Streptococcus pneumoniae serotype 12F in Alaska: insights from molecular characterization of isolates associated with rural community outbreaks.

Zulz T, Wenger JD, Rudolph K, Robinson DA, Rakov AV, Bruden D, Singleton RJ, Bruce MG, Hennessy TW.

Source

Arctic Investigations Program, DPEI, NCEZID, Centers for Disease Control and Prevention, 4055 Tudor Centre Drive, Anchorage, AK, 99508, USA.

Abstract

Outbreaks of invasive pneumococcal disease (IPD) caused by serotype 12F Streptococcus pneumoniae were observed in two neighboring regions of rural Alaska in 2003-2006 and 2006-2008. IPD surveillance data from 1986-2009 and carriage survey data from 1998-2004 and 2008-2009 were reviewed to identify patterns of 12F transmission. Pulsed field gel electrophoresis was performed on all available isolates, and selected isolates were characterized by additional genetic subtyping methods. Serotype 12F IPD occurred in two waves in Alaska between 1986 and 2008. While cases of disease occurred nearly every year in Anchorage, in rural regions 12F IPD occurred with rates 10 to 20-fold higher than in Anchorage, often with many years between disease peaks, and generally caused by a single predominant genetic clone. Carriage occurred predominantly in adults, except early in rural outbreaks when most carriage was in persons <18 1-3="" 12f="" a="" after="" appear="" been="" but="" carriage="" centers="" clones.="" clones="" completely="" consistent="" different="" disappeared="" epidemiologic="" episodically="" for="" form="" from="" have="" highly="" immunogenic="" immunologically="" in="" into="" introduced="" ipd="" is="" larger="" lasting="" leading="" may="" na="" of="" old.="" outbreaks.="" outbreaks="" p="" pattern="" pneumococcus.="" population.="" population="" populations="" rapidly="" regions="" reservoir="" rural="" spread="" the="" then="" these="" this="" to="" ve="" virulent="" widely="" with="" years="" young="">