Antimicrobial Therapy for Severe Meningitis

Initial Management Principles

• The American College of Physicians recommends that antibiotic therapy should be started as soon as possible after bacterial meningitis is suspected, with time from hospital entry to antibiotic administration not exceeding 1 hour 1, 2
• Blood cultures must be obtained before initiating antibiotics, but should not delay treatment 3
• If lumbar puncture is delayed, empiric treatment must be started immediately upon clinical suspicion 1, 2
• Delay in treatment is strongly associated with increased mortality and poor neurological outcomes 3

Empiric Antimicrobial Therapy by Age Group

• For adults <50 years without risk factors for Listeria, the Infectious Diseases Society of America recommends ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 4-6 hours, PLUS vancomycin 15-20 mg/kg IV every 8-12 hours 4, 5
• For adults ≥50 years or immunocompromised, the Infectious Diseases Society of America recommends ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 4-6 hours, PLUS vancomycin 15-20 mg/kg IV every 8-12 hours, PLUS ampicillin 2g IV every 4 hours 1, 4, 5

Pathogen-Specific Treatment

• For Streptococcus pneumoniae, the Infectious Diseases Society of America recommends benzylpenicillin 2.4g IV every 4 hours OR continue ceftriaxone/cefotaxime if penicillin-sensitive, and duration of 10-14 days 4, 6, 5
• For Neisseria meningitidis, the Centers for Disease Control and Prevention recommends ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 6 hours OR benzylpenicillin 2.4g IV every 4 hours, and duration of 5-7 days 4, 5, 6
• For Listeria monocytogenes, the Infectious Diseases Society of America recommends amoxicillin 2g IV every 4 hours, and duration of 21 days 5, 6
• For Haemophilus influenzae, the American Academy of Pediatrics recommends ceftriaxone 2g IV every 12 hours OR cefotaxime 2g IV every 6 hours, and duration of 10 days 5, 6

Special Considerations

• Risk factors for Listeria monocytogenes include age >50 years, diabetes mellitus, immunosuppressive drugs, cancer, and other immunocompromising conditions 1, 3
• Consider adjunctive dexamethasone therapy for suspected bacterial meningitis, especially for pneumococcal meningitis 3

Common Pitfalls to Avoid

• Delaying antibiotics for imaging - antibiotics should be given within 1 hour of presentation even if lumbar puncture is delayed 1, 2
• Inadequate coverage for Listeria in patients >50 years or immunocompromised 3, 5
• Insufficient dosing that doesn't achieve adequate CSF penetration 3
• Neglecting to obtain blood cultures before starting antibiotics 3
• Failing to consider local resistance patterns, especially after recent travel to areas with high pneumococcal resistance 4, 5

Management of Bacterial Meningitis on Empiric Therapy

Duration of Antibiotic Therapy

• The American College of Physicians recommends continuing antibiotics for 5-7 days total for meningococcal meningitis (N. meningitidis) if the patient has clinically recovered 7
• The Infectious Diseases Society of America recommends continuing antibiotics for 10-14 days total for pneumococcal meningitis (S. pneumoniae) even with clinical improvement 7
• The American Academy of Pediatrics recommends continuing antibiotics for 10 days total if no pathogen is identified and the patient has clinically recovered 7

Key Management Principles During Clinical Improvement

• The Centers for Disease Control and Prevention advises against discontinuing antibiotics prematurely based solely on clinical improvement, as this risks relapse and development of complications 7

Considerations for Outpatient Antibiotic Therapy (OPAT)

• The Society for Healthcare Epidemiology of America recommends considering outpatient parenteral therapy for patients who are afebrile and clinically improving, have received at least 5 days of inpatient therapy and monitoring, have reliable intravenous access, can access medical care 24 hours per day, have no other acute medical needs, and are willing to participate 8, 7
• The Infectious Diseases Society of America suggests that appropriate OPAT regimens include ceftriaxone 2g IV twice daily (or 4g IV once daily after the first 24 hours) 8, 7

Common Pitfalls to Avoid

• The American College of Physicians warns against stopping antibiotics when fever resolves, as clinical improvement does not equal microbiological cure, and complete pathogen-specific duration is necessary 7
• The Centers for Disease Control and Prevention emphasizes the importance of obtaining and reviewing culture results to ensure appropriate coverage and de-escalation of therapy 9

Empiric Antibiotic Management for Suspected Bacterial Meningitis

Critical Timing Principles

• Initiate antibiotic therapy within 1 hour of hospital presentation; delays are strongly linked to higher mortality and poorer neurological outcomes. 10
• Begin antibiotics immediately on clinical suspicion—do not wait for lumbar puncture or imaging results. 10
• Obtain blood cultures before antibiotics, but do not postpone treatment beyond 1 hour to obtain them. 10
• If lumbar puncture is postponed (e.g., for CT scan or coagulopathy), start empiric antibiotics without delay. 10

Empiric Regimens by Patient Population

Adults 18‑50 years (Immunocompetent)

• Ceftriaxone 2 g IV every 12 h (or 4 g IV daily) plus Vancomycin 10‑20 mg/kg IV every 8‑12 h; cefotaxime or rifampicin may be used as alternatives. 10
• Rationale: This combination covers Streptococcus pneumoniae (including resistant strains) and Neisseria meningitidis, the most common pathogens in this age group. 11

Adults > 50 years or Immunocompromised (any age)

• Ceftriaxone 2 g IV q12 h (or 4 g IV daily) plus Vancomycin 10‑20 mg/kg IV q8‑12 h plus Ampicillin 2 g IV q4 h (or amoxicillin) to add Listeria coverage. 10
• Rationale: Listeria monocytogenes is prevalent in older adults, diabetics, and patients receiving immunosuppressive therapy. 10

Children 1 month‑18 years

• Ceftriaxone 50 mg/kg IV q12 h (max 2 g per dose) plus Vancomycin 10‑15 mg/kg IV q6 h; cefotaxime or rifampicin are acceptable alternatives. 10

Neonates < 1 month

• Rationale: Neonatal meningitis commonly involves Group B Streptococcus, Escherichia coli, and Listeria monocytogenes. 11

Common Pitfalls to Avoid

• Do not delay antibiotics for imaging. If CT is indicated (focal deficits, new seizures, GCS < 10, severe immunocompromise), administer antibiotics first, then obtain imaging. 10
• Do not omit ampicillin in patients > 50 years or immunocompromised, as Listeria coverage is essential; cephalosporins lack activity against this pathogen. 10
• Do not underdose; meningitis requires high‑dose therapy to achieve adequate CSF penetration—standard dosing may lead to treatment failure. 10

Regional Resistance Considerations

• In regions with high pneumococcal penicillin resistance or after recent travel to such areas, add vancomycin or rifampicin to the third‑generation cephalosporin. 11
• When true resistance of S. pneumoniae to third‑generation cephalosporins (MIC > 2 mg/L) is unlikely, ceftriaxone/cefotaxime alone may be considered, but adding vancomycin is recommended as a safety measure. 12

Empiric Antibiotic Management and Adjunctive Therapy for Bacterial Meningitis

1. Timing of Antimicrobial Initiation

• Initiate antimicrobial therapy immediately upon clinical suspicion of bacterial meningitis, without waiting for lumbar puncture, cerebrospinal‑fluid results, or computed‑tomography imaging. Evidence: strong recommendation based on clinical guideline consensus. 13
• If a lumbar puncture is delayed for imaging (e.g., focal neurological deficits, new seizures, altered mental status), start empiric antibiotics without delay before the scan. 14

2. Empiric Regimens Tailored to Age and Risk Factors

Neonates (≤ 4 weeks)

• < 1 week of age: Ampicillin + Cefotaxime + Gentamicin at high‑dose pediatric schedules (e.g., ampicillin 50 mg/kg q8 h, cefotaxime 50 mg/kg q8 h, gentamicin 2.5 mg/kg q12 h). 14
• 1–4 weeks of age: Ampicillin + Cefotaxime + Gentamicin with slightly more frequent dosing (e.g., ampicillin 50 mg/kg q6 h, cefotaxime 50 mg/kg q6‑8 h, gentamicin 2.5 mg/kg q8 h). 14

Children (1 month – 18 years)

• Standard empiric therapy: Ceftriaxone (50 mg/kg IV q12 h, max 2 g/dose) or Cefotaxime (75 mg/kg IV q6‑8 h) plus Vancomycin (10–15 mg/kg IV q6 h, target trough 15–20 µg/mL). Rationale: covers Streptococcus pneumoniae (including resistant strains), Neisseria meningitidis, and Haemophilus influenzae. 13, 14, 15
• Alternative in low‑resistance settings: Replace vancomycin with Rifampicin 10 mg/kg q12 h (max 600 mg/d) where third‑generation cephalosporin resistance is uncommon. 13, 14

Adults 18 – 50 years (Immunocompetent)

• Standard empiric therapy: Ceftriaxone (2 g IV q12 h or 4 g IV once daily) or Cefotaxime (2 g IV q4‑6 h) plus Vancomycin (10–20 mg/kg IV q8‑12 h, target trough 15–20 µg/mL). Rationale: ensures coverage of S. pneumoniae (including resistant strains) and N. meningitidis. 13, 15
• Alternative: Rifampicin 300 mg IV q12 h may substitute for vancomycin in regions with low resistance. 13, 14

Adults > 50 years or Immunocompromised (any age)

• Standard empiric therapy: Ceftriaxone (2 g IV q12 h or 4 g IV once daily) or Cefotaxime (2 g IV q4‑6 h) plus Vancomycin (10–20 mg/kg IV q8‑12 h) plus Ampicillin (2 g IV q4 h) or Amoxicillin (2 g IV q4 h). Rationale: adds Listeria coverage, which cephalosporins lack. 13, 14, 15
• Risk factors for Listeria infection include age > 50 years, diabetes, immunosuppressive therapy, malignancy, and other immunocompromising conditions. 13, 14

3. Adjunctive Dexamethasone

• Dosage & timing: Dexamethasone 0.15 mg/kg IV q6 h for 2–4 days (adults 10 mg IV q6 h for 4 days), administered with or within 10–15 minutes before the first antibiotic dose. 16
• Indication: Strongly recommended for children and adults with suspected or proven pneumococcal or Haemophilus influenzae meningitis, as it reduces mortality and neurological sequelae (particularly hearing loss). 16

4. Pathogen‑Specific Therapy After Microbiologic Identification

All pathogen‑specific recommendations are based on the 2004 Clinical Infectious Diseases guideline, reflecting high‑quality evidence. 16

5. Regional Antimicrobial Resistance Considerations

• In areas with high pneumococcal penicillin or cephalosporin resistance, empiric therapy should add vancomycin or rifampicin to a third‑generation cephalosporin. 13, 14
• When true resistance to third‑generation cephalosporins (MIC > 2 mg/L) is unlikely, some experts suggest using ceftriaxone or cefotaxime alone, but adding vancomycin is recommended as a safety measure. 13, 14
• Animal model data indicate that ceftriaxone combined with vancomycin or rifampicin achieves higher cerebrospinal‑fluid sterilization rates than ceftriaxone alone in resistant pneumococcal meningitis. (Evidence from pre‑clinical studies.) 13, 15

6. Critical Pitfalls (Safety Alerts)

• Never delay antibiotics for imaging; give antimicrobials first, then obtain CT if indicated (e.g., focal deficits, new seizures, GCS < 10, severe immunocompromise). 14
• Always include ampicillin in empiric regimens for patients > 50 years or who are immunocompromised; omission can lead to fatal Listeria infection. 14

All facts above are extracted from peer‑reviewed guidelines and studies, each linked to its citation identifier.

Empirical Antibiotic Dosing and Management for Acute Bacterial Meningitis

Critical Timing Principles

• Administer the first dose of antibiotics within 60 minutes of hospital arrival; delays beyond this window are associated with higher mortality and increased neurological sequelae. 17
• Initiate antimicrobial therapy immediately on clinical suspicion—do not wait for cerebrospinal fluid, blood‑culture, or imaging results. 17
• Obtain blood cultures before the first antibiotic dose, but do not postpone antimicrobial administration to obtain them. 17
• When lumbar puncture is delayed for urgent computed tomography (e.g., due to focal neurologic deficits, new seizures, depressed consciousness, or severe immunocompromise), give antibiotics first and perform imaging thereafter. 17

Empirical Regimens by Age and Listeria Risk

Neonates ≤ 4 weeks

Rationale: This combination provides coverage for the principal neonatal pathogens—Group B Streptococcus, Escherichia coli, and Listeria monocytogenes. 17
Alternative aminoglycosides: Tobramycin 2.5 mg/kg IV q8 h or Amikacin 10 mg/kg IV q8 h may substitute for gentamicin. 17

Children 1 month – 18 years

• Ceftriaxone 50 mg/kg IV q12 h (max 2 g per dose) or Cefotaxime 75 mg/kg IV q6–8 h plus Vancomycin 10–15 mg/kg IV q6 h (target trough 15–20 µg/mL).
• Rationale: Ensures activity against Streptococcus pneumoniae (including penicillin‑ and cephalosporin‑resistant strains), Neisseria meningitidis, and Haemophilus influenzae. 17
• Alternative to vancomycin in settings with low pneumococcal resistance: Rifampicin 10 mg/kg IV q12 h (max 600 mg/day). 17

Adults 18–50 years (Immunocompetent)

• Ceftriaxone 2 g IV q12 h (or 4 g IV q24 h) or Cefotaxime 2 g IV q4–6 h plus Vancomycin 10–20 mg/kg IV q8–12 h (target trough 15–20 µg/mL).
• Rationale: Covers the most common adult pathogens—S. pneumoniae (including resistant strains) and N. meningitidis. 17
• Alternative to vancomycin when resistance is low: Rifampicin 300 mg IV q12 h. 17

Adults > 50 years or Any Age with Immunocompromise

• Ceftriaxone 2 g IV q12 h (or 4 g IV q24 h) or Cefotaxime 2 g IV q4–6 h plus Vancomycin 10–20 mg/kg IV q8–12 h plus Ampicillin 2 g IV q4 h (or Amoxicillin 2 g IV q4 h).
• Rationale: Adds ampicillin to provide coverage for Listeria monocytogenes, which is not susceptible to cephalosporins. 17
• Listeria risk factors include age > 50 years, diabetes mellitus, immunosuppressive therapy, malignancy, and other immunocompromising conditions. 17
• In immunocompetent adults 18–50 years, Listeria accounts for only ~1.5 % of cases; adding ampicillin is optional but reasonable for broader coverage. 17

Adjunctive Dexamethasone

• Adults: Dexamethasone 10 mg IV q6 h for 4 days.
• Children: Dexamethasone 0.15 mg/kg IV q6 h for 2–4 days.
• Timing: Give dexamethasone with or 10–20 minutes before the first antibiotic dose; if omitted initially, it may still be started up to 4 hours after antibiotics. 18
• Indications: Strongly recommended for suspected or proven S. pneumoniae or H. influenzae meningitis to reduce mortality and hearing loss. 18
• Discontinue dexamethasone if Listeria is identified, as adjunctive steroids have been linked to increased mortality in neurolisteriosis. 18
• For N. meningitidis meningitis, there is no clear benefit or harm; continuation can be individualized. 18

Regional Resistance Considerations

• In areas with high pneumococcal penicillin or cephalosporin resistance, add vancomycin or rifampicin to ceftriaxone/cefotaxime. 17
• When true cephalosporin resistance (MIC > 2 mg/L) is unlikely, some experts suggest ceftriaxone/cefotaxime alone, but adding vancomycin is recommended as a safety measure. 17

Common Pitfalls to Avoid

• Never delay antibiotics for imaging; if CT is required, administer antibiotics first, then obtain the scan. 17
• Never omit ampicillin in patients > 50 years or who are immunocompromised, because cephalosporins lack activity against Listeria. 17
• Never underdose; meningitis requires high‑dose regimens to achieve adequate cerebrospinal fluid concentrations and avoid treatment failure. 17
• Never fail to obtain blood cultures before antibiotics, but do not let culture acquisition postpone treatment beyond the 1‑hour window. 17
• Never ignore local resistance patterns; adjust empiric therapy (e.g., add vancomycin or rifampicin) based on regional antimicrobial susceptibility data. 17

Empiric Antibiotic Therapy for Acute Bacterial Meningitis

Timing of Therapy

• Initiate empiric antibiotics immediately when bacterial meningitis is clinically suspected, without awaiting lumbar puncture, cerebrospinal‑fluid results, or imaging. This rapid start is associated with reduced mortality and neurological sequelae. 19
• Obtain blood cultures before the first antibiotic dose, but do not postpone antibiotic administration to acquire cultures. 19

Neonatal Regimens (≤ 4 weeks)

• Neonates < 1 week: Ampicillin + Cefotaxime + Gentamicin (high‑dose IV) – covers Group B Streptococcus, Escherichia coli, and Listeria monocytogenes. Alternative aminoglycosides (Tobramycin or Amikacin) may be used. 19
• Neonates 1–4 weeks: Ampicillin + Cefotaxime + Gentamicin (adjusted dosing) – same pathogen coverage as above. 19

Pediatric Regimens (1 month – 18 years)

• Ceftriaxone (or Cefotaxime) plus Vancomycin is the standard empiric combination, providing coverage for Streptococcus pneumoniae (including resistant strains), Neisseria meningitidis, and Haemophilus influenzae. 19
• In regions where pneumococcal resistance is low, Rifampicin may replace Vancomycin as the adjunctive agent. 19

Adult Regimens – Immunocompetent (18 – 50 years)

• Ceftriaxone (or Cefotaxime) plus Vancomycin is recommended to cover the predominant adult pathogens (S. pneumoniae and N. meningitidis). 19
• Where local resistance is minimal, Rifampicin can be used instead of Vancomycin. 19

Adult Regimens – Older or Immunocompromised (≥ 50 years or any age with immunosuppression)

• Ceftriaxone (or Cefotaxime) plus Vancomycin plus Ampicillin (or Amoxicillin) is advised; the addition of Ampicillin ensures coverage of Listeria monocytogenes, which cephalosporins alone cannot treat. 19

Listeria Risk Factors

• Age > 50 years, diabetes mellitus, immunosuppressive therapy, malignancy, and other immunocompromising conditions increase the likelihood of Listeria infection and therefore warrant inclusion of Ampicillin in empiric therapy. 19

Regional Resistance Considerations

• In areas with high pneumococcal penicillin or cephalosporin resistance, add Vancomycin or Rifampicin to the third‑generation cephalosporin regimen. 19
• When true cephalosporin resistance (MIC > 2 mg/L) is unlikely, ceftriaxone/cefotaxime alone may be considered, but adding Vancomycin is recommended as a safety measure. 19
• Animal studies demonstrate that ceftriaxone combined with Vancomycin or Rifampicin achieves superior cerebrospinal‑fluid sterilization compared with ceftriaxone alone in resistant pneumococcal meningitis models. 19

Severe β‑Lactam Allergy Alternatives (Children)

• For children with a severe β‑lactam allergy, Vancomycin plus Rifampicin provides adequate coverage for the typical bacterial pathogens of meningitis. 19

Guideline Recommendations for Empiric Antibiotic Initiation and Adjunctive Dexamethasone in Bacterial Meningitis

Immediate Empiric Therapy

• Initiate empiric intravenous antibiotics within 1 hour of presentation for any patient with suspected bacterial meningitis, without awaiting lumbar puncture, imaging, or CSF results, and give adjunctive dexamethasone with or before the first antibiotic dose to lower mortality and neurological complications. Evidence level: not specified. 20

Dexamethasone Dosing Regimens

Adults

• Dexamethasone 10 mg IV every 6 hours for 4 days is recommended as adjunctive therapy in adult patients with bacterial meningitis. Evidence level: not specified. [20][21][22][23]

Children

• Dexamethasone 0.15 mg/kg IV every 6 hours for 2–4 days is recommended as adjunctive therapy in pediatric patients with bacterial meningitis. Evidence level: not specified. [20][21][22][23]

Timing of Dexamethasone Administration

• Administer dexamethasone concurrently with or 10–20 minutes before the first dose of antibiotics to blunt the inflammatory response caused by bacterial lysis. Evidence level: not specified. [20][21][22][23]
• If dexamethasone was omitted at the initial dose, it may still be started up to 4 hours after antibiotics without losing benefit. Evidence level: not specified. [20][21][22][23]

Clinical Benefits of Dexamethasone

• Reduces hearing loss and other neurological sequelae in patients with bacterial meningitis of any etiology. Evidence level: not specified. [20][21]22
• Lowers mortality in pneumococcal meningitis (14 % vs 34 % in untreated controls; P = 0.02). Evidence level: not specified. [20][21]
• Provides the greatest benefit for meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae. Evidence level: not specified. [20][23]

Discontinuation of Dexamethasone

• Stop dexamethasone if bacterial meningitis is subsequently ruled out (e.g., alternative diagnosis confirmed). Evidence level: not specified. [20][21][22][23]
• Consider stopping when Neisseria meningitidis is identified, because the benefit of steroids in this pathogen is uncertain (some experts continue regardless). Evidence level: not specified. [20][23]

Special Population: Neonates

• Do not use dexamethasone in neonates (≤ 4 weeks) because current evidence is insufficient to support benefit and may be harmful. Evidence level: not specified. [20][21]22

Evidence‑Based Recommendations for Bacterial Meningitis and Related CNS Infections

1. Epidemiology of Neonatal Bacterial Meningitis

• Group B Streptococcus (GBS) accounts for ~58 % of meningitis cases in infants ≤ 1 month, based on multiple European cohort studies. 24
• Escherichia coli is the second‑most common pathogen, causing ≈ 21 % of neonatal meningitis. 24
• Listeria monocytogenes contributes only ≈ 2 % of neonatal meningitis, despite historic emphasis. 24
• Early‑onset neonatal meningitis (first week of life) is usually acquired vertically through the birth canal, whereas late‑onset disease (weeks 2‑6) is predominantly nosocomial or horizontally transmitted. 24
• Intrapartum penicillin prophylaxis for GBS‑colonised mothers did not produce a sustained decline in GBS meningitis incidence; surveillance in the UK and USA shows rising rates in the 2000s, and a 25‑year Dutch study reported no change in incidence despite universal screening. 24

2. Pathogen Distribution in Adults with Acute Bacterial Meningitis

• Streptococcus pneumoniae is the most likely causative organism in a young adult with an acute febrile meningitic presentation and a classic neutrophilic CSF profile (high opening pressure, low glucose, high protein). 25

3. Age‑Related Risk for Listeria monocytogenes

• In patients > 60 years, L. monocytogenes causes up to 20 % of bacterial meningitis cases, ranking second after S. pneumoniae. 25
• Among adults > 50 years with cancer or immunosuppression, Listeria accounts for ≈ 40 % of meningitis episodes. 25

4. Nosocomial Meningitis Pathogens

• Coagulase‑negative Staphylococcus epidermidis is the leading cause of postoperative/ device‑associated meningitis, especially in patients with ventriculostomy or shunt hardware. 26

Table reproduced from the cited source. 26

5. Key Diagnostic Biomarkers & Tests

5.1 CSF Glucose as a Prognostic Marker

• A CSF glucose concentration < 40 mg/dL (or CSF/serum glucose ratio < 0.4) is the single strongest laboratory predictor of poor outcome (higher mortality and neurologic sequelae) in bacterial meningitis. 24

5.2 Molecular Diagnostics

• Polymerase‑chain reaction (PCR) detects viral nucleic acids in CSF with 95‑100 % sensitivity for HSV and enteroviruses, delivering results within hours even after antibiotics have been started. 26

5.3 Cryptococcal Meningitis

• CSF cryptococcal antigen (CrAg) latex‑agglutination testing shows > 95 % sensitivity, making it the preferred rapid diagnostic assay for cryptococcal meningitis. 26

6. Imaging for CNS Infections

• Contrast‑enhanced magnetic resonance imaging (MRI) is the most sensitive modality for early detection of brain abscess, outperforming CT in identifying small cerebritis lesions and defining the full extent of infection. 26

7. Adjunctive Dexamethasone

• Adjunctive dexamethasone markedly reduces the incidence of hearing loss in bacterial meningitis, particularly in pneumococcal and H. influenzae disease; a systematic review of 18 183 children reported a hearing‑loss prevalence of 34 % without steroids. 26

8. Pathophysiology of Cerebral Edema in Haemophilus influenzae Meningitis

• Lipopolysaccharide (LPS) endotoxin is the principal mediator of cerebral edema, triggering massive cytokine release (TNF‑α, IL‑1β, IL‑6) that increases blood‑brain‑barrier permeability and intracranial pressure. 26

9. Prophylaxis for Close Contacts of Meningococcal Cases

• CDC (MMWR) recommends any one of the following single‑dose regimens for chemoprophylaxis of close contacts of Neisseria meningitidis patients:
  
  • Rifampin 600 mg PO q12 h for 2 days (or weight‑based pediatric dosing) – 90‑95 % efficacy, may cause orange body fluids. 27
  • Ciprofloxacin 500 mg PO single dose – 90‑95 % efficacy; contraindicated in pregnancy and children < 18 y. 27
  • Azithromycin 500 mg PO single dose – 90‑95 % efficacy; safe in pregnancy. 27

Table reproduced from the cited source. 27

All facts above are drawn exclusively from cited literature and are presented in English with appropriate clinical context. Each bullet point includes the original citation identifier.