There are many different causes of meningitis, but the two most common organisms are viruses and bacteria.
Viral meningitis is usually a mild disease, but it can make people very unwell. Many thousands of cases occur each year, mostly affecting babies and children. Although most people will make a full recovery, some are left with serious and debilitating after-effects.
Bacterial meningitis can be life-threatening and needs urgent medical attention. Most people who suffer from bacterial meningitis recover, but many can be left with a variety of after-effects and one in 10 will die.
Neonatal meningitis occurs in babies under one month old. Other causes of meningitis are all serious and need medical attention.
Neonatal meningitis is the term used to describe meningitis that occurs in the first 28 days of life. Many different organisms can cause neonatal meningitis, broadly grouped as bacteria, viruses and fungi. However, the most common causes are bacteria; in particular group B streptococcus (GBS) and Escherichia coli (E coli).
GBS bacteria live harmlessly in the vagina and intestinal tract of approximately 10 to 30% of women. These bacteria can sometimes be passed to the baby during delivery.
The result is usually colonization of the skin surfaces and only a small percentage of babies go on to become ill with serious infection. When a baby becomes ill in the first six days of life this is called early onset disease. When a baby becomes ill between seven and 28 days after birth this is called late onset disease. Rarely, infection may occur as late as three months of age.
E coli are common bacteria found in the large intestine of nearly all healthy people and, like GBS, may be passed to a baby during delivery. Although most strains of E coli do not cause disease, serious infections may occur if the bacteria invade areas of the body in which they are not normally found, such as the urinary tract, blood stream or meninges.
Another rare cause of neonatal meningitis is Listeria monocytogenes. Generally acquired as a food-borne infection, Listeria may cause a flu-like illness with diarrohoea in a pregnant woman, but may also be passed to the baby in the womb across the placenta.
Infection may cause premature labour, and the baby will usually be unwell from the time of birth, although late onset disease is also recognized.
Very few cases of Listeria meningitis now occur because of education campaigns warning about the dangers of eating unpasteurized soft cheeses, pate and other foods that might harbour Listeria bacteria during pregnancy.
GBS, E coli and Listeria bacteria can cause both meningitis and septicaemia, which can either occur separately or together.
Meningitis can affect anyone of any age at any time, however there are at risk groups including babies, toddlers and young children under five who are the most at risk group for meningitis, with over 50% of all cases occurring in this age group.
Babies and young children are particularly vulnerable to meningitis as they cannot easily fight infection because their immune system is not yet fully developed. Babies and toddlers can’t tell you how they are feeling, so it can be easy to miss vital signs and symptoms of meningitis.
Full details and information on meningitis can be found at www.meningitis.org.nz