Can malaria cause aseptic meningitis?

Does Malaria Cause Aseptic Meningitis?

Malaria does not typically cause aseptic meningitis, though it can cause cerebral malaria which is a distinct neurological complication with different pathophysiology and clinical manifestations.

Understanding Aseptic Meningitis and Malaria

Definition of Aseptic Meningitis

• Aseptic meningitis is characterized by symptoms of meningism and raised numbers of cells in the cerebrospinal fluid (CSF) with a sterile bacterial culture 1
• It is typically associated with viral infections, drug reactions, or other non-bacterial causes 2

Neurological Complications of Malaria

• Cerebral malaria is the primary neurological complication of malaria, particularly with Plasmodium falciparum infection 3
• Cerebral malaria presents with impaired consciousness, seizures, and other signs of severe disease, rather than the classic meningeal signs seen in aseptic meningitis 3
• Malaria should be excluded in all patients with a history of fever returning from the tropics, as it is the most important potentially fatal cause of febrile illness in travelers 1

Differential Diagnosis in Returning Travelers

Importance of Considering Both Conditions

• In patients returning from endemic areas with fever and neurological symptoms, both malaria and meningitis should be considered in the differential diagnosis 1
• Thrombocytopenia or malaria pigment in neutrophils and monocytes may be clues to malaria, even if blood films are negative 1, 4

Diagnostic Approach

• For suspected meningitis: Lumbar puncture should be performed if there are no contraindications 5
• For suspected malaria: Three thick films/rapid diagnostic tests over 72 hours should be performed to exclude malaria with confidence 1
• If cerebral malaria seems likely and there will be a delay in obtaining the malaria film result, anti-malarial treatment should be considered and specialist advice obtained 1

Treatment Considerations

Management of Cerebral Malaria

• Intravenous artesunate is the first-line treatment for cerebral malaria, administered at 2.4 mg/kg at 0,12,24, and 48 hours 5, 3
• Parasitemia should be monitored every 12 hours until decline to <1%, then every 24 hours until negative 5, 3
• Steroids should not be used for cerebral malaria as they have an adverse effect on outcome 3

Management of Aseptic Meningitis

• Most cases of aseptic meningitis are viral and require supportive care 2
• Treatment should focus on symptom management and identifying the underlying cause 2

Important Clinical Considerations

When Both Conditions Are Suspected

• If both conditions are suspected, prioritize treatment for malaria while continuing diagnostic workup for meningitis 5
• Start antibiotics if concomitant bacterial infection is suspected, but continue only if blood cultures are positive 5, 3

Monitoring and Complications

• Monitor for seizures, which are common in cerebral malaria, and treat appropriately 5, 3
• Use caution with fluid therapy, as overload can precipitate pulmonary edema or ARDS and worsen cerebral edema 5, 3
• Monitor blood glucose levels regularly, as hypoglycemia is a common complication in malaria 5, 3

Common Pitfalls and Caveats

• Misdiagnosis of meningitis as malaria (or vice versa) is common and can delay appropriate treatment 6
• Presumptive malaria treatment at home often delays formal treatment seeking 6
• Not all fever with neurological symptoms in returning travelers is malaria or meningitis - other causes such as viral encephalitis should be considered 7
• Drug-induced aseptic meningitis is a rare but important consideration in patients on certain medications 8, 9