24th April is observed as World Meningitis Day every year. The theme for 2019 is “#AfterMeningitis” with the aim to raise awareness about the condition.
Worldwide, meningitis is one of the major causes of high morbidity and mortality in children below five years of age. In the pediatric population, it accounts for about 180,000 deaths annually. Haemophilus influenzae type b(Hib), Streptococcus pneumoniae, and Neisseria meningitidis were reported to be the commonest causes for bacterial meningitis across different parts of the world. Studies from India have attributed pneumonia and meningitis as the leading causes of deaths among children below five years of age. Together, both these diseases account to around 22% of deaths that occur in kids. This world meningitis day, let’s know a little about this deadly disease including its types, causes, symptoms, and prevention.
What Is Meningitis?
Meningitis is a potentially fatal inflammation of the meninges, which is a thin membrane that layers the brain and the spinal cord. It can occur when the fluid present in the space between the layers of the brain become infected. The causes of meningitis may be broadly classified as infectious (bacterial, viral, fungal) and noninfectious. Viral and bacterial infections are the most common causes of infectious meningitis whereas health problems such as head injury or cancer belong to the non-infectious causes of inflammation in the brain. Here is more on the types of meningitis:
Viral meningitis: It is the most common type of meningitis and accounts for 85 percent of the cases with an incidence rate of 10.9 per 100,000 people. The common causative viruses include enteroviruses (especially the Coxsackie virus). The other viruses that can cause this condition include herpes simplex virus, influenza virus, mumps virus and human immunodeficiency virus (HIV).
Bacterial meningitis: The next common type of meningitis is bacterial meningitis which occurs in about 3 per 100,000 people on a yearly basis. The pathogens that cause this type of meningitis include Streptococcus pneumoniae, Neisseria meningitidis (meningococcus), Haemophilus influenzae, Listeria monocytogenes, and Staphylococcus aureus. The bacteria that causes tuberculosis, Mycobacterium tuberculosis, can also cause the inflammation of the meninges.
N.meningitidis is the leading cause of meningitis worldwide and a dreaded disease in most countries. Meningococcal meningitis most commonly affects individuals from 3 years of age to adolescence. It rarely occurs in individuals older than 50 years. In developing countries, the mortality rate from bacterial meningitis is often higher (20–40%) than in developed countries. The disease is found more in males than in females.
Fungal meningitis: It is relatively uncommon and usually results in chronic meningitis. As the name suggests, it is caused by a fungus which infects the body and spreads through the blood to the brain and spinal cord. Cryptococcal meningitis is a common fungal form of the disease. It affects people with immunodeficiencies, such as the acquired immunodeficiency syndrome or cancer.
Parasitic meningitis: It is less common as compared to viral and bacterial meningitis and mostly caused by parasites present in dirt, feces, grains or poultry. The infection is caused when the eggs of the parasite are ingested and not through mere coughing or touching a person with the condition. Amebic meningitis, a type of parasitic meningitis is one of the most dangerous infections. It is caused when an Ameba (a microscopic parasite not visible by naked eyes) enters the body on inhalation of contaminated water from lakes and rivers.
Noninfectious meningitis: It is basically not an infection but a side-effect or complication of an underlying health problem. The conditions that can lead to an inflammation of the brain tissue include systemic lupus erythematosus, drug-induced, head trauma, brain surgery, and cancer-related problems.
Fungal, parasitic and non-infectious meningitis is not contagious but viral and bacterial meningitis are highly contagious. It can spread through contact with a person suffering from the condition through droplets of infected fluid via coughing and sneezing.
What Are The Symptoms Of Meningitis?
More than 2/3rd of cases of meningitis occur in infants and mostly in the first 2 years of life. This could be due to decreased immunity and high vascularity of the brain, which puts kids at high risk of infection. Moreover, the symptoms of the infection are also vague due to the immaturity of the central nervous system (CNS) in infants and children. This is the reason why doctors mostly depend on the diagnosis based on blood tests and Cerebrospinal fluid (or CSF which is present in the meninges) rather than the symptoms.
However, there are few signs and symptoms which can help suspect meningitis and aid in the diagnosis of the condition.
-Fever for more than a week
-Nausea and vomiting
-Altered or reduced level of consciousness
How Is It Treated?
The treatment is based on the cause of meningitis. Bacterial meningitis is treated with antibiotics and may require immediate hospitalization. This may help to prevent brain damage and death. Fungal meningitis might require the use of antifungal medications to treat the condition. Viral meningitis may resolve on its own but to know the cause and the right treatment you may need to consult a doctor. Parasitic meningitis can be treated based on the symptoms.
Untreated bacterial meningitis is highly fatal causing serious neurological complications. Early complications of bacterial meningitis include seizures, increased intracranial pressure, cerebral thrombosis, and hydrocephalus. It may result in brain damage, hearing loss or a learning disability in 10–20% of survivors, as well as amputations in some cases.
Certain types of meningitis can be prevented with vaccination. The vaccines that can prevent the infection are Haemophilus influenzae type B (Hib) vaccine, pneumococcal vaccine, and meningococcal vaccine. From the year 2012, the Indian Government has introduced the Pentavalent Vaccine (DPT+Hep B + Hib) in the Universal Immunization Programme (UIP) across the country.
(The article is reviewed by Dr. Lalit Kanodia, General Physician)
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