Which are leading causes of neonatal meningitis?

• A. Haemophilus influenzae type B
• B. Group B streptococci and Escherichia coli
• C. Listeria monocytogenes
• D. Neisseria meningitidis

Answer: (B)

In newborns, meningitis is most often caused by bacteria transmitted from the mother during birth, taking advantage of an immature immune system. The two most frequent culprits are Group B streptococci (Streptococcus agalactiae) and Escherichia coli. Group B strep commonly colonizes the maternal genital tract and can be passed to the infant during labor, leading to early meningitis and sepsis. Escherichia coli, especially certain virulent strains like the K1 type, is another common neonatal pathogen that can invade the meninges in the first days to weeks of life. Together, they account for the majority of neonatal meningitis cases. Haemophilus influenzae type B used to be a notable cause before vaccination but is now rare in newborns; Neisseria meningitidis tends to affect older infants and children; Listeria monocytogenes is a recognized cause in neonates but is less common than the two leading pathogens.