Meningitis is an inflammation of the membranes (meninges) surrounding your brain and spinal cord.The swelling from meningitis typically triggers symptoms such as headache, fever and a stiff neck.Most cases of meningitis in the United States are caused by a viral infection, but bacterial, parasitic and fungal infections are other causes. Some cases of meningitis improve without treatment in a few weeks. Others can be life-threatening and require emergent antibiotic treatment.
Symptoms
Early meningitis symptoms may mimic the flu (influenza). Symptoms may develop over several hours or over a few days.
Possible signs and symptoms in anyone older than the age of 2 include:
- Sudden high fever
- Stiff neck
- Severe headache that seems different than normal
- Headache with nausea or vomiting
- Confusion or difficulty concentrating
- Seizures
- Sleepiness or difficulty waking
- Sensitivity to light
- No appetite or thirst
- Skin rash (sometimes, such as in meningococcal meningitis)
- Signs in newborns
Newborns and infants may show these signs:
- High fever
- Constant crying
- Excessive sleepiness or irritability
- Inactivity or sluggishness
- Poor feeding
- A bulge in the soft spot on top of a baby’s head (fontanel)
- Stiffness in a baby’s body and neck
Types of meningitis:
Viral and bacterial infections are the most common causes of meningitis. There are several other forms of meningitis. Examples include cryptococcal, which is caused by a fungal infection, and carcinomatous, which is cancer-related. These types are less common.
Viral meningitis
Viral meningitis is the most common type of meningitis. Viruses in the Enterovirus category cause 85 percent of cases. These are more common during the summer and fall, and they include:
- coxsackievirus A
- coxsackievirus B
- echoviruses
Viruses in the Enterovirus category cause about 10 to 15 million infections per year, but only a small percentage of people who get infected will develop meningitis.
Bacterial meningitis
Bacterial meningitis is contagious and caused by infection from certain bacteria. It’s fatal if left untreated. Between 5 to 40 percent of children and 20 to 50 percent of adults with this condition die. This is true even with proper treatment.
The most common types of bacteria that cause bacterial meningitis are:
Streptococcus pneumoniae, which is typically found in the respiratory tract, sinuses, and nasal cavity and can cause what’s called “pneumococcal meningitis”
Neisseria meningitidis, which is spread through saliva and other respiratory fluids and causes what’s called “meningococcal meningitis”
Haemophilus influenza, which can cause not only meningitis but infection of the blood, inflammation of the windpipe, cellulitis, and infectious arthritis
Listeria monocytogenes, which are foodborne bacteria
Staphylococcus aureus, which is typically found on the skin and in the respiratory tract, and causes “staphylococcal meningitis”
Fungal meningitis
Fungal meningitis is a rare type of meningitis. It’s caused by a fungus that infects your body and then spreads from your bloodstream to your brain or spinal cord.
People with a weakened immune system are more likely to develop fungal meningitis. This includes people with cancer or HIV.
The most common funguses related to fungal meningitis include:
- Cryptococcus, which is inhaled from dirt or soil that is contaminated with bird droppings
- Blastomyces, another type of fungus found in soil, particularly in the Midwestern United States
- Histoplasma, which is found in environments that are heavily contaminated with bat and bird droppings, especially in the Midwestern States near the Ohio and Mississippi Rivers
- Coccidioides, which is found in soil in specific areas of the U.S. Southwest and South and Central America
Parasitic meningitis
This type of meningitis is less common than viral or bacterial meningitis, and it’s caused by parasites that are found in dirt, feces, and on some animals and food, like snails, raw fish, poultry, or produce.
One type of parasitic meningitis is rarer than others. It’s called eosinophilic meningitis (EM). Three main parasites are responsible for EM. These include:
- Angiostrongylus cantonensis
- Baylisascaris procyonis
- Gnathostoma spinigerum
- Parasitic meningitis is not passed from person to person. Instead, these parasites infect an animal or hide out on food that a human then eats. If the parasite or parasite eggs are infectious when they’re ingested, an infection may occur.
Causes of meningitis:
Each type of meningitis has a slightly different cause, but each ultimately acts in the same way: A bacterium, fungus, virus, or parasite spreads through the bloodstream until it reaches the brain, or spinal cord. There, it sets up in the lining or fluids around these vital body parts and starts developing into a more advanced infection.Non-infectious meningitis is the result of a physical injury or other condition; it doesn’t involve an infection.
How is meningitis treated?
Your treatment is determined by the cause of your meningitis.
Bacterial meningitis requires immediate hospitalization. Early diagnosis and treatment will prevent brain damage and death. Bacterial meningitis is treated with intravenous antibiotics. There’s no specific antibiotic for bacterial meningitis. It depends on the bacteria involved.
Fungal meningitis is treated with antifungal agents.
Parasitic meningitis may either involve treating just the symptoms or attempting to treat the infection directly. Depending on the cause, this type may get better without antibiotic treatment. If it worsens, however, your doctor may try to treat the infection itself.
Viral meningitis may resolve on its own, but some causes of viral meningitis will be treated with intravenous antiviral medications.
How contagious is meningitis?
Several types of meningitis are not contagious. Fungal, parasitic and non-infectious meningitis are not contagious.Viral meningitis is contagious. It’s spread through direct contact with body fluids, including mucus, feces, and saliva. Droplets of infected fluid can be spread and shared with sneezing and coughing. You do not have to come into direct contact with an infected person to pick up this infection.Bacterial meningitis, the most serious form of meningitis, can also be contagious, especially if it’s meningococcal meningitis. It’s spread through extended contact with an infected person. Schools, daycare centers, military barracks, hospitals, and college dormitories are prime locations for sharing this infection. Some types of meningitis are spread through person-to-person contact but not all. Learn more about the types that are contagious and how you can avoid them.
