Rare strain of meningitis on rise but current vaccines fail to give immunity
A rare form of deadly meningitis is on the rise in Ireland following a pattern seen in other countries, disease specialists have revealed.
The number of cases of the W strain has increased from one in the year 2014 to 12 last year. There has also been an increase in meningitis Y over the same period, up from three to eight.
Neither strain is currently included in the vaccines to protect against meningitis which are commonly given to children.
The increase follows a similar trend in the Netherlands and the United Kingdom which has in turn led to the MenACWY vaccine now being offered by health services to teenagers and college and university students.
No such vaccination programme has been introduced here yet but the rise in cases will have to be examined by the group of experts which advises the HSE on what jabs should be given free to various groups of patients.
Like other forms of the disease it can be very serious if not treated quickly with antibiotics.
Without emergency treatment it can lead to life-threatening blood poisoning, and result in permanent brain or nerve damage.
The report from the Health Protection Surveillance Centre, the country's disease watchdog, said that during January there were 17 cases of different forms of meningitis.
Four of these involved the W and Y strains. Two people died from meningitis during January.
Overall, the incidence of meningitis in Ireland has fallen in the past two decades.
In the past the meningitis B and C strains presented the highest risk, but the introduction of vaccines for both has led to a fall in circulation of both.
The report pointed out that in 2000 the meningitis C vaccine began to be routinely given to children, which went along with a catch-up programme for teenagers.
Since the introduction of the meningitis C vaccine the annual incidence of the strain has decreased substantially from 135 cases in 1999 to 20 last year.
A vaccine to protect against meningitis B was introduced in recent years, but only for children born after October 2016, leaving parents of older children to pay €300 to have the job privately.
The annual incidence of meningitis B has also reduced considerably from 292 cases in 1999 to 46 cases in 2018 .
The report said that changing trends in the incidence of the infection have been reported in other European countries in recent years.
In Italy, the number of meningococcal W cases has been increasing since 2013.
"The Netherlands has also seen an increase in reported cases of meningococcal W cases which had been very rare prior to 2015.
"Between 2010 and 2014 an average of four cases of meningococcal W were reported annually but increased substantially over the following years to 80 cases in 2017.
"This rapid upsurge in meningococcal W in the Netherlands has been attributed to a meningococcal W," it added.
The report said that 17 cases and two related deaths were reported from January 1-29 this year.
"This was slightly less than in the same period last year when 19 cases - and two related deaths - were notified.
"Amongst the 17 cases notified from January 1 to January 29, 2019 different strains were reported and different age groups were affected."
The report added that although meningitis notifications have been stable in the first four weeks of 2019 compared to the previous year, ongoing monitoring of trends is needed "to assess the circulation, distribution and evolution of specific control strategies, particularly preventive vaccination programmes, and to inform national vaccination policy".