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 symptoms 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). Diagnosis by bacterial culture remains the gold standard; this usually takes at least 48 to 72 hours for confirmation.
Pneumococcal bacteria can infect persons of any age group, and anyone is susceptible to pneumococcal disease. However it appears to be most prevalent among the young and elderly, those with weakened immune systems (e.g., those with HIV, cancer or who are on immunosuppressants), those with chronic heart and lung conditions (including diabetes) and those with an absent or removed spleen. Pneumococcal disease affects children in much the same way as it does adults – by causing infections in the lungs (pneumonia), ears (otitis media), blood (bacteraemia) and 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 two years of age, the elderly and those who are 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 day-care centres are more likely to become infected due to their increased exposure to the bacteria. Over 20% of those who contract pneumococcal meningitis do not survive; 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.
There are rapid methods of identifying pneumococcal bacteria via antigen
detection, but such methods are not always readily available and can be
Samples of sputum or nasal aspirate or even the urine maybe analysed by certain
test kits, but these tests are of varying sensitivities and specificities.
Thus, the test may not be particularly useful in actual practice. Many of these
tests are unable to differentiate between the normal presence of the
pneumococcal bacteria (which is common in children) and an infection. Hence the
identification of the bacterial antigen may not actually be diagnostic of an
infection, and test results can be misleading unless correctly interpreted.
Personal hygiene and proper hand washing are the most effective ways to prevent the transmission of pneumococcal bacteria , while vaccination is the most effective way to prevent the development of pneumococcal disease.
The pneumococcal conjugate vaccine (PCV7 is the only one available presently) is the vaccine that we are referring to. The 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 less than two years of age, which is the age range at highest risk of pneumococcal infection and its complications. The Pneumococcal conjugate vaccine protects against disease caused by seven strains of the pneumococcal bacteria. These seven 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 from four doses in babies less than months old, three doses in those six to 12 months old, two doses in those between 12 and 24 months old and one dose in those greater than 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 to infants as young as six weeks of age. Since prevention is certainly better than cure, it is important for parents to protect their child against infection.