World Meningitis Day was observed recently. Meningitis is the commonest infection of the central nervous system. It is an infection of the lining of the brain and spinal cord. It is caused by a viral or bacterial infection. Causes vary from common infections, viruses, bacteria, fungi and parasites. Symptoms can present from acute to chronic, the duration and symptoms depending on the age, immune status and other factors of the patient as well as the responsible organism.The disease if not detected in time and treated, can lead to adverse health impacts. Yet, very few people including young medical professionals fully understand the implications of this disease.
The Sunday Observer spoke to Consultant microbiologist, Sri Jayawardenepra Hospital for more insights into this disease Dr Kushlani Jayatilleke, how it is caused and available treatment. She also offers simple hygienic rules to follow to prevent it. Following are excerpts ...
Excerpts of the interview;
Q. What are the causes of meningitis?
A. Commonly infections. Viruses, bacteria, fungi and parasites can cause meningitis. Also it can be caused rarely with non-infectious diseases such as cancers.
Q. What are the features of meningitis?
A. Meningitis can present as acute, that is, presenting with severe symptoms of a short duration, or sub-acute or chronic, with gradual low grade symptoms over weeks to months or even years, depending on the age, immune status and other factors of the patient, as well as the responsible micro-organism.
The common clinical features of meningitis are, fever, headache, photophobia (increased sensitivity to light) and altered mental status.This may vary from drowsiness, confusion and disorientation to coma, depending on the severity of the infection.
In some patients the inflammation may spread to the adjacent brain (sometimes referred to as meningo-encephalitis) and cause seizures.
Q. What are the viruses responsible for meningitis?
A. Most often enteroviruses, but also HIV, mumps virus, and herpes simplex viruses are responsible for acute meningitis.
Q. What are the bacterial causes of meningitis?
A. The bacteria responsible for acute meningitis vary according to age group:
Neonates (in the 1st 28 days of life): Group B Streptococcus, Listeria monocytogenes, Escherichia coli
Children older than 1 month : : Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b (Hib), group B Streptococcus
Adults: Streptococcus pneumoniae, Neisseria meningitidis,
Adults older than 65 years: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b (Hib), group B Streptococcus, Listeria monocytogenes Chronic or subacute meningitis can be caused by mycobacteria (especially, Mycobacterium tuberculosis), spirochetes (e.g., Treponema pallidum and Borreliaburgdorferi), and fungi (e.g., Cryptococcus neoformans and Coccidioidesspp.)
Q. What is the outcome of this disease?
A. Viral meningitis can be mild and self-limiting. If not treated early with the appropriate antibiotics in correct doses, most patients with bacterial meningitis will die and some will have permanent disabilities such as brain damage, hydrocephalus (enlargement of the fluid containing cavities of the brain), hearing loss, and learning disabilities.
Q. How can meningitis be diagnosed?
A. Blood and Cerebrospinal fluid (CSF) for culture will be obtained prior to starting antibiotics whenever possible. CSF is the fluid in the brain and the spinal cord. Doctors will have to draw some fluid through a lumbar puncture, or “spinal tap” by inserting a needle into the space between two vertebrae in the lower spine. This is a relatively safe procedure and done using a local anaesthetic.
Q. What is the treatment for bacterial meningitis?
A. Early treatment of bacterial meningitis with appropriate antibiotics in high doses, usually, intravenously (through a vein) is critical. Duration of treatment may vary from a minimum of two weeks up to one year (in meningitis due to TB).
Supportive therapy is also important to control inflammation, control brain swelling and manage complications such as seizures.
Q. How does meningitis spread?
A. Most bacteria that cause meningitis spread from one person to another. Certain bacteria, such as Listeria monocytogenes, can spread through food.
Some people may carry this bacteria in their body without getting sick. They can spread these bacteria to other individuals who are prone to get this infection and then they become sick.
Example:
Group B Streptococcus and Escherichia coli are organisms which can be found in the genital areas of females. When these organisms are spread to their babies during labour they can develop meningitis.
Hib and Streptococcus pneumoniae can be found in the upper respiratory tract of healthy persons and by coughing or sneezing while in close contact with others these bacteria can spread to another via the respiratory system. Neisseria meningitidis can be in the upper respiratory tract of healthy people and can spread by respiratory or throat secretions (saliva or spit).
This typically occurs during close (coughing or kissing) or lengthy (living in the same household) contact. Listeria monocytogenes is found in soil and water. Vegetables can become contaminated from the soil or from manure used as fertilizer.
Animals can carry the bacterium without appearing ill and can contaminate foods of animal origin such as meat and dairy products.Listeria monocytogenes can spread by eating contaminated food, especially, milk and meat products and vegetables.
Pregnant women are at increased risk of developing listeriosis, an infection caused by the bacteria Listeria monocytogenes.
Pregnant women with listeriosis typically experience only fever and other flu-like symptoms, such as, fatigue and aches. Infection during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn, including meningitis.
Q. How can we prevent getting meningitis?
A. The most effective way to protect you and your child against certain types of bacterial meningitis is to get vaccinated. There are vaccines for three types of bacteria that can cause meningitis:
- Hib
- Streptococcus pneumoniae
- Neisseria meningitidis
In Sri Lanka, Hib vaccine is now incorporated into the pentavalent vaccine given at 2, 4 and 6 months of age.
As with any vaccine, the vaccines that protect against these bacteria are not 100% effective.
The vaccines also do not protect against all the types (strains) of each bacteria. For these reasons, there is still a chance for you to develop bacterial meningitis even if you were vaccinated. Pregnant women will be given antibiotics at labour to prevent meningitis and other infections with group B Streptococcus(GBS)in the baby, in following conditions:
- GBS carriage (positive high Vaginal Swab culture)
- GBS bacteriuria( positive urine culture) previously GBS infected baby
- maternal pyrexia (fever) in labour (≥ 38o C)
- rupture of membranes ≥ 18 hours
Pregnant women, people 65 years and older and people with compromised immunity can reduce the risk of meningitis caused by Listeria monocytogenes in their babies (pregnant women) or in them by avoiding certain food items such as, milk products like cheese and yoghurt made of unpasteurised milk or not hygienically prepared salads, raw or partially cooked meat
For the high risk categories of people mentioned above washing hands well after food preparation is also important. If someone has bacterial meningitis, a doctor may recommend antibiotics to help prevent other people from getting sick. Doctors call this prophylaxis.
Prophylaxis is recommended for:
Close contacts of someone with meningitis caused by Neisseria meningitidis
Family members, especially, if they are at increased risk, of someone with a serious Hib infection
You can also help protect yourself and others from bacterial meningitis by maintaining healthy habits:
- Don’t smoke, and avoid cigarette smoke
- Get plenty of rest
- Avoid close contact with people who are sick
This is especially important for people at increased risk of the disease, including:
Young babies, older adults, people with weak immune systems, people without a spleen or a spleen that doesn’t work the way it should (functional asplenia)