Winter brings with it a rise in many infectious diseases. During the peak of the influenza season, we also had two reported cases of meningitis. Every year around 11 local cases of bacterial meningitis are reported.
Meningitis is an inflammation of the membranes that surround the brain and spinal cord. Most cases of meningitis are caused by a viral infection, but bacterial, parasitic and fungal infections are other causes encountered. Some cases of meningitis improve without treatment in a few weeks. However, others can be life-threatening and require emergency treatment.
What are its symptoms?
Early meningitis symptoms may be very similar to those of a common cold or the flu. Symptoms may develop over several hours or over a few days. For children, the most common symptoms include sudden high fever, stiff neck, severe headache, headache with nausea or vomiting, sensitivity to light and reduced appetite.
In some cases, there is confusion or difficulty concentrating, and even seizures. In a specific type of bacterium, a skin rash may develop. The symptoms in newborns usually include high fever, constant crying, excessive sleepiness or irritability, inactivity or sluggishness, poor feeding and stiffness in the baby’s body and neck.
Medical care needs to be provided immediately if someone has a fever, severe unrelenting headache, confusion, vomiting and stiff neck. Bacterial meningitis is serious and can be fatal within days without prompt antibiotic treatment. The consequences of delayed treatment include increased risk of permanent neurological damage, hearing loss, memory difficulty, learning disabilities, brain damage, gait problems, seizures, kidney failure, shock and death.
What causes meningitis?
Meningitis can be caused by various microbes. Viral infections are the most common cause of meningitis. Viruses such as herpes simplex virus, HIV, mumps, West Nile virus and varicella are types of viruses that can cause viral meningitis.
Bacterial meningitis can be very serious. Several strains of bacteria can cause bacterial meningitis. The most common are:
Neisseria meningitidis (meningococcus). Meningococcal disease is caused by the bacterium Neisseria meningitidis. The bacterium is often detected in the back of the nose and throat without causing disease, a situation described as asymptomatic carriage, which is present in five to 10 per cent of people and which does not do any harm to the individual.
The bacteria occasionally invade the body and cause meningococcal infection, which is an acute severe bacterial infection. This bacterium is a leading cause of bacterial meningitis. It is most common in young children, followed by adolescents and young adults. A vaccine can help prevent infection from some types of this bacteria.
Streptococcus pneumoniae (pneumococcus). Asymptomatic carriage of the bacteria in the back of nose and throat with this bacterium is very common, ranging from 20 to 40 per cent in children and from five to 10 per cent in adults.
The organism may spread locally from the nasopharynx to the sinuses or middle ear cavity, causing sinusitis or ear infection. Sometimes this pathogen invades the body and causes bacteraemia, sepsis, meningitis and osteomyelitis. Meningitis from pneumococci is more common in infants, young children and adults. Transmission is from person to person by respiratory droplets. A vaccine can help prevent this infection.
Haemophilus influenzae (haemophilus). Haemophilus influenzae type b (Hib) bacterium was once the leading cause of bacterial meningitis in children. Haemophilus influenzae type b causes pneumonia, septicaemia, meningitis, epiglottitis, septic arthritis, cellulitis, otitis media and purulent pericarditis, as well as less common invasive infections such as endocarditis, osteomyelitis and peritonitis. Hib vaccines have greatly reduced the number of cases of this type of meningitis.
Are there risk factors?
There are many factors which increase the risk for meningitis. The first is skipping vaccinations. Risk rises for anyone who hasn’t completed the recommended childhood or adult vaccination schedule. There are vaccines that are on the national free vaccination schedule while others are available in the private sector. It is recommended to get all the vaccinations as these are effective and can save lives.
Every year around 11 local cases of bacterial meningitis are reported
Age also affects meningitis risk. Most cases of viral meningitis occur in children younger than five, while bacterial meningitis is common in those aged under 20. The risk for several forms of meningitis decreases after young adulthood. However, after the age of 60, the risk starts to rise again. This is because of underlying diseases or health conditions that weaken the immune systems of older people.
As with most infectious diseases, having a compromised immune system increases the risk. AIDS, alcoholism, diabetes, the use of immunosuppressant drugs and other factors that reduce immunity make a person more susceptible to meningitis. Having the spleen removed also increases the risk of getting meningitis.
What happens when a case is reported?
When the health authorities are notified of a case of meningitis, public health specialists carry out an urgent investigation and risk assessment to identify if any immediate public health measures need to be taken. The authorities liaise with the hospital in charge of the patient, as well as with the laboratory to confirm the diagnosis and the infectious agent causing meningitis.
If the meningitis is viral in nature, no additional public health measures are required. Viral meningitis is self-limiting and no prophylactic antibiotics or vaccine are recommended to close contacts of the patient.
In the case of bacterial meningitis, a detailed history is gathered from the patient and/or relatives to assist the authorities in their investigation and to identify the people who were in close contact with the patient. If indicated, prophylactic antibiotics and vaccines are offered to the identified close contacts. This varies in accordance with the causative agent, and any measures taken follow evidence-based protocols.
Whenever needed, the authorities also organise meetings with the school or workplace frequented by the patient to address any concerns and disseminate information. In addition, further follow-up is carried out on clinical samples to identify the strain of the bacteria causing the meningitis.
How can I help prevent meningitis?
Prevention is possible in many instances. Most of the bacteria and viruses that can cause meningitis are spread through coughing, sneezing, kissing or sharing eating utensils and close contact. The following measures are recommended to lower the risk of contracting meningitis:
Washing of hands. Careful hand-washing helps prevent the spread of germs. It is important to wash hands often, especially before eating and after using the toilet, spending time in a crowded public place or petting animals.
Practice good hygiene. Don’t share drinks, foods, straws, eating utensils, lip balms or toothbrushes with anyone else.
Stay healthy. Maintain your immune system by getting enough rest, exercising regularly and eating a healthy diet with plenty of fresh fruits, vegetables and whole grains.
Cover your mouth. When you need to cough or sneeze, be sure to cover your mouth and nose and dispose of tissues safely.
If you’re pregnant, take care with food. A bacterium called Listeria can also cause meningitis. One can reduce the risk of Listeria infection by cooking meat properly to a temperature of over 74ºC and by not eating cheeses made from unpasteurised milk.
The best protection for certain forms of bacterial meningitis is through immunisation. There are vaccines for three types of bacteria which can cause meningitis.
Haemophilus influenzae type b (Hib) vaccine. This vaccine is on the free national schedule and children receive this vaccine in four doses at the ages of six weeks, three months, four months and 18 months.
Pneumococcal vaccine (PCV). The pneumococcal conjugate vaccine (PCV10 and PCV13) protect against pneumococcal infections. It is best to be given in the first year of life. This is usually given in regimes of three or four doses. Additional doses are recommended for children between the ages of two and five who are at high risk of pneumococcal disease, including children who have chronic heart or lung disease or cancer.
Pneumococcal polysaccharide vaccine (PPSV23). Older children and adults who need protection from pneumococcal bacteria may receive this vaccine.
Meningococcal conjugate vaccine. There are two kinds of meningococcal vaccines. The meningococcal conjugate vaccine protects against four types of meningococcal bacteria (types A, C, W, and Y) and the meningococcal B vaccine (MenB) protects against a fifth type of meningococcal bacterium (called type B).
Meningitis can be very serious. Knowing more about the condition, early identification of symptoms and referral to medical care and taking preventative measures can help to reduce the risks posed by this infection.
Professor Charmaine Gauci is Superintendent of Public Health.