title: An outbreak of conjunctivitis due to atypical Streptococcus pneumoniae.
abstract: BACKGROUND
  In February 2002, clinicians at the Dartmouth College Health Service recognized an outbreak of conjunctivitis; cultures of conjunctival swabs implicated Streptococcus pneumoniae. An investigation was begun to determine the extent of the outbreak, confirm the cause, identify modes of transmission, and implement control measures.
  
  
  METHODS
  Investigators reviewed the health service's data base for diagnoses of conjunctivitis. Viral and bacterial cultures were obtained from ill students. Bile-soluble isolates that were susceptible to ethylhydrocupreine (optochin) and therefore were presumed to be pneumococci underwent serotyping, capsular staining, pulsed-field gel electrophoresis, a DNA probe, and multilocus sequence typing. A cohort study of risk factors was conducted with the use of the Internet. Control measures included distribution of alcohol-based hand gel and messages about prevention.
  
  
  RESULTS
  Among 5060 students, 698 (13.8 percent) received a diagnosis of conjunctivitis from January 1, 2002, through April 12, 2002, including 22 percent of first-year students. Presumed pneumococci were isolated from 43.3 percent of conjunctival swabs (110 of 254); viral cultures performed on 85 specimens were negative. DNA probes and multilocus sequence typing confirmed that the organisms were pneumococci, although the bacteria did not have the characteristic capsule. On pulsed-field gel electrophoresis, strains were found to be identical to pneumococci that caused outbreaks of conjunctivitis in other parts of the country in 1980. Analysis of survey data from 1832 students indicated that close contact with a student with conjunctivitis, wearing contact lenses, membership on a sports team, and attending parties at or living in a fraternity or sorority house were associated with conjunctivitis. The rate of diagnosis of conjunctivitis declined after the implementation of control measures and after spring break.
  
  
  CONCLUSIONS
  This large outbreak of conjunctivitis on a college campus was caused by an atypical, unencapsulated strain of S. pneumoniae that was identical to strains that had caused outbreaks two decades earlier.
authors.affiliation: Respiratory Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Martin
authors.forename: John H
authors.initials: JH
authors.lastname: Turco
authors.forename: Michael E
authors.initials: ME
authors.lastname: Zegans
authors.forename: Richard R
authors.initials: RR
authors.lastname: Facklam
authors.forename: Samir
authors.initials: S
authors.lastname: Sodha
authors.forename: John A
authors.initials: JA
authors.lastname: Elliott
authors.forename: John H
authors.initials: JH
authors.lastname: Pryor
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: Dean D
authors.initials: DD
authors.lastname: Erdman
authors.forename: Yolanda Y
authors.initials: YY
authors.lastname: Baumgartner
authors.forename: Paul A
authors.initials: PA
authors.lastname: Sanchez
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Schwartzman
authors.forename: José
authors.initials: J
authors.lastname: Montero
authors.forename: Anne
authors.initials: A
authors.lastname: Schuchat
authors.forename: Cynthia G
authors.initials: CG
authors.lastname: Whitney
mesh_terms: D003228:Conjunctiva / Q000382:microbiology; D003234:Conjunctivitis, Bacterial / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009513:New Hampshire / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D012307:Risk Factors; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000302:isolation & purification; D014495:Universities