Viral and bacterial meningitis have different causes — a virus causes one, and bacteria causes the other, as their names imply. The most important difference between viral and bacterial meningitis, however, is the seriousness of the disease. Someone suffering from viral meningitis usually will get better, even without treatment. Bacterial meningitis is considered an emergency condition, usually requiring immediate hospitalization and treatment with antibiotics. With treatment, there is still the possibility of brain damage or even death.
Meningitis is an infection of the meninges, which are membranes that cover the brain and spinal cord. Most cases are caused by bacteria or viruses, although in rare occurrences, the cause can be medications or environmental chemicals. The two main types of meningitis are viral meningitis and bacterial meningitis.
Viral meningitis is more common and is brought on by a virus. This type of meningitis usually does not lead to a serious illness. In more extreme cases, a patient might exhibit prolonged fever and seizures. Many people never realize that they have viral meningitis, because the symptoms are often very similar to those of the flu.
Acute bacterial meningitis is a much more serious condition, and it requires medical attention. Bacteria enters the bloodstream, sometimes because of an ear or sinus infection or a skull fracture, and migrates to the brain and spinal cord. Early detection and treatment is vital.
Symptoms are similar for viral and bacterial meningitis. Adults and children commonly display headache, high fever and a stiff neck. They might also suffer from nausea, vomiting, sensitivity to light, disorientation and sleepiness.
Infants do not present with the same symptoms and often are difficult to diagnose. They might exhibit irritability or lethargy and have diminished appetite. In later stages, infected individuals of all ages might progress to seizures.
Doctors use several techniques for diagnosing viral and bacterial meningitis. Along with a physical exam that often concentrates on looking for signs of infection in the spinal area and around the head, ears and throat, there are specific diagnostic tests that can be run. One common procedure is the cerebrospinal fluid (CSF) total protein test, which measures the amount of protein in the cerebrospinal fluid. This is done through the use of a lumbar puncture, commonly referred to as a spinal tap. An abnormal amount of protein in the collected sample is indicative of the possibility of a meningitis infection.
Viral and bacterial meningitis are both contagious. Infection can be passed through coughing, sneezing and other close contact. Prevention is best accomplished through safe hygiene practices. There also are vaccines available for some strains of bacterial meningitis.