title: Correlating epidemiologic trends with the genotypes causing meningococcal disease, Maryland.
abstract: Epidemic meningococcal infection is generally caused by single clones; whether nonepidemic increases in infection are clonal is unknown. We studied the molecular epidemiology of meningococcal infection during a period that the incidence increased in two age groups. Serogroup C and Y meningococcal isolates were analyzed by pulsed-field gel electrophoresis and multilocus sequence typing. From 1992 to 1999, 96.4% (27/28) of serogroup C isolates from persons 15-24 years of age were in clonal group 1, compared with 65.6% (21/32) of isolates from persons < or =14 years, and 64.3% (9/14) of isolates from adults > or =25 years (p < or = 0.01). The proportion of clonal group 2 serogroup Y strains increased from 7.7% (1/13) in 1992 to 1993 to 52.0% (13/25) in 1998 to 1999 (p < 0.01). The nonepidemic age-specific increases in serogroup C meningococcal infection in Maryland were clonal in nature and the changes in serogroup Y incidence were associated with a shift in the genotypes of strains causing invasive disease.
authors.affiliation: University of Pittsburgh Graduate School of Public Health and School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: M Catherine
authors.initials: MC
authors.lastname: McEllistrem
authors.forename: John A
authors.initials: JA
authors.lastname: Kolano
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Pass
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Caugant
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Mendelsohn
authors.forename: Antonio Guilherme
authors.initials: AG
authors.lastname: Fonseca Pacheco
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Shutt
authors.forename: Jafar
authors.initials: J
authors.lastname: Razeq
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D015994:Incidence; D008396:Maryland / Q000453:epidemiology; D008585:Meningitis, Meningococcal / Q000145:classification / Q000453:epidemiology* / Q000235:genetics; D017720:Molecular Epidemiology; D009345:Neisseria meningitidis / Q000145:classification* / Q000302:isolation & purification; D011159:Population Surveillance / Q000379:methods; D012703:Serotyping