What is Acute Bacterial Meningitis?

Acute bacterial meningitis is a potentially life-threatening infection marked by the pronounced inflammation of the meninges — the delicate membranous tissues that house the brain and spinal cord. Responsible for an estimated 150,000 deaths globally each year, acute bacterial meningitis often has recognizable symptoms that require prompt, appropriate treatment to prevent irreversible complications. Steroidal and antibiotic medications are generally given to reduce inflammation and eliminate infection associated with acute bacterial meningitis infection. Individuals who receive well-timed treatment generally make a full recovery.

A diagnosis of acute bacterial meningitis most often occurs in individuals 18 years of age and younger. When persistent or worsening symptoms prompt a visit to a physician or emergency room, a physical examination will likely detect characteristic meningitic symptoms. A blood panel and spinal tap, which involves obtaining a sample of cerebrospinal fluid, are most often performed to confirm a diagnosis.

Symptomatic individuals who do not receive prompt medical attention are at significant risk for complications. Loss of motor and sensory skills, paralysis, and widespread organ failure are not uncommon. Aside from the potential for convulsions and irreversible brain damage, acute bacterial meningitis can lead to a significant drop blood pressure that can cause one to go into shock.

Streptococcus pneumoniae and Haemophilus influenzae are among the bacteria most often responsible for acute bacterial meningitis infection worldwide. These naturally occurring, ubiquitous bacteria normally do not pose a meningitic threat unless they invade one’s cerebrospinal fluid by way of the bloodstream. Transmitting acute bacterial meningitis requires direct contact with the saliva or mucus of an infected person.

Early-stage meningitic symptoms are usually flu-like. Individuals often start to feel lethargic as fever and nausea develop. As infection progresses and meningeal inflammation develops, which can be within a matter of hours, the individual usually experiences neck stiffness, the hallmark symptom of meningitis. Nausea, vomiting and decreased appetite often deplete the body of vital fluids and nutrients, leaving the individual dehydrated. In some cases, the individual may also develop a skin rash that can progress to resemble mild to moderate bruising.

The aggressive nature of acute bacterial meningitis infection can cause a rapid deterioration in one’s condition if treatment is delayed. Generally, if meningitis is suspected, intravenous antiviral and antibiotic medications are administered at the outset. Identifying the infectious bacteria responsible is essential to determining treatment, specifically the most appropriate antibiotic.

An increase in intracranial pressure, known as cerebral edema, is often caused by meningeal inflammation and fluid accumulation within the skull. To prevent brain damage and herniation, corticosteroids may be administered to ease pressure and reduce inflammation. Severe cases may require a catheter to remove excess fluids.