What prophylactic treatment is recommended for close contacts of an individual diagnosed with meningococcal disease, particularly in household members or intimate contacts?

Meningococcal Post-Exposure Prophylaxis

Primary Recommendation

Close contacts of individuals with meningococcal disease should receive ciprofloxacin 500 mg as a single oral dose within 24 hours of case identification, as this is the first-line prophylaxis recommended by the CDC and American Academy of Pediatrics. 1, 2

Who Requires Prophylaxis

Close contacts at 400-800 fold increased risk include: 1, 3

• Household members living or sleeping in the same dwelling 3
• Intimate contacts directly exposed to oral secretions (kissing contacts, shared utensils) 1, 3
• Child care center contacts with direct exposure 2
• Dormitory roommates and university students sharing kitchens 3

Important caveat: Classmates and casual contacts do NOT require prophylaxis unless they meet the close contact criteria above. 3

First-Line Antibiotic Regimens

Ciprofloxacin (Preferred)

• Adults and children >16 years: 500 mg oral single dose 1, 2, 3
• Children 5-12 years: 250 mg oral single dose 3
• Children <5 years: 30 mg/kg (maximum 125 mg) oral single dose 3

Advantages: Single dose, high efficacy, convenient administration 1

Alternative: Ceftriaxone

• Adults: 250 mg IM single dose 1, 2
• Children: 125 mg IM single dose 2

When to use: Preferred in areas with documented ciprofloxacin resistance (≥20% of cases in a 12-month period) or when oral administration is not feasible. 4 Ceftriaxone demonstrated superior efficacy to rifampin at 1-2 weeks follow-up. 5

Alternative: Rifampin

• Adults and children >12 years: 600 mg orally twice daily for 2 days 1, 2, 6
• Children 3 months-12 years: 10 mg/kg orally twice daily for 2 days 2, 6
• Infants <3 months: 5 mg/kg orally twice daily for 2 days 2, 6

Critical limitation: Rifampin use is associated with emergence of resistant isolates, making it less preferred than ciprofloxacin or ceftriaxone. 1, 5

Timing and Implementation

Prophylaxis must be initiated within 24 hours of case identification for maximum effectiveness. 1, 2, 3 The window of highest risk is the first 7 days after exposure, with secondary attack rates of 2-4 per 1000 population. 1

Special Considerations

Emerging Ciprofloxacin Resistance

Since 2019, ciprofloxacin-resistant N. meningitidis strains have increased in the United States, particularly among serogroup Y isolates. 4, 7 Health departments should preferentially use ceftriaxone or rifampin when both criteria are met in a 12-month period: (1) ≥2 cases of ciprofloxacin-resistant disease, and (2) ≥20% of all cases are ciprofloxacin-resistant. 4

Index Patient Considerations

Patients who received IV ceftriaxone for treatment do not need additional prophylaxis before discharge. 1 However, patients treated with other antibiotics should receive prophylaxis to eradicate nasopharyngeal carriage. 8

Monitoring Requirements

• Droplet precautions should continue until contacts have received 24 hours of effective prophylaxis 1, 2
• Monitor all contacts for symptoms for at least 10 days after exposure, even after receiving prophylaxis 1, 3
• Increased risk persists for 6 months after exposure despite prophylaxis 1, 3

Vaccination Considerations

• Meningococcal C vaccine should be offered to unvaccinated contacts of non-B serogroup cases 3
• Serogroup B vaccination should be offered to all household contacts if ≥2 cases of serogroup B disease occur in the same family 3

Common Pitfalls to Avoid

1. Delaying prophylaxis beyond 24 hours significantly reduces effectiveness 1, 3
2. Over-treating casual contacts (classmates, coworkers) who don't meet close contact criteria wastes resources and promotes resistance 3
3. Using rifampin as first-line when ciprofloxacin or ceftriaxone are available, given resistance concerns 1, 5
4. Failing to notify public health authorities immediately for contact tracing and surveillance 3