title: An upsurge in pertussis: epidemiology and trends.
abstract: OBJECTIVE
  The objective of the study was to review the 2010 pertussis upsurge occurring within California and recent experiences at a large tertiary care children's hospital within California.
  
  
  METHODS
  A retrospective review of all specimens submitted for Bordetella pertussis polymerase chain reaction assay from the emergency department at a large tertiary care children's hospital from January 2009 to August 2010. Outcome measures were the number of specimens submitted, the number of positive specimens, and the percentage of positive specimens.
  
  
  RESULTS
  The last peak incidence of pertussis, in the Unite States, was seen in 2005 with an annual incidence of 25,616 reported cases. Comparing 2010 with 2009 during the same period, the total number of positive cases increased from 13 to 94, a 723% increase at our institution. The median monthly number of positive specimen was 1.5 for 2009 and 6.5 for 2010 (P = 0.0169).
  
  
  CONCLUSIONS
  Hospitals, private practitioners, and the California Department of Public Health need to emphasize prompt diagnosis and treatment of this contagious infection to limit the spread to susceptible individuals. A more widespread safe and effective vaccination program will hopefully enhance protection against pertussis infection.
authors.affiliation: Divisions of Emergency and Transport Medicine, Children's Hospital Los Angeles, CA 90027, USA. gmarconi@chla.usc.edu
authors.forename: Greg P
authors.initials: GP
authors.lastname: Marconi
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Ross
authors.forename: Alan L
authors.initials: AL
authors.lastname: Nager
mesh_terms: D002140:California / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D012189:Retrospective Studies; D014917:Whooping Cough / Q000175:diagnosis / Q000453:epidemiology*