title: Geotemporal analysis of Neisseria meningitidis clones in the United States: 2000-2005.
abstract: BACKGROUND
  The detection of meningococcal outbreaks relies on serogrouping and epidemiologic definitions. Advances in molecular epidemiology have improved the ability to distinguish unique Neisseria meningitidis strains, enabling the classification of isolates into clones. Around 98% of meningococcal cases in the United States are believed to be sporadic.
  
  
  METHODS
  Meningococcal isolates from 9 Active Bacterial Core surveillance sites throughout the United States from 2000 through 2005 were classified according to serogroup, multilocus sequence typing, and outer membrane protein (porA, porB, and fetA) genotyping. Clones were defined as isolates that were indistinguishable according to this characterization. Case data were aggregated to the census tract level and all non-singleton clones were assessed for non-random spatial and temporal clustering using retrospective space-time analyses with a discrete Poisson probability model.
  
  
  RESULTS
  Among 1,062 geocoded cases with available isolates, 438 unique clones were identified, 78 of which had ≥2 isolates. 702 cases were attributable to non-singleton clones, accounting for 66.0% of all geocoded cases. 32 statistically significant clusters comprised of 107 cases (10.1% of all geocoded cases) were identified. Clusters had the following attributes: included 2 to 11 cases; 1 day to 33 months duration; radius of 0 to 61.7 km; and attack rate of 0.7 to 57.8 cases per 100,000 population. Serogroups represented among the clusters were: B (n = 12 clusters, 45 cases), C (n = 11 clusters, 27 cases), and Y (n = 9 clusters, 35 cases); 20 clusters (62.5%) were caused by serogroups represented in meningococcal vaccines that are commercially available in the United States.
  
  
  CONCLUSIONS
  Around 10% of meningococcal disease cases in the U.S. could be assigned to a geotemporal cluster. Molecular characterization of isolates, combined with geotemporal analysis, is a useful tool for understanding the spread of virulent meningococcal clones and patterns of transmission in populations.
authors.affiliation: Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Ann E
authors.initials: AE
authors.lastname: Wiringa
authors.affiliation: Infectious Diseases Epidemiology Research Unit, University of Pittsburgh Graduate School of Public Health and School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Shutt
authors.affiliation: Infectious Diseases Epidemiology Research Unit, University of Pittsburgh Graduate School of Public Health and School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Jane W
authors.initials: JW
authors.lastname: Marsh
authors.affiliation: Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Cohn
authors.affiliation: Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Messonnier
authors.affiliation: New York State Department of Health, Albany, New York, United States of America.
authors.forename: Shelley M
authors.initials: SM
authors.lastname: Zansky
authors.affiliation: Connecticut Department of Public Health, Hartford, Connecticut, United States of America.
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.affiliation: Emory University and VA Medical Center, Atlanta, Georgia, United States of America.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Farley
authors.affiliation: Colorado Department of Public Health and Environment, Denver, Colorado, United States of America.
authors.forename: Ken
authors.initials: K
authors.lastname: Gershman
authors.affiliation: Minnesota Department of Health, St. Paul, Minnesota, United States of America.
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.affiliation: University of California, Berkeley, Berkeley, California, United States of America.
authors.forename: Arthur
authors.initials: A
authors.lastname: Reingold
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.affiliation: Oregon Public Health Division, Portland, Oregon, United States of America.
authors.forename: Jamie
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Shawn T
authors.initials: ST
authors.lastname: Brown
authors.affiliation: Public Health Computational and Operations Research (PHICOR), University of Pittsburgh School of Medicine and Graduate School of Public Health, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Bruce Y
authors.initials: BY
authors.lastname: Lee
authors.affiliation: Infectious Diseases Epidemiology Research Unit, University of Pittsburgh Graduate School of Public Health and School of Medicine, Pittsburgh, Pennsylvania, United States of America ; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000145:classification / Q000235:genetics*; D002999:Clone Cells; D062665:Epidemiological Monitoring; D015870:Gene Expression; D006801:Humans; D008589:Meningococcal Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D058885:Multilocus Sequence Typing; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics*; D012189:Retrospective Studies; D012703:Serotyping; D062211:Spatio-Temporal Analysis; D014481:United States / Q000453:epidemiology
chemical_list: D001425:Bacterial Outer Membrane Proteins