Meningitis: Causes, Symptoms, Diagnosis, and Treatment

Meningitis is an inflammation of the meninges, the protective membranes covering the brain and spinal cord. This condition can be caused by various infectious agents, including viruses, bacteria, and fungi, as well as less common causes such as atypical drug reactions and systemic lupus erythematosus. Meningitis can affect anyone, but it presents with varying degrees of severity depending on its cause.

Causes of Meningitis

The two most common causes of meningitis are viral and bacterial infections. Viral meningitis, often caused by enteroviruses, is generally less severe and resolves on its own within a week to 10 days. Enteroviral meningitis is more prevalent in children and tends to occur during mid-summer to early autumn, though it can arise at any time of year. Other viruses that can cause meningitis include herpes simplex and mumps, but these are less common.

Bacterial meningitis is a more serious and potentially fatal condition. Historically, the main culprits were Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae. However, with the advent of effective vaccines, the incidence of bacterial meningitis caused by these pathogens has significantly decreased. Bacterial meningitis can affect otherwise healthy individuals but is more common in infants, the elderly, and those with chronic diseases or compromised immune systems. Additionally, meningitis can be caused by fungi, though this is rare and usually occurs in individuals with severe immune system deficiencies.

Symptoms of Meningitis

Symptoms of meningitis vary depending on the cause and the age of the patient. Common signs include:

Headache: A persistent, severe headache is often the first symptom.
Fever: Elevated body temperature is a common response to infection.
Stiff Neck: Difficulty in bending the neck forward can be a significant indicator.
Sensitivity to Light: Light sensitivity can accompany the other symptoms.
Nausea and Vomiting: These symptoms often accompany the headache and fever.
Drowsiness and Confusion: Mental status changes are common, especially in bacterial meningitis.

In infants and very young children, symptoms can be less specific and may include irritability, vomiting, refusal to eat, and reduced activity. In severe cases of bacterial meningitis, individuals may experience seizures and loss of consciousness.

Diagnosis

Diagnosing meningitis typically involves analyzing cerebrospinal fluid (CSF) obtained through a spinal tap or lumbar puncture. This procedure involves inserting a needle into the lower back to collect CSF, which is then tested for bacteria, viruses, or other pathogens. The presence of certain infection-fighting cells or abnormalities in the CSF can help confirm the diagnosis. Additional tests may include blood tests and imaging studies to identify the causative agent and assess the extent of the infection.

Expected Duration

The duration of meningitis varies based on its cause. Viral meningitis usually resolves within seven to 10 days with supportive care, including rest and fluids. Bacterial meningitis requires prompt treatment with high-dose intravenous antibiotics and, depending on the case, may involve corticosteroids like dexamethasone. Without early diagnosis and treatment, bacterial meningitis can lead to severe complications and even death.

Prevention

Preventing meningitis involves several strategies:

Vaccination: Vaccines are available for some of the most common bacterial causes of meningitis, such as Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae. These vaccines have significantly reduced the incidence of bacterial meningitis.
Hygiene Practices: Good hygiene, including regular handwashing and avoiding close contact with infected individuals, can help prevent the spread of meningitis-causing viruses and bacteria.
Antibiotic Prophylaxis: If you have been in close contact with someone diagnosed with bacterial meningitis, your doctor might prescribe antibiotics as a preventive measure.

Unfortunately, no vaccine currently exists for the most common types of viral meningitis.

Treatment

Treatment for meningitis varies depending on the cause. Viral meningitis is managed similarly to the flu, with rest, hydration, and over-the-counter medications to alleviate symptoms. Bacterial meningitis, however, is a medical emergency that requires immediate treatment with intravenous antibiotics in a hospital setting. In some cases, corticosteroids like dexamethasone may be administered to reduce inflammation and improve outcomes.

When to Call a Professional

If you or your child exhibit symptoms of meningitis, it is crucial to seek medical attention immediately. Early diagnosis and treatment are essential for the best outcomes, especially in cases of bacterial meningitis.

Prognosis

The outlook for individuals with viral meningitis is generally positive, with most people recovering fully. The prognosis for bacterial meningitis depends on several factors, including the patient’s age, the specific bacterium involved, and how promptly treatment was initiated. Prompt medical intervention can significantly improve outcomes and reduce the risk of long-term complications.