Meningitis is an acute inflammation of the protective membrane covering the brain and spinal cord, known as meninges. Meningitis can be divided into several categories. Given below are the types and the associated signs and symptoms. If you see your child developing any of the same, it is recommended that you consult a pediatrician at the earliest. Note that early detection and timely treatment is pivotal.
Acute Bacterial Meningitis
Bacterial meningitis is one of the most potentially serious infections occurring in infants and older children. This is the infection of meninges, the covering of brain. Meningitis is very serious disease with high rate of acute complication and risk of long term morbidity- sequalae- neurological hearing deficits. Meningitis can be divided into 2 groups- one, in neonatal period and second, beyond neonatal period. This is because of type of bacteria invading the meninges.
Meningitis In Neonatal Period
Neonatal infection encompassing first 1-3 months postnatal period can be divided into two groups- Early onset sepsis and late onset sepsis. Early onset sepsis is first 3 to 7 days after birth. Late onset is 7 days after birth. Early onset meningitis is very rare but late onset sepsis CSF examination is part of sepsis investigation protocol. Early onset sepsis caused by bugs from maternal uro-genital canal, while late onset pathogens can be from mother as well as from immediate contacts. Pathogens are: E.coli, Enterococci, Coagulase negative as well as positive Streptococcus aurieus etc. Group B Streptococcus is very uncommon in our country.
Beyond Neonatal Meningitis
Meningitis can be bacterial and viral besides small percentage of other causes. Practically beyond two months of age meningitis in early infancy to early childhood period is caused by – H.influenza, Streptococcus pneumonia and Neisseria meningitidis. Beyond early childhood Streptococcus Pneumonea and Neisseria are the commonest bugs. Alteration of host defense resulting from anatomic defects or immune deficits increases the risk of meningitis from less common pathogens such as Pseudomonas aerugenosa, Staph aureus, Coagulase negative, Salmonella, Anaerobes and Listeria monocytogenes. Bacterial meningitis results most commonly from hematogenous dissemination of micro-organism from a distant site of infection. Nasopharyngeal colonization of a potentially pathogenic micro-organism is the usual source of infection. Prior or concurrent viral upper respiratory infection may enhance the pathogenecity of bacteria causing meningitis. Viral meningitis/ meningoencephalitis, may be confused with bacterial meningitis. Severity in both may vary. Both may have a milder or more fulminant pattern. Viral meningoencephalitis is caused by viruses, Enterovirus being the commonest. Other viruses are Arbovirus, Herpes Simplex Family viruses- type I being the important cause of severe sporadic encephalitis in children and adults. Other viruses are though less common are Varicella, EB virus, Mumps etc.
Important aspects associated with Meningitis:
Meningitis in children has two predominant patterns- a more dramatic sudden onset rapidly progressing is fortunately less common. More common pattern being several days of fever accompanied by URI or GI symptoms- followed by CNS infection.
Suspicion is the key- fever with headache, vomiting, irritability, altered sensorium and neck stiffness, lethargy, stupor, obtundation and may be coma, bulging anterior fontanel- when anterior fontanel opens and neck retraction may be sole finding in infants besides irritation.
Neisseria Meningitis especially has rapid course with symptoms of CNS irritation associated with rash and bleeding spots/ patches. Lumber puncture is the key.
Early suspicion and diagnosis and prompt antibiotics increase the success of treatment and decrease the later neurological complication.
Antibiotics are used by intravenous routes- duration being 7 days to even 6 weeks. Vaccination and antibiotic prophylaxis of susceptible contacts at risk reduce the likelihood of bacterial meningitis.
Vaccines are available for H. influenza, streptococcus pneumonia and Neosseria meningitis. Appropriate antibiotic therapy and supportive care have reduced the mortality and morbidity- neurological sequalea drastically. All patients with meningitis should have careful audiologic evaluation in hospital, after discharge and may be frequent reassessment in OPD basis.