Staphylococcal meningitis, SM, is a bacterial infection affecting the meninges, the protective covering around your spinal cord and brain. The condition is rare and can be fatal. SM is defined as either hospital- or community-acquired. Both infections are dangerous. The only difference is where they were obtained. When Staphylococcal meningitis is caused by Staphylococcal aureus or Staphylococcal epidermidis bacteria, it is usually from a surgical procedure.
Early symptoms of SM are vague. They may not be taken seriously because they resemble a cold or flu. The symptoms grow more serious as the infection worsens. Diagnosis requires finding S. aureus or S. epidermidis bacteria in your body. Your doctor may also do blood tests and take imaging scans of your brain to aid in diagnosis.
Treatment is difficult because the condition is rare, and doctors don’t see it much. Many patients are given the wrong antibiotics upon arrival at the hospital. Even with correct antibiotics, the risk of death is very high. People with underlying chronic conditions have a higher risk of mortality.
Because the symptoms of SM are common to many other diseases, it can be difficult to diagnose. Common symptoms of SM include a fever, a headache, and vomiting.
Less common symptoms include shock, very low blood pressure, and decreased consciousness.
There are two ways a person can contract Staphylococcal meningitis. Hospital-acquired transmission means that you got the infection while being treated at a hospital or nursing home. Community-acquired means you got the infection outside of a hospital or healthcare setting. Both infections are treated the same way.
Once you get the infection, germs cross the blood-brain barrier to infect the brain. Once inside the brain, the bacteria infect the meninges.
It’s very important to know the risk factors for SM. These include:
- history of inflammation of your organs
- diabetes, as periods of high blood sugar may cause a problem in your blood-brain barrier, making it easier for bacteria to enter your brain
- history of hospital stays and surgical procedures
- taking immunosuppressant drugs
Diagnosis is based on clinical tests of positive cultures for the germs that cause the disease. It is necessary to determine which specific type of germ is causing the meningitis in order to treat it properly. The most common causes of meningitis are viruses and bacteria, such as:
- Streptococcus pneumonia
- Neisseria meningitides
- Haemophilus influenza
- Listeria monocytogenes
In order to correctly identify the type of germ causing your meningitis, your doctor will usually perform the following tests:
- bacterial culture, when bacteria are swabbed from your nose or throat and left to grow on a culture plate in order to identify the type of bacteria present
- magnetic resonance imaging, MRI, to look for signs of inflammation in the brain
- lumbar puncture, also called a spinal tap, to look for signs of infection in the cerebrospinal fluid
- complete blood count, CBC, to look for signs of infection in your blood
Treatment with the correct antibiotics must be given quickly. Blood cultures should let doctors know which medications to prescribe. Most are given intravenously to reach the infection as quickly as possible.
Correct antibiotics to treat SM include:
- methicillin, although most cases of SM are now resistant to this antibiotic
The following antibiotics should not be prescribed:
Treatment for worsening cases of SM may include mechanical ventilation by mask or throat tube to give your brain more oxygen. Also, dialysis may be used because your kidneys may begin to shut down.
SM has a very high mortality rate. Many patients receive the wrong antibiotics upon hospital arrival. The rarity of the disease and the difficulty in diagnosing it means that physicians do not always suspect its presence.
Even with proper antibiotics, the condition is affecting the most sensitive organ in the body, your brain. Survivors have a high chance of suffering permanent brain damage.
People with underlying conditions such as diabetes and heart disease have a much higher risk of mortality.
Prevention aims at practicing good hygiene habits like washing your hands and covering your mouth when you cough, to stop the spread of the bacteria. Maintaining a healthy and strong immune system will also help your body fight any potentially harmful bacteria. You may also take antibiotics if you have come into contact with someone with SM, and vaccination may also be an option.
You Asked, We Answered
- How common is staphylococcal meningitis?
Staphylococcal meningitis is uncommon in people with competent immune systems. Less than 6 percent of all meningitis patients in the United States have a Staphylococcal infection. Those patients with HIV, IV drug users, those undergoing hemodialysis or peritoneal dialysis, and those having neurosurgical procedures are more prone to this bacterial infection.- George Krucik, MD, MBA