Meningitis is inflammation of the three membranes (meninges) that line the brain and spinal cord.

Although meningitis can affect people of any age, babies under 2 are at the highest risk of getting meningitis. Your baby can get meningitis when bacteria, viruses, or a fungus infecting another part of their body travels in the bloodstream to their brain and spinal cord.

Out of 1,000 live births, about 0.1 to 0.4 neonates (a baby less than 28 days old) get meningitis, estimates a 2017 review. It’s a serious condition, but 90 percent of these babies survive. The same study notes anywhere from 20 to 50 percent of them have long-term complications, like learning difficulties and vision problems.

It’s always been uncommon, but the use of vaccinations against bacterial meningitis has dramatically reduced the number of babies getting it.

Before there was a pneumococcal vaccine, 10 out of 100,000 babies under 1 year old got pneumococcal meningitis, reports the Centers for Disease Control and Prevention (CDC). From 2002 through 2007, when the vaccine was routinely used, only about 8 out of 100,000 babies age 1 to 23 months got any type of bacterial meningitis, estimates a 2011 article.

Symptoms of meningitis in babies

The symptoms of meningitis can come on very rapidly. Your baby may be hard to comfort, especially when they’re being held. Other symptoms in a baby may include:

  • developing a sudden high fever
  • not eating well
  • vomiting
  • being less active or energetic than usual
  • being very sleepy or hard to wake up
  • being more irritable than usual
  • bulging of the soft spot on their head (the fontanel)

Other symptoms may be difficult to notice in a baby, such as:

  • severe headache
  • neck stiffness
  • sensitivity to bright light

Occasionally, a baby may have a seizure. Many times this is due to the high fever and not the meningitis itself.

Causes of meningitis in babies

Bacteria, viruses, or a fungus can cause meningitis in a baby.

Viral meningitis has long been the most common cause of meningitis. Since the development of vaccines to prevent bacterial meningitis, this type of meningitis has become increasingly uncommon. Fungal meningitis is rare.

Viral meningitis

Viral meningitis usually isn’t as serious as bacterial or fungal meningitis, but some viruses do cause a severe infection. Common viruses that usually cause mild disease include:

  • Non-polio enteroviruses. These viruses cause most cases of viral meningitis in the United States. They cause many kinds of infections, including colds. A lot of people contract them, but very few get meningitis. The viruses spread when your baby comes in contact with infected stool or oral secretions.
  • Influenza. This virus causes the flu. It’s spread through contact with secretions from the lung or mouth of a person infected with it.
  • Measles and mumps viruses. Meningitis is a rare complication of these very contagious viruses. They’re easily spread through contact with infected secretions from the lungs and mouth.

Viruses that can cause very severe meningitis include:

  • Varicella. This virus causes chickenpox. It’s easily spread by contact with a person infected with it.
  • Herpes simplex virus. A baby usually gets it from their mother in the womb or during birth.
  • West Nile virus. This is transmitted by a mosquito bite.

Children under 5, including babies, have a higher risk of getting viral meningitis. Babies between birth and 1 month of age are more likely to develop a severe viral infection.

Bacterial meningitis

During the first 28 days of life, bacterial meningitis is most often caused by bacteria called:

  • Group B Streptococcus.This usually spreads from a mother to her baby at birth.
  • Gram-negative bacilli, such as Escherichia coli (E. coli) and Klebsiella pneumoniae.E. coli can spread via contaminated food, food prepared by someone who used the bathroom without washing their hands afterward, or from mother to baby during birth.
  • Listeria monocytogenes.Neonates usually get this from their mom in the womb. Occasionally a baby may get it during delivery. The mother gets it by eating contaminated food.

In children under 5 years, including babies over 1 month old, the most common bacteria that cause meningitis are:

  • Streptococcus pneumoniae. This bacterium is found in the sinuses, nose, and lungs. It spreads through breathing in air that a person infected with it sneezed or coughed into. It’s the most common cause of bacterial meningitis in babies younger than 2 years.
  • Neisseria meningitidis. This is the second most common cause of bacterial meningitis. It spreads through contact with secretions from the lungs or mouth of a person infected with it. Babies less than 1 year old are at highest risk of getting this.
  • Haemophilus influenzaetype b (Hib). This is spread by contact with secretions from the mouth of a person who’s a carrier. Carriers of the bacteria usually aren’t sick themselves but can make you sick. A baby must be in close contact with a carrier for a couple days to get it. Even then, most babies will only become carriers and not get meningitis.

Fungal meningitis

Fungal meningitis is very rare because it usually only affects people with a weak immune system.

Several types of fungi can cause meningitis. Three types of fungus live in the soil, and one type lives around bat and bird droppings. The fungus enters the body by being breathed in.

Babies born prematurely who don’t weigh very much have a higher risk of getting a blood infection from a fungus called Candida. A baby usually contracts this fungus in the hospital after birth. It can then travel to the brain, causing meningitis.

Diagnosis of meningitis in babies

Tests can confirm the diagnosis of meningitis and determine what organism is causing it. Tests include:

  • Blood cultures. Blood removed from your baby’s vein is spread on special plates that bacteria, viruses, or a fungus grows well on. If something grows, that’s probably the cause of the meningitis.
  • Blood tests. Some of the blood removed will be analyzed in a lab for signs of infection.
  • Lumbar puncture. This test isalso called a spinal tap. Some of the fluid that surrounds your baby’s brain and spinal cord is removed and tested. It’s also put on special plates to see if anything grows.
  • CT scan. Your doctor may get a CT scan of your baby’s head to see if there’s a pocket of infection, called an abscess.

Treatment of meningitis in babies

The treatment for meningitis depends on the cause. Babies with some types of viral meningitis get better without any treatment.

However, always take your baby to the doctor as soon as possible any time you suspect meningitis. You can’t be sure what’s causing it until your doctor does some tests because the symptoms are similar to other conditions.

When needed, treatment has to start as soon as possible for a good outcome.

Viral meningitis

Most of the time, meningitis due to non-polio enteroviruses, influenza, and mumps and measles viruses is mild. However, young infants are at higher risk of having severe disease. A baby who has it may get better within 10 days without needing any treatment.

Meningitis caused by other viruses, like varicella, herpes simplex, and West Nile virus, can be serious. This may mean your baby needs to be hospitalized and treated with intravenous (IV) antiviral medication.

Bacterial meningitis

Antibiotics are used to treat bacterial meningitis. They’re often given through an IV. Your baby will probably have to stay in the hospital.

Fungal meningitis

Fungal infections are treated with IV antifungal medication. Your baby will most likely have to get treatment in the hospital for a month or more. This is because fungal infections are hard to get rid of.

Preventing meningitis in babies

Vaccines can prevent many, but not all, kinds of meningitis if they’re given as recommended by the CDC. None are 100 percent effective, so even babies that are vaccinated can get meningitis.

Note that although there’s a “meningitis vaccine,” it’s for one specific type of bacterial meningitis called meningococcal meningitis. It’s generally recommended for older children and teens in the United States. It’s not used in babies.

In some countries such as the United Kingdom, babies often do receive a meningitis vaccine.

Viral meningitis

Vaccines against viruses that can lead to meningitis are:

  • Influenza. This protects against meningitis caused by the flu virus. It’s given every year starting at 6 months of age. Although younger babies don’t get this vaccine, it does offer protection when family members and others who will be around your baby are vaccinated.
  • Varicella. This vaccine protects against chickenpox. The first is given when your baby is 12 months old.
  • Measles, mumps, rubella (MMR). If your baby gets the measles or mumps, it can lead to meningitis. This vaccine protects against those viruses. The first dose is given at 12 months of age.

Bacterial meningitis

Vaccines to prevent infections that can lead to bacterial meningitis in babies are:

  • Haemophilus influenzae type b (Hib) vaccine. This protects against H. influenza bacteria. In developed countries, like the United States, this vaccine has nearly eliminated this type of meningitis. The vaccine protects a baby from getting meningitis and from becoming a carrier. Reducing the number of carriers leads to herd immunity. This means that even babies who aren’t vaccinated have some protection since they’re less likely to come in contact with a carrier. The first dose is given at 2 months of age.
  • Pneumococcal (PCV13) vaccine. This protects against meningitis due to many strains of Streptococcus pneumoniae. The first dose is given at 2 months of age.
  • Meningococcal vaccine. This vaccine protects against Neisseria meningitidis. It’s not routinely given until age 11, unless there’s an issue with a baby’s immune system or they’re traveling to countries where the bacterium is common. If that’s the case, then it’s given starting at 2 months of age.

For group B strep, antibiotics can be given to the mother during labor to help prevent the baby from getting it.

Pregnant women should avoid cheese made with unpasteurized milk because it’s a common source of Listeria. This helps prevent the mother from contracting Listeria and then transferring it to her baby.

Follow general precautions to avoid infections and help lower the risk of getting meningitis from any bacteria or viruses:

  • Wash your hands often, especially before handling food and after:
    • using the bathroom
    • changing your baby’s diaper
    • covering your mouth to sneeze or cough
    • blowing your nose
    • taking care of someone who might be contagious or has an infection
  • Use proper hand-washing technique. This means washing with soap and warm water for at least 20 seconds. Make sure to wash your wrists and under your nails and rings.
  • Cover your mouth with the inside of your elbow or a tissue every time you sneeze or cough. If you use your hand to cover, wash it right away.
  • Don’t share things that may carry saliva, such as straws, cups, plates, and utensils. Avoid kissing a person who’s sick.
  • Don’t touch your mouth or face if your hands aren’t washed.
  • Frequently clean and disinfect objects you often touch, such as your phone, computer keyboard, remote controls, doorknobs, and toys.

Fungal meningitis

There are no vaccines for fungal meningitis. Babies aren’t normally in the environments where most fungi live, so they’re unlikely to get fungal meningitis.

Since it’s usually picked up in the hospital, using routine infection precautions can help prevent a Candida infection, which can lead to meningitis, in low-weight premature babies.

Long-term effects and outlook

Meningitis is an uncommon but serious, life-threatening infection. However, a baby will almost always fully recover when it’s diagnosed and treated early.

If treatment is delayed, a baby can still recover, but they may be left with one or more long-term effects, including:

  • blindness
  • deafness
  • seizures
  • fluid around the brain (hydrocephalus)
  • brain damage
  • learning difficulties

The CDC estimates 85 to 90 percent of people (babies and adults) with meningitis due to meningococcal bacteria survive. Around 11 to 19 percent will have long-term effects.

This may sound scary, but put another way, about 80 to 90 percent of people who recover have no long-term effects. The CDC estimates estimated 92 percent of children with meningitis due to pneumococcus survive.