Charlotte, NC
Gauri Adhikari, MD
Meningitis is the inflammation of the meninges, which are the protective layers of tissue surrounding the brain and spinal cord. It can affect individuals of any age but is more prevalent in younger children [1]. Meningitis is a significant global health issue, with epidemics occurring worldwide, especially in sub-Saharan Africa. In the United States, bacterial meningitis occurs in about 1.38 out of every 100,000 people each year, and about 14.3% of those who get it die from the disease. [2, 3]
Meningitis can be serious if not treated properly. Bacterial meningitis, in particular, is the most dangerous type. If not treated properly, it can be fatal within 24 hours [1].
Meningitis can occur in several forms, each with distinct causes and characteristics. Here are the 4 types of meningitis:
This is the most severe form of meningitis and is caused by bacteria such as Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Bacterial meningitis can develop rapidly, and without immediate antibiotic treatment, it can lead to brain damage, hearing loss, or even death. [2, 4]
This is caused by viruses like enteroviruses, herpes simplex virus, or HIV. Viral meningitis is more common than bacterial meningitis and is usually less severe, with most people recovering fully within a few weeks without specific antiviral treatment.[2, 5]
It is rare but more serious. Fungi like Cryptococcus cause fungal meningitis. It generally affects people with weakened immune systems, such as those with HIV/AIDS or those undergoing chemotherapy. [2]
This type is caused by parasites, though it is rare. It is often associated with environmental factors, such as contaminated water or food. The infection can be severe, especially in those with weakened immune systems. [6] Non-infectious meningitis occurs due to conditions like cancer, certain medications, or autoimmune diseases. It is not caused by an infection but still leads to inflammation of the meninges. [1, 2]
The causes and risk factors of meningitis are:
Viral or bacterial infections are the most common cause of meningitis. Viruses like enteroviruses are common, and bacteria like Neisseria meningitidis are often responsible for outbreaks, particularly in crowded settings. [2, 4, 5]
Meningitis-causing bacteria and viruses can spread easily through respiratory droplets or close contacts, such as in schools, dormitories, or military barracks.[1, 2]
Newborns, infants, and young children are particularly vulnerable to meningitis, as their immune systems are not fully developed. Adults over 60 are also at higher risk, as the immune system weakens with age. [1, 2]
Conditions like HIV/AIDS, cancer, or immunosuppressive treatments (e.g., chemotherapy or steroids) can increase the risk of developing meningitis. [1, 2]
Traveling to regions where bacterial meningitis is common, such as parts of sub-Saharan Africa, increases the risk, especially in unvaccinated individuals. [1, 2]
Head trauma or surgery that affects the brain can increase the risk of developing meningitis by providing a pathway for bacteria or viruses to enter the meninges. [1, 2]
Meningitis spreads through respiratory droplets from coughing or sneezing, particularly bacterial meningitis. Neisseria meningitidis transmits through droplets from both symptomatic cases and non-symptomatic carriers. After bacteria reach the upper part of our throat, they grow in number and later enter the bloodstream. From blood, bacteria enter the fluid-filled space around the brain and spinal cord (the sub-arachnoid space) and cross the protective blood-brain barrier (BBB), leading to meningitis. [2] Similarly, bacteria can enter the cerebrospinal fluid (CSF) from nearby areas like the ear in cases of ear infections (otitis media) or from the sinuses (sinusitis). They can also be introduced into the CSF through head injuries or during surgical procedures. [2]
The symptoms of meningitis can come on quickly and feel like a bad flu at first. Here’s what you should look out for:
You might feel a pounding headache that doesn’t go away and feels worse than anything you’ve experienced. [6]
Turning or moving your neck could feel difficult or painful. It might feel like your muscles are unusually tight.[6]
A sudden spike in your body temperature could be one of the first warning signs. You may also feel chills or sweats. [6]
The classical triad of symptoms of meningitis includes fever, neck stiffness, and confusion. However, this triad is not always present. In adult cases of meningitis, headache, fever, neck stiffness, and confusion are the most common symptoms. Up to 95% of patients present with at least two of these four symptoms. [6]
Bright lights might hurt your eyes or worsen your headache, causing you to avoid well-lit places. [2]
You may feel foggy, confused, or unable to think clearly. It might be hard to stay focused or remember things. [2]
If you have bacterial meningitis caused by Neisseria meningitidis, you might notice small purplish spots or blotches on your skin that don’t fade when pressed. [7]
For babies and young children, the symptoms can be harder to spot. If your baby has meningitis, they may: [8]
Diagnosing meningitis requires careful evaluation through specific tests and procedures. Below are a few key points to consider for diagnosis of meningitis:
A lumbar puncture, or spinal tap, is a common and safe procedure for diagnosing meningitis. It is also the most definitive test for meningitis. During the procedure, you will either lie on your side with your knees pulled up to your chest or sit and lean forward to allow the doctor access to your lower back. The area on your lower back is cleaned thoroughly, and a numbing medicine is injected to ensure you don’t feel pain. Once the area is numb, a thin needle is gently inserted into the space between the bones in your lower spine, where cerebrospinal fluid surrounds your brain and spinal cord. Your doctor collects a small amount of this fluid in a sterile tube for testing. While you may feel pressure during the procedure, it is usually not painful. After the fluid is collected, the needle is removed, and a small bandage is placed over the site. The entire process typically takes about 15–30 minutes. Once the sample is analyzed, it helps confirm if meningitis is present and identifies the type, which is crucial for deciding on the best treatment. [7]
Blood tests are essential to diagnosing meningitis and assessing the severity of the infection. While they can’t directly confirm meningitis, blood tests help identify signs of infection, inflammation, and potential complications. A complete blood count (CBC) can reveal elevated white blood cell counts, indicating an immune response to infection. Blood cultures are also taken to detect bacteria or fungi in the bloodstream, which is important for diagnosing bacterial meningitis and guiding antibiotic treatment. Additionally, blood tests may assess markers of inflammation, such as C-reactive protein (CRP) and procalcitonin, which can help differentiate between bacterial and viral infections.[9]
A CT scan is typically the first test to quickly rule out other conditions and detect issues like brain swelling or bleeding. While it can’t directly diagnose meningitis, it helps assess immediate risks. An MRI provides more detailed images and examines the brain for inflammation or complications, such as fluid buildup or swelling. These imaging techniques complement a lumbar puncture. [10]
Polymerase chain reaction (PCR) testing is a highly sensitive and specific method used to diagnose meningitis by detecting genetic material from pathogens in cerebrospinal fluid. It is especially useful for identifying viral, bacterial, and fungal causes of meningitis when traditional cultures may take too long or fail to provide results. PCR can quickly identify pathogens such as Neisseria meningitidis, Streptococcus pneumoniae, and enteroviruses, common causes of meningitis. This test is particularly valuable when the cause of meningitis is uncertain or when patients are already receiving antibiotics, which may hinder the growth of bacteria in cultures. [11]
The treatment of meningitis varies based on its cause and the patient’s condition. Here are some essential points to keep in mind for proper care and recovery.
Immediate treatment with broad-spectrum antibiotics is crucial if bacterial meningitis is suspected. Once the specific bacteria are identified, antibiotics may be adjusted to target the bug directly. For newborns, the treatment includes Ampicillin and Cefotaxime, plus Acyclovir. For older infants and children, Ampicillin and Ceftriaxone are used. Adults aged 18-49 are treated with Ceftriaxone and Vancomycin, while those 50 and older or immunocompromised receive Ceftriaxone, Vancomycin, and Ampicillin. [2, 7]
For viral meningitis caused by herpes simplex virus or other specific viruses, antiviral medications may be prescribed to help reduce the severity and duration of symptoms. However, treatment for other viral meningitis is primarily supportive. [2]
Amphotericin B, flucytosine, and fluconazole are the standard treatments for cryptococcal meningitis, particularly in immunocompromised patients. And for tubercular meningitis, a combination of isoniazid, rifampin, pyrazinamide, and ethambutol is recommended, often with adjunctive corticosteroids. [2]
Corticosteroids, such as dexamethasone, are typically administered concomitantly with or just before the first dose of antibiotics. This timing is crucial to mitigate the inflammatory response induced by bacterial lysis. Steroids can help reduce inflammation in the brain and prevent complications like hearing loss or brain damage, particularly in cases of bacterial meningitis. [2]
Over-the-counter medications like acetaminophen or ibuprofen can help manage symptoms like headache, fever, and body aches. [2]
In severe cases, hospitalization is needed to provide intravenous fluids, manage complications, and monitor your condition closely. Rest and hydration are also important parts of recovery. [2]
Meningitis can lead to serious complications, especially if not treated promptly. The prognosis of bacterial meningitis remains serious despite advances in medical care. A low level of consciousness, such as being very drowsy or unresponsive, indicates a poor prognosis. One of the most concerning outcomes is brain damage, which can affect your memory, concentration, or overall cognitive abilities. Hearing loss is another common complication, as the infection can damage the nerves responsible for hearing. Seizures may develop during or after the illness due to inflammation in the brain. [2] Meningitis can be life-threatening, with a significant risk of death. [2]
In severe cases, meningitis can lead to hydrocephalus, a condition where fluid builds up in the brain, causing increased pressure. The infection can also spread to other parts of your body, leading to life-threatening conditions like septicemia (blood poisoning), which may cause organ failure or tissue damage requiring amputation. In children, meningitis can sometimes result in developmental delays or learning difficulties. [12]
The disease spreads through respiratory droplets from coughing or sneezing, putting close contacts of the patient at significant risk. Preventive treatment( chemoprophylaxis) is most effective when started within 24 hours of exposure, though it can still be beneficial if initiated up to 14 days later. [13]
Prevention of meningitis focuses on those closely interacting with the patient, such as household members, intimate contacts, roommates, healthcare workers exposed to the patient’s respiratory secretions during procedures, and anyone who traveled with the patient for more than eight hours. Casual contacts, like sharing drinks or cigarettes, typically don’t require prophylaxis unless they meet the close contact criteria. [13]
Recommended antibiotics for preventing meningococcal disease include rifampicin, ciprofloxacin, and ceftriaxone, which eliminate the bacteria from the body and reduce transmission risk. Additionally, the CDC advises chemoprophylaxis with rifampin for household contacts of patients with Haemophilus influenzae meningitis, particularly children under four who are not fully vaccinated or are immunocompromised. [14]
Vaccination is one of the most effective ways to prevent meningitis and protect against severe complications. Several vaccines target the most common causes of meningitis, including bacterial forms. The meningococcal vaccine helps protect against Neisseria meningitidis, a leading cause of bacterial meningitis. It is typically recommended for adolescents, young adults, and individuals at higher risk, such as those living in close quarters like dormitories or military barracks. A booster dose is often advised for continued protection. [15]
The Haemophilus influenzae type b (Hib) vaccine is given to infants as part of routine childhood immunizations and has significantly reduced cases of meningitis caused by this bacterium. The pneumococcal vaccine protects against Streptococcus pneumoniae, another major cause of bacterial meningitis. It is recommended for young children, older adults, and individuals with weakened immune systems or certain chronic conditions. [2, 15]
