The Burden of Infant Meningococcal Disease in the United States.

Abstract

In the United States, invasive meningococcal disease occurs at the highest rates in infants, with a second peak in adolescents. Early symptoms are nonspecific and may resemble viral infection, which poses a diagnostic challenge for clinicians. Moreover, the stakes of diagnostic confusion may be high because the disease may become life threatening within hours. Sequelae among survivors may be profound. In adolescent age groups, control of meningococcal disease caused by serogroups A, C, W-135, and Y rests upon universal vaccination beginning at 11–12 years of age; vaccines for serogroup B are not currently available. One 4-valent vaccine is licensed for use in infants beginning at 9 months of age but is only recommended for those at high risk. Licensure of new vaccines for infants is expected soon, and a universal immunization program is being debated. A wide range of bacteria can cause meningitis in infants and young children. In neonates aged <3 months, group B streptococcus causes most bacterial meningitis in many developed countries, followed by Escherichia coli and other Gram-negative enteric bacilli. Listeria monocytogenes can also be seen in this age group [1]. Historically, for infants and children aged <5 years, the 3 most common causes of bacterial meningitis and sepsis were Haemophilus influenzae type b (Hib), Streptococcus pneumoniae, and Neisseria meningitidis [1]. Annual disease cases due to Hib in US children aged <5 years have been reduced by 99%, and there has been a substantial decline in pediatric invasive pneumococcal disease due to routine infant immunization programs introduced in the 1990s and 2000s [2, 3]. This leaves N. meningitidis as one of the most important causes of bacterial meningitis in infants and young children. Since 2005, the Centers for Disease Control and Prevention's (CDC's) Advisory Committee on Immunization Practices (ACIP) has recommended routine vaccination against N. meningitidis for all adolescents; recommendations for vaccination of children aged 9 months–10 years are restricted to high-risk groups [4–10]. At the present time, there are no meningococcal conjugate vaccines licensed for use in infants aged <9 months, although there are vaccines currently under review by the Food and Drug Administration (FDA). This article discusses the burden of meningococcal disease in infants in order to provide a backdrop for considering prevention strategies.