Meningitis in newborns is an infection of the membranes surrounding the brain and spinal cord, occurring in roughly 0.1 to 0.4 out of every 1,000 live births. It is more common in premature babies and those with extended hospital stays. Unlike meningitis in older children or adults, newborn meningitis is harder to spot because the symptoms overlap with many other newborn illnesses, and the classic signs like neck stiffness are rarely present.
What Causes It
Bacteria cause the most dangerous forms of newborn meningitis. The primary culprits are Group B Streptococcus (GBS), a type of E. coli, and Listeria. Which bacteria are involved often depends on timing. Infections that appear within the first 72 hours of life, called early-onset meningitis, are typically caused by GBS and Listeria picked up from the mother during delivery. Infections that develop after 72 hours, called late-onset meningitis, are more often linked to bacteria encountered in the environment or hospital setting, including skin-dwelling bacteria like Staphylococcus epidermidis alongside GBS.
Viruses actually account for about two-thirds of central nervous system infections in babies under 90 days old. Enteroviruses are the most common viral cause and typically produce a milder illness. Most babies with enteroviral meningitis develop a nonspecific fever or mild brain-lining inflammation and recover quickly without lasting effects. Herpes simplex virus (HSV) is far less common, affecting roughly 1 in 10,000 births in Europe, but it is significantly more dangerous. HSV meningitis carries higher mortality rates and a greater risk of long-term brain damage compared to enterovirus infections.
Signs That Are Easy to Miss
The tricky thing about meningitis in newborns is that the symptoms look a lot like other common newborn problems. The most frequently reported signs are temperature instability (either fever or an unusually low body temperature), lethargy, poor feeding, and low blood pressure. These are vague enough that they could signal dozens of conditions, which is part of why newborn meningitis is difficult to diagnose early.
In larger newborns weighing over about 5.5 pounds, the pattern shifts slightly. Fever, irritability, seizures, and a bulging soft spot on the head (the fontanelle) become more prominent. A UK review found that seizures occurred in 28% of confirmed cases, a bulging fontanelle in 22%, and coma in 6%. Neck stiffness, the hallmark sign in older patients, showed up in only 3% of newborns. So parents and even clinicians cannot rely on the “classic” meningitis picture when dealing with a newborn.
One pattern worth knowing is paradoxical irritability: a baby who cries more when picked up or held, rather than being soothed. This happens because movement increases pressure on inflamed membranes around the brain. Combined with poor feeding or temperature changes, it can be an early red flag.
How It Is Diagnosed
The definitive test is a lumbar puncture, commonly called a spinal tap. A small needle draws a sample of cerebrospinal fluid (CSF) from the lower back, and that fluid is tested for signs of infection. In a baby with bacterial meningitis, the fluid typically shows a sharp rise in white blood cells, elevated protein, and lower-than-normal sugar levels. One study of preterm infants found that babies with culture-confirmed meningitis had a median white blood cell count of 110 cells per cubic millimeter in their spinal fluid, compared to just 6 in uninfected babies. Protein levels were also notably higher: 217 mg/dL versus 130 mg/dL.
The fluid is also cultured to identify exactly which bacterium or virus is responsible, which guides treatment decisions. Blood cultures and sometimes imaging of the brain are done alongside the spinal tap to get the full picture.
Treatment and What to Expect
Bacterial meningitis in a newborn is a medical emergency treated with intravenous antibiotics in a hospital, typically a neonatal intensive care unit. Treatment often starts before the spinal fluid culture results come back, because waiting can be dangerous. Once the specific bacterium is identified, the antibiotic regimen is narrowed to target it directly. Treatment courses for bacterial meningitis are long compared to many other infections, often lasting two to three weeks or more depending on the organism and how the baby responds.
Viral meningitis caused by enteroviruses generally does not require specific antiviral treatment and resolves on its own with supportive care. HSV meningitis, however, requires prompt antiviral therapy, and delays in starting treatment worsen outcomes significantly.
During hospitalization, babies are closely monitored for complications like seizures, fluid buildup in the brain, and changes in head size. Some infants need additional interventions to manage these problems as they arise.
Survival and Long-Term Effects
In developed countries, the mortality rate for bacterial meningitis in newborns ranges from about 6% to 15%. Studies from the U.S., UK, and Canada have reported death rates between 7% and 9% in recent years. That means the large majority of babies survive, but survival does not always mean a full recovery.
Long-term neurological effects are common. A Canadian study found that 74% of survivors had some form of lasting effect, while a U.S. study reported 30%. The wide range reflects differences in how broadly “lasting effects” are defined and how long children are followed. A large matched study from Denmark and the Netherlands found that children who survived bacterial meningitis in infancy were about five times more likely to have moderate or severe developmental problems by age 10 compared to children who never had meningitis. Hearing loss is one of the most well-documented complications, along with vision problems, learning difficulties, and motor delays. Babies who had pneumococcal or GBS meningitis faced particularly elevated risks.
Because these effects can emerge gradually as a child grows, babies who recover from meningitis are typically followed with developmental assessments and hearing tests over several years.
Prevention Before Birth
The single most impactful prevention strategy targets Group B Streptococcus, the leading bacterial cause. The CDC recommends that all pregnant women be screened for GBS bacteria during the 36th or 37th week of each pregnancy. This screening is recommended even when a cesarean delivery is planned. Women who test positive receive antibiotics during labor, which dramatically reduces the chance of passing the bacteria to the baby during delivery.
GBS screening is recommended with every pregnancy, not just the first, because a woman’s GBS status can change between pregnancies. For Listeria, prevention is primarily through food safety during pregnancy: avoiding unpasteurized dairy products, deli meats that haven’t been reheated, and other high-risk foods. There is currently no routine prenatal screening for Listeria.