What are the key clinical signs and symptoms that should raise suspicion for bacterial meningitis in adults?

Key clinical signs and symptoms that should raise suspicion for bacterial meningitis in adults include the red flag combination of:

• Fever (though less common in older adults)
• Headache
• Neck stiffness (including subtle discomfort or reluctance to move the neck, harder to identify in older adults or those with dementia or arthritis)
• Altered level of consciousness or cognition (including confusion or delirium)

Other important signs and symptoms to consider are:

• Non-blanching petechial or purpuric rash, mainly in meningococcal meningitis
• Ill appearance
• Unexplained body pain (limb, back, or abdominal pain)
• Vomiting
• Seizures
• Early signs of sepsis or shock
• Focal neurological deficits
• Photophobia
• Unusual behaviour such as agitation, aggression, or subdued state

Note that bacterial meningitis may be missed in older adults or young adults due to atypical presentations or misattribution of altered behaviour to other causes such as alcohol or substance misuse.

Heightened suspicion is warranted especially if risk factors are present, such as missed relevant immunisations, reduced spleen function, complement deficiency, close contact with cases, or previous meningitis.

Strong suspicion should prompt urgent hospital transfer without delay.

References: ¹,²,³