Sequelae of Meningococcal Serogroup B Infection (2013)

Viner RM, Booy R, Johnson H, et al. Outcomes of invasive meningococcal serogroup B disease in children and adolescents (MOSAIC): a case-control study. Lancet Neurology. 2012; 11(9): 774-783; doi: 10.1016/S1474-4422)12)70180-1Researchers from University College London examined the long-term outcomes of pediatric serogroup B meningococcal disease (SBMD). They recruited children with meningococcal disease from a database containing 92% of reported meningococcal cases in England. Eligible cases were children who survived culture- or PCR-confirmed SBMD and were 1 month to 13 years of age at the time of disease. Cases and age- and gender-matched controls derived from the same physician practices.The primary outcomes of interest were the physical, psychological, and neurocognitive outcomes of cases 3 years after their illness. Major deficits were defined as intellectual disability (IQ <70), seizures, bilateral sensorineural hearing loss of ≥40 dB, disabling motor impairment (eg, amputation of part of a limb), significant visual loss, and major communication disability (eg, unintelligible speech). Parents completed several validated questionnaires which assessed the physical and mental health of their children, including the Annotated Scale of Bodily Injuries Regulation (ASBIR),1 which measures total physical disability. Researchers masked to case-control status assessed study participants’ neurocognitive function using IQ, memory, attention, and executive function tests. Assessment of hearing was done using audiometry. Hospital discharge summaries provided clinical data, such as length of hospital stay, disease type (septicemia, meningitis, or both), and time in the ICU.Investigators recruited 246 cases (46% of those eligible) and 328 controls. The mean age was 6.5 years for cases and 6.9 years for controls. Among cases, the median age at time of disease was 1.6 years, the median length of hospital stay was 5 days, 29% were admitted to the ICU, and 63% had septicemia, 14% had meningitis, and 18% had both. Recruited and nonrecruited cases did not differ by age, sex, or length of ICU stay.Cases were significantly more likely than controls to have bilateral sensorineural hearing loss of ≥40 dB, higher ASBIR scores, lower IQ scores, and a psychological disorder. Cases were also significantly more likely than controls to have deficits in memory and global executive function, but not attention. In total, 9% of cases had a major disabling deficit compared with 2% of controls (OR = 5.0).There was no association between age at disease and risk of any deficit. Individuals with meningitis were significantly more likely to have sensorineural hearing loss of ≥40 dB than those with septicemia (OR = 6.0). Hospital length of stay and admission to ICU were associated with higher ASBIR scores.The authors conclude that about a tenth of survivors of SBMD have a major disabling deficit.In the United States, meningococcal infection peaks in infancy and adolescence. Serogroup B is responsible for 50% to 60% of disease in infants. In adolescents, 75% of cases are caused by serogroups C, Y, or W-135, serogroups contained in existing vaccines.2 Infants as young as 9 months may receive the MCV4, and the American Academy of Pediatrics recommends that 11- to 12-year-olds receive this vaccine and a booster at 16 years of age.In the United Kingdom, vaccination with a monovalent vaccine against serotype C Neisseria meningitidis has been universal for infants since the 1990s. Despite this protection, meningococcal disease remains a common cause of life-threatening invasive disease; there is no vaccine against serogroup B.3In the current study, rates of major sequelae were comparable to those found in a comprehensive global study published in 20104; however, these rates are lower than those reported in a 2001 US study of adolescents and young adults.5 One limitation of the current study was that some of the children identified from the registry never responded and those children were more likely to live in highly deprived areas (33% of nonrecruited children and 16% of recruited children). The authors, however, did attempt to adjust for this deprivation. Another limitation is the difficulty of masking during personal assessments, as disabilities such as amputations and hearing loss are evident.Despite these limitations, this study is a rigorous examination of the burden of SBMD in young children, with important implications for their future needs. It is a unique study as it identifies both neurocognitive and physical burdens. Since SBMD comprises the majority of infant infections in the United States and United Kingdom, it has a significant lifelong impact on surviving children, their families, and society. The effort to develop a successful vaccine against SBMD must continue if this burden is to be lessened. (See also AAP Grand Rounds, April 2008;19[4]:38-39.6)