Meningitis

What causes meningitis

Bacterial meningitis

The most serious form. In the US, the main causes are:

Bacteria usually reach the meninges through the bloodstream, or spread from nearby infections or through skull defects.

Viral meningitis

Enteroviruses cause most cases, especially in summer and fall. Other causes include herpes simplex, varicella-zoster, mumps, measles, influenza, West Nile virus and HIV. Most people recover fully within 7 to 10 days.

Other causes

• Fungal: cryptococcal meningitis in people with weakened immunity, such as advanced HIV.
• Tuberculous meningitis: develops slowly over weeks.
• Parasitic: rare, including Naegleria fowleri from warm freshwater entering the nose.
• Non-infectious: some medicines, cancers, lupus and other inflammatory conditions.

Symptoms

Teens and adults

• sudden fever
• severe headache
• stiff neck, especially when bending the chin to the chest
• sensitivity to light (photophobia)
• nausea and vomiting
• confusion, drowsiness or difficulty waking
• seizures
• rash (particularly with meningococcal infection)

Not everyone has all symptoms. Older adults may have only confusion and fever.

Babies and young children

• fever, or a low temperature in newborns
• irritability, a high-pitched cry, or not wanting to be held
• poor feeding or vomiting
• drowsiness, floppiness or stiffness
• bulging fontanelle (soft spot)
• rash

The meningococcal rash and the glass test

Meningococcal disease can cause sepsis with a rash of small red or purple pinprick spots that spread into larger bruise-like blotches. To check, press the side of a clear drinking glass firmly against the rash. If the spots do not fade under the glass, seek emergency care immediately. On darker skin, the rash can be harder to see; check paler areas such as the palms, soles, inside the eyelids and the roof of the mouth. Do not wait for a rash: it can appear late or not at all.

Bacterial vs viral meningitis

They cannot be reliably told apart without tests, so all suspected cases are treated as emergencies.

Diagnosis

• Lumbar puncture (spinal tap): a needle in the lower back collects cerebrospinal fluid to test for white cells, protein, sugar, bacteria and viruses. This is the key test.
• Blood tests and blood cultures.
• CT scan of the head before lumbar puncture in some people, such as those with confusion, seizures or signs of raised brain pressure.
• PCR tests to identify specific bacteria and viruses.

Antibiotics are started immediately when bacterial meningitis is suspected, even before test results.

Treatment

Bacterial meningitis

• Intravenous antibiotics given as quickly as possible, usually a combination (such as ceftriaxone with vancomycin, plus ampicillin for those at risk of Listeria), then narrowed once the bacterium is identified.
• Dexamethasone (a steroid) given with or before the first antibiotic dose in certain cases reduces hearing loss and other complications, particularly in pneumococcal meningitis.
• Intensive care for sepsis, seizures and brain swelling.
• Preventive antibiotics for close contacts of people with meningococcal or Hib disease.

Viral meningitis

• rest, fluids and pain relief
• acyclovir for herpes simplex or varicella-zoster meningitis
• most people recover in 7 to 10 days, though fatigue and headaches can linger

Complications

Bacterial meningitis can lead to:

• hearing loss, so all survivors should have a hearing test
• brain damage, learning difficulties, memory problems
• seizures and epilepsy
• hydrocephalus
• limb loss from meningococcal sepsis
• death, in roughly 10 to 15% of bacterial meningitis cases even with treatment

Prevention

• Meningococcal vaccines: MenACWY at age 11 to 12 with a booster at 16 in the US; MenB for ages 16 to 23 based on shared decision-making or outbreak risk; and for high-risk groups.
• Pneumococcal vaccines: for all infants, adults 50 and older, and people with risk conditions.
• Hib vaccine: routine for infants.
• Other vaccines: MMR, chickenpox and flu reduce viral causes.
• Group B strep screening in pregnancy, with antibiotics during labor if positive.
• Good hygiene: handwashing, not sharing drinks or utensils.
• Food safety in pregnancy: avoid unpasteurized dairy and deli meats unless heated to steaming, to prevent Listeria.

Frequently asked questions

What are the first signs of meningitis?

Early signs often include fever, headache, vomiting and feeling unwell, followed by a stiff neck, sensitivity to light, confusion or a rash. In babies, early signs are fever, irritability, poor feeding and drowsiness. Seek emergency care if meningitis is possible.

What does a meningitis rash look like?

It starts as small red or purple pinprick spots that can spread into larger purple blotches. The rash does not fade when a glass is pressed against it. It can be harder to see on darker skin. Not everyone with meningitis develops a rash.

Is meningitis contagious?

The germs that cause meningitis can spread through close contact, coughing, sneezing and kissing, but most people exposed do not develop meningitis. Close contacts of someone with meningococcal or Hib meningitis are given preventive antibiotics.

How is viral meningitis different from bacterial meningitis?

Viral meningitis is more common and usually resolves on its own within 7 to 10 days. Bacterial meningitis is less common but can be fatal within hours and needs immediate antibiotics. Only tests can tell them apart, so treat any suspected case as an emergency.

Can you survive meningitis?

Yes. Most people with viral meningitis recover fully. With prompt treatment, most people survive bacterial meningitis, though around 10 to 15% die and up to 1 in 5 survivors have lasting effects such as hearing loss or brain damage.