Pneumococcal disease

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Pneumococcal disease is caused by the Streptococcus pneumoniae bacteria. There are 90 types of Streptococcus pneumoniae producing a range of symptoms from relatively minor to very serious. Some types are more likely to cause infections in particular parts of the body than others, such as the sinuses (sinusitis) and in the ear (otitis media or middle ear infection).

If the pneumococcal bacteria pass into the blood, they can cause pneumonia and invasive pneumococcal disease including bacteraemia (blood infection) and meningitis (inflammation of the membranes covering the brain).

A brief history

The bacteria was first isolated and grown in the laboratory in 1886. Over the following 10 years it was shown to be main cause of pneumonia. The first pneumococcal vaccines used sugars from the outside of the bacteria to generate an immune response. However, children less than two years of age do not respond well to this type of vaccine and second-generation pneumococcal vaccines, that join the bacterial sugars to a protein, were developed.

NZ Situation

Pneumococcal disease occurs throughout the year but is more common in autumn and winter. Pneumococci are the leading cause of bacterial pneumonia in young children and adults aged 65 years and older.

In the years 1998-2005 the average yearly rate of invasive pneumococcal disease (IPD) in children less than 2 years of age was 100 cases per 100,000. Since introduction of the pneumococcal conjugate vaccine (PCV7) for children in 2008, the rate of IPD in this age group decreased by almost 71%.

Māori and Pacific children are affected by pneumococcal disease more than other ethnicities in New Zealand.

Carriage of pneumoococci is common in New Zealand children, they are likely to be the major reservoir for infection in adults.

In 2010 there was a reduction in IPD across all age groups in New Zealand. The commencement of immunisation of young children with PCV7 in June 2008 has reduced the number of children carrying the bacteria in their nose and throat, reducing spread of the bacteria and protecting some older children and adults who had not had the vaccine. This 'herd immunity' effect was also seen in the US after introduction of the pneumococcal conjugate vaccine.

Symptoms

Local infection can cause ear infections (otitis media) and sinusitis that are unpleasant and painful but not life threatening.If the pneumococcal bacteria pass into the blood, the early stages of serious pneumococcal infection may appear a bit like influenza with general aches, pains and fever, but can at times progress very quickly (within hours) and they almost always result in hospitalisation.

Pneumococcal pneumonia is the most common form of serious pneumococcal disease. Pneumonia starts with a sudden fever and shaking chills, chest pain, cough, shortness of breath and rapid breathing or grunting. As the infection worsens the heart rate increases and hypoxia (lack of oxygen) may occur. This can be life threatening.

Pneumococcal meningitis and bacteraemia are also very serious and need immediate medical attention. A baby or child with meningitis may have a fever, be irritable, refuse drinks or feeds, vomit, be sleepy or difficult to wake, dislike bright light, and/or have a headache. With bacteraemia they may only have a fever and be irritable.

The bacteria can occasionally infect the heart muscle and more rarely other sites in the body such as joints and the abdomen.

How do you get it?

Pneumococcal bacteria are carried in the nose and throat and are easily passed from person to person by coughing, sneezing and close contact. Not everyone who catches or carries pneumococcal bacteria gets sick from it.

What are the risks?
  • Ear infections are painful and complications can lead to deafness, often compounding into learning difficulties during childhood.
  • Streptococcus pneumoniae is the leading cause of bacterial pneumonia.
  • Pneumococcal meningitis is very serious, one quarter to half the children affected go on to have long term disabilities.
  • Pneumococcal infections can be difficult to treat particularly because some of the bacteria are resistant to antibiotics.

 

 

Who is the most at risk?
  • Healthy children less than 5 years of age and the elderly are at risk from pneumococcal disease but the highest risk of serious disease is for infants less than one year of age, Māori, Pacific Peoples and older people.
  • The risk of invasive pneumococcal disease for Māori is just over three times and for Pacific Peoples almost four times higher than the risk for NZ Europeans.
  • Being exposed to cigarette smoke, living in crowded conditions, and/or having some medical conditions can also increase the risk of pneumococcal disease.
  • Some people with medical conditions that affect their immune system have an increased risk of infection, e.g. their spleen has been removed or doesn’t work properly, and those who are immune compromised from a disease or treatment of a disease.
Treating the symptoms

Combination antimicrobial medication is the first line of treatment for all types of pneumococcal disease. However, drug resistant pneumococcal bacteria is an increasing problem.

In addition to antimicrobial medication strong anti-inflammatory medicine may be used to treat pneumococcal meningitis. If the person is not improving within 48 hours of treatment then a lumbar puncture, where a sample of fluid from around the spinal cord is collected, should be performed. The fluid can be checked for pneumococcus that can be tested to find out what antimicrobial drugs the bacteria is sensitive to.

Other treatment is supportive care and may include intravenous fluids, oxygen therapy, prevention of pressure points from lying in one position, maintainenance of hygiene and comfort.

Preventing the disease from spreading

It is extremely difficult to avoid coming into contact with such a common bacteria but good hygiene practices, covering coughs and sneezes, hand washing, and avoiding contact with smoking and crowded living conditions may help.

Babies born to mothers who have high levels of pneumococcal disease protection (antibodies) may be born with some protection from the disease. However, by two months of age almost one third of the maternal antibodies have gone and the majority by seven months of age.

Babies and young children cannot develop their own effective protection when they are exposed to pneumococcal bacteria in our environment until about two years old. They can develop effective protection when they receive the pneumococcal vaccine Prevenar 13® that is provided for free as part of the National Immunisation Schedule.

On-time immunisation at 6 weeks, 3 months, 5 months and 15 months of age is the best way to protect babies and young children from pneumococcal disease.

 

Risk of disease vs. vaccine side effects
Pneumococcal disease Effects of disease Side effects of vaccine

Pneumococcal infections are caused by the bacterium Streptococcus pneumoniae.

 

  • Sinusitis, ear infection (otitis media).
  • Pneumonia.
  • Blood infection (septicaemia).
  • Inflammation of the membranes around the brain (meningitis).
  • Around 3 people out of 10 cases with meningitis die.
  • Of the meningitis survivors, up to half will have serious disabilities.
Common side effects
  • Mild pain, redness and swelling around injection site.
  • Decreased appetite.
  • Increased or decreased sleep.
Uncommon side effects
Rare/very rare side effects
  • HIves.
  • Hypotonic, hyporesponsive episode (HHE) in infants.
  • Convulsion associated with fever.
  • Severe allergic reaction (anaphylaxis).

Pneumococcal disease is caused by the Streptococcus pneumoniae bacteria. There are 90 types of Streptococcus pneumoniae producing a range of symptoms from relatively minor to very serious. Some types are more likely to cause infections in particular parts of the body than others, such as the sinuses (sinusitis) and in the ear (otitis media or middle ear infection).

If the pneumococcal bacteria pass into the blood, they can cause pneumonia and invasive pneumococcal disease including bacteraemia (blood infection) and meningitis (inflammation of the membranes covering the brain).

Causative organism

Streptococcus pneumoniae are lancet shaped. gram-positive diplococci. At least 90 types have been identified on the basis of the polysaccharide (sugar) capsule surrounding the bacteria. The polysaccharide capsule determines the virulence of the bacteria by protecting it from phagocytosis.

The human nasopharynx is the only natural reservoir. Colonisation of the nasopharynx is the first step in the development of pneumococcal infections however most people who carry S. pneumoniae do not develop the disease. Young children and adolescents are more likely to carry the bacteria in their nose and throat than adults. Reducing carriage rates in children by vaccination can result in less spread to and disease in adults.

Clinical signs, symptoms and complications
  • In most cases pneumococci are carried in the mucosa of the nasopharynx without any symptoms.
  • After infection the incubation period may be as short as 1-3 days.
  • Local infection can cause otitis media, sinusitis and pneumonia.

  • Invasive disease can present as bacteraemia or meningitis. These are associated with a high risk of mortality.
  • Pneumococcus rarely infects the heart muscle causing endocarditis, joints, the peritoneal cavity and the fallopian tubes.
  • Diagnosis is made by isolating pneumococci in the blood or another normally sterile site however the delay in obtaining culture results means they are not useful in early treatment decisions.
  • Not everyone with pneumococcus pneumoniae develops bacteraemia. Obtaining positive culture results may also be influenced by early/prior administration of antibiotics.
Method of transmission

Pneumococcal bacteria are carried in the nose and throat and are easily passed from person to person by coughing, sneezing and close contact. Not everyone who catches or carries pneumococcal bacteria gets sick from it.

Public health significance

Carriage of Streptococcus pneumoniae is common in New Zealand children, they are likely to be the major reservoir for infection in adults.

Pneumococcal pneumonia is the most common form of serious pneumococcal disease.

Healthy children less than five years of age and the elderly are at risk from pneumococcal disease but the highest risk of serious disease is for infants less than one year of age, Māori, Pacific Peoples and older people.

Being exposed to cigarette smoke, living in crowded conditions, and/or having some medical conditions can also increase the risk of pneumococcal disease.

In 2010 there was a reduction in invasive pneumococcal disease (IPD) across all age groups in New Zealand. The commencement of immunisation of young children with the pneumococcal conjugate vaccine (PCV7) in June 2008 has reduced the number of children carrying the bacteria in their nose and throat, reducing spread of the bacteria and protecting some older children and adults who had not had the vaccine. This 'herd immunity' effect was also seen in the US after introduction of PCV7.

There has been some increase in IPD caused by non-PCV7 serotype 1 since the introduction of the vaccine. Other countries have reported an increase in serotype 19A following the introduction of the PCV7 vaccine but this has not occurred in New Zealand.

New Zealand epidemiology

The incidence of invasive pneumococcal disease (IPD) in infants <2 years old has reduced 70.9% since the introduction of the seven valent pneumococcal conjugate vaccine (PCV7) in June 2008. The reduction in IPD caused by PCV7 serotypes in this age group is even more striking than the reduction in all IPD.

Rates of IPD in Pacific Peoples and Māori were 5.9 and 3.6 times, respectively, the rate among Europeans. Just over half of IPD cases, for whom the information was reported, were recorded as having a chronic illness, just over half were less than 5 years of age and in childcare, and just under half of cases less than 5 years of age were exposed to smoking in the household.

Among the 34 cases who had received ≥1 dose of PCV7, and for whom the serotype causing disease was known, 27 (79.4%) had IPD due to a non-PCV7 type. Of the seven cases who had received ≥1 dose of PCV7 and had disease due to a PCV7 type, five had serotype 19F disease, one had type 6B disease and one had type 14 disease.

There has been some increase in IPD caused by non-PCV7 serotypes since the introduction of the vaccine PCV7. This increase has been predominantly due to serotype 1 disease. An increase in serotype 1 IPD was first noted in 2007 and appears to have peaked in 2009, with the rate of type 1 disease halving between 2009 and 2010. The introduction of PCV10 on the 2011 National Immunisation Schedule provides coverage for serotypes 1, 3 and 7F and may prevent future increases in IPD caused by serotype 1. Other countries have reported an increase in serotype 19A following the introduction of the PCV7 vaccine but this has not occurred in New Zealand.

Source: Heffernan H, Morgan J, Woodhouse R. Invasive pneumococcal disease in New Zealand, 2010. Porirua: Kenepuru Science Centre, Institute of Environmental Science and Research Ltd (ESR); 2011.

Prevention

It is extremely difficult to avoid coming into contact with such a common bacteria but good hygiene practices, covering coughs and sneezes, hand washing, and avoiding contact with smoking and crowded living conditions may help.

  • Babies born to mothers who have high levels of pneumococcal disease protection (antibodies) may be born with some protection from the disease. However, by two months of age almost one third of the maternal antibodies have gone and the majority by seven months of age.
  • Infants cannot develop their own effective protection against pneumococcal bacteria until about two years old.

Prophylactic antibiotics are not indicated for close contacts of cases of invasive pneumococcal disease unless the contact is at increased risk of invasive disease and their condition means their response to immunisation may be poor.

Two types of pneumococcal vaccines are currently available, pneumococcal polysaccharide capsular vaccine (PPV) and pneumococcal conjugate protein vaccine (PCV).

  • PPVs only include the capsular polysaccharides from the bacteria. They do not induce immunological memory. Antibodies and protection return to around pre-vaccination levels within a few years of vaccination. The first PPV dose may blunt the immune response to subsequent PPVs.
    • Infants and children under 2 years of age have a poor response to polysaccharide bacteria and PPVs, probably due to an immature immune system. Children aged 2 years or older and adults vaccinated with PPVs require a single re-vaccination after 5 years and depending on their age when revaccinated may require a third vaccination at age 65.
    • Only serotype-specific antibodies are induced. PPVs do not induce mucosal immunity and therefore do not affect carrier rates or herd immunity.
    • The 23-valent vaccine formulations contain capsular polysaccharides of serotypes 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F and 33F.
    • Only 4% of older adults respond well to all 23 pneumococcal serotypes in the vaccine. Non-responders to immunisation are more frequent in those with certain underlying illnesses however research has provided evidence that use of PPV is clinically useful.
  • PCVs include a carrier protein joined to the capsular polysaccharides from the bacteria. They induce immunological memory. Antibodies and protection are longer lasting than that from PPVs. Subsequent immunisation with PCVs stimulates an immune response and production of more antibodies.
    • Infants and children less than 2 years of age produce higher antibody concentrations to PCVs than to PPVs.
    • Some existing vaccines are thought to provide cross protection against other pneumococcal serotypes that are not in the vaccine. PCVs induce a mucosal immune response which enables vacinees to eradicate colonisation by the pneumococci contained in the vaccine and provide indirect protection of non-immunised individuals, the herd immunity effect.
    • Some studies have shown an increase in non-vaccine serotypes since the widespread use of PCVs in industrialised nations and debate has ensued as to whether or not this is related to the use of PCVs.
      • The 7-valent vaccine formulation contain capsular polysaccharides of serotypes 4, 6B, 9V, 14, 18C, 19F, 23F each conjugated to a protein.
      • The 10-valent vaccine formulation contain capsular polysaccharides of serotypes 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F and 23F each conjugated to a protein.
      • The 13-valent vaccine formulation contain capsular polysaccharides of serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F each conjugated to a protein.
Treatment

In the early stages of illness the type of bacteria causing the disease is not usually known. Combination antimicrobial medication is the first line of treatment for all types of pneumococcal disease. However, drug resistant pneumococcal bacteria is an increasing problem.

Dexamethasone may be used in addition to antimicrobial medication to treat pneumococcal meningitis.
If a person with pneumococcal meningitis the has not improved after 48 hours of treatment and the bacteria is not sensitive to the antimicrobial medication being used or sensitivity results are not available then a lumbar puncture should be performed. Antimicrobial sensitivity testing of the pneumococcus isolated from the CSF can be carried out.

Other treatment provided is supportive care and may include intravenous fluids, oxygen therapy, prevention of pressure points from lying in one position, maintainenance of hygiene and comfort.

Synflorix®

PCV10

Synflorix® is used for primary and booster vaccination of infants and children up to their 5th birthday to protect against disease caused by 10 types of streptococcus pneumoniae.

Listed below are the available videos for this disease