Meningitis: Symptoms, Causes & Treatment

Written by: Editorial Team

Medically reviewed by: Dr. Sandhya Manorenj - Senior Consultant Neurologist

Overview | Epidemiology | Types | Symptoms | Causes | Risk Factors | Complications | Diagnosis | Treatment | Prevention | Viral meningitis vs Bacterial meningitis | FAQs | When to consult a Doctor

Meningitis definition

Meningitis is a serious infection or inflammation of the meninges, the membranes that protect the brain and spinal cord. This condition happens when these membranes get infected, which can happen with bacteria or viruses, but it can also happen with fungi or parasites. Inflammation can put pressure on the brain, which can cause a number of different symptoms. Common symptoms include severe headache, stiff neck, fever, nausea, and vomiting. More severe cases can cause seizures, confusion, or even coma. The condition typically develops rapidly and requires immediate medical attention.

Bacteria, viruses, fungi, and parasites are the most common causes of meningitis. There are also non-infectious causes, such as autoimmune disorders. People with weak immune systems are more likely to get infections from fungi and some parasites. Brain damage, hearing loss, and hydrocephalus (fluid buildup in the brain) are some of the problems that can happen. In severe cases, untreated bacterial meningitis can lead to death. Early diagnosis and treatment by neurologists and general physicians are important for better outcomes.

Meningitis remains a major public health problem around the world, with about 25 lakh cases reported every year. The disease causes the death of about 2.3 to 2.5 lakh people each year, even though there are vaccines and treatments available. Children under 5 years old are the most affected, making up a large number of cases and deaths. The disease occurs all over the world, but it is most common in the "meningitis belt" of sub-Saharan Africa, where there are often large seasonal outbreaks.

Meningitis is classified primarily by etiology into infectious and non-infectious types. Understanding these types helps doctors determine the appropriate treatment and prevention strategies. The following are the different types of meningitis:

Infectious types

• Bacterial meningitis
• Viral meningitis
• Fungal meningitis
• Parasitic meningitis
• Amoebic meningitis

Non-Infectious Types

• Autoimmune meningitis
• Carcinomatous (neoplastic) meningitis
• Drug-induced aseptic meningitis
• Post-traumatic meningitis

Infectious types of meningitis are caused by microorganisms that invade the meninges, triggering inflammation and requiring antimicrobial therapy.

Bacterial meningitis

Bacterial meningitis is a serious and life-threatening type of meningitis that is caused by bacteria like Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. If not treated quickly, the infection can get worse quickly and cause problems like brain damage or hearing loss. To lower the risk of complications, it is important to get a quick diagnosis and start taking antibiotics immediately. Some types of bacterial meningitis can be prevented by getting vaccinated.

Viral meningitis

Viral meningitis is the most common type of meningitis and is generally less severe than bacterial meningitis. It is commonly caused by viruses such as enteroviruses, herpes viruses, and the mumps virus. Many people recover with supportive care, although symptoms such as headache, fever, and neck stiffness may occur. Hospital observation may be required in some cases.

Fungal meningitis

Fungal meningitis is a rare infection that is caused when fungi spread to the brain and spinal cord through the blood. People with weak immune systems, like those with chronic illnesses or immunosuppression, are the most likely to get it. This kind of meningitis doesn't spread from one person to another. Long-term antifungal therapy is usually needed for treatment.

Parasitic meningitis

Parasites infect the meninges, which are the protective membranes around the brain and spinal cord, and this causes parasitic meningitis. It is rare and may occur due to exposure to contaminated food, water, or infected animals. Some infections can cause eosinophilic meningitis, which is characterized by an increase in eosinophils in the cerebrospinal fluid. Headaches, fever, and problems with the nervous system are some of the symptoms.

Amoebic meningitis

Primary amoebic meningoencephalitis (PAM), also known as amoebic meningitis, is a rare but serious infection caused by the amoeba Naegleria fowleri. When a person swims in warm freshwater that has been contaminated, the organism usually gets into the body through the nose. It quickly hurts brain tissue and causes a lot of swelling. The first signs are similar to those of bacterial meningitis, but they get worse quickly and need to be treated immediately.

Non-infectious meningitis is inflammation of the meninges caused by factors other than infections. It includes the following:

Autoimmune meningitis

Autoimmune meningitis occurs when the body's immune system attacks the meninges, often as part of a systemic autoimmune disease like lupus. It can result in chronic inflammation and neurological symptoms. Treatment typically involves immunosuppressive medications to control the immune response.

Carcinomatous (neoplastic) meningitis

Cancer cells that spread to the meninges, often from primary tumors like breast, lung, or melanoma, cause this type of meningitis. It can cause serious neurological problems and needs specific treatments like chemotherapy or radiation. For effective management, early detection is very important.

Drug-induced aseptic meningitis

Certain medications, such as NSAIDs or antibiotics, can trigger an aseptic meningitis reaction, causing inflammation without infection. It often resolves upon discontinuation of the causative drug. Symptoms can mimic those of infectious meningitis but typically improve after drug withdrawal.

Post-traumatic meningitis

Head injuries, like skull fractures or surgery, can cause post-traumatic meningitis by making the meninges swell. This condition can happen when bacteria or other foreign substances get into the meninges during an injury, but it can also happen without an infection. The primary goal of treatment is to control inflammation and any injuries that are potentially responsible for it.

The signs and symptoms of meningitis in infants may differ from those seen in older children and adults. They include:

• Bulging fontanelle
• Stiff body, be floppy, or unresponsive
• Poor feeding
• Irritability
• Abnormal or high-pitched crying

Bulging fontanelle: A bulging fontanelle is a swelling of the soft spot on the top of an infant’s head. It can occur due to increased pressure inside the skull caused by infection or inflammation. This sign may indicate meningitis and requires prompt medical attention.

Stiff body, be floppy, or unresponsive: Infants with meningitis may appear unusually stiff or very floppy due to effects on the nervous system. Some babies may also become less responsive or difficult to wake. These changes may indicate serious brain involvement and require urgent evaluation.

Poor feeding: Babies with meningitis may refuse to breastfeed or bottle-feed or may have difficulty sucking. Illness and discomfort can lead to reduced appetite and weakness. Persistent feeding problems in infants should be medically assessed.

Irritability: Infants with meningitis may become very irritable and difficult to soothe. They may cry frequently and remain restless even when comforted. This can occur due to pain, discomfort, and brain inflammation.

Abnormal or high-pitched crying: A high-pitched or unusual cry may occur in infants with meningitis. This cry often sounds different from normal crying and may be persistent. It can be caused by increased pressure or irritation affecting the brain and nervous system.

Meningitis can occur when infectious microorganisms or certain medical conditions lead to inflammation of the meninges. The cause may be infectious or non-infectious factors affecting the nervous system. The causes are:

Infectious causes

• Bacterial infections
• Viral infections
• Fungal infections
• Parasitic infections
• Amoebic infections

Non-infectious causes

Bacterial infections

Bacterial infection is a major cause of meningitis that needs to be treated immediately. Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae are some of the most common bacteria. These organisms can spread through droplets in the air or from infections that are nearby, including sinus or ear infections.

Viral infections

Viral infections are the common cause of meningitis and are usually less severe than bacterial meningitis. Enteroviruses are the most frequent cause, although viruses such as herpes simplex virus and mumps virus can also lead to infection. Many people recover with supportive care.

Fungal infections

Fungal meningitis occurs when fungi get into the brain and spinal cord through the blood. It mostly affects people whose immune systems are weak, like those with HIV/AIDS or other long-term illnesses. A common cause is getting infected with the Cryptococcus species.

Parasitic infections

Certain parasites can infect the meninges and lead to inflammation. These infections may occur through contaminated food, water, or exposure to infected animals. Some parasitic infections cause a form known as eosinophilic meningitis.

Amoebic infections

Amoebic meningitis is a rare but severe infection caused by the amoeba Naegleria fowleri. The organism usually enters the body through the nose during swimming or diving in warm freshwater. It can rapidly affect the brain and cause severe neurological damage.

Meningitis can also occur due to certain medications, cancers, autoimmune diseases, or head injuries. In these cases, inflammation of the meninges occurs without infection. These forms are referred to as non-infectious meningitis.

Several conditions and environmental factors can increase the likelihood of developing meningitis. Recognizing these risk factors helps in early prevention, timely diagnosis, and reducing the risk of severe complications. It includes:

• Age
• Lack of vaccination
• Close contact with infected individuals
• Living in crowded environments
• Weakened immune system
• Pregnancy
• Certain medical conditions
• Head injury or neurosurgical procedures
• Ear or sinus infections

Age: Certain age groups have a higher risk of developing meningitis. According to public health authorities, infants, young children, teenagers, and older adults are more susceptible because their immune defences may not fully protect them against certain bacteria and viruses that cause meningitis.

Lack of vaccination: People who have not received recommended vaccines are at higher risk of meningitis caused by bacteria such as Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Vaccination programs significantly reduce the occurrence of these infections and help protect individuals and communities.

Close contact with infected individuals: Meningitis-causing bacteria and viruses can spread through respiratory droplets, saliva, or close personal contact. Living with or spending prolonged time near an infected person increases the chance of exposure and transmission.

Living in crowded environments: Crowded areas such as college dormitories, military barracks, hostels, or refugee camps increase the risk of meningitis outbreaks. Close living quarters allow infectious organisms to spread more easily between individuals.

Weakened immune system: People with weak immune systems are more prone to infections, including meningitis. Conditions or treatments that reduce immune function make it harder for the body to fight bacteria or viruses that can invade the protective membranes of the brain and spinal cord.

Pregnancy: Certain bacteria, especially Listeria monocytogenes, are more likely to infect pregnant women. This infection can lead to meningitis and may also harm the fetus or newborn, making immediate medical care important if symptoms develop.

Certain medical conditions: Some health conditions increase susceptibility to meningitis. For example, people with HIV infection, those who lack a functioning spleen (asplenia), or those with complement immune system deficiencies are at increased risk of severe bacterial infections such as meningococcal meningitis.

Head injury or neurosurgical procedures: Trauma to the head or surgeries involving the brain or spinal cord can create openings that allow bacteria to enter the central nervous system. This disruption of protective barriers can increase the likelihood of meningitis.

Ear or sinus infections: Untreated or severe infections of the middle ear (otitis media) or sinuses (sinusitis) can sometimes spread to nearby tissues. In rare cases, bacteria from these infections may reach the meninges and cause meningitis.

Meningitis is very common in India, but it varies across regions and age groups. About 1 to 3 people out of every 100,000 get bacterial meningitis each year, and the rates are higher for children under five. National disease surveillance systems report thousands of cases every year. Vaccination programs and better healthcare services have helped reduce its overall occurrence.

Yes, if left untreated, meningitis can be fatal if it is caused by certain types of bacteria. Severe inflammation and infection may harm the brain, nerves, and other organs, which can cause serious problems. Getting a diagnosis and medical treatment early increases the chances of recovery and lowers the risk of death.

Yes, there are vaccines for meningitis. Vaccines can help stop infections caused by bacteria like Haemophilus influenzae type b, meningococcal, and pneumococcal. Vaccines are an excellent choice for children, adolescents, and some high-risk groups. Getting vaccinated lowers the chances of getting sick and spreading meningitis.

Meningococcal vaccines usually protect for 3-5 years. Immunity can decrease over time, so booster doses are recommended for specific age groups. For instance, adolescents vaccinated at ages 11-12 should receive a booster around age 16 to sustain immunity.

There are a number of ways to protect from meningitis. The best way to stay protected from certain types is to get vaccinated. Germs spread less when people wash their hands often and cover their mouths when they cough and sneeze. Staying away from people who are sick with meningitis lowers the risk even more.

The long-term effects of meningitis can vary depending on the severity and type of infection. People who survive may lose their hearing, have seizures, damage their brains, or have problems with their nervous systems, like weak limbs or trouble speaking. Other possible problems are issues with vision, learning disabilities, and, in the worst cases, amputations. Up to one in five people who survive bacterial meningitis may have these effects.

There are several types of meningitis, but they can mostly be grouped into bacterial, viral, fungal, parasitic, and non-infectious. Bacterial meningitis is the most common type. It is caused by bacteria like Neisseria meningitidis and Streptococcus pneumoniae. Viral meningitis is the second most common type. It is usually caused by enteroviruses. Fungal meningitis, which is caused by fungi like Cryptococcus, is less common. There are also less common types of meningitis, such as parasitic meningitis and non-infectious meningitis.

Fever, headache, stiff neck, and nausea or vomiting are common symptoms of meningitis in adults. Other signs may be being sensitive to light (photophobia), being confused, having seizures, or being sleepy or having trouble waking up. Adults may develop a skin rash, especially in cases of meningococcal meningitis. It's important to get medical help immediately because meningitis can get worse quickly and become life-threatening.

Bacterial Meningitis is a dangerous infection that causes inflammation of the membranes covering the brain and spinal cord. Bacteria like Streptococcus pneumoniae and Neisseria meningitidis are the most common causes. Some of the most common symptoms are a high fever, a severe headache, a stiff neck, and confusion. It is a medical emergency that needs immediate antibiotic treatment to prevent problems or death. 

Pyogenic Meningitis is a serious type of bacterial meningitis that happens when pus-forming organisms infect the meninges of the brain and spinal cord. Bacteria like Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the most common causes. It causes a high fever, headache, stiff neck, and changes in consciousness, and it needs immediate antibiotic treatment.

Yes, an untreated or severe ear infection can spread to nearby tissues and, in rare cases, cause meningitis. The infection could spread from the middle ear to the brain coverings through the surrounding bone or blood. Getting treatment for ear infections early lowers this risk and stops serious problems from happening.

Yes, although rare, Salmonella can cause meningitis, particularly in infants, elderly individuals, or those with weakened immunity. It usually spreads through the bloodstream from a primary infection such as gastroenteritis. Early diagnosis and treatment are important to prevent serious complications. 

Meningitis is considered a disease, but it is commonly caused by an infection such as bacteria, viruses, or fungi. It is the inflammation of the protective membranes around the brain and spinal cord. Thus, meningitis is a disease that commonly results from underlying infections.

Consult a doctor for meningitis if you experience symptoms such as severe headache, stiff neck, high fever, or nausea and vomiting. Other signs that indicate a need for medical attention include:

• Sensitivity to light (photophobia)
• Confusion or difficulty concentrating
• Seizures or loss of consciousness
• Skin rash (particularly with meningococcal meningitis)

If these symptoms persist, it’s important to see a meningitis doctor for an accurate diagnosis and treatment. Seek emergency medical attention if any sudden confusion, severe headache, or any rash that doesn't fade when pressed, as these may indicate a serious infection. A neurologist or general physician can provide the best meningitis treatment to manage symptoms and prevent complications.