If you are heading off to college or to join the military, you doctor may have warn you about the risk of meningitis. That’s because people who live in close proximity in a large group setting, such as a dormitory or barracks, are at increased risk for the condition.
“Meningitis is an inflammation of the tissues between the brain and the skull, usually caused by an infection,” says UNC Health infectious diseases specialist Joseph Alexander Duncan, MD. “Bacterial infections of meningitis are generally fatal if untreated, so it’s important to recognize the symptoms.”
We spoke to Dr. Duncan about the causes, symptoms and treatment of meningitis.
Causes of Meningitis
Viral and bacterial infections are the most common causes of meningitis, though it can also be caused by parasites, fungi, chemicals and some medications.
Viral meningitis is the most common type of meningitis. Many common viruses, including those that cause colds, flu and gastrointestinal symptoms, can also lead to meningitis.
Several types of bacteria can lead to bacterial meningitis.
- Neisseria meningitidis is the most dangerous, though not the most common form of bacterial meningitis. Meningitis of this type is called meningococcal disease, and cases have jumped in the United States in recent years, to 415 in 2023, according to the Centers for Disease Control and Prevention. People with this infection get sick quickly and become rapidly worse in a short period of time.
- Streptococcus pneumoniae is the most common form of bacterial meningitis, causing an estimated 2,000 cases in the United States per year. It leads to a variety of conditions, including pneumonia and sinus infections, particularly in infants and young children.
- Haemophilus influenzae, a bacterium that causes pneumonia and ear infections, used to be a major source of bacterial meningitis, but the Hib vaccines, given to children younger than 5 years old, have led to a major reduction in cases.
N. meningitidis, S. pneumoniae and H. influenzae are all carried in respiratory droplets and passed from person to person, but the foodborne bacteria Listeria monocytogenes can also cause meningitis.
Meningitis Symptoms
Viral and bacterial meningitis have the same symptoms. The most common are fever and headaches, usually accompanied by neck stiffness. In their mild form, these symptoms sometimes are mistaken for other conditions, such as the flu.
“While headaches are generally common, a severe headache with a fever is a good reason to seek medical care, especially if the headache seems to be getting worse over a few hours,” Dr. Duncan says.
In severe cases of meningitis, people can experience nausea and vomiting due to pressure in the brain. They might also lose consciousness or show confusion or changes in personality. Infections caused by N. meningitidis typically also include rashes and bruising on the extremities.
“Viral meningitis is not as dangerous as bacterial meningitis, but a person won’t be able to tell whether their symptoms are caused by a virus or bacteria without seeing a physician,” Dr. Duncan says. “If you are experiencing symptoms, you want to prevent them from progressing to a dangerous stage.”
Meningitis Diagnosis and Treatment
Meningitis is diagnosed with a lumbar puncture to measure pressure in the cerebrospinal fluid. Doctors will begin treatment immediately while the fluid is sent to a lab to confirm the cause of the infection, which may take a few days.
“Because of the severity of bacterial meningitis, the protocol is to treat for bacterial meningitis until the cause is proved otherwise,” Dr. Duncan says.
When the lumbar puncture indicates bacterial meningitis, intravenous antibiotics are administered that are designed to treat the most common bacterial infections.
The stakes are high. If the meningitis is caused by N. meningitidis, as many as 1 in 5 people have long-term issues related to the illness, including loss of hearing, loss of a limb and brain damage, and 10 to 15 percent of people die, even if treated with antibiotics.
Viral meningitis, on the other hand, typically does not require treatment, as viruses don’t respond to antibiotics. Dr. Duncan says acetaminophen or ibuprofen can help with symptom relief for viral meningitis.
Fortunately, bacterial meningitis is relatively rare in the United States, thanks to vaccines. The CDC recommends meningococcal, pneumococcal and Hib vaccines for children, which reduce the risk for the major causes of bacterial meningitis.
Concerned about a meningitis infection? Talk to your doctor. Need a doctor? Find one near you.