It can be caused by several different kinds of bacteria. Some of the more common bacteria that cause meningitis are H. influenzae, S. pneumoniae, and N. meningitidis.

The symptoms in adults and children can appear suddenly and include high fever, severe headache, stiff neck, discomfort with bright light, nausea, and vomiting. The symptoms in newborns may be subtle and include fever, lethargy, poor feeding, problems breathing, irritability, and vomiting. As the disease gets worse, the person may have seizures.

Even if treated, some types of bacterial meningitis can lead to brain damage, hearing loss, or learning disability. Because the first symptoms of bacterial meningitis and the much milder viral meningitis are so similar, you can't diagnose yourself. It's important to see your healthcare provider right away.

The Hib (Haemophilus influenzae type b) vaccine has reduced the number of cases of meningitis caused by this germ. Today, the leading causes of bacterial meningitis are S. pneumoniae and N. meningitidis. A vaccine is available for S. pneumoniae. It's recommended for people over age 65, people with a chronic illness such as diabetes or heart disease, and people who have a weakened immune system or who are HIV-positive. A vaccine for N. meningitidis, which causes meningococcal meningitis, is recommended for children ages 11 and 12, teenagers, and college freshman, as well as anyone between ages 2 and 55 who is at increased risk for getting the disease.

Some forms of bacterial meningitis are mildly contagious and can be spread through coughing or kissing. Most cases occur in children. But the incidence among teens and young adults 15 to 24 years old is increasing. Meningococcal meningitis, a form of meningitis caused by N. meningitidis, can spread easily wherever a large number of people live, such as among college students in dormitories. The CDC now recommends that children ages 11 and 12, teens, and college freshmen who live in dorms be vaccinated against this particular form of meningitis.

Because of this, the CDC recommends that adults 65 and older get a vaccine against S. pneumoniae, which causes pneumococcal meningitis.

But in some cases, the bacterial infection can progress so quickly that the person dies within 48 hours, even with treatment. The bacteria that cause meningitis are becoming resistant to many of the antibiotics that were once used to treat it. Newer, more expensive medicines must now be used.

A healthcare provider uses a physical exam and health history to diagnose meningitis. They then confirms the diagnosis through a sample of spinal fluid, obtained through a spinal tap. The results of the spinal tap can also help the provider find out whether the meningitis is caused by a bacteria or virus. It can also tell the provider which antibiotic will work best if it is a bacterial meningitis. Antibiotics do not affect the viral form of meningitis. This is usually a much milder disease that clears up within 10 days.