What prophylaxis is recommended for individuals with close exposure to someone with bacterial meningitis?

Prophylaxis for Close Contacts of Bacterial Meningitis

Antibiotic prophylaxis should be given to all close contacts of patients with invasive meningococcal disease using ceftriaxone, ciprofloxacin, or rifampin to prevent secondary cases and eradicate nasopharyngeal carriage. 1

Who Needs Prophylaxis

Prophylaxis is indicated for close contacts of patients with meningococcal disease, defined as:

• Household members 1
• Child care center contacts 1
• Anyone directly exposed to the patient's oral secretions within 7 days before symptom onset (e.g., through kissing, mouth-to-mouth resuscitation) 1
• Healthcare personnel who managed an airway or were exposed to respiratory secretions 1
• Passengers seated directly next to an index patient on prolonged flights (≥8 hours) 1

The attack rate for household contacts is estimated to be 4 cases/1,000 persons exposed, which is 500-800 times greater than the general population risk 1.

Timing of Prophylaxis

Prophylaxis should be administered as soon as possible, ideally within 24 hours after identification of the index patient, as the risk of secondary disease is highest immediately after onset 1. Prophylaxis administered >14 days after exposure has limited or no value 1.

Recommended Prophylactic Regimens

For Meningococcal Disease:

1. Rifampin 1, 2:

   • Adults: 600 mg orally every 12 hours for 2 days
   • Children ≥1 month: 10 mg/kg (max 600 mg) orally every 12 hours for 2 days
   • Children <1 month: 5 mg/kg orally every 12 hours for 2 days
   • Not recommended for pregnant women (except after first trimester)

2. Ciprofloxacin 1:

   • Adults >16 years: 500 mg orally, single dose
   • Not generally recommended for persons <18 years, pregnant or lactating women

3. Ceftriaxone 1:

   • Adults: 250 mg intramuscular, single dose
   • Children <15 years: 125 mg intramuscular, single dose
   • First choice during pregnancy

Effectiveness of Prophylactic Antibiotics

Ceftriaxone, rifampin, and ciprofloxacin are the most effective agents for preventing secondary cases and eradicating N. meningitidis from the nasopharynx 1, 3. Recent evidence suggests ceftriaxone may be more effective than rifampin after 1-2 weeks of follow-up 3.

Special Considerations

1. Pregnancy: Ceftriaxone is the first choice during pregnancy 1. Rifampin should only be used after the first trimester 1.

2. Ciprofloxacin resistance: In areas with documented ciprofloxacin resistance, alternative antibiotics (rifampin, ceftriaxone, or azithromycin) should be considered, particularly when:

   • Two or more cases of ciprofloxacin-resistant strains have been reported in a 12-month period, AND
   • ≥20% of reported cases are caused by ciprofloxacin-resistant strains 4

3. Patients treated with penicillin: These patients should also receive clearance-effective antibiotics before discharge. Patients who received ceftriaxone for treatment do not need additional prophylaxis 1.

When Prophylaxis is NOT Recommended

• For contacts of patients with evidence of N. meningitidis only in non-sterile sites (oropharyngeal swab, endotracheal secretions, conjunctival swab) 1
• For asymptomatic nasopharyngeal carriers 1
• For contacts of meningitis caused by Streptococcus pneumoniae 5

Vaccination Considerations

In addition to antibiotic prophylaxis, vaccination may be recommended in certain situations:

• Pneumococcal vaccine is recommended after an episode of pneumococcal meningitis 1
• Vaccination with pneumococcal, H. influenzae type b, and N. meningitidis vaccines should be considered for patients with CSF leakage 1

Key Pitfalls to Avoid

1. Delayed prophylaxis: Effectiveness decreases significantly when administered >14 days after exposure
2. Relying on nasopharyngeal cultures: These are not helpful in determining the need for prophylaxis and may delay preventive measures 1
3. Using ciprofloxacin in areas with known resistance: This may result in prophylaxis failure 4
4. Neglecting to provide prophylaxis to healthcare workers: Those who managed airways or were exposed to respiratory secretions are at increased risk 1

By following these evidence-based recommendations, secondary cases of meningococcal disease can be effectively prevented, reducing morbidity and mortality associated with this serious infection.