What is the leading cause of life-threatening infections in newborns?

The leading cause of life-threatening infections in newborns is Group B Streptococcus (GBS). This bacterium can be found in the gastrointestinal and genitourinary tracts of healthy adults, but it can pose a serious risk to newborns during delivery if the mother is colonized.

When a pregnant woman is a carrier of GBS, the bacteria can be transmitted to the infant during labor and delivery. This can lead to early-onset sepsis, pneumonia, and sometimes meningitis in newborns, which can progress rapidly and may result in severe complications or death if not treated promptly. The significance of GBS in neonatal infections has made screening and antibiotics during labor a critical standard care practice for expectant mothers who are found to be carriers.

The other options represent entities associated with infections or health risk factors but are not the primary cause of life-threatening infections in newborns. For instance, bacterial vaginosis is more related to complications in pregnancy rather than a direct cause of severe neonatal infections. Human immunodeficiency virus (HIV) poses risks to the mother and may lead to transmission to the child, but the instance of life-threatening infections in newborns specifically is not as direct as with GBS. Candidiasis, while