World Meningitis Day -24 April 2014

Imagine the devastating effect on a community of a completely healthy child suddenly developing fever and a headache and dying within a day. Meningitis is an inflammation of the meninges, which are the coverings of the brain and spinal cord. It is most often caused by a bacterial, viral or fungal infection. Meningitis is an extremely serious disease, and even with appropriate treatment up to 10% of the patients can die and unfortunately among the survivors about 20% can have long-term sequelae such as deafness or brain damage. HIV infection is a risk factor for many forms of meningitis and sub-Saharan Africa has been particularly adversely affected due to the HIV epidemic, with a population HIV prevalence of 12% in South Africa in 2012.

Other factors which could increase the risk of meningitis include overcrowding, cross border travel from or into epidemic or highly endemic countries, coexisting viral infection and young age.

The three most common bacterial causes of meningitis are; Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis. Another important cause of meningitis in South Africa particularly in HIV-infected individuals is the fungus Cryptococcus neoformans.

Haemophilus influenzae (particularly Haemophilus influenzae type b (Hib)) is a bacterium that can cause acute meningitis. It largely affects infants and children younger than five years of age. It can cause lifelong disability and be deadly. The introduction of Hib conjugate vaccine into the South African routine child immunisation schedule in 1999 has significantly reduced the burden of Haemophilus influenzae type b in South African children by at least 65% among children less than one year old.

Streptococcus pneumonia (the pneumococcus) is a common cause of meningitis and also the commonest cause of bacterial pneumonia globally. Pneumonia is the commonest cause of death in South Africa. The pneumoccal conjugate vaccine (PCV) was introduced into the South African routine immunisation programme in 2009. This vaccine has been found to be more than 90% effective in preventing pneumococcal meningitis in South Africa.

Meningococcal disease is caused by a type of bacteria called Neisseria meningitidis which is spread by close contact with an infected person, such as living together or kissing. Speedy medical attention is vital where meningococcal disease is suspected. About 11 to 19 out of every 100 meningococcal disease survivors will have long-term disabilities, such as loss of limb(s), deafness, nervous system problems, or brain damage. No meningococcal vaccines are routinely given to infants or adolescents in South Africa, but conjugate meningococcal vaccines are currently being licensed in the country and will hopefully become available for prevention of this form of meningitis in the future.

Meningitis caused by the fungus, Cryptococcus neoformans, is fatal in >50% of treated patients in routine care in South Africa. This form of meningitis occurs mainly among HIV-infected adults, especially among those with very low CD4 counts, and in this group, is more common than all causes of bacterial meningitis combined. Unlike other forms of meningitis, this infection does not pass from person-to-person. Although there is no vaccine to prevent cryptococcal meningitis, early diagnosis of HIV infection and timely initiation of antiretroviral treatment is the best way to prevent cryptococcal meningitis. South Africa is currently phasing in a screen-and-treat programme to actively find HIV-infected adults with early cryptococcal disease and treat them with antifungal medicines before meningitis develops.

Enteroviruses are the main causative agent of viral meningitis also referred to as aseptic meningitis (cerebrospinal fluid is clear). Enteroviruses are mainly spread from person to person via the oro-fecal route due to poor hygiene practices. Herpesviruses also contribute significantly to viral meningitis and other viral causes include mumps virus, measles virus, influenza virus and arboviruses. Very young children and persons that are immunocompromised are most at risk for viral meningitis. No specific treatment is available except for specific viral infections such as herpes and influenza viruses. Supportive symptomatic treatment is advised.

What can be done to reduce the burden caused by meningitis and its complications?

The most effective way to protect individuals against vaccine-preventable bacterial meningitis is to complete the recommended vaccine schedule. Information on vaccine schedule is available from health care providers (primary health care clinics or private practitioners). For treatment to be effective it is important to seek medical treatment as soon as possible.

Useful links:

1) GERMS South Africa Annual Report 2012. Available at: http://www.nicd.ac.za/assets/files/GERMS-SA%202012%20Annual%20Report.pdf

2) Guidelines for the management of acute meningitis in children and adults in South Africa http://www.sajei.co.za/index.php/SAJEI/article/viewFile/528/686

Information supplied by the National Institute for Communicable Diseases (NICD )