Viral meningitis - never to be ignored

This week is viral meningitis awareness week. There are about 2,500 cases of bacterial meningitis every year in the UK, but viral meningitis is much more common.

It's a word that strikes fear into all our hearts - meningitis. This inflammation of the 'meninges' - the lining of the brain and spinal cord - often makes headlines when a cluster of cases affects children in particular. Bacterial meningitis can strike with deadly speed and charities have worked hard to raise awareness of the warning signs.

The most deadly forms of meningitis are caused by bacterial infections. Some of these can be prevented by immunisation - Haemophilus influenza type B (Hib) and meningococcus group C among them. We have seen an announcement last week that teenagers will be given a booster to protect against meningococcus group C, to reduce outbreaks in colleges and schools. We can prevent meningitis by some viruses by immunising against polio and mumps. More work needs to be done on developing new vaccines - at present there is no effective immunisation against meningococcus group B, one of the most common causes of bacterial meningitis - but real progress has been made.

At the other end of the worry spectrum, who hasn't been told by a doctor that 'it's a virus' and there's nothing to worry about? This week is viral meningitis awareness week. There are about 2,500 cases of bacterial meningitis every year in the UK, but viral meningitis is much more common. Because it doesn't cause such dramatic symptoms, nobody is sure exactly how many people are affected. The principle is the same as other forms of meningitis - an infection reaches the lining of the brain, causing inflammation and similar symptoms to bacterial meningitis. The feature it doesn't cause is the blotchy skin rash that doesn't go pale when you press a glass against it - this is due to infection in the blood with meningococcus.

Without treatment, most patients with bacterial meningitis will die. It's a very good thing that the same does not apply to viral meningitis, since antibiotics don't make the slightest difference to viral infections. But while most people with viral meningitis will recover, it seems the long term complications are sometimes underestimated. A new survey by Meningitis Now shows that sufferers can be left with tiredness, headaches, memory loss and lack of concentration.

It's more common in under-fives and people with a weakened immune system. Some viruses that cause meningitis are found in countries like Japan and the USA, so do let your doctor know if you get symptoms and have been abroad. It's also more common in summer and autumn, and with a few days of sun behind us over the Bank Holiday, maybe it's not quite so hard to remember that summer is officially just around the corner.

Mollaret's meningitis - when the nightmare returns

Anyone who suffers from cold sores knows the survival tactics of the herpes simplex virus. There are two main kinds - type 1, the most common cause of cold sores, and type 2, which usually causes genital herpes. Once you're infected with the virus it lives on in your body after your first attack of herpes. It can remain hidden and inactive for months or years before it becomes active again, multiplying and causing another attack of the same symptoms. Another virus in the same family behaves in a similar way. The chickenpox virus causes the common childhood illness, with its blistering rash. Once the initial infection settles, the virus lives on in hibernation in the nerve roots beside your spinal cord. Years later it can emerge again to cause shingles.

An uncommon cause of viral meningitis is the herpes simplex type 2 virus. About one in five people infected with this kind of meningitis will get another episode. Rarely, the symptoms recur more than three times, and can cause the same inflammation time and time again for up to five years. This is Mollaret's meningitis. Even though most (although not all) people eventually recover completely, it can change your life for all the wrong reasons, making normal functioning impossible for years.

Although there is no treatment for many virus infections, a medicine called acyclovir can help with this highly distressing condition. It can be given at the start of an attack to shorten the illness, or long term to cut the frequency of attacks.

When does 'don't worry' mean something else?

I've taught other doctors training to become GPs for nearly 20 years. One of the first rules I drum into them is the importance of 'safety netting' - that's explaining to the patient when the reassurance they've just given doesn't count anymore and they should seek help again.

When doctors read newspaper headlines about children sent home from the doctor hours before dying of meningitis, we shiver with horror. We know that all too often, the early symptoms of serious conditions are identical to the symptoms of the hundreds of virus infections that leave children moaning helplessly one minute and bouncing back to full health by the next morning. Needless to say, while they're tugging at the bedclothes asking to go to the park, their parents are still reeling from lack of sleep and concern that their child was going to die.

Doctors in training need to learn that they can't admit every child to hospital 'just in case'. Hospital wards would go into meltdown, the really sick children would have their treatments delayed and thousands of parents would be thrown into panic with no need. But when doctors do reassure a parent that there are no worrying signs, they must always explain that there's no cause for concern now. Just occasionally, a child will get worse, not better, and a clean bill of health three hours ago counts for nothing if that happens. New symptoms should never be ignored.

Dr Sarah is unable to provide medical advice or respond directly to questions concerning your health. If you have health concerns we recommend contacting your GP.