What is the recommended prophylaxis for casual exposure to Neisseria bacteria?

Prophylaxis for Casual Exposure to Neisseria Bacteria

For casual exposure to Neisseria meningitidis, rifampin is the recommended prophylactic antibiotic, with ciprofloxacin, ceftriaxone, or azithromycin as alternatives depending on local resistance patterns. 1, 2, 3

Understanding Neisseria Exposure and Transmission

• Neisseria meningitidis is considered contagious from 7 days before symptom onset until 24 hours after starting effective antibiotic therapy 1
• Transmission occurs primarily through close contact with respiratory secretions or large aerosol droplets from the respiratory tract of infected persons 1
• Close contacts are defined as household members, child-care center contacts, and persons directly exposed to the patient's oral secretions (through kissing, mouth-to-mouth resuscitation, endotracheal intubation, or endotracheal tube management) 1
• The attack rate for household contacts exposed to patients with meningococcal disease is approximately 4 cases per 1,000 persons exposed, which is 500-800 times greater than the general population 1
• Healthcare personnel exposed to patients with meningococcal disease have an attack rate 25 times higher than the general population 1

Recommended Prophylactic Regimens

For Adults:

• Rifampin: First-line treatment for asymptomatic carriers of Neisseria meningitidis to eliminate meningococci from the nasopharynx 2
• Ciprofloxacin: 500-750 mg single oral dose (alternative option) 3
• Ceftriaxone: Single intramuscular dose (alternative option) 3
• Azithromycin: Single oral dose (alternative option) 3

Timing of Prophylaxis:

• Prophylaxis should be administered as soon as possible, ideally within 24 hours after identification of the index patient 1
• Prophylaxis administered more than 14 days after exposure has limited or no value 1

Special Considerations

Ciprofloxacin Resistance:

• Since 2019, the number of meningococcal disease cases caused by ciprofloxacin-resistant strains has increased in the United States 3
• Health departments should consider using antibiotics other than ciprofloxacin when:
  1. Two or more invasive meningococcal disease cases caused by ciprofloxacin-resistant strains have been reported in a local catchment area during a 12-month period, AND
  2. ≥20% of all reported invasive meningococcal disease cases are caused by ciprofloxacin-resistant strains 3

Healthcare Workers:

• Healthcare workers should adhere to precautions to prevent exposure to respiratory droplets, such as wearing masks 1
• Postexposure prophylaxis is advised for healthcare workers who have had intensive, unprotected contact with infected patients 1

Important Caveats

• Rifampin should not be used indiscriminately; diagnostic laboratory procedures, including serotyping and susceptibility testing, should be performed when possible 2
• Rifampin is not indicated for the treatment of meningococcal infection (only for prophylaxis) because of the possibility of rapid emergence of resistant organisms 2
• The usefulness of rifampin should be preserved by using it only when the risk of meningococcal disease is high 2
• Ongoing monitoring for antibiotic resistance of meningococcal isolates through surveillance and reporting of prophylaxis failures is essential to guide future prophylaxis recommendations 3

Prophylaxis for Other Neisseria Species

• For Neisseria gonorrhoeae exposure, doxycycline postexposure prophylaxis (doxy PEP) can be considered for specific high-risk populations 4
• CDC recommends that men who have sex with men and transgender women who have had a bacterial STI (including gonorrhea) diagnosed in the past 12 months should receive counseling about doxy PEP 4
• The recommended dose of doxy PEP is 200 mg taken within 72 hours after sex, not exceeding a maximum dose of 200 mg every 24 hours 4
• However, there are concerns that doxycycline prophylaxis may select for resistance to other antimicrobials in Neisseria gonorrhoeae 5