What is Meningitis?
Meningitis is an inflammation of the meninges, or the membranes that cover the brain and spinal cord. Meningitis occurs when the fluid surrounding these membranes gets infected.
The two most common causes of meningitis are viral and bacterial infections, but there are other ways to contract meningitis, including:
- chemical irritation
- drug allergies
Some types of viral and bacterial meningitis are contagious and can be transmitted by coughing, sneezing, or close contact.
What Causes Meningitis?
The causes of meningitis usually derive from either a bacterial or a viral infection that begins in the body besides the brain, like your ears, sinuses, or throat.
However, there are several other forms of meningitis, such as cryptococcal, caused by a fungal infection, and carcinomatous, which is cancer-related. These are much less common than bacterial or viral infections.
Viral meningitis is the most common type of meningitis, and make up about 85 percent of cases. This type usually happens most often during the summer and fall, and they include:
- coxsackievirus A
- coxsackievirus B
Other viruses can cause meningitis. These include:
- West Nile virus
- herpes viruses
- Coltivirus, which causes Colorado tick fever
Viral meningitis usually goes away without treatment. However, some of the more severe cases and their causes should be treated by medical professions.
Bacterial meningitis is the other most common form of meningitis. It’s very contagious and is caused by an infection from certain kinds of bacteria, and can be fatal if left untreated.
Some of the most common types of bacteria that cause bacterial meningitis are:
- Streptococcus pneumoniae, found in the respiratory tract, sinuses, and nasal cavity and can cause what’s called “pneumococcal meningitis”
- Neisseria meningitidis, spread through saliva and other respiratory fluids and causes what’s called “meningococcal meningitis”
- Haemophilus influenza, can cause both meningitis but also a blood infection, inflammation of the windpipe, cellulitis, and infectious arthritis
- Listeria monocytogenes, which is foodborne bacteria
- Staphylococcus aureus, typically found on the skin and in the respiratory tract, and causes “staphylococcal meningitis”
Fungal meningitis is rarer than the other types of meningitis which is caused by a fungus that infects the body and spreads from the bloodstream to the brain or spinal cord.
Those with a weakened immune system are more likely to develop this type of infection, including people with certain cancers or HIV.
The most common funguses related to fungal meningitis are:
- Cryptococcus, inhaled from dirt or soil contaminated with bird droppings
- Blastomyces, also found in soil, particularly in the Midwestern United States
- Histoplasma, found in environments heavily contaminated with bat and bird droppings, such as the Midwestern States near the Ohio and Mississippi Rivers
- Coccidioides, found in soil in specific areas of the U.S. Southwest and South and Central America
This type of meningitis is also less common than other types of meningitis infections, and is caused by parasites found in dirt, feces, and on some animals and food, such as snails, raw fish, poultry, or produce.
Parasitic meningitis isn’t passed from person to person, but instead by parasites that infect an animal or are found in food that humans eat. If the parasite or its eggs are infectious when ingested, a parasitic meningitis infection can occur.
Non-infectious meningitis is not an infection, but rather a type of meningitis caused by previous medical conditions or treatments, such as:
- a head injury
- brain surgery
- certain medications
Is Meningitis Contagious
Most bacterial meningitis infections are mildly to moderately contagious.
Some types viral of meningitis are contagious but other types are not.
Fungal, parasitic, and noninfectious meningitis are not considered contagious from one person directly to another.
How Long is Meningitis Contagious
The amount of time meningitis is contagious depends on which infectious agents are causing the sickness. Generally, when an infected person is secreting or producing viruses or bacteria, they’re considered contagious, and when they stop secreting or producing infectious agents they’re no longer considered contagious.
Viral meningitis can be contagious from 3 days after infection starts to about 10 days after symptoms develop.
Bacterial meningitis is usually less contagious than viral meningitis. It’s generally contagious during the incubation period and an additional 7 to 14 days. It’s also possible for it to be contagious for a lot longer if the infected person becomes a carrier.
Contagious periods may be shortened with antibiotic treatments from a medical professional.
When Should You Seek Medical Attention for Meningitis
Meningitis, especially bacterial meningitis, is considered a medical emergency.
If you think you’ve been exposed to any type of meningitis, you should contact a medical caregiver as soon as possible.
Infants infected with certain types of meningitis may develop a firm or bulging soft spot on their heads. And at any age, people exposed to meningitis can experience seizures, altered consciousness, and difficulty breathing. People with these types of symptoms should immediately seek emergency medical care.