Reduction in high rates of antibiotic-nonsusceptible invasive pneumococcal disease in tennessee after introduction of the pneumococcal conjugate vaccine.
BACKGROUND
Invasive pneumococcal disease (IPD) is a burgeoning problem, with rates of antibiotic-nonsusceptible IPD, in particular, increasing during the past decade. One measure to combat IPD is vaccination with the recently introduced 7-valent pneumococcal conjugate vaccine (PCV).


METHODS
To evaluate the effects of the introduction of PCV in 2000 on the epidemiology of antibiotic-nonsusceptible IPD, a database of IPD cases from January 1995 through December 2002 identified through active surveillance in 5 Tennessee counties was examined. For each case, clinical data were collected, and antibiotic susceptibility testing and serotyping were performed on available isolates.


RESULTS
Among children younger than 2 years, IPD rates peaked at 235 cases per 100,000 in 1999 before decreasing, after PCV licensure, to 46 cases per 100,000 in 2002 (P<.001). The proportion of penicillin-nonsusceptible IPD isolates from this age group declined from 59.8% in 1999 to 30.4% in 2002 (P<.01). After 2001, similar decreases in IPD rates and in the proportion of antibiotic-nonsusceptible isolates recovered were seen among persons aged 2 years and older (P<.01). Rates of IPD due to PCV-associated serotypes declined after PCV introduction in all age groups (P<.001), whereas the rate of IPD due to nonvaccine serotypes increased among persons aged 2 years and older.


CONCLUSIONS
In the 2 years since licensure, widespread PCV vaccination of children has resulted in dramatic declines in the proportion of antibiotic-nonsusceptible isolates in Tennessee. PCV vaccination of children also appears to be a highly effective method for reducing the burden of IPD in adults.
Talbot
Thomas R
TR
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA. tom.talbot@vanderbilt.edu
Poehling
Katherine A
KA
Hartert
Tina V
TV
Arbogast
Patrick G
PG
Halasa
Natasha B
NB
Mitchel
Ed
E
Schaffner
William
W
Craig
Allen S
AS
Edwards
Kathryn M
KM
Griffin
Marie R
MR
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D011159:Population Surveillance / Q000379:methods; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D013714:Tennessee / Q000453:epidemiology; D018074:Vaccines, Conjugate / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate