Meningitis

Meningitis is inflammation of protective tissue layers that cover the brain and spinal cord, collectively known as the meninges. The inflammation leads to some symptoms like a stiff neck, headache, fever, and seizures. The causative agents of meningitis are infectious bacteria, viruses, fungi, etc. it may also be caused by other inflammatory conditions like SLE, sarcoidosis, drugs, chemicals, etc. If treatment is started on time, the prognosis is good; otherwise, it can lead to serious complications.

Meningitis may be caused by bacteria, viruses, fungi, parasites, and sometimes by certain drugs.

Bacterial Meningitis: Streptococcus pneumoniae causes bacterial meningitis. This is the most common cause of meningitis in newborns, young children, and adults. Neisseria meningitis (meningococcus), Haemophilus Influenza (Haemophilus) Listeria Monocytogenes (Listeria) are other causes of bacterial meningitis. Bacterial meningitis can quickly spread from one person to another. It can be transmitted by coughing, sneezing, or by close contact.

Viral Meningitis: It is also called aseptic meningitis and is among the most typical causes of meningitis. Usually, it’s the milder type. Coxsackievirus A, Coxsackievirus B, and echoviruses are responsible for the viral kinds of meningitis. Some other viruses include Influenza, West Nile Virus, HIV, measles, Herpes Virus, mumps, and Coltivirus.

Fungal Meningitis: is a rare type of meningitis that happens after inhaling bacterial spores from the soil, bird droppings, etc.; it is not transferred from person to person.

Parasitic Meningitis: the parasites responsible for this kind of meningitis are Angiostrongylus, tapeworm, Baylisacaris procyonis, and cerebral malaria. This type is transferred from person to person. These parasites infect animals or hide out on food that humans eat, where infection occurs.

Chronic meningitis: when meningitis stays for more than four weeks, it is called chronic meningitis. It is caused by Brucellae, a small bacteria found in animals, mycobacterium tuberculosis (acid fast bacteria that caused tuberculous meningitis), Cryptococcus neoformans (a fungus found in pigeon droppings), etc.

Non- infectious Meningitis: This can be caused by other medical conditions such as lupus, a head injury, brain surgery, cancer, and certain medications.

The incidence of meningitis depends upon the type of infectious agent and its prevalence in a geographical area.  Bacterial Meningitis is more prevalent in underdeveloped countries with low access to preventive services and sanitation. It is found in young adults and children. Viral meningitis is common worldwide, and it more commonly affects newborns and very young children.

Risk factors for meningitis include

• Age: Very old (more than 65 years of age) or very young (less than five years of age)
• Some chronic conditions like Diabetes Mellitus, Chronic kidney Failure, Cystic Fibrosis, Adrenal Insufficiency, hypoparathyroidism.
• Immunosuppression, HIV infection increases the risk of opportunistic infections and acute bacterial meningitis.
• Alcoholics, IV drug abusers
• Sickle cell disease and splenectomy may increase the risk of infections. Some organisms are special to have capsules on them as the spleen plays a significant role in eradicating such bacteria.
• Crowding like that found in military troops increases the risk of meningococcal meningitis

The symptoms of meningitis can mimic each other. However, bacterial meningitis symptoms are much more severe and develop suddenly. Symptoms vary with varying ages. The older children and adults may have the following symptoms:

• Fever
• Stiff neck
• Confusion
• Nausea & vomiting
• Headache
• Increased sensitivity to light
• Seizures
• Purple or bruised skin rashes (bacterial)

New-born: Viral meningitis in a newborn may cause

• Reduced hunger
•  Restlessness
• Crying
•  Irritability  
• Bulging fontanelle
• High fever
• Stiff neck

The diagnosis is made on clinical symptoms and physical examination. Other tests are advised to confirm the diagnosis.

Blood tests: In this test, organisms are grown in the lab to check for the specific agent and the sensitive medicine. A complete blood count may show an increase in the number of WBCs. Other parameters are also checked, like electrolytes, glucose, urea, and nitrogen.
Lumbar Puncture is the procedure in which fluid in your brain and spinal cord, called cerebrospinal fluid, is taken out by a needle inserted in your vertebral column. The diagnosis is made based on different parameters, like pressure, predominant cells, proteins, and glucose.
Brain Imaging:  It is not useful for diagnosis but may discover complications and rule out other diagnoses.

Following diseases may mimic the signs and symptoms of meningitis;

• Encephalitis
•  Brain abscess
• Subarachnoid hemorrhage
• Cerebral malaria
• Brain tumor
• Leptospirosis
• Subdural empyema

The meningitis is treated with Antibiotics and adjunctive therapy such as Mannitol, glucocorticoids, and anti-epileptics.

Bacterial meningitis is treated with antibiotics. The choice of antibiotics depends upon blood culture results; however, a broad-spectrum antibiotic must be started without waiting for the result. The most commonly used broad-spectrum antibiotics are Ampicillin with cefotaxime/ gentamicin in newborns and infants, Ceftriaxone in older children and young adults, Penicillin G, and Ceftriaxone in Older patients.
Viral meningitis is treated with symptomatic treatment to control pain and fever, bed rest, and fluids.

Prognosis is good if the diagnosis is made earlier and treatment is started. Sometimes patients have complications like brain abscesses, sinuses, seizures, shock, and death.

• Taking care of basic hygiene like washing hands, keeping things clean, and discouraging sharing toothbrushes and towels.
• A healthy and clean diet with essential vitamins and minerals
• Covering of mouth during sneezing and coughing
• Vaccinations: many vaccinations have been used for the prevention of bacterial diseases like the Haemophilus influenza type b (Hib) vaccine., Pneumococcal polysaccharide vaccine (PPSV23). Pneumococcal conjugate vaccine (PCV13), Meningococcal conjugate vaccine.