What are the signs of meningitis infection?

Signs and Symptoms of Meningitis Infection

The classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of adults with bacterial meningitis, making it essential to maintain a high index of suspicion even when classic symptoms are absent. 1

Adult Presentation

• Headache is reported in 58-87% of adult cases 1, 2
• Fever occurs in 77-97% of adult patients 1, 2
• Neck stiffness is present in 65-83% of cases 1, 2
• Altered mental status is reported in 30-69% of cases 1, 2
• Nausea/vomiting occurs in 45-74% of patients 1
• Petechial rash is identified in 20-52% of patients and is indicative of meningococcal infection in over 90% of cases 1, 2
• Focal neurologic deficits are present in 15-34% of cases 1
• Seizures may occur in adults, with higher frequency in pneumococcal meningitis 1

Pediatric Presentation

• Fever is the most common symptom in children beyond neonatal age (92-93% of cases) 1, 2
• Headache is reported in 2-9% of children up to 1 year of age and 75% of children older than 5 years 1, 2
• Vomiting occurs in 55-67% of pediatric cases 1, 2
• Neck stiffness is present in 40-82% of pediatric cases 1, 2
• Altered mental status is reported in 13-56% of pediatric cases 1, 2
• Seizures occur in 10-56% of children 1
• Petechial/purpuric rash is usually associated with meningococcal disease (61% of cases) but can also occur in pneumococcal meningitis (9% of cases) 1, 2

Neonatal Presentation

• Neonates typically present with nonspecific symptoms 1, 3
• Irritability, poor feeding, respiratory distress, pale or marble skin, and hyper- or hypotonia 2
• Fever is present in only a minority (6-39%) of neonatal cases 1, 2
• Seizures occur in 9-34% of neonatal cases, more commonly with Group B streptococcal meningitis 1, 2
• Respiratory distress or failure is frequently reported as an initial symptom 1

Diagnostic Challenges

• Meningeal signs have poor diagnostic accuracy for bacterial meningitis 1
• Sensitivity of neck stiffness is only 51% in children and 31% in adults 1, 2
• Kernig sign has a sensitivity of 53% in children and 11% in adults 1, 2
• Brudzinski sign has a sensitivity of 66% in children and 9% in adults 1, 2
• Up to 95% of patients will have at least two of the following four cardinal symptoms: fever, nuchal rigidity, altered mental status, and headache 4

Age-Specific Considerations

• The younger the patient, the more subtle and atypical the symptoms 1, 2
• Elderly patients are more likely to have altered consciousness and less likely to have neck stiffness or fever 1
• Age can indicate likely causative agents: Listeria or pneumococcal disease is more common in older people, viral meningitis in adults 20s-40s, and meningococcal infection in adolescents and young adults 1

Important Clinical Pitfalls

• Absence of classic symptoms cannot be used to rule out bacterial meningitis 1, 2
• Bacterial meningitis should not be ruled out solely on the absence of classic symptoms 1
• A severe headache that worsens, is abrupt in onset, or is the worst of the patient's life could indicate meningitis or subarachnoid hemorrhage 5
• Meningococcal sepsis can present with hypotension, altered mental state, and rash; patients can deteriorate rapidly even if initially appearing well 1
• Cerebrospinal fluid examination is essential for diagnosis when bacterial meningitis is suspected, as clinical features alone cannot distinguish between viral and bacterial disease 1, 4