How do you get meningitis?
Meningitis, an inflammation of the meninges, the membranes that cover the brain and spinal cord, can be caused by various factors, including infections and non-infectious causes. Here are the main ways meningitis can be acquired:
1. Bacterial Meningitis:
- Direct Contact: Certain bacteria, such as *Streptococcus pneumoniae* (pneumococcus), *Neisseria meningitidis* (meningococcus), and *Haemophilus influenzae* type b (Hib), can spread through close contact with respiratory droplets or saliva of an infected person, such as through coughing, sneezing, or kissing.
2. Viral Meningitis:
- Respiratory Transmission: Viral meningitis is often caused by viruses that commonly cause respiratory illnesses. These viruses can spread through respiratory droplets or contact with contaminated surfaces. Examples include enteroviruses (e.g., coxsackievirus and echovirus), mumps virus, measles virus, and influenza virus.
- Arthropod-Borne Viruses: Some viruses that cause meningitis are transmitted by arthropod vectors, such as mosquitoes or ticks. Examples include West Nile virus, Eastern equine encephalitis virus, St. Louis encephalitis virus, and tick-borne encephalitis virus.
3. Fungal Meningitis:
- Exposure to Fungi: Fungal meningitis can occur due to exposure to certain fungi, often in immunocompromised individuals. For example, *Cryptococcus neoformans* can be acquired by inhaling spores from contaminated soil or bird droppings.
4. Parasitic Meningitis:
- Parasitic Infections: In rare cases, parasites like *Naegleria fowleri* (a free-living amoeba commonly found in warm freshwater) can cause meningoencephalitis through nasal contact during swimming or diving in contaminated water.
5. Non-infectious Causes:
- Head Injury or Surgery: Trauma to the head or surgical procedures near the brain or spinal cord can lead to inflammation of the meninges, known as aseptic meningitis.
- Systemic Diseases: Some underlying medical conditions, such as certain autoimmune diseases (e.g., lupus), cancer, or drug reactions, can cause inflammation of the meninges.
6. Meningitis Outbreaks:
- Close Quarters or Crowded Conditions: Meningitis outbreaks can occur in settings where people are in close contact, such as schools, dormitories, military barracks, or during mass gatherings. These outbreaks are more commonly associated with bacterial meningitis, especially meningococcal meningitis.
It's essential to practice good hygiene, including frequent handwashing, covering your mouth and nose when coughing or sneezing, maintaining up-to-date vaccinations (e.g., pneumococcal, meningococcal, and Hib vaccines), and avoiding contact with contaminated water sources to reduce the risk of meningitis. If you experience symptoms such as severe headache, fever, stiff neck, confusion, nausea, or vomiting, seek immediate medical attention. Early diagnosis and treatment of meningitis are crucial for a better outcome.