Different types of meningitis

Types of Meningitis

What is meningitis?

Meningitis is an inflammation of the fluid and membranes that cover the brain and spinal cord. Every year over 1 million1-3 people worldwide are affected by meningitis. Infection is by far the most common cause of meningitis and is caused by many different germs: viruses, bacteria, fungi and parasites.

  • Bacterial meningitis

Bacterial meningitis is aggressive, develops quickly within a few hours and can lead to permanent disability or death in a matter of hours.

It is fatal in up to 10 to 20% of cases and accounts for around 170,000 deaths around the world each year1. The great majority of these deaths occur within 24-48 hours after the onset of symptoms.

Most cases of bacterial meningitis are caused by Neisseria meningitidis (the meningococcus) , Streptococcus pneumoniae (the pneumococcus) and Haemophilus Influenzae Type B (Hib) .

There are different types of all three bacteria called serogroups or serotypes. For example, meningococcus serogroups A, B, C, W and Y are responsible for over 95% of meningococcal meningitis and septicaemia cases.

Septicaemia (blood poisoning) is a potentially life-threatening infection that occurs when the bacteria that cause meningitis get into the bloodstream. The infection may be seen alone or in addition to meningitis.

Many people carry meningitis bacteria in their nose and throat. These bacteria usually cause no harm and help to build up immunity against infection. Only on rare occasions do the bacteria invade the body and cause disease. .

The bacteria spread from person to person through respiratory droplets for example, by coughing and close contact such as kissing)

Other bacteria that can cause meningitis include Escherichia coli and Group B Streptococcus (common causes of neonatal meningitis) and Mycobacteria tuberculosis (TB).

There are vaccines available for many types of bacterial meningitis. Read more about meningitis prevention and treatment.

  • Viral meningitis

Viral meningitis is the most common kind of meningitis and is usually less severe. Most patients recover without any permanent damage, although full recovery can take many weeks or months.
Many viruses can cause meningitis, and these usually spread through respiratory droplets (kissing, coughing, sneezing) or by faecal contamination. The most common group, enteroviruses, live in the respiratory and intestinal tracts and can cause colds and sore throats usually with fever, headache, and muscles aches. From time to time, enteroviruses spread to the meninges and cause meningitis.

The mumps virus can also cause meningitis, but due to the combined measles-mumps-rubella vaccine (MMR), this form of meningitis is now rare in countries with high MMR immunisation rates.
Vaccines are not available to protect against many types of viral meningitis, but good hygiene can help prevent spread.

  • Fungal meningitis

Fungal meningitis can be severe but occurs infrequently.

Fungal meningitis is not contagious and spreads by inhaling fungal spores from the environment. Most cases occur in people with impaired immune systems, including people with AIDS.

Vaccines are not available to protect against fungal meningitis.

Other Types of Meningitis

It is also possible to contract meningitis from parasites or through non-infectious means like cancers, lupus, certain drugs, head injuries, brain surgery, or an existing condition of the skull or spine.

Contact your local healthcare professional about the vaccines available in your country that prevent meningitis.

  1. Murray CJL, Vos T, Naghavi, et al. Disability-adjusted life years (DALYS) for 291 diseases and injuries in 21 regions, 1990-2010: a systemic analysis for the Global Burden of Disease Study. Lancet 2012;380:2197-223.
  2. Paireau J, Chen A, Brautin H, et al. Season dynamics of bacterial meningitis: a time-series analysis. Lancet Glob Health 2016;4:e470-7.
  3. McIntyre PB, O’Brien KL, Greenwood B, van de Beck D. Effect of vaccines on bacterial meningitis worldwide. Lancet 2012; 380: 1703–11

PMC

Bacterial meningitis is a very serious disease

Each year there are over 1000 cases of bacterial meningitis in Canada. At least 50 species of bacteria can cause meningitis. Most cases are caused by one of the following bacteria:

  • Meningococcus (scientific name Neisseria meningitis)

  • Pneumococcus (scientific name Streptococcus pneumoniae)

  • group B streptococcus (scientific name Streptococcus agalactiae)

  • E coli (scientific name Escherichia coli)

The following are now uncommon causes of bacterial meningitis in Canada.

  • H flu b or Hib (scientific name Haemophilus influenzae type b)

  • Listeria (Scientific name Listeria monocytogenes)

  • Tuberculosis or TB (scientific name Mycobacterium tuberculosis)

Before 1992, Hib was the most common cause of bacterial meningitis. Most cases occurred in children younger than five years of age. It is very rare in Canada now because all infants are immunized with a very effective Hib vaccine, starting at two months of age.

Listeria meningitis occurs mainly in newborn babies, elderly people and people with immune systems weakened by diseases such as cancer and human immunodeficiency virus (HIV), or treatment such as an organ transplantation. Only a few cases of Listeria meningitis occur each year in Canada, but the death rate is up to 30%.

TB meningitis can occur at any age, but is most frequent in infants. It is not common in Canada. Diagnosis can be difficult because unlike other bacterial forms of meningitis, it most often develops slowly over time rather than over one to three days.

Viral meningitis is more common, but generally less serious, than bacterial meningitis. Almost all patients with viral meningitis recover completely, and it is rarely life-threatening.

Fungal meningitis is quite rare. The following types of fungus can cause meningitis.

  • Candida albicans is a fungus that normally causes thrush. In rare cases, the fungus can cause a dangerous form of meningitis, primarily in premature babies with a very low birth weight or in persons with disorders of the immune system.

  • Cryptococcus neoformans is a fungus that is commonly found in soil. It causes most cases of fungal meningitis. It generally only occurs in people with AIDS, cancer or diabetes. It is life-threatening and requires treatment with antifungal drugs.

  • Histoplasma is a common fungus commonly found in soil in some parts of Canada. It can cause meningitis and other illnesses in people with disorders of the immune system (AIDS, cancer, etc).

Understanding the 5 Types of Meningitis

How much do you know about meningitis? You may have heard that the disease involves an inflammation of the protective membranes surrounding the brain and spinal cord, and you may know that it can be life-threatening.

And while meningitis is most often caused by bacteria or a virus, did you know that physical injury, illness, and certain medications can also lead to the condition? There are actually five types of meningitis — bacterial, viral, parasitic, fungal, and non-infectious — each classified by the cause of the disease.

Symptoms are similar for each type of meningitis, but there are some differences, says Lorene Cathey, RN, MSN, manager of infection prevention at The University of Tennessee Medical Center in Knoxville. The severity and treatment of the disease differs depending on the cause, so identifying which type a person has is important so he can get the right treatment.

Here’s what you should know about the different types of meningitis.

Bacterial Meningitis

Bacterial meningitis is a potentially life-threatening form of the disease that can cause serious complications such as brain damage, hearing loss, and ultimately death if not diagnosed and treated promptly. This form of meningitis usually occurs when bacteria gets into the bloodstream and travels to the brain and spinal cord. Types of bacteria that can cause bacterial meningitis include Haemophilus influenzae (usually type b), Streptococcus pneumoniae, and Neisseria meningitidis. These bacteria can spread from person to person through coughing and sneezing or saliva transfer during kissing or mouth-to-mouth resuscitation. Certain forms of bacterial meningitis can be caused by eating contaminated food, though sometimes the source is never known.

Sudden onset of symptoms such as headache, fever, and stiff neck is common with bacterial meningitis. Other symptoms, such as rash, nausea and vomiting, light sensitivity, and confusion may appear, typically within three to seven days of exposure to disease-causing germs. The symptoms of bacterial meningitis often get mistaken for the flu, which can make diagnosis difficult. Bacterial meningitis can be treated with antibiotics, so it’s important to seek treatment as soon as possible.

The best way to protect yourself from bacterial meningitis is to get vaccinated. “Some forms of bacterial meningitis can be prevented by vaccination,” Cathey says. “Meningococcal vaccines protect against most types of meningococcal disease, although they do not prevent all cases.” Pneumococcal conjugate and polysaccharide vaccines are recommended for specific age groups and individuals with certain risk factors, she adds. Haemophilus influenza type b, or Hib, vaccination is recommended for all children younger than 5 years old in the U.S., and it is usually given to infants starting at 2 months old. “Individuals fully vaccinated against Hib may also need additional doses, and unimmunized older children, adolescents, and adults with certain medical conditions should receive Hib,” Cathey says.

Viral Meningitis

Viral meningitis is more common than bacterial meningitis, and usually less severe. Most cases of viral meningitis are caused by enteroviruses, but other common viruses such as measles, mumps, and chicken pox, as well as some viruses spread through mosquitos or other insects, can also lead to the disease.

Viral meningitis has the same types of symptoms as bacterial meningitis, including sudden fever, headache, and stiff neck, but it’s different in that it’s aseptic, meaning bacteria will not grow in the cerebrospinal fluid. It often resolves on its own, without specific treatment, although it may be treated with antiviral medication. In some cases, it can be fatal, depending on factors such as the type of virus causing the infection, the patient’s age, and whether he or she has a weakened immune system.

This form of meningitis can be spread by fecal contamination, typically when proper hand washing isn’t practiced after changing diapers or using the toilet. The enteroviruses that cause viral meningitis can also spread through eye, nose, and mouth secretions, or blister fluid, Cathey says. To prevent viral meningitis, wash your hands thoroughly and often, avoid direct contact with someone who has the disease, and make sure you have been vaccinated against measles, mumps, rubella, and chicken pox.

Parasitic Meningitis

A parasite called Naegleria fowleri is the source for primary amebic meningoencephalitis (PAM), a very rare type of parasitic meningitis. This form of the disease causes a brain infection that progresses rapidly — one to 12 days on average, Cathey says — and is usually fatal. In fact, of the 31 confirmed cases of PAM in the U.S. between 2003 and 2012, all were fatal. Standard meningitis symptoms appear one to seven days after infection, potentially followed by confusion, loss of balance, seizures, hallucinations, and lack of attention to your surroundings.

Naegleria fowleri has been detected all over the world in warm freshwater sources (such as lakes, rivers, and hot springs), soil, warm water discharged from industrial sources, poorly treated swimming pools, and water heaters. The microscopic organism enters the body through the nose and travels to the brain where it begins to destroy brain tissue. Parasitic meningitis cannot be transferred by person-to-person contact.

Fungal Meningitis

Another rare form of meningitis, fungal meningitis, occurs when a fungus enters the bloodstream. Anyone can get this form of the disease, but people with a weakened immune system are at an increased risk. Fungal meningitis is most often caused by inhaling fungal spores from contaminated soil or from bird or bat droppings. Treatment consists of long courses of high-dose antifungal drugs, usually administered in the hospital through an IV. The type of fungus and state of the patient’s immune system determine the length of treatment.

Non-Infectious Meningitis

Like parasitic and fungal meningitis, non-infectious meningitis cannot be caught from another person. It typically occurs as the result of cancer, lupus, a head injury, brain surgery, or from certain medications. Symptoms are typical of meningitis in general — a sudden onset of fever, stiff neck, and headache, and possibly nausea and vomiting, light sensitivity, and an altered mental state.

Meningitis (all types)

Some forms of bacterial meningitis can be prevented by vaccination:

  • Haemophilus influenzae type b – Hib vaccine is recommended as part of the National Immunisation Program and is available free for all children at 6 weeks, 4 months, 6 months and 12 months of age and is administered in a combination vaccine.
  • Meningococcal
    • a vaccine is available for the meningococcal B strain; however, this vaccine is not currently on the National Immunisation Schedule; for more information visit your GP or immunisation provider.
    • a vaccine for meningococcal C strain is recommended as part of the National Immunisation Program and the vaccine is available free for all children at 12 months of age.
    • a vaccine against meningococcal A, C, W and Y strains is being offered free to all Year 10 students in Queensland through the School Immunisation Program in 2017, and to young people 15 to 19 years of age through their doctor or immunisation provider from June 2017 until May 2018.
    • Pneumococcal – pneumococcal vaccine is recommended as part of the National Immunisation Program and is available free for all children at 6 weeks, 4 months, 6 months with additional doses for children in certain high-risk groups.

    See the specific fact sheets listed below for further information on vaccination.

    The spread of viruses that can cause viral meningitis can be minimised by simple measures. In particular you should wash your hands thoroughly, with warm soapy water for at least 15 seconds, after going to the toilet, blowing your nose, and before eating.

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