Prevention is still the best cure

THE first concern when a case of meningitis is reported in an area is whether it is an isolated case or the beginning of an epidemic. Unfortunately there is currently very little that can be done to prevent further cases of meningitis if they are going to occur in the wider community.

There is no vaccine available for the commonest type of meningitis in Ireland - meningococcal meningitis type B, which is responsible for almost two thirds of cases. Experts predict that it will be at least 10 years before one is available.

A preventative vaccine is available for type A meningitis and recommended for those travelling to Africa. A vaccine exists for type C although it is not routinely available. It is normally only given to those who have been in close contact with a patient diagnosed with it or to individuals travelling to "risk" areas abroad. It is not effective in children under 18 months.

For most viral meningitis there is no vaccine, but immunisations with the MMR vaccine greatly reduce the chances of contracting mumps meningitis.

Dr Jerry Fogarty, a specialist in public health medicine with the Western Health Board, has done a lot of research into meningococcal disease. "There is reasonable optimism that there will be a vaccine for group C in a few years for everyone, effective from early childhood. A difficulty at present with the available group C vaccine is that the effects only last for about three years. We still do not know why people die, so the real hope is the vaccine. But that is a bit down the line."

According to the Report of the Working Group on Bacterial Meningitis, it is policy in Ireland that preventative antibiotics are given to close contacts of confirmed or suspected cases of bacterial meningitis as soon as there is notification of a case. The risk is highest seven days after a case, and falls after that. It is given to protect the individual who is not a carrier of the organism or one who may have recently acquired it. The reason for this is that the antibiotic is given to eliminate the organism from the carrier and reduce its subsequent spread to another susceptible person.

Close contacts are defined as those living in the same house, including baby-minders, those who have kissed the patient on the mouth, or were in the same creche. In this instance creches are viewed as being the same as living in the same house.

These antibiotics are not considered necessary for the class-mates of a student who has got meningitis unless there are two or more cases of the same strain in the school during the same term. If the cases occur in the same class, all students and staff should receive the antibiotics.

If it occurs in different classes the public health division of the local health board will take various things into consideration including the interval between the cases, the size of the contact group, whether the cases are due to vaccine-preventable strains, and the degree of public concern.

It is not recommended that they be given routinely to passengers on public transport where a case has been identified. Although it is recommended that special consideration should be given if there was a house party in the previous seven days and pre-school children were present, or where there is greater interaction between members of an extended family.

In Ireland there is a difficulty with the reporting of meningitis figures because so far the routinely reported statistics do not provide the quality of information to describe accurately the epidemiology of the infections. Figures from the Department of Health include all cases initially reported as meningitis but make no distinction between what strain - A, B or C - of the organism may be involved. Also there is no mechanism for removing a case from the notified statistics when an alternative diagnosis is subsequently made.

Doctors involved in meningitis research also point out that initiatives in recent years have led to better efficiency in the reporting and some of the increase in figures could be explained by this. According to Dr Darina O'Flanagan, specialist in public health medicine with the EHB, there is always more overall reporting of bacterial meningitis than confirmed meningococcal disease. Of the 155 reported cases of bacterial meningitis in the Eastern Health Board area last year, 81 were definite meningococcal meningitis, 51 were Group B and 27 were group C, some were not definitely identified.

This situation should improve considerably with the work being carried out by the National Meningococcal Reference Laboratory in Temple Street Hospital. Director Dr Mary Cafferky said that the lab, which is funded by the Department of Health, is important for "actual diagnosis of meningococcal disease". Laboratories from around the country are required to send a sample from all cases of suspected meningitis to be tested.

"We need to get a clear picture of the organism, how many different types there are and whether it is an epidemic. However, even with the best lab conditions in the world you will not detect all cases. It is an organism that can be very fastidious and may not grow in the lab. We are also increasingly seeing patients who have had anti-biotics, which is recommended, and this will affect the result."

If a patient is admitted to hospital with suspected meningitis, an immediate course of antibiotics is given. A lumbar puncture may be done and the hospital will take a specimen of blood or throat swab on admission and send it to Temple Street.

There they have a rapid technique for detecting the bacteria which cause meningitis, with a diagnosis time of less than 30 minutes. This PCR test was pioneered at the University of Wales, and the Temple Street lab is one centre taking part in clinical trials.

Initial results look very promising. This test avoids the need to lumbar puncture which can be painful and dangerous. It will not only help individuals, it will also give public health doctors a much earlier warning on the strain involved, and whether a specific vaccine is appropriate.

One type old meningitis that has virtually disappeared from this country is haemophilus influenzae type b (Hib) which usually affects children under school-going age. Dr Jerry Fogarty first became interested in meningitis when he spent time while training at the Centre for Disease Control in Atlanta and saw how effective the Hib vaccine was.

When he returned to Ireland, together with Dr Anne Moloney, a consultant microbiologist, he began a two-year study into this type of meningitis to establish a baseline in Ireland. The vaccine was introduced here in 1992 and there has since been a dramatic 99 per cent reduction in the incidence. It is given to babies at two months, four months and six months. "It is really a modern-day success story in disease prevention. It just goes to show what an effective vaccine can do."

Dr Fogarty spoke of the need for a communicable diseases centre in Ireland to monitor the incidence and type of the disease. "It is very cumbersome to be having to make contact with labs over the telephone. If something occurs in one particular part of the country and this type of system is not in place you cannot see if it is related to something else. We need a centre involved in epidemiology. It has been shown to work very well in the UK and the US and in other European countries. In the UK they had an outbreak in Exeter and were able to link it to students going home at weekends. They were able to trace the people moving around. But you would also be able to link up Europe-wide."

Siobhan Coulter Eec, Ireland co-ordinator of the Meningitis Research Foundation, agrees. "We need this centre because so much needs to be done. We need to identify why we are the highest. Is it because we are in a cycle or is it something else? We need to know why there is an increase in young adults or whether parents are spotting symptoms in young kids quicker. We have to get the overall picture."

Dr Fogarty says it is too difficult to predict what will happen in the future with meningitis. "We are not sure what stage we are at in the cycle. It is likely, looking at the most recent figures, that we are on the way down. However we cannot reassure people because it is too unpredictable and we are limited in what we can do, except through information and prevention."