You are reading 1 of 15 free-access articles allowed for 30 days

Person receiving a vaccine
Photo: Getty Images

Emergence of additional meningitis strains worrying

Emergence of additional meningitis strains prompts broadening of vaccine in September `

A small but steady worrying increase in meningitis C (MenC) and the appearance of MenW and MenY cases are recent emerging trends in Ireland, according to leading consultant in infectious disease and acute medicine, Dr Corinna Sadlier.

Booster vaccination of MenACWY is to begin in September this year for the 12 to 13-year-old age group to prevent any spread of the serotypes.

Dr Sadlier will discuss trends in emerging serotypes of meningitis at the Royal College of Physicians of Ireland Masterclass on infectious diseases, due to take place at Brookfield Health and Sciences at University College Cork on Wednesday, May 22.

MenB an MenC still account for the majority of cases here but MenW and MenY cases have emerged in Ireland in parallel with the United Kingdom and other European countries, such as the Netherlands, where there has been a hypervirulent strain of MenW which would be associated with a high mortality rate.

That type of meningitis can present with more atypical symptoms; GI symptoms abdominal pain diarrhoea, with sepsis, as opposed to what people would associate as the classical signs of meningitis.

Definitely, Dr Sadlier believes frontline clinicians are becoming aware of the emergence of this new strain and the atypical presentation. The Health Protection Surveillance Centre are keeping a very close eye from a surveillance point of view on serotypes that are circulating. This has allowed them to advise the Department of Health on optimising vaccine strategy to broaden the meningitis vaccine coverage to include serotypes W and Y in the MenACWY vaccine.

Not all serogroups are covered in the vaccine but MenACWY would cover the vast majority of cases of meningitis.

The incidence of MenC has reduced dramatically, and with the introduction of MenB vaccine in 2016, we are seeing significant reductions in MenB as well. In other countries as MenC and MenB cases have reduced other serotypes have emerged but Dr Sadlier hopes that the rapid introduction of MenACWY vaccine will prevent that trend in Ireland.

The first group to be targeted with the broader vaccine of MenACWY in September will be 12 to 13 year olds for their booster and whether or not it needs to be rolled out to other groups will depend on what happens from a surveillance perspective.

Traditionally, people travelling to Africa or areas where meningitis was almost epidemic would have received the MenACWY vaccine as a travel vaccine.

Up to 1:4 in the teenage group will carry meningococcus in nose or throat asymptomatically, and are the highest carriers of the bacteria. By vaccinating 12 or 13 year olds, the aim is to provide individual protection, but vaccination also provides herd immunity as carriage is decreased in this population.  

The same holds for pneumococcus. Asymptomatic carriers will develop immunity by carrying it but vaccine is the best way.

Ireland has one of the highest rates of meningitis in Europe second only to Lithuania which has a higher rate.

In the last two years, there has been a slow increase in MenC cases in the context of decreased vaccine uptake. The uptake rates for boosters for MenC have dropped off in the last two to three years down to about 80 per cent. From a herd protection level, it is probably having an impact and is letting MenC creep back in, whether the drop in uptake stems from hesitancy to take the HPV vaccine – which has reversed – or complacency, uptake is down to 70 per cent in some areas and that needs to be tackled.

With 1,000 cases of mumps so far this year, the emergence of other vaccine preventable infections is both “terrible and preventable”, stated Dr Sadlier, stressing the need for Ireland to act to increase vaccine coverage in the population.

For registration details, please visit www.rcpi.ie. 

valerie.ryan@imt.ie

Leave a Reply

Your email address will not be published. Required fields are marked *

*