title: Molecular epidemiology of the pertussis epidemic in Washington State in 2012.
abstract: Although pertussis disease is vaccine preventable, Washington State experienced a substantial rise in pertussis incidence beginning in 2011. By June 2012, the reported cases reached 2,520 (37.5 cases per 100,000 residents), a 1,300% increase compared with the same period in 2011. We assessed the molecular epidemiology of this statewide epidemic using 240 isolates collected from case patients reported from 19 of 39 Washington counties during 2012 to 2013. The typing methods included pulsed-field gel electrophoresis (PFGE), multilocus variable number tandem repeat analysis (MLVA), multilocus sequence typing (MLST), and pertactin gene (prn) mutational analysis. Using the scheme PFGE-MLVA-MLST-prn mutations-Prn deficiency, the 240 isolates comprised 65 distinct typing profiles. Thirty-one PFGE types were found, with the most common types, CDC013 (n = 51), CDC237 (n = 44), and CDC002 (n = 42), accounting for 57% of them. Eleven MLVA types were observed, mainly comprising type 27 (n = 183, 76%). Seven MLST types were identified, with the majority of the isolates typing as prn2-ptxP3-ptxA1-fim3-1 (n = 157, 65%). Four different prn mutations accounted for the 76% of isolates exhibiting pertactin deficiency. PFGE provided the highest discriminatory power (D = 0.87) and was found to be a more powerful typing method than MLVA and MLST combined (D = 0.67). This study provides evidence for the continued predominance of MLVA 27 and prn2-ptxP3-ptxA1 alleles, along with the reemergence of the fim3-1 allele. Our results indicate that the Bordetella pertussis population causing this epidemic was diverse, with a few molecular types predominating. The PFGE, MLVA, and MLST profiles were consistent with the predominate types circulating in the United States and other countries. For prn, several mutations were present in multiple molecular types.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Bowden
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Williams
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Cassiday
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Milton
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pawloski
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Marsenia
authors.initials: M
authors.lastname: Harrison
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Stacey W
authors.initials: SW
authors.lastname: Martin
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Meyer
authors.affiliation: Seattle Children's Hospital, Seattle, Washington, USA.
authors.forename: Xuan
authors.initials: X
authors.lastname: Qin
authors.affiliation: Washington State Department of Health, Communicable Disease Epidemiology, Shoreline, Washington, USA.
authors.forename: Chas
authors.initials: C
authors.lastname: DeBolt
authors.affiliation: Washington State Department of Health, Communicable Disease Epidemiology, Shoreline, Washington, USA.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Tasslimi
authors.affiliation: Washington State Department of Health, Public Health Laboratories, Office of Microbiology, Shoreline, Washington, USA.
authors.forename: Nusrat
authors.initials: N
authors.lastname: Syed
authors.affiliation: Washington State Department of Health, Public Health Laboratories, Office of Microbiology, Shoreline, Washington, USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Sorrell
authors.affiliation: Washington State Department of Health, Public Health Laboratories, Office of Microbiology, Shoreline, Washington, USA.
authors.forename: Mike
authors.initials: M
authors.lastname: Tran
authors.affiliation: Washington State Department of Health, Public Health Laboratories, Office of Microbiology, Shoreline, Washington, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Hiatt
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA mlt5@cdc.gov.
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Tondella
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001886:Bordetella pertussis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D058872:Epidemics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D014481:United States; D014861:Washington / Q000453:epidemiology; D014917:Whooping Cough / Q000453:epidemiology*; D055815:Young Adult