Things You Need to Know About Meningitis

Meningitis is an inflammation (swelling) of the protective membranes covering the brain and spinal cord. A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling.

The inflammation can be caused by infection with bacteria, virus or other microorganisms and less commonly by injuries, cancer and certain drugs.

It is very important to know that most infections are due to viruses, with bacteria, fungi, and protozoa being the next most common causes.

The knowledge of the exact cause of meningitis is very important as it help in the treatment because the treatment differs depending on the cause.

Although viral meningitis is the most common, it is less severe compared to bacterial meningitis.

Causes, Signs and Symptoms, Diagnosis and Treatment of Meningitis

Bacterial Meningitis

Bacterial meningitis is very serious and can be deadly. Death can occur in as little as a few hours. Most people recover from meningitis. But on the other hand, permanent disabilities (such as brain damage, hearing loss, and learning disabilities) can be the outcome from the infection.

Causes
The types of bacteria that cause bacterial meningitis differ according to the infected individual's age group.

For unborn and newborns up to three months old,the bacteria that causes meningitis are group B streptococci (subtypes III which normally inhabit the vagina and are mainly a cause during the first week of life) and bacteria that normally inhabit the digestive tract such as Escherichia coli. Listeria monocytogenes is transmitted by the mother before birth and may cause meningitis in the newborn.

Older children are more commonly affected by Neisseria meningitidis (meningococcus) and Streptococcus pneumoniae and those under five by Haemophilus influenzae type B.

In adults, Neisseria meningitidis and Streptococcus pneumoniae jointly cause 80% of bacterial meningitis cases. The risk of infection with Listeria monocytogenes is increased in persons over 50 years old.

These bacteria can also be associated with another serious illness, sepsis. Sepsis is the body’s overwhelming and life-threatening response to infection that can cause tissue damage, organ failure, and death.

Risk Factors

Certain people are at higher risk for bacterial meningitis. Some of the risk factors include:

Age

Babies are at higher risk for bacterial meningitis compared to people in other age groups. On the other hand, people of any age can develop bacterial meningitis.

Community Setting

Infectious diseases tend to spread where large groups of people gather together.

Some Medical Conditions

There are certain medical conditions, medications, and surgical procedures that put people at higher risk for meningitis.

Contact with meningitis-causing pathogens

Scientists routinely exposed to meningitis-causing bacteria are at increased risk for meningitis.

Travel

Travelers may be at high risk for meningococcal disease, caused by N. meningitidis, if they travel to certain meningitis endemic places.

How Bacterial Meningitis Spreads

In general, the microorganisms that cause bacterial meningitis spread from one person to another. Some microbes, such as Listeria monocytogenes, can spread through food.

The spread of the microbes by human depends on the type of bacteria. It is also important to know that people can carry these bacteria in or on their bodies without being sick. These people are “carriers.” Most carriers never become sick, but can still spread the bacteria to others.

Here are some of the most common examples of how people spread each type of bacteria to each other:

Mothers can pass group B Streptococcus and Escherichia coli to their babies during labour and birth.
People spread Hib and Streptococcus pneumoniae by coughing or sneezing while in close contact with others, who breathe in the bacteria.
People spread Neisseria meningitidis by sharing respiratory or throat secretions (saliva or spit). This typically occurs during close (coughing or kissing) or lengthy (living in the same household) contact.
People can get Escherichia coli by eating food prepared by people who did not wash their hands well after using the toilet.

People usually get sick from Escherichia coli and Listeria monocytogenes by eating contaminated food.

Signs and Symptoms of Bacterial Meningitis

The symptoms include sudden onset of fever, headache, and stiff neck. Other symptoms include;

Nausea
Vomiting
Photophobia (high sensitivity to light)
Altered mental status (confusion)

In newborns and babies, the meningitis symptoms of fever, headache, and neck stiffness may be absent or difficult to notice. The baby may be irritable, vomit, feed poorly, or appear to be slow or inactive.

Symptoms of bacterial meningitis can appear quickly or over several days. Typically they develop within 3 to 7 days after exposure

Apart for the signs and symptoms listed above, late symptoms of bacterial meningitis can be very serious (e.g., seizures, coma). Therefore, anyone who thinks they may have meningitis should see a doctor as soon as possible.

Diagnosis of Bacterial Meningitis

In someone suspected of having meningitis, samples of blood or cerebrospinal fluid (fluid near the spinal cord) are collected. These samples are tested in the laboratory to see the cause of the infection. It is important to know the specific cause of meningitis, so that the right treatment can be done.

Treatment of Bacterial Meningitis

Bacterial meningitis is treated with a number of antibiotics. It is important to start treatment as soon as possible.

Prevention of Bacterial Meningitis

The most effective way to parents and children against certain types of bacterial meningitis is to get vaccinated. There are vaccines for three types of bacteria that can cause meningitis:

Neisseria meningitidis
Streptococcus pneumoniae
Hib

Like 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 one can develop bacterial meningitis even if you were vaccinated.

Pregnant women can also reduce their risk of meningitis caused by Listeria monocytogenes. Women should avoid certain foods during pregnancy and safely prepare others.

Viral Meningitis

Viral meningitis is the most common type of meningitis, an inflammation of the tissue that covers the brain and spinal cord. It is often less severe than bacterial meningitis, and most people get better without treatment.

Nevertheless, it’s very important for anyone with symptoms of meningitis to see a healthcare provider on time because some types of meningitis can be very serious, and only a doctor can determine if you have the disease, the type of meningitis, and the best treatment, which can sometimes be lifesaving.

Babies younger than 1 month old and people with weakened immune systems are more likely to have severe illness from viral meningitis.

Causes of Viral Meningitis

Viruses that cause meningitis include enteroviruses, herpes simplex virus (generally type 2, which produces most genital sores; less commonly type 1), varicella zoster virus (known for causing chickenpox and shingles), mumps virus, HIV, and LCMV. Mollaret's meningitis is a chronic recurrent form of herpes meningitis; it is thought to be caused by herpes simplex virus type 2.

People at Risk

People can get viral meningitis at any age. However, some people have a higher risk of getting the disease, including

children younger than 5 years old, and
people with weakened immune systems caused by diseases, medications (such as chemotherapy), and recent organ or bone marrow transplantations.

Babies younger than 1 month old and people with weakened immune systems are more likely to have severe illness.

How Viral Meningitis Spreads

If one has close contact with a person who has viral meningitis, one may likely become infected with the virus that made that person sick. But, the person may not likely develop meningitis. That’s because only a small number of people who get infected with the viruses that cause meningitis will actually develop viral meningitis. Viruses that can cause meningitis spread in different ways.

Symptoms of Viral Meningitis

Common symptoms in babies

Fever
Irritability
Poor eating
Sleepiness or trouble waking up from sleep
Lethargy (a lack of energy)

Common symptoms in adults

Fever
Headache
Stiff neck
Sensitivity to bright light
Sleepiness or trouble waking up from sleep
Nausea
Vomiting
Lack of appetite
Lethargy (a lack of energy)

Most people with viral meningitis usually get better on their own within 7 to 10 days.

Initial symptoms of viral meningitis are similar to those for bacterial meningitis. But, bacterial meningitis is typically severe and can cause serious complications, such as brain damage, hearing loss, or learning disabilities.

Diagnosis of Viral Meningitis

Meningitis can only be diagnosed by doing specific lab tests on specimens from a person suspected of having meningitis. Samples can be collected for testing by

swabbing your nose and/or throat,
swabbing your rectum,
taking some blood, or
drawing fluid from around your spinal cord.

The stool may also be used for diagnosis.

Treatment of Viral Meningitis

In most cases, there is no specific treatment for viral meningitis. Most people who get viral meningitis completely recover on their own within 7 to 10 days.

However, people with meningitis caused by certain viruses such as herpesvirus and influenza, will usually need and get better from treatment such as an antiviral medicine.

Antibiotics do not help viral infections, so they are not useful in the treatment of viral meningitis. However, antibiotics do fight bacteria, so they are very important when treating bacterial meningitis.

People who develop severe illness, or at risk for developing severe illness, such as babies, and people with weakened immune systems may need to be hospitalized.

Prevention of Viral Meningitis

There are no vaccines to protect against non-polio enteroviruses, which are the most common cause of viral meningitis. You can take the following steps to help lower your chances of getting infected with non-polio enteroviruses or spreading them to other people:

Wash your hands often with soap and water, especially after changing diapers, using the toilet, or coughing or blowing your nose.

Avoid touching your face with unwashed hands.

Avoid close contact such as kissing, hugging, or sharing cups or eating utensils with people who are sick.

Cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your hands.

Clean and disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.

Stay home when you are sick.

Some vaccinations can protect against diseases such as measles, mumps, chickenpox, and influenza that can lead to viral meningitis. Avoid bites from mosquitoes and other insects that carry diseases that can infect humans.

Control mice and rats.

Outbreak of Meningitis in Nigeria

According to the report of World Health Organization (WHO), as of 19^th March 2017 (epidemiological week 11), a total of 1407 suspected cases of meningitis and 211 deaths (case fatality rate: 15%) have been reported from 40 local government areas (LGAs) in five states of Nigeria since December 2016. Zamfara, Katsina and Sokoto account for 89% of these cases. Twenty-six LGAs from all five states reported 361 cases in epidemiological week 11 alone.

Twenty-two wards in 15 LGAs have crossed the epidemic threshold. Three of these LGAs share borders with Niger. The most affected age group were 5 to 14 year olds and they are responsible for about half of reported cases. Both sexes are almost equally affected.

The report of the Federal Ministry of Health says that as of 11^th April, 2017 about 489 people had been killed in the outbreak of meningitis in Nigeria.

The report says that 4,637 cases of cerebrospinal meningitis were recorded across the country as at the time of the report. Among the cases, 171 were confirmed to be the Type C meningitis with Zamfara, Sokoto, Katsina, Niger and Kebbi states most affected.

In a bid to combat this outbreak, about 823,000 doses of conjugated Type C were delivered to the Federal Government by the UK government, while UNICEF had delivered over 1 million Type A of the vaccines.

The federal government had collaborated with the states governments and international development partners to tackle to the outbreak in some 26 states so far affected in the country.

References

Shalabi, M. & Whitley, R. J. (2006). "Recurrent Benign Lymphocytic Meningitis". Clinical Infectious Diseases. 43 (9), 1194–1197.

Tebruegge M, & Curtis, N. (Ju2008). "Epidemiology, etiology, pathogenesis, and diagnosis of recurrent bacterial meningitis". Clinical Microbiology Reviews. 21 (3), 519–3

"Bacterial Meningitis". CDC.

Viral Meningitis CDC

Outbreak of Meningitis in Nigeria WHO

Update on Meningitis in Nigeria FMOH

Labels: Educative Article