With this ever-growing world population, the occurrence of infectious diseases is on the rise. Infectious disease, by definition, is a disease caused by microorganisms like bacteria, viruses, fungi or parasites. I’m sure most of us have caught a cold once in our life which is nothing but an infection caused by a virus. Most of such infections are easily treatable with a class of drugs known as antibiotics. However, there are certain severe disorders that are caused by infectious agents. One such disease is meningitis.

Meningitis involves swelling up of the protective coverings of your brain that leads to certain common symptoms like headaches, nausea, confusion, etc. The most common types of meningitis are caused by bacteria and viruses. A study conducted in the UK in 2018 showed that the estimated annual incidence of viral meningitis was 2·73 per 100,000 and that of bacterial meningitis was 1·24 per 100,000.¹⁶ Bacterial meningitis has a much higher severity than viral meningitis and in certain cases can lead to death without prompt antibiotic treatment.

However, it does not have to be this dramatic. The old saying “Prevention is better than cure” seems apt in this case. Several risk factors and prevention strategies have been discussed in this article that will help you prevent this disease from occurring in future.

Introduction

Definition Of Meningitis

Meningitis is a condition which involves inflammation or the swelling of the protective membranes and the fluid surrounding the brain and spinal cord. These membranes are called the meninges.¹ Meninges consist of three layers, namely, the dura mater, arachnoid mater and pia mater, from outermost to innermost.² It can be caused by various microorganisms like bacteria, viruses, fungi, parasites or amoeba which are further discussed in detail.¹ 

Causes and Types

There are various types of meningitis depending on the microorganism that is the cause of the disease. 

Bacterial Meningitis

Bacterial meningitis, as the name suggests, is caused due to bacterial infection. This can be further divided into 3 types:

• Meningococcal meningitis: It is caused by Neisseria meningitidis, also known as meningococcus. It can lead to outbreaks, especially in crowded areas.³ 
• Pneumococcal meningitis: It is caused due to Streptococcus pneumoniae, and often leads to pneumonia and ear infections.
• Hib meningitis: Its causative organism is Haemophilus influenzae type b. There are very rare occurrences of this type of meningitis, mainly due to vaccination.⁴ 

Viral Meningitis

Viral meningitis is mainly caused due to a specific group of viruses called the non-polio enterovirus like coxsackievirus and echovirus. It is usually less severe than bacterial infections. Other viruses that can lead to meningitis include:

• Mumps virus
• Herpes viruses like Epstein-Barr virus, herpes simplex virus and varicella-zoster virus.
• Measles virus
• Influenza virus⁵ 

Fungal Meningitis

Fungal meningitis is caused due to fungal pathogens of species like Cryptococcus neoformans, Histoplasma capsulatum and Blastomyces. The fungus Candida also causes meningitis. Usually, fungal infection causes meningitis when it spreads from the lungs to the brain or spinal cord. Fungal meningitis does not spread among people.⁶ 

Parasitic Meningitis

Parasitic meningitis is an extremely rare type of meningitis called eosinophilic meningitis, eosinophilic meningoencephalitis, or EM. It is usually caused by three main parasites, namely Angiostrongylus cantonensis, Baylisascaris procyonis and Gnathostoma spinigerum. Naegleria meningitis is another type of parasitic meningitis caused by Naegleria fowleri that is associated with swimming in contaminated water. Neurocysticercosis is caused by Taenia solium larvae and can result from ingesting contaminated food.⁷ 

Non-infectious Meningitis

Non-infectious meningitis is a type of meningitis that is not caused by any of the above infection-causing agents. It caused due to the following reasons:

• Systemic diseases with meningeal involvement, for example: sarcoidosis, Behçet's disease, Sjögren's syndrome and systemic lupus erythematosus
• Drug-induced aseptic meningitis (most commonly reported with non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics (sulfamides, penicillins), intravenous immunoglobulin, and monoclonal antibodies)
• Neoplastic meningitis (that could be related to either solid cancer metastasis or lymphoma/leukaemia.⁸ 

Symptoms and Risk Factors

Patients who are suffering from meningitis show various symptoms that include fever, headache, stiff neck, nausea and vomiting, confusion, skin rash, joint pain and fatigue. Some patients also experience difficulty when exposed to bright light settings. In severe cases, seizures are experienced when the infection is affecting the brain.⁹ 

There are several risk factors that can lead to meningitis. Some of them are listed below:

• Infants, young children and adolescents are more susceptible due to an immature immune system.
• Certain disorders like HIV/AIDS suppress the immune system and in such a state, a person is more likely to catch this disease.
• Living in crowded spaces makes it easier to get infected by the pathogens causing meningitis.
• Lack of vaccination against certain bacteria or viruses that can cause meningitis increases susceptibility.
• Chronic alcohol use is also one of the risk factors that can lead to meningitis.¹⁰ 

Prevention Strategies

Vaccination

Importance of Vaccination

Vaccination is a simple and safe method of protecting you against harmful diseases. It is crucial for preventing diseases like meningitis by bolstering the body's immune response against the bacteria and viruses that cause the disease. Vaccination involves treatment with a vaccine which is a biological preparation that is injected into the patient’s body. It uses your body’s natural defences to build resistance to specific infections and makes your immune system stronger.¹¹ 

In the case of meningitis, vaccines significantly reduce the risk of meningitis and its potentially devastating consequences, including brain damage and death. Moreover, widespread vaccination creates herd immunity, protecting vulnerable individuals who cannot be vaccinated and helping to control outbreaks in communities.¹² 

Types of Meningitis Vaccines

There are numerous vaccines against different types of meningitis available. Most of them have to be taken right after birth within intervals of a few weeks up to 1 year. A few of them are to be taken in adolescence and in adulthood as well. Here is the list of vaccines along with the age at which they need to be taken.

• Haemophilus influenzae type b (Hib) Vaccine: It provides protection against bacterial meningitis caused by Hib bacteria, primarily in children. It is to be taken as early as 8 weeks post-birth and booster doses are also to be taken within 1 year of age.
• Meningococcal B (MenB) Vaccine: It specifically targets the B strain of Neisseria meningitidis and is also given in 8 weeks after birth with booster doses up to 1 year.
• Pneumococcal Vaccine: It guards against Streptococcus pneumoniae, a bacterium that can cause bacterial meningitis, especially in infants and older adults. Hence it is given once as an infant at 12 weeks of age with a booster dose at 1 year, as well as, a stronger version of the same at the age of 65 years.
• Meningococcal C (MenC) Vaccine: It offers protection against a type of bacteria called meningococcal group C bacteria, which can cause meningitis.Babies are offered a combined Hib/MenC vaccine at 1 year of age.¹³
• Measles, Mumps and Rubella (MMR) Vaccine: Although primarily it is used for preventing measles, mumps and rubella, MMR vaccine indirectly helps reduce the risk of viral meningitis caused by mumps.
• Meningococcal A,C,W and Y (MenACWY) Vaccine: It shields against various strains of Neisseria meningitidis, namely A,C,W and Y.¹⁴ 

Hygiene Practices

As discussed before in this article, meningitis is an infectious disease that is caused by numerous microorganisms. Hence, following certain basic hygiene practices can prevent the occurrence of the infection. A few are mentioned below.

• Frequent washing of hands with soap and water, especially after using the bathroom, before eating, and after coughing or sneezing.
• Covering your mouth and nose with a tissue or a napkin while coughing or sneezing prevents the spread of respiratory droplets.
• Avoid sharing personal items like eating utensils, drinking cups, toothbrushes, etc, which can transfer bacteria or viruses.
• Keeping your surroundings clean and well-ventilated, along with regular disinfection of touched surfaces like doorknobs, light switches, and countertops.
• Avoiding close contact with infected individuals and not sharing your personal belongings with them is crucial in preventing the spread of meningitis. This prevents your exposure to their respiratory droplets containing infectious agents.¹⁵ 

Maintaining a Healthy Lifestyle

Maintaining a healthy lifestyle is essential for having a strong immune system that can fight off infections. Consuming a balanced diet rich in all the essential nutrients, staying hydrated, getting adequate sleep and regular physical activity are important in having a strong immunity. Chronic stress can impair the immune system and make individuals more vulnerable to infections. Engaging in stress-reducing activities such as mindfulness, meditation, yoga, or hobbies can help mitigate the negative effects of stress on the immune system. Avoiding harmful substances like alcohol, drugs and tobacco products also is essential for maintaining strong immunity.¹⁵

FAQs

What is the standard prevention method for bacterial meningitis?

Ans: Vaccines are the safest and most effective way to provide protection for many types of bacterial meningitis.

How can TB meningitis be prevented?

Ans: The vaccine BCG is effective in preventing TB meningitis. It is effective in infants and young children. This vaccine can provide better protection against severe forms of TB like TB meningitis.

What are the WHO guidelines for the treatment of meningitis?

Ans: A range of antibiotics like penicillin, ampicillin and ceftriaxone are recommended by WHO for the treatment of meningitis. Licensed vaccines for meningococcal disease are also available.

Summary

• Meningitis is a condition that includes inflammation of protective membranes and fluid surrounding the brain and spinal cord.
• Different types of meningitis are bacterial, viral, fungal, parasitic and non-infectious meningitis. Out of these, bacterial and fungal are most common.
• Vaccination is the most important and effective in the prevention of bacterial and viral meningitis.
• Basic hygiene practices and maintaining a healthy lifestyle are key in the prevention of meningitis.