Meningitis is an inflammation of the protective membranes covering the brain and spinal cord, known as the meninges. This condition can be caused by various pathogens including bacteria, viruses, fungi, or parasites, or by non-infectious causes such as certain medications, systemic diseases, or chemical irritation.
- Bacterial Meningitis - This form is the most severe. Common causative bacteria include Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae (before the Hib Vaccine).
- Viral Meningitis - Often less severe, caused by enteroviruses, mumps virus, and others. It can sometimes resolve without specific treatment.
- Fungal Meningitis - Less common, but can be serious, especially in immunocompromised individuals. Pathogens include Cryptococcus neoformans.
- Parasitic Meningitis - Rare, caused by parasites like Angiostrongylus cantonensis.
- Non-infectious Meningitis - Can result from cancer, lupus, certain drugs, or other systemic diseases.
Historical Context
The term "meningitis" was first used in the 19th century. One of the earliest recorded outbreaks was in 1805 in Geneva, described by the physician André Matthey. Since then, Meningitis has been recognized as a significant public health concern, with major epidemics occurring in various parts of the world, particularly in the Meningitis Belt in sub-Saharan Africa.
Symptoms and Diagnosis
- High fever
- Headache
- Stiff neck
- Nausea and vomiting
- Photophobia (sensitivity to light)
- Altered mental status
Diagnosis typically involves a combination of clinical examination, lumbar puncture to analyze cerebrospinal fluid (CSF), blood tests, and imaging studies like CT or MRI scans to rule out other causes of symptoms.
Treatment
Treatment depends on the cause:
- Bacterial - Requires immediate antibiotic therapy, often with corticosteroids to reduce inflammation.
- Viral - Often supportive care, with antiviral drugs for some specific viruses like herpes simplex.
- Fungal - Long-term antifungal treatment.
- Parasitic - Treatment varies based on the parasite.
- Non-infectious - Treating the underlying condition or stopping the offending drug.
Prevention
Vaccines are available for some forms of bacterial meningitis:
Other preventive measures include:
- Good hygiene practices
- Avoiding close contact with infected individuals
- Post-exposure prophylaxis for close contacts in bacterial cases
Complications
If not treated promptly, Meningitis can lead to:
- Seizures
- Hearing loss
- Brain damage
- Amputation (due to sepsis)
- Death
Sources
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