How long is someone contagious with Neisseria meningitidis?

Contagious Period for Neisseria meningitidis

Individuals with Neisseria meningitidis are considered contagious until they have received effective antibiotic therapy for 24 hours. 1

Understanding Meningococcal Transmission

Neisseria meningitidis is transmitted through direct contact with respiratory secretions from infected individuals. The key aspects of transmission include:

• Transmission occurs primarily through close contact with respiratory secretions or large aerosol droplets from the respiratory tract of infected persons 1
• The period of contagiousness begins 7 days before symptom onset in the infected individual 1
• Contagiousness continues until 24 hours after starting effective antibiotic therapy 1
• Close contacts are defined as:
  • Household members 1
  • Child-care center contacts 1
  • Persons directly exposed to the patient's oral secretions (e.g., through kissing, mouth-to-mouth resuscitation, endotracheal intubation, or endotracheal tube management) 1

Risk of Secondary Transmission

The risk of secondary transmission is significant for close contacts:

• The attack rate for household contacts exposed to patients with sporadic meningococcal disease is estimated to be four cases per 1,000 persons exposed 1
• This rate 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

Prophylaxis for Close Contacts

Due to the high risk of secondary transmission, antimicrobial prophylaxis is recommended for close contacts:

• 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
• Recommended prophylactic antibiotics include:
  • Rifampin: For children and adults (various dosing based on age) 1
  • Ciprofloxacin: Single 500 mg dose for adults 1
  • Ceftriaxone: Single intramuscular dose (125 mg for children <15 years, 250 mg for adults) 1
  • In areas with ciprofloxacin resistance, alternative antibiotics should be considered when specific resistance criteria are met 2

Important Clinical Considerations

• Oropharyngeal or nasopharyngeal cultures are not helpful in determining the need for prophylaxis and might delay institution of this preventive measure unnecessarily 1
• Prophylaxis is not recommended for close contacts of patients with evidence of N. meningitidis only in nonsterile sites such as oropharyngeal swab, endotracheal secretions, or conjunctival swab 1
• There is no indication to treat persons who are asymptomatic nasopharyngeal carriers 1
• For patients with meningococcal meningitis who are receiving treatment, the recommended duration of therapy is 7 days 1

Preventing Transmission in Healthcare Settings

Healthcare workers should take specific precautions:

• Adhere to precautions to prevent exposure to respiratory droplets 1
• Postexposure prophylaxis is advised for healthcare workers who have had intensive, unprotected contact with infected patients 1
• Examples of high-risk exposures include intubating, resuscitating, or closely examining the oropharynx of patients without wearing a mask 1

By understanding the contagious period and implementing appropriate prophylaxis for close contacts, the risk of secondary cases of meningococcal disease can be significantly reduced.