Meningitis: community-acquired

Bacterial meningitis is a medical emergency and requires prompt treatment with effective antimicrobials.
Cases should be discussed with ICU (intensive care unit).
Cerebrospinal fluid should be sent for microscopy, culture and PCR (Do not delay antibiotics)
Take blood cultures and EDTA blood sample for pneumococcal and meningococcal PCR
Consult Micro/ID
Screen for HIV
For cases with a relevant travel history within 3 months consider cerebral malaria

Treatment duration is pathogen dependent - see community-acquired meningitis - Pathogen Specific guideline

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Consider use of dexamethasone base 8.25mg (2.5ml of 3.3mg/ml solution per dose) iv qds for up to 4 days especially in suspected or proven pneumococcal or haemophillus influenzae infection. Stop if no evidence of pneumococcal or haemophillus influenzae infection in initial microbiology results.

For the older person (over 60 years), pregnant, immunocompromised consider listeria: ADD amoxicillin 2g iv 4-hourly.

For cases with confusion, seizures or obtundation:

consider Encephalitis (herpes simplex virus, HSV)
ADD aciclovir 10mg/kg iv tds (use adjusted body weight for obese patients)

For penicillin allergy (severe)

chloramphenicol 2g iv qds for 24-48 hours THEN reduce to 12.5mg/kg* iv qds (maximum 1g qds). * Use adjusted body weight to calculate dose if actual body weight is greater than 20% of ideal body weight.

For the older person (over 60 years), pregnant, immunocompromised consider listeria: ADD co-trimoxazole** 120mg/kg/day iv in 4 divided doses. Round each dose to the nearest 480mg, see table below for suggested dosing.

** For obese patients (BMI 30 or more) use adjusted bodyweight (AdjBW).

For cases with confusion, seizures or obtundation:

consider Encephalitis (herpes simplex virus, HSV)
ADD aciclovir 10mg/kg iv tds (use ideal body weight for obese patients).

Table for suggested co-trimoxazole iv dosing:

Patient weight (AdjBW if obese)	Total daily co-trimoxazole iv dose	Suggested split dosing for four times daily administration
Patient weight (AdjBW if obese)	Total daily co-trimoxazole iv dose	06:00	12:00	18:00	00:00
40 – 44kg	4800 mg	1440 mg	1440 mg	960 mg	960 mg
45 - 49 kg	5280 mg	1440 mg	1440 mg	1440 mg	960 mg
50 - 54 kg	5760 mg	1440 mg	1440 mg	1440 mg	1440 mg
55 - 59 kg	6240 mg	1920 mg	1440 mg	1440 mg	1440 mg
60 - 64 kg	7200 mg	1920 mg	1920 mg	1920 mg	1440 mg
65 - 69 kg	7680 mg	1920 mg	1920 mg	1920 mg	1920 mg
70 - 74 kg	8160 mg	2400 mg	1920 mg	1920 mg	1920 mg
75 - 79 kg	8640 mg	2400 mg	2400 mg	1920 mg	1920 mg
80 - 84 kg	9600 mg	2400 mg	2400 mg	2400 mg	2400 mg
85 - 89 kg	10,080 mg	2880 mg	2400 mg	2400 mg	2400 mg
90 – 94 kg	10,560 mg	2880 mg	2880 mg	2400 mg	2400 mg
95 – 99 kg	11,040 mg	2880 mg	2880 mg	2880 mg	2400 mg
100 kg and over	11,520 mg	2880 mg	2880 mg	2880 mg	2880 mg

Consider penicillin allergy assessment

NICE 240. Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management. March 2024. Available online Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management. Accessed February 2025.
NHS Tayside University Hospitals. CNS Infection Guidance in Adults. Updated July 2024. Available online Tayside University Hospitals. Accessed February 2025.

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