Mumps vaccination and teenage swelling

UPDATE: 21 July 2010: Well, whadya know – swab result positive! I discussed it with the nurse specialist who did a lecture at my Imms and Vaccs study day last week and she said how there are pockets of mumps infection (and another notifiable disease that children are immunised against across the country, and that it’s only a matter of time before a further booster against these two are added to the national immunisation programme. Remember – you saw it here first!

Today’s SciScoop post is from a guest blogger who is a UK practice nurse with considerable clinical experience and concerns for the nation’s teens.

Over the course of the past couple of weeks, some interesting stats have come to my attention. Before I go any further, I will explain how I came to stumble over them. It would seem that my 17 year-old son, who has been given the MMR vaccine in the standard fashion as a small child, has nevertheless contracted mumps!

One evening recently he complained of feeling as though he had been punched on one side of his neck and jaw. That night he brewed up a fever and woke with a noticeable swelling where the pain had been. A visit to the GP led to a diagnosis of suspected ear infection. He was prescribed antibiotics, and instructed to return in a couple of days if there was no improvement. Dosed up to the eyeballs, he attended college on the next day and on the following day he didn’t drag himself to college but instead went back to the doctor during the day while my husband and I were at work.

On my return he told me that he had stayed at home and had gone to the surgery. The GP told him that she suspected mumps and he was asked to produce a urine sample to test this hypothesis…wrong!

As a practice nurse we have had two or three suspected cases of mumps over the last year. Mumps is a notifiable disease in the UK. The correct procedure is to inform the Health Protection Unit; they send you a swab and paperwork for that patient which you then send to their labs for testing. This is how they collect data on the incidence of notifiable diseases and adapt the national immunisation programmes accordingly.

Needless to say, I was taken aback at the ignorance of the GP, although to be fair mumps is still rare and younger GPs are unlikely to have seen a case before. I contacted our local labs the following day. They were bemused that a urine sample had been sent to test for mumps and it had been thrown out by the virologist.

On my return from work on the following day, my son and husband had been to the surgery again; the other side of son’s neck/jaw had swollen up and he was in a great deal of pain. The (older) senior GP they saw this time examined my son briefly and said that he had a classic case of mumps, but needed to confirm with a swab. Okay, now we were getting somewhere!

He was signed off school (missing his first two AS-level exams, and spending his 17th birthday in isolation at home). This is when I googled mumps to learn more. A clinical website (Clinical Knowledge Summaries) gave me everything I needed to know.

Mumps is potentially much worse in teenagers and young adults than in children. This is because they are much more susceptible to complications such as epididymo-orchitis in boys, oophoritis in girls, pancreatitis, viral meningitis and encephalitis.

When children receive the MMR immunisation 95% are immune in a short time. This then wanes to 85% six to seven years later, just when they are entering their teens! Therefore, should they be exposed to the virus, these teenagers have a 15% chance of contracting mumps – at precisely the age that they really don’t want to catch it! (See Niall et al reference cited below for more details on mumps orchitis).

Into this mix we throw the results of Andrew Wakefield’s scaremongering about the MMR jab causing autism (it doesn’t). There are now a significant minority of teenagers and younger children who haven’t been immunised. These kids are at risk themselves and their exposure is also endangering the 15% of those immunised who are no longer immune – the herd immunity is being eroded. Should we be giving 12yr olds an MMR booster to bring the 85% immunity back up to 95% when they are most vulnerable?

We older folks (the pre-MMR generation) are okay – due to natural exposure as children we have developed an active immunity of 98% that presumably works well throughout our lives.

At the time of writing the swab results have not yet come back. However, my son has had pain in his right groin and testicle a week after onset of symptoms – another classic symptom of mumps. I don’t think there is much doubt about the result. Let’s hope his fertility will not be adversely affected.

Research Blogging IconDavis, N., McGuire, B., Mahon, J., Smyth, A., O’Malley, K., & Fitzpatrick, J. (2010). The increasing incidence of mumps orchitis: a comprehensive review BJU International, 105 (8), 1060-1065 DOI: 10.1111/j.1464-410X.2009.09148.x