Bacterial meningitis: ways of diagnosing
Bacterial meningitis is a serious infection of the membranes that cover the brain and spinal cord. It can cause fever, headache, stiff neck, confusion, seizures, and sometimes death. Bacterial meningitis can be caused by different types of bacteria, such as Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, and Listeria monocytogenes. The diagnosis and treatment of bacterial meningitis are important to prevent complications and improve outcomes.
Diagnosis of bacterial meningitis
The diagnosis of bacterial meningitis is based on a combination of clinical signs, laboratory tests, and imaging studies. The main diagnostic test for bacterial meningitis is a spinal tap (lumbar puncture), which involves taking a sample of fluid from around the spinal cord and analyzing it for bacteria, white blood cells, protein, and glucose. A spinal tap can also help to measure the pressure in the central nervous system and identify inflammation or infection. A spinal tap is usually done after a head CT scan or MRI scan to rule out any brain swelling or other problems that may make the procedure unsafe.
Other tests that may help to diagnose bacterial meningitis include:
– Blood cultures: A blood sample is placed in a special dish to see if it grows microorganisms such as bacteria. This can help to identify the type and sensitivity of the bacteria causing the infection.
– Blood tests: A complete blood count (CBC) can check for elevated white blood cell count, which indicates infection or inflammation. Other blood tests can check for markers of inflammation, such as C-reactive protein (CRP) or procalcitonin (PCT).
– X-rays: Chest X-rays can help to diagnose pneumonia or tuberculosis, which can spread to the brain and cause meningitis. Sinus X-rays can help to diagnose sinusitis, which can also be a source of infection.
– Polymerase chain reaction (PCR): This is a DNA-based test that can detect specific bacteria or viruses in the cerebrospinal fluid or blood. This test can be useful for diagnosing viral meningitis or tuberculosis meningitis.
Treatment of bacterial meningitis
The treatment of bacterial meningitis depends on the type and severity of the infection. The main treatment is intravenous antibiotics, which are given as soon as possible after the diagnosis is confirmed or suspected. The choice of antibiotics depends on the type of bacteria causing the infection and their sensitivity to different drugs. Some common antibiotics used for bacterial meningitis are cefotaxime, ceftriaxone, penicillin, ampicillin, vancomycin, and meropenem.
In addition to antibiotics, other treatments that may be given for bacterial meningitis include:
– Corticosteroids: These are anti-inflammatory drugs that can help to reduce swelling and pressure in the brain. They may also reduce hearing loss and neurological damage in some cases. Examples of corticosteroids are prednisone, dexamethasone, and hydrocortisone.
– Anticonvulsants: These are drugs that can help to prevent or stop seizures, which can occur in some cases of bacterial meningitis. Examples of anticonvulsants are phenytoin, levetiracetam, and valproic acid.
– Fluids and electrolytes: These are given intravenously to maintain hydration and balance the levels of sodium, potassium, calcium, and other minerals in the body. Fluids and electrolytes are especially important if there is dehydration, shock, or low blood pressure due to bacterial meningitis.
– Oxygen therapy: This is given through a mask or nasal cannula to provide extra oxygen to the body. Oxygen therapy is especially important if there is low oxygen saturation or difficulty breathing due to bacterial meningitis.
– Surgery: This may be needed in some cases of bacterial meningitis to drain any infected sinuses or mastoids (the bones behind the outer ear that connect to the middle ear), or to relieve pressure in the brain by removing part of the skull (craniotomy).
Prevention of bacterial meningitis
The prevention of bacterial meningitis involves reducing the risk of exposure to infectious agents, boosting the immune system, and getting vaccinated against certain types of bacteria. Some preventive measures include:
– Practicing good hygiene: This includes washing hands frequently with soap and water or using alcohol-based hand sanitizer; covering mouth and nose when coughing or sneezing; avoiding sharing food, drinks, utensils, or personal items with others; and cleaning and disinfecting surfaces and objects that may be contaminated.
– Avoiding contact with sick people: This includes staying away from people who have symptoms of meningitis or other respiratory infections; wearing a mask or respirator if working in health care settings or crowded places; and seeking medical attention if experiencing any signs of infection.
– Strengthening the immune system: This includes eating a balanced diet, drinking plenty of fluids, getting enough sleep, exercising regularly, managing stress, and avoiding smoking and alcohol.
– Getting vaccinated: There are vaccines available for some of the bacteria that can cause meningitis, such as Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b, and Listeria monocytogenes. These vaccines are recommended for certain age groups and people with certain medical conditions or risk factors. Consult your health care provider about which vaccines you may need and when to get them.
References:
– Mayo Clinic. (2020). Meningitis – Diagnosis and treatment. Retrieved from https://www.mayoclinic.org/diseases-conditions/meningitis/diagnosis-treatment/drc-20350514
– CDC. (2020). Bacterial Meningitis. Retrieved from https://www.cdc.gov/meningitis/bacterial.html
– Johns Hopkins Medicine. (n.d.). Bacterial Meningitis. Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/bacterial-meningitis
– Cedars-Sinai. (n.d.). Bacterial Meningitis. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/b/bacterial-meningitis.html
