By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University
The number of cases of infection with Neisseria meningitidis is increasing in the United States. The majority of presentations are with bacteremia; meningitis is infrequent.
CDC Health Alert Network. Increase in invasive serogroup Y meningococcal disease in the United States. March 28, 2024. https://emergency.cdc.gov/han/2024/han00505.asp
The Centers for Disease Control and Prevention (CDC) has issued an alert regarding an increasing number of infections due to Neisseria meningitidis in the United States. The 422 cases reported in 2023 had been the most since 2014, but in the first 84 days of 2024 (i.e., as of March 25), 143 cases had been reported. That is 62 more cases than were reported for this interval in 2023.
This occurrence has been predominantly due to infections by N. meningitidis serogroup Y with sequence type (ST) 1466 accounting for 101 of the 148 (68%) cases in 2023 for which ST was available. Infections with this ST have been associated with greater than expected frequencies in individuals 30-60 years of age, Black people, and those with human immunodeficiency virus (HIV) infection, accounting for 65%, 63%, and 15% of cases, respectively. Also of note is that most patients did not have meningitis — 64% presented with bacteremia and at least 4% presented with septic arthritis. While the case fatality rate of serogroup Y infections in 2017-2021 was 11%, 17 of 94 (18%) with known outcomes in 2023 died.
COMMENTARY
The CDC recommends that healthcare providers (HCPs) be acutely aware of these infections, including their non-meningeal presentation, especially among those groups seemingly disproportionately affected. In addition, HCPs also should make efforts to assure that individuals in their care for whom it is recommended remain up to date with vaccination.
While they are not the only population for whom vaccination is recommended, adolescents make up an important target group. All individuals 11-12 years of age should receive a MenACWY conjugate vaccine as well as a booster when they reach 16 years of age.1 Adolescents with medical conditions associated with an increased risk of severe meningococcal disease or facing an outbreak should receive primary vaccination with the quadrivalent vaccine, followed by subsequent booster doses every five years. In addition, vaccination against group B N. meningitidis (and subsequent regular booster doses) is strongly recommended for individuals 16-23 years of age with late complement component deficiency or who are receiving complement inhibitor therapy or have anatomic or functional asplenia.
Either ceftriaxone or cefotaxime is recommended for initial empiric therapy of patients with suspected meningococcal infection. The increasing number of N. meningitidis isolates in the United States that are resistant to ciprofloxacin has led the CDC to warn that its use for prophylaxis in anyone having had close contact with individuals with invasive meningococcal infection in areas with identified resistance to this fluoroquinolone might lead to failure. In those cases, one of the following should instead be used for prophylaxis: azithromycin, ceftriaxone, or rifampin.
Increasing reports of ciprofloxacin resistance (and beta-lactamase production) among serogroup Y isolates in the United States have magnified this concern. However, this resistance has occurred in a strain different from ST 116 and, fortunately, none of the ST 116 isolates tested have proven resistant to ciprofloxacin.
REFERENCE
- Centers for Disease Control and Prevention. Meningococcal vaccine recommendations. Last reviewed Nov. 20, 2023. https://www.cdc.gov/vaccines/vpd/mening/hcp/recommendations.html
