by the bacterium, Streptococcus pneumoniae (pneumococcus). Infection usually starts with a colonising event in the nose and throat, which is asymptomatic, and most infections do not amount to anything beyond colonisation. Some, however, spread locally or invasively to cause disease. Certain pneumococcal diseases are non-invasive, such as middle-ear infections (otitis media), sinusitis or bronchitis.4 Others are invasive, involve the blood or a major organ and are potentially life-threatening. Examples of invasive pneumococcal diseases (IPDs) include septicaemia (sepsis), meningitis or bacteraemic pneumonia. Pneumococci usually possess a polysaccharide capsule, which occurs as more than 90 serotypes, and immunity to the organism is capsule typespecific. Although many serotypes cause disease, only a few cause most infections. The predominant serotypes vary with age, time and geography.
Pneumococcal disease is mainly treated using β-lactam antibiotics, though pneumococci bacteria are increasingly developing antibiotic resistance. Strains have variably become resistant to penicillin, cephalosporins, macrolides, tetracycline, clindamycin and the quinolones.
Transmission occurs through respiratory droplets from people with pneumococcal disease or healthy carriers. If the infected person coughs or sneezes in close proximity of others, infection may spread. Following acquisition, the bacterium becomes established in the nasopharynx of the host with asymptomatic colonisation. It may then spread to other parts of the body where it causes disease. The bacteria’s polysaccharide capsule helps it to resist phagocytosis. If no anti-capsular antibody pre-exists, alveolar macrophages cannot kill the pneumococci.
The major clinical syndromes of IPD are pneumonia, septicaemia and meningitis.2,8 Symptoms of pneumonia include fever, chills, coughing, rapid or difficult breathing, chest pain, rigors, tachycardia, rusty-coloured sputum, cough productive of mucopurulent, dyspnea, tachypnea, hypoxia, or, in older patients, confusion or low alertness. Meningitis, although least common, is the most severe category of IPD and is often fatal.2,3 Symptoms include a stiff neck, fever, lethargy, nuchal rigidity, cranial nerve signs, seizures, coma, headache, pain when looking into bright lights, confusion, or, in babies, poor eating and drinking, low alertness or vomiting. Septicaemia is the most common IPD among young children. Symptoms include fever, chills and low alertness. By 12 months, most children have also experienced otitis media. Pneumococcus is detected in 28 to 55% of middle ear aspirates from children with otitis media. Symptoms include ear pain, a red, swollen eardrum, fever, and sleepiness. Complications of otitis media may include mastoiditis and meningitis.
Anyone can contract IPD though some groups are at heightened risk. These include people younger than two years of age or older than 70; children in group childcare; children in developing countries; nursing homes residents; smokers; people suffering from chronic conditions such as lung, heart, liver or kidney disease, asthma, diabetes or alcoholism; people with cochlear ear implants, cerebrospinal fluid (CSF) leaks or impaired immunity for any reason, including those arising from conditions such as HIV/AIDS, cancer or a damaged or absent spleen; and Aboriginal and Torres Strait Islander people.
Immunocompromised persons who are unable to mount an adequate immune response to pneumococcal capsular antigens, including those with asplenia, have the highest risk of IPD.1,2,4 Aboriginal and Torres Strait Islander people have a disproportionately high burden of IPD.1,12,13
Vaccination is strongly recommended for groups at risk.
IPD still causes serious illness and occasional deaths.
By 2011 this had become much less common than it was before the widespread introduction of infant pneumococcal vaccine in 2005. However, several harmful strains of the pneumococcal germ continue to circulate and cause illness.
The introduction of Prevenar 13® in 2011 is expected to provide protection against the most important of these remaining strains. Routine vaccination of children under the age of three is recommended.
People aged over 70 years
Pneumococcal disease is an important cause of pneumonia in adults aged 70 years or older. The elderly are especially at risk of serious illness and death from this disease.
People with underlying medical risk conditions
Adults and children with the following serious medical conditions are at a greater risk of life threatening infection and hospitalisation from pneumococcal disease:
– people with chronic illnesses such as diabetes, heart, lung or kidney disease
– people without a spleen or whose spleen does not work properly
– people with serious problems with their immune system
– Aboriginal and Torres Strait Islander people
All Aboriginal and Torres Strait Islander people over the age of 50 should be offered pneumococcal vaccine.
There are two different types of pneumococcal disease vaccines – pneumococcal conjugate vaccine (PCV) and pneumococcal polysaccharide vaccine (PPV).
23-valent pneumococcal polysaccharide vaccine (23vPPV)
23vPPV contains capsular polysaccharides derived from the 23 most frequent or most virulent types of S. pneumonia. PPV induces significant immune responses in immunocompetent adults, including the elderly, with no substantial differences in immune response between older and younger subjects, but poor responses in the immunocompromised.15 23vPPV is poorly immunogenic for most serotypes in children aged <2 years and does not induce immune memory.
Pneumococcal conjugate vaccines (PCV)
The immunogenicity of capsular polysaccharides can be enhanced by conjugation to carrier proteins.
PCV formulations vary in the number of pneumococcal serotypes included and the conjugating proteins used. Pneumococcal conjugate vaccines are immunogenic in young infants and can induce an immune memory response.
The dose of pneumococcal conjugate vaccines (10vPCV, 13vPCV) is 0.5 mL, to be given by IM injection, in the opposite limb to other injectable vaccines, if possible.
The dose of pneumococcal polysaccharide vaccine (23vPPV) is 0.5 mL, to be given by either IM or SC injection, in the opposite limb to other injectable vaccines, if possible. The IM route is preferred, as a 3-fold greater rate of injection site reactions is found following administration of 23vPPV by the SC route.15 A vaccine dose administered subcutaneously does not need to be repeated.
– 10vPCV (Synflorix) is registered for use in infants and children aged 6 weeks up to 5 years.
– 13vPCV (Prevenar 13) is registered for use in infants and children aged 6 weeks up to 17 years and adults aged ≥50 years.
– 23vPPV (Pneumovax 23) is registered for use in children aged ≥2 years and in adults.
Pneumococcal disease vaccination is recommended for all children < 5 years of age and is funded by the National Immunisation Program. Children > 5 years and adults with medical conditions associated with an increased risk of invasive pneumococcal disease should receive pneumococcal disease vaccinations. Non-indigenous adults ≥ 70 years and Indigenous adults ≥ 50 years should routinely be offered pneumococcal disease vaccination. The type and number of doses of pneumococcal disease vaccination vary in different age groups and risk groups. See the Australian Immunisation Handbook for further details.
23vPPV is not routinely recommended for pregnant or breastfeeding women – deferral of vaccination with 23vPPV until after delivery is recommended unless there is an increased risk of IPD. 23vPPV may be given to breastfeeding women.
Data on use the use of 10vPCV and 13vPCV during pregnancy or lactation are not available.
The PneumoSmart Vaccination Tool has been created using the pneumococcal disease vaccination recommendations in the Australian Immunisation Handbook online edition, and has been developed to assist GPs, medical specialists and other immunisation providers to comply with them.
Access the PneumoTool here.
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Page published: 8 March 2017
Page updated: 1 July 2020