Invasive Meningococcal Capsular Group Y Disease, England and Wales, 2007–2009 - Vol. 18 No. 1 - January 2012 - Emerging Infectious Disease journal - CDC
Volume 18, Number 1—January 2012
Invasive Meningococcal Capsular Group Y Disease, England and Wales, 2007–2009
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Invasive meningococcal disease is associated with substantial rates of illness and death worldwide (1), with most infections caused by 5 capsular groups, namely A, B, C, W135, and Y (2). In the United Kingdom, where capsular group C (MenC) conjugate vaccines have been routinely used since 1999 (3,4), capsular group B (MenB) causes >80% of confirmed cases, particularly among infants and adolescents (5). Invasive infections caused by other capsular groups are infrequent and sporadic (6,7).
AbstractEnhanced national surveillance for invasive meningococcal disease in England and Wales identified an increase in laboratory-confirmed capsular group Y (MenY) disease from 34 cases in 2007 to 44 in 2008 and 65 in 2009. For cases diagnosed in 2009, patient median age at disease onset was 60 years; 39% of patients had underlying medical conditions, and 19% died. MenY isolates causing invasive disease during 2007–2009 belonged mainly to 1 of 4 clonal complexes (cc), cc23 (56% of isolates), cc174 (21%), cc167 (11%), and cc22 (8%). The 2009 increase resulted primarily from sequence type 1655 (cc23) (22 cases in 2009, compared with 4 cases each in 2007 and 2008). cc23 was associated with lpxL1 mutations and meningitis in younger age groups (<25 years); cc174 was associated with nonmeningitis, particularly pneumonia, in older age groups (>65 years). The increase in MenY disease requires careful epidemiologic and molecular monitoring.
Invasive capsular group Y (MenY) has historically been uncommon in the United Kingdom and until recently accounted for <30 cases annually (5). After 2006, however, enhanced surveillance by the Health Protection Agency (HPA) identified an increase in invasive MenY cases in England and Wales. In addition, recent surveys suggest that MenY carriage in England increased substantially during the past decade (8,9). Consequently, the HPA investigated the clinical, epidemiologic, and microbiologic characteristics of invasive MenY disease in England and Wales during 2007–2009.