DOCTORS WIELD NEW WEAPON TO FIGHT AN OFTEN DEADLY CHILDHOOD DISEASE
After years of research, a new vaccination programme against meningitis is to be launched in the UK this autumn.
Under the campaign, highest risk groups - namely children over 4 and less than 12 months - will be immunised first, followed by children between the ages of one to five year before the start of winter's meningitis season.
Meningitis is an inflammation of the meninges membrane which surrounds the brain. The disease has two causes; bacterial and viral. The viral is more common with an almost 100% recovery rate. There are many bacterial strains, which can cause meningitis.
The bacterial strains known to cause the disease in Ireland are Menigococcus B and C. In 1998, 50% of identified cases were attributed to B and C. Last year, cases caused by strain B decreased.
"The new vaccine works like all other vaccines tricking the immune immune system infection into thinking it is seeing a real infection," says UCC Professor of Microbiology Kevin Collins.
The new vaccination is the first to 100% protection to adults and children over 2-3 months against type C of the Meningococcal strain. To date, there has been no effective vaccine available for children under one year. Time will reveal the success of the vaccination.
However, hopes are high as it adopts similar technology to the haemophilus strain vaccination developed in the United States.
"About 5% of the human population act as carriers of the menigococcus, a bacterial strain, which causes - meningitis with no effect," says Collins. Meningitis occurs when "the bacteria goes beyond being a passenger in the naso-pharynx gets into the bloodstream, eventually crosses the blood brain barrier and causes the infection and inflammation of the lining the brain called the meninges," says the professor.
The fatality of the disease depends on which organism causes it.
"Any form of meningitis is considered a medical emergency because there are very few organisms whereby you can develop symptoms and have the target dead within hours. It demands immediate intervention therapy.
"The earlier the better 30 minutes is important. Very effective treatment is available in Penicillin and Chloramphenicol. Often by the time a diagnosis is made on the physical symptoms namely headache, a stiff neck, photophobia - i.e. sensitivity to light, rash and impaired concentration is very late," says Collins.
PCR techniques adopted at the National Centre or Meningitis have now enabled a quicker, easier and more accurate diagnosis of meningitis. These techniques allow for the replication of DNA from human specimens and are used for DNA fingerprinting.
"Everybody is at risk, but there are two major risk groups. Very young children who will meet the strain for the first time. They would have lost the maternal antibodies and have no protection. "They are also the most difficult to diagnose because many babies have fevers and minor rashes which need to be discriminated against. The second would be the so-called kissing group - the adolescent group aged 15-19,' says Collins.
'Whereby children for example may be colonised with one type and then pick up another type from a carried - i.e. somebody else who doesn't have any disease but is carrying a carriage form - and have no immunity to the other strain.
"While the contagious risk is quite low, children may pass it on via saliva to another by sharing a pencil which both have been sucking on for example. Because treatment does not eliminate the carriage form in the naso-pharynx close relatives of a patient are treated with prophylactic drug called rifampicin, which eliminates the carriage form of the meningitis." Normally professionals in healthcare do not protect themselves against meningitis with the drug unless they give mouth-to-mouth resuscitation.
One of the major factors which induce the onset of meningitis, is stress - an immune suppressing factor.
There have been consistent increases in the total number of cases of meningococcal infection in England in recent years.
Currently, over 1000 thousand cases of menigococcal infections are reported in England and Wales, although the true burden of the disease may be at least 30% higher due to lack of notification. The vaccine has been extensively tested by the manufacturers and by the Public Health Laboratory Service in England and has been found to have excellent imniunogenicity and safety profiles in all ages.
It is currently undergoing the necessary procedures for licensing at the Medicines Control Agency.