Bacterial meningitis

Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges ^[1]. The inflammation may result from infectious causes, including viruses, bacteria, fungi, and parasites, as well as from non-infectious causes such as malignancy, subarachnoid hemorrhage, chronic inflammatory disease, and certain drugs ^[1]. The condition is classified as a medical emergency due to its proximity to the central nervous system and its potential for life-threatening complications ^[1].

The most common symptoms are fever, intense headache, vomiting, neck stiffness, and occasionally photophobia ^[1]. Other symptoms include confusion or altered consciousness, nausea, and an inability to tolerate loud noises, and a non-blanching rash may also be present ^[1]. Young children often exhibit only nonspecific symptoms such as irritability, drowsiness, or poor feeding ^[1].

Since the 1980s, many countries have included immunization against Haemophilus influenzae type B in their routine childhood vaccination schemes, which has practically eliminated this pathogen as a cause of meningitis in young children in those countries, although the vaccine remains too expensive in countries with the highest disease burden ^[1]. Similarly, immunization against mumps has led to a sharp fall in the number of cases of mumps meningitis, which before vaccination occurred in 15% of all cases of mumps ^[1]. Meningococcus vaccines exist against groups A, B, C, W135, and Y, and in countries where the group C vaccine was introduced, cases caused by this serogroup declined substantially ^[1].

Bacterial and viral meningitis can spread from person to person, and close contacts of affected individuals may require preventive measures ^[2].

Some forms of meningitis are preventable by immunization with the meningococcal, mumps, pneumococcal, and Hib vaccines ^[1]. Vaccines offer the best protection against common types of bacterial meningitis, and maternal Group B streptococcus vaccines to prevent invasive GBS disease in infants are in the final stages of clinical development ^[1][2]. Giving antibiotics to people with significant exposure to certain types of meningitis may also be useful for preventing transmission ^[1].

1. 1Wikipedia contributors. Meningitis - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026.Available from: https://en.wikipedia.org/wiki/Meningitis
2. 2World Health Organization. Meningitis [Internet]. cited 3 Sept 2026.Available from: https://www.who.int/news-room/fact-sheets/detail/meningitis