Pneumococcal Disease (Children)

The pneumococcal bacteria can affect any age group. Anyone can get Pneumococcal Disease but it appears to be of highest prevalence in the young and elderly, also in those with weakness in the immune system (e.g. HIV, cancer and patients on immunosuppressants), those with chronic heart and lung conditions (including diabetes) and in those with absent spleen or have had the spleen removed.

Pneumococcal Disease is transmitted by coughing, sneezing or contact with respiratory secretions of an infected person and can attack different parts of the body resulting in infection of the middle ear (otitis media), lungs (pneumonia), infections of tissues surrounding the brain and spinal cord (meningitis) and blood infection (bacteraemia).

It affects children in much the same way as they do adults by causing infections in the lungs (pneumonia), ears (otitis media), blood (bacteraemia), membranes covering the brain (meningitis).

The spectrum of infections caused by the pneumococcus is similar in the young and the elderly although the relative prevalence can differ.

Those most susceptible to pneumococcal infections are children less than 2 years of age, the elderly and the immunocompromised due to deficiencies or immaturity of their bodies' immune system to fight off the pneumococcal bacteria.

A high proportion of preschool children are carriers of the pneumococcus bacteria. Thus children who attend daycare centres are more likely to become infected due to the increased exposure to the bacteria.

Over 20% of those who contract pneumococcal meningitis die and 50% experience long-term health complications such as deafness, paralysis (loss of limb function) or mental retardation.

Pneumococcal pneumonia can also cause damage to the lungs and spread of infection into the blood stream and its attendant complications as described above.

Ear infections can also result in hearing impairment.

The early symptoms of Pneumococcal Disease can be non-specific and difficult to distinguish from common infections of childhood.

As the Pneumococcal Disease progresses, it may localise to specific organ systems and manifest symptoms which bring the diagnosis to attention.

These include pneumonia (infection in the lungs), meningitis (infection of the outer coverings of the brain), middle ear infections or even bacteraemia (infection that has spread into the bloodstream).

The gold standard of diagnosis is still by bacterial cultures which usually take at least 48 to 72 hours for confirmation.

Patients can present with fever, cough, progressing to breathlessness and chest pain and other constitutional symptoms such as lethargy and poor appetite.

Patients can present with ear pain, discharge or just fever. Younger children can present with tugging at the ear or irritability.

Most of the symptoms and signs are similar for both the bacterial and the viral meningitis, and there is no one symptom or sign that are specifically indicate one or the other. The common clinical symptoms that may indicate meningitis are fever associated with seizures, impairment of consciousness, irritability, lethargy, nausea and/or vomiting.

The important signs indicating meningitis includes neck stiffness (pain or resistance to someone flexing the child's neck) and increased sensitivity to light (photophobia), usually in the presence of drowsiness or irritability.

For young infants where the anterior fontanelle (the soft spot on the top of the head) has not closed, this could be under increased pressure and bulging out of the scalp (bulging fontanelle). Signs of bleeding under the skin (purpuric rash) together with other symptoms or signs indicating involvement of the brain may also suggest bacterial meningitis.

Bacterial meningitis is the most serious and potentially fatal disease caused by the pneumococcal bacteria.

Any form of bacterial meningitis is serious, and death can occur due to septicemic (blood poisoning) shock from the bacterial invasion of the blood stream. Death can also occur due to severe brain swelling that result in compression/pressure on the vital centres in the brainstem. Mortality from bacterial meningitis is approximately 5% - 20% depending on the virulence of micro-organism involved.

There are quicker methods to identify the pneumococcal bacteria through the detection of its antigen using various techniques but this is not always available and can sometimes be costly.

Some can be applied to samples of sputum or nasal aspirate or even the urine. These are available in some test kits but are of varying sensitivities and specificities i.e. the accuracy of the test and may not be that useful in real life; many of these tests are unable to differentiate between a normal carriage of the pneumococcal bacteria (which is not uncommon in children) and hence the identification of the bacterial antigen may not actually be diagnostic of an infection. The results may be misleading unless correctly interpreted.

Personal hygiene and proper hand washing are the most effective ways to prevent the transmission of the disease while vaccination is the most effective way to prevent the development of Pneumococcal Disease.

PCV7 is the only vaccine available presently.

PCV7 is very effective in stimulating an immune memory that is important for a good protective effect as well as long-lasting protection. It is also the only vaccine that can be effectively used in children <2 years of age - which is the age range at highest risk of pneumococcal infection and its complications.

PCV7 protects against disease caused by 7 strains of the pneumococcal bacteria. These 7 pneumococcal strains account for up to 80% of the invasive (severe) pneumococcal infections in infancy and early childhood. The dosing schedule is different for babies or children at different ages. This can range form 4 doses in babies <6 months old, 3 doses in 6 to 12 months old, 2 doses in those between 12 and 24 months old and 1 dose in those >24 months old. It is important to note that the earlier the vaccine is taken, the earlier the protection takes effect and hence the vaccine should be taken as early as possible.

Data from the west where this vaccine has been included in the standard national immunisation schedule has indicated that it is effective in preventing the disease as well as reducing the carriage of the bacteria. The latter is potentially important for reducing the spread of the bacteria to others at risk, including the elderly.

In fact data also shows that with the widespread use of this vaccine in the USA, the incidence of pneumococcal disease in the elderly has also decreased. This vaccine can be given as young as 6 weeks of age and since prevention is certainly better than cure, it is important for parents to be aware of this infection and its prevention through vaccination and protect their child against it.