Meningitis – types, symptoms, diagnosis, treatment, and prevention
What is meningitis?
Meningitis is the inflammation of the meninges. The human brain and the spinal cord is covered by three membranes. Namely the dura, arachnoid and pia mater. These membranes are called the meninges. Mostly, but not always, this occurs due to infections. It is considered a medical emergency since it has the potential to affect the brain functions, either temporary or permanent.
It can affect any human irrespective of the age group. But the causative organisms, clinical manifestations, and outcomes differ depending on the affected age group.
Signs & symptoms of meningitis
Neonatal and infantile meningitis
- High fever
- Constant crying
- Irritable and drowsy
- Poor feeding
- Vomiting
- bulging of fontanelles (fontanelles are areas of the skull that are not ossified)
- Skin rash – in meningococcal meningitis
- Stiffness of the neck
- In some babies’ irritability and poor feeding may be the only symptoms.
Adult and childhood meningitis
- High fever
- Nausea and vomiting
- Photophobia and phonophobia – Difficulty in facing lights and sounds respectively
- Neck stiffness is characteristic to meningitis
The following symptoms indicate severe disease where the inflammation has advanced towards the brain.
- Confusion and altered mental status
- Seizures
- Drowsiness or coma
Types
It can be classified depending on the etiology as non-infective and infective causes. Non-infective causes are relatively uncommon. Systemic inflammatory diseases like sarcoidosis, certain types of cancers, drugs are examples for them. Infective causes are further classified according to the type of microorganisms.
Viral meningitis
It is the most common out of all the types. Herpes simplex, varicella-zoster, HIV, enteroviruses and influenza are well-known causes. Viral meningitis rarely causes much of a problem. It’s contagious, yet resolves on its own as our immune system counteracts its activity.
Bacterial meningitis
Despite being not that common as viral meningitis, this holds a high healthcare burden. It almost always lethal if not diagnosed on time or left untreated. Common bacteria that cause meningitis include,
- Streptococcus pneumoniae – Pneumococcal meningitis
- Escherichia coli
- Haemophilus influenza
- Neisseria meningitides – Meningococcal meningitis
- listeria monocytogenes
Fungal meningitis
It is extremely rare among the normal healthy population. It primarily affects those who are having weakened immune systems as such in poorly controlled diabetic or HIV AIDS patients. Cryptococcus fungus is notorious to cause meningitis among AIDs patients.
Is meningitis contagious?
The above-mentioned viruses are extremely contagious. However, the infection of those viruses rarely progresses till meningitis in most of the people. Out of the bacteria, Meningococcal meningitis is the most contagious. Fungi are contagious among the immunocompromised people, but not for the normal population.
Complications
Due to its close relationship with the brain, meningitis has the potential to cause several devastating complications.
- Hearing loss and blindness
- Developmental abnormalities and low IQ if occurred during the neonatal period
- Permanent brain damage
- Paralysis
- Subdural effusions – Fluid collection inside the dura meter
- Hydrocephalus – cerebrospinal fluid accumulation inside the brain
- Coma and death
Diagnosis and treatment
This disease is diagnosed by clinical suspicion. If a person is suspected to have it, depending on the symptoms treatments should be initiated without waiting for the confirmation.
Bacterial meningitis is treated with intravenous strong antibiotics. Viral meningitis is managed supportive and doesn’t usually require any antiviral medications.
Hearing tests should be offered to every infant diagnosed to have meningitis once the child has been recovered.
Infective meningitis is diagnosed by isolating the pathogen in cerebrospinal fluid. For this, unless contraindicated, a lumbar puncture is done and cerebrospinal fluid (CSF) is collected. A blood sample is also simultaneously collected. Subsequently, CFS and blood cultures are done to diagnose the pathogen and its antibiotic sensitivity pattern.
If the patient is having severe symptoms like seizures and altered consciousness, neuroimaging including CT and MRT scans of the brain are done to exclude brain abscesses.
Prevention
Bacterial meningitis commonly occurs as a sequel of another infection of the head and neck. This may an ear infection, throat or nasal infection or a head injury. Therefore, if you are having an infection for a considerable duration of time, seek immediate medical treatment.
Practice good hygiene
Cover your mouth when you cough or sneeze
Avoid exposure to people who are having bacterial meningitis.
Vaccinations. Currently, vaccinations are available for S. pneumoniae, H. influenzae, N. meningitides. Vaccinate yourself and your family with the help of a doctor.
Prophylactic treatment with rifampicin or ciprofloxacin to the close contacts of N. meningitides infected people is recommended by WHO.
Some Good reads
Centers of Disease Control and prevention
