What is viral meningitis?

Meningitis is the inflammation of the meninges (the soft tissue membranes which cover the brain and spinal cord underneath the skull and spinal column). In common usage, it usually refers to infections caused by viruses, bacteria, or fungi.

Most cases of viral meningitis are usually mild and most people make an excellent recovery. However on rare occasions viral meningitis can be life threatening or cause lasting after effects, particularly if people have problems with their immune system.

Viral meningitis is more common in children however it can occur in any age group.


What are the symptoms of viral meningitis?

The symptoms of viral meningitis may be the same as bacterial meningitis, with the latter potentially able to cause death within hours. Consequently it is important that people seek medical attention as soon as possible, if they are concerned that they may have meningitis.

Meningitis Symptoms CardThe symptoms of viral meningitis are usually milder than those associated with bacterial meningitis and may begin with flu like symptoms. The symptoms may include a headache, nausea or vomiting, fever, general malaise, neck stiffness, an aversion to bright lights, joint aches and pains, muscle aches, drowsiness or confusion, and also may include a rash, sore throat, stomach pains and diarrhoea.

The symptoms may occur in any order and may not all be present at the same time or during the course of the illness.

Download the meningitis symptom card from Publications Available.

 

What is the incidence of viral meningitis?

Viral meningitis is more common than bacterial meningitis and the number of cases usually increases during the summer. Viral meningitis usually occurs as isolated or sporadic cases. Epidemics of viral meningitis are uncommon but do occur occasionally in Australia and in other parts of the world.

 

What is the risk of developing viral meningitis?

Viral infections are relatively common, however very few people infected with the vast range of viruses which infect humans develop meningitis. However, occasionally a viral infection may develop into viral meningitis.

The risk of getting viral meningitis following contact with someone who has viral meningitis, is low. However, people who are in close personal contact with a person who has viral meningitis may become infected with the same virus and develop 'normal symptoms' associated with the virus.


What types of viruses cause meningitis?

Viral meningitis is usually an uncommon complication of some common viral illnesses. For example, measles, mumps, chicken pox, herpes simplex, enteroviruses and some arboviruses may occasionally cause viral meningitis. Measles and mumps are now very rare causes of viral meningitis due to vaccination programs. Chicken pox can also be prevented by vaccination.

Enteroviruses, such as echoviruses and coxsackie viruses, are the most common cause of viral meningitis. Enteroviruses are a group of viruses that live in people's intestines. Enteroviruses can be passed between people through contact with respiratory secretions or through poor personal hygiene. It is for this reason that enterovirus infections occur most commonly in preschool-aged children. However very few people who are exposed to enteroviruses become ill, and if they do develop symptoms these are usually mild such as sore throat, flu like symptoms, conjunctivitis (inflammation of the eye and eyelids) or skin rashes. Enteroviruses are a very common cause of viral infection in Australia usually causing mild flu like symptoms and skin rash illnesses. Even though meningitis is uncommon with an enterovirus infection, because the viruses are so common, they are also the leading cause of viral meningitis in the Australian community.

Some of these viruses can also cause encephalitis (infection of the brain substance itself rather than just of the membranes covering the brain). In severe cases, both the membranes and the brain itself may become infected; so called meningo-encephalitis. Approximately one in 2000 children with measles develops encephalitis and one in every 200 children with mumps develops encephalitis. About one in every 5000 people with chickenpox will develop encephalitis (Information taken from The Australian Immunisation Handbook 9th Edition 2008 NHMRC. Enteroviruses and arboviruses (eg Murray Valley Encephalitis virus) may occasionally cause encephalitis as well.

The measles, mumps and rubella vaccine (MMR) has been part of the free childhood immunisation schedule in Australia for many years. Vaccination provides high levels of protection for children against these diseases, including the infrequent but serious complications of viral meningitis and/or encephalitis.

The chicken pox vaccine (Varicella-Zoster vaccine, VZV) ) is now recommended for all children. For information regarding chickenpox vaccine recommendations, please consult your doctor. The Immunisation Infoline may be contacted on 1800 671 811, or visit Immunise Australia.

Arboviruses are a group of viruses that are spread from infected insects to people by insects that suck blood, such as mosquitoes and ticks. On rare occasions, these viruses may cause meningitis or encephalitis. The arbovirus which causes Murray Valley Encephalitis is transmitted to humans by mosquitoes. This virus periodically causes disease outbreaks in Australia.


How are viruses contracted?

Some viruses are spread from person to person by respiratory secretions, others through inadvertent contact with faecal matter.

Some viruses are transmitted to people from blood sucking insects. The way a virus is spread between people depends on the specific virus.

It is usually difficult to avoid exposure to human viruses, however good hygiene practices such as hand washing after visiting toilets will minimise the risk of contracting enteroviruses.

For arboviruses, the use of insect repellents, and avoiding exposure to biting insects by avoidance of peak biting times such as at dusk, together with use of appropriate clothing during the biting time is also a positive way of reducing the risk of contracting viral illnesses. Regional health departments will typically put out public advisory statements regarding precautions to take during at risk seasonal periods for arbovirus infection.

 

What is the incubation period?

The incubation period for viral meningitis may range from a few days to some weeks, depending on the type of virus.

 

How is viral meningitis diagnosed and treated?

Diagnosis of viral meningitis is based on the clinical findings following examination of the patient and detailed laboratory analysis of the fluid surrounding and supporting the brain (the cerebrospinal fluid (CSF)). This fluid is collected by performing a lumbar puncture. This is a medical procedure where a sterile thin needle is inserted into the fluid bathing the brain and spinal cord in the low back region. Other blood tests are also required, and often questions will be asked regarding your vaccination status, possible contact with other patients or animals, or recent travel both within Australia and overseas as well as many others.

Currently, for the most common type of meningitis due to enteroviruses, there is no specific antiviral agent which can be given. Thus, treatment for this type of viral meningitis involves supportive care, which may include re-hydration of a patient who has lost fluids from vomiting or the provision of pain relief medication for headaches and generalised body or muscle or joint pain. Recovery is dependent upon the body developing antibodies and hence immunity to the infecting virus and usually occurs within a week or two.

For some particular types of severe viral meningitis (eg, herpes simplex meningitis/encephalitis), early treatment has been clearly shown to be very beneficial. Consequently, antiviral agents will often be given immediately until the cause of the meningitis symptoms has been determined. Test results which determine what agent was causing the infection may take some days. As the symptoms of viral meningitis often resemble those of bacterial meningitis, antibiotics are often prescribed in addition to antiviral agents for severe cases until the cause is exactly determined. Antibiotics by themselves have no action against viruses.


What happens during recovery?

Viral meningitis is not generally a life threatening disease. Most people recover within a week or two. However some people may have recurrent headaches and experience tiredness, problems concentrating and/or may be irritable or depressed.

Concerns and possible after effects should be discussed with a doctor.

Very occasionally, people can be left with serious long term neurological after effects. This nowadays is most commonly seen with Herpes simplex viral encephalitis. Approximately 40% of children who develop measles encephalitis are left with long-term brain damage. (Information taken from The Australian Immunisation Handbook 9th Edition 2008 NHMRC.


Disclaimer

The Meningitis Centre is a 'not for profit' support organisation based in Australia, not a professional medical authority. Consequently the text on this web site provides general information about meningitis and septicaemia, not medical advice and is not intended for use in the diagnosis or treatment of the diseases. Please consult your doctor to discuss the information or if you are concerned someone may be ill.


Bibliography

1. Maxson S and Jacobs R. F. Viral meningitis. Tips to rapidly diagnosis treatable causes. Post Graduate Medicine 1993;93(8):153 - 164.

2. Meningitis Research Foundation. Viral Meningitis [online]. 2002 [cited July 2004]. Available from: http://www.meningitis.org

3. Wingfield F. The Aftermath. Nursing Times 1999;95(22):23 - 25.

4. The Encephalitis Society. Encephalitis Information Resource [online]. 2002 [cited June 2004]. Available from: http://www.encephalitis.info

5. Meningitis Trust. Disease Information, Types of meningitis, Viral meningitis [online]. 2003 [cited June 2004]. Available from: http://www.meningitis-trust.org