Chemoprophylaxis for Close Contacts of Acute Bacterial Meningitis

Meningococcal Meningitis

• Close contacts (household members, intimate partners, persons with direct oral‑secretions exposure, and children sharing a closed childcare space) must receive antibiotic chemoprophylaxis within the first 24 hours after the index case is identified【1】【2】.
• Ciprofloxacin is the preferred single‑dose regimen over rifampicin because it can be given as a one‑time oral dose and is immediately available; UK guidelines (2016) endorse this preference even during pregnancy【1】.
• Recommended ciprofloxacin dose:
  
  • Adults and children > 16 years – 500 mg orally, single dose.
  • Children 5–12 years – 250 mg orally, single dose.
  • Children < 5 years – 30 mg/kg (maximum 125 mg) orally, single dose【1】.
• Rifampicin is an alternative when ciprofloxacin cannot be used:
  
  • Adults and children > 12 years – 600 mg orally twice daily for 2 days【3】.
  • Children 1–12 years – 10 mg/kg orally twice daily for 2 days【3】.
• Prophylaxis administered more than 14 days after disease onset provides little or no benefit【2】.
• Close contacts have a 400–800‑fold higher risk of meningococcal disease, with a secondary attack rate of 2–4 per 1,000 exposed persons【1】.
• The elevated risk persists for up to 6 months after exposure even when prophylaxis is given; records of all close contacts should be flagged for future medical alerts【1】.
• Vaccination against non‑B serogroups (A, C, W, Y) should be offered to unvaccinated close contacts of cases caused by vaccine‑preventable serogroups【1】; a booster dose of serogroup C vaccine is recommended at hospital discharge for previously immunised patients【3】.
• If two or more serogroup B cases occur in the same household, all domestic contacts should receive serogroup B vaccine regardless of the interval between cases or strain differences【1】.

Haemophilus influenzae type B (Hib)

• Chemoprophylaxis with rifampicin is indicated only when the household contains at‑risk individuals: children < 10 years (other than the index case) or any immunocompromised person【3】【1】.
• When indicated, all household contacts and the index case receive rifampicin:
  
  • Adults and children > 3 months – 20 mg/kg (maximum 600 mg) orally once daily for 4 days【3】.
  • Infants < 3 months – 10 mg/kg orally once daily for 4 days【3】.
• Unvaccinated household contacts younger than 10 years should receive the Hib vaccine according to the national immunisation schedule【3】【1】.

Pneumococcal Meningitis

• Close contacts of pneumococcal meningitis cases do not require antibiotic chemoprophylaxis because their risk of disease is not increased【3】.
• In the event of a cluster in a nursing‑home setting, the situation should be discussed with local public‑health authorities【3】.

Implementation and Monitoring

• All cases of acute bacterial meningitis must be reported immediately to public‑health authorities【1】.
• Initiation of contact prophylaxis is normally the responsibility of the public‑health team, although clinical teams may be asked to prescribe the medication【1】.
• Oropharyngeal or nasopharyngeal cultures are not useful for deciding on chemoprophylaxis and may cause unnecessary delay; decisions should be based on exposure criteria【2】.
• Do not postpone prophylaxis while awaiting microbiologic confirmation; start treatment within 24 hours based on clinical suspicion【1】.
• The index case also requires chemoprophylaxis if treated with antibiotics other than ceftriaxone or other third‑generation cephalosporins【2】.
• Despite prophylaxis, the increased risk of meningococcal disease remains for up to 6 months, underscoring the need for ongoing vigilance【1】.

Meningitis Prophylaxis Guidelines

Meningococcal Meningitis Prophylaxis

• Close contacts, including household members and those directly exposed to oral secretions, must receive prophylaxis within 24 hours of case identification, as the risk of meningococcal disease increases 400-800 fold in close contacts, with secondary attack rates of 2-4 per 1000 population 4, 5, 6
• The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend ciprofloxacin 500 mg oral single dose as the first-line treatment for adults, due to its convenience and high efficacy 4, 5
• Ceftriaxone 250 mg IM single dose is an alternative for adults, with a similar efficacy profile 5, 6
• Rifampin 600 mg orally twice daily for 2 days is also an alternative, although its use is associated with a higher risk of resistance 4, 5
• Patients who received IV ceftriaxone for treatment do not need additional prophylaxis before discharge, according to the Infectious Diseases Society of America 5, 6
• An increased risk of meningococcal disease persists for 6 months after exposure, even with prophylaxis, and general practice records should be flagged accordingly 4, 7

Haemophilus influenzae Type B Prophylaxis

• Prophylaxis is required only when households contain an at-risk individual, such as a child under 10 years or an immunosuppressed person of any age, as recommended by the American Academy of Pediatrics 4, 7
• All household contacts and the index case should receive rifampin if an at-risk individual is present, with dosing regimens varying by age and weight 4, 7

Pneumococcal Meningitis

• Close contacts of pneumococcal meningitis do not require antibiotic prophylaxis, as they are not at increased risk, according to the Centers for Disease Control and Prevention 4, 7
• Patients who have had pneumococcal meningitis should receive pneumococcal vaccination to reduce recurrence risk, which is approximately 1-5%, as recommended by the Infectious Diseases Society of America 5, 6

Implementation and Monitoring

• Prophylaxis should not be delayed and must be initiated within 24 hours of case identification for maximum effectiveness, as emphasized by the Centers for Disease Control and Prevention 5, 6
• Droplet precautions should continue until contacts have received 24 hours of effective prophylaxis, and contacts should be monitored for symptoms for at least 10 days after exposure, even after receiving prophylaxis 8