Considered a public health challenge, meningitis is the inflammation of the membranes that surround the brain, called meninges. The disease can be caused by bacteria, viruses or fungi, with bacterial meningitis having the greatest global impact.
This Sunday, April 24th, the world meningitis day highlights the importance of prevention, diagnosis, treatment and improvement of support measures for those suffering from the disease. In 2021, the Confederation of Meningitis Organizations proposed moving the official date to October 5th, with the aim of reaching a wider audience.
The World Health Organization (WHO) warns that meningitis is a devastating disease with a high fatality rate, which can lead to serious long-term sequelae. It is estimated that more than 5 million people are affected by meningitis annually worldwide, with one out of ten patients, one dies from the disease and two others are left with sequelae. According to the WHO, about 10% of people who contract bacterial meningitis have serious complications.
According to the Ministry of Health, the meningitis is considered an endemic disease in Brazil. In this context, cases are expected throughout the year, with occasional outbreaks and epidemics. According to the folder, the occurrence of bacterial meningitis is more common in the autumn and winter period, while cases of the disease caused by viruses are more common in spring and summer.
causes of meningitis
Meningitis can be caused by bacteria, viruses, fungi and parasites. Viral and bacterial meningitis are the most important for public health, due to the possibility of causing outbreaks of the disease.
Among the main species of bacteria associated with meningitis are neisseria meningitidis (meningococcus), Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, Mycobacterium tuberculosis, Streptococcus sp., listeria monocytogenes, Escherichia coli, Treponema pallidumamong others.
Viral meningitis can be caused by non-polio Enteroviruses (such as Coxsackie virus and Echovirus), Herpes simplex, Varicella zoster, Epstein-Barr, Cytomegalovirus, arboviruses (such as dengue, Zika, chikungunya, yellow fever, and West Nile fever), measles, mumps, rubella, adenovirus, among others.
According to the Ministry of Health, the disease can also originate from inflammatory processes, such as cancer (metastases to the meninges), lupus, reaction to some drugs, head trauma and brain surgeries.
How is meningitis transmitted?
In general, transmission happens from one person to another, through the respiratory tract, by droplets and secretions from the nose and throat. Another type of transmission occurs through ingestion of contaminated water and food in contact with feces.
Know the details of the transmission of bacterial and viral meningitis:
bacterial meningitis
Usually, the bacteria that cause bacterial meningitis are spread through the airways, droplets, and secretions from the nose and throat. Other bacteria can spread through food, such as Escherichia coli and the listeria monocytogenes.
viral meningitis
Viral meningitis can be transmitted in different ways, depending on the virus causing the disease.
In the case of Enteroviruses, contamination occurs through close contact, such as shaking hands, with an infected person. In addition to touching objects or surfaces with the virus and then touching the eyes, nose or mouth before washing hands, changing an infected person’s diapers, drinking water or eating raw foods that contain the virus.
Arboviruses, such as dengue, are transmitted through the bite of infected mosquitoes, such as Aedes aegypti.
symptoms of meningitis
Bacterial meningitis is usually more serious and symptoms include fever, headache and stiff neck. Other symptoms are malaise, nausea, vomiting, sensitivity to light and mental confusion. Worsening of the disease can lead to convulsions, delirium, tremors and coma.
In newborns and infants, signs include irritation, vomiting, lack of appetite and abnormal response to stimuli and reflexes.
Early signs of viral meningitis are similar to bacterial meningitis, including lack of appetite, irritability, drowsiness or difficulty waking up, and lethargy.
Diagnosis
Faced with symptoms compatible with the disease, medical attention should be sought for clarification, since the clinical picture of meningitis can be severe.
The diagnosis can be made from different laboratory tests, including analysis of the cerebrospinal fluid present in cavities in the brain and spinal cord, in addition to bacterial investigations and molecular diagnosis.
Laboratory tests for the diagnosis of meningitis can be performed by the Unified Health System (SUS) at the request of health professionals or epidemiological surveillance.
Treatment
Patients with suspected cases of meningitis should be admitted to a hospital due to the possibility of worsening of the clinical picture.
Treatment can be performed with the use of antimicrobials in a hospital environment. Medications vary depending on the causes and symptoms of the disease.
According to the Ministry of Health, most cases of viral meningitis are not treated with antiviral drugs. In general, people are hospitalized and monitored while they recover spontaneously.
Vaccination
Bacterial meningitis can be prevented through vaccination. The immunizers are available in the childhood vaccination schedule of the National Immunization Program (PNI).
- Meningococcal C (conjugate) vaccine: protects against meningococcal disease caused by serogroup C
- 10-valent pneumococcal vaccine (conjugated): protects against diseases caused by Streptococcus pneumoniaeincluding meningitis
- Pentavalent: protects against invasive diseases caused by Haemophilus influenzae serotype B, such as meningitis
Overview of meningitis in Brazil
From 2007 to 2020, 393,941 suspected cases of meningitis were reported in Brazil, according to the Ministry of Health. Of these, 265,644 cases were confirmed associated with various causes, with viral meningitis being the most frequent (121,955), followed by bacterial (87,993).
Among the cases of bacterial meningitis, the most frequent were due to various bacteria (40,801), meningococcal disease (26,436), pneumococcal meningitis (14,132) and tuberculous meningitis (4,916).
In relation to meningococcal disease, there was a reduction in the total incidence coefficient after the introduction of the meningococcal C (conjugate) vaccine, from an average coefficient of 1.5 in the period prior to vaccination (2007-2010) to 0.4 per 100 thousand inhabitants, in the last four years of records of the folder (2017-2020).
Source: CNN Brasil
