Symptoms of Typhoid Meningitis
Typhoid meningitis presents with fever, headache, altered mental status, and abdominal symptoms, though it is a rare complication occurring in less than 1% of typhoid fever cases, and can be difficult to distinguish from other causes of bacterial meningitis or cerebral malaria. 1
Core Clinical Features
The neuropsychiatric manifestations of typhoid fever are common, occurring in up to 84% of cases, with meningo-encephalitis being one of the rarer but serious complications 1:
- Acute confusional state is the most common neurological manifestation, occurring in 73% of cases with neuropsychiatric complications 1
- Meningo-encephalitis occurs in only 0.5% of typhoid cases but carries significant morbidity 1
- Encephalitis alone occurs in 0.25% of cases 1
Presenting Symptoms
Systemic Features
- Fever is nearly universal, though the classic pattern may vary 2
- Abdominal symptoms including vomiting, abdominal pain, and diarrhea are particularly contributive signs that help distinguish typhoid from other causes of meningitis 2
- Prolonged fever preceding neurological symptoms is characteristic 2
Neurological Manifestations
- Headache that may be delayed in onset compared to systemic symptoms 2
- Altered mental status ranging from confusion to coma 2, 1
- Prostration and severe weakness 2
- Seizures can occur but are less common 1
Laboratory Abnormalities
- Leukopenia (low white blood cell count) is characteristic and helps distinguish typhoid from typical bacterial meningitis 2
- Lymphocytopenia (low lymphocyte count) 2
- Thrombocytopenia (low platelet count) 2
- Hepatitis with elevated liver enzymes 2
- Rhabdomyolysis may be present in severe cases 2
Critical Diagnostic Considerations
The absence of classic meningeal signs does not rule out typhoid meningitis, as the classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of bacterial meningitis cases. 3, 4
Key Distinguishing Features
- Geographic history from endemic zones is essential for diagnosis 2
- Combination of sepsis with leukopenia should raise suspicion, as most bacterial meningitis causes leukocytosis 2
- Abdominal symptoms preceding neurological symptoms is a particularly helpful clue 2
- Negative malaria testing in endemic areas where both diseases overlap 2
Diagnostic Approach
- Blood cultures are critical, as Salmonella typhi can be isolated from blood in bacteremic cases 2
- CSF examination should be performed unless contraindications exist, showing pleocytosis with elevated protein and low glucose 3, 4
- CSF Gram stain and culture for bacterial identification 4
Treatment Principles
Immediate empiric antibiotic therapy with ceftriaxone 2-4g IV daily should be initiated for suspected bacterial meningitis, which provides coverage for typhoid meningitis. 5, 2
- Ceftriaxone 4g per day for at least 5 days is effective for typhoid meningitis 2
- Supportive care including fluid resuscitation with colloid and crystalloid fluids 2
- Vasopressor support with dopamine or other agents if septic shock is present 2
- Never delay antibiotics while awaiting diagnostic confirmation, as mortality remains high in untreated bacterial meningitis 5
Common Pitfalls to Avoid
- Do not exclude typhoid meningitis based on absence of neck stiffness, as meningeal signs have poor sensitivity (31% for neck stiffness in adults) 3, 4
- Do not assume all fever with altered mental status in endemic areas is malaria, as typhoid can present identically 2
- Do not wait for CSF results before starting antibiotics in suspected bacterial meningitis 5
- Do not overlook the combination of leukopenia with sepsis, which is atypical for most bacterial meningitis but characteristic of typhoid 2