Molecular epidemiology of Clostridium difficile over the course of 10 years in a tertiary care hospital.
BACKGROUND
The molecular epidemiology of endemic and outbreak Clostridium difficile strains across time is not well known.


METHODS
HindIII restriction endonuclease analysis (REA) typing was performed on available clinical C. difficile isolates from 1982 to 1991.


RESULTS
The annual incidence of C. difficile infection (CDI) ranged from 3.2 to 9.9 cases per 1000 discharges and was significantly higher in 1982, 1983, 1985, and 1991 (high-incidence years) than in other years (mean standard deviation number of cases for the high- vs the low-incidence years, 121.8 +/-20.4 and 70.0 +/-15.0; P =.002). A total of 696 (76.6%) of 908 C. difficile isolates were available for REA typing over the 10-year period. Large clusters (>or=10 CDI cases in consecutive months) were caused by REA types B1 and B2 in 1982 and 1983, F2 and B1 in 1985, and K1 in 1991 (high-incidence years). Small clusters of 4-9 CDI cases in consecutive months were caused by REA types G1 (1984), Y4 and Y6 (1987), Y2 (1988), L1 (1989), Y1 (1990), and K1 (1991). Current epidemic REA group BI (unrelated to type B1) was isolated 6 times, twice in 1984, 1988, and 1990.


CONCLUSIONS
Years with a high incidence of CDI were associated with large clusters of specific REA types that changed yearly. The molecular epidemiology of CDI in this hospital was characterized by a wide diversity of C. difficile types and an ever-changing dominance of specific C. difficile types over time. The current epidemic BI group was found sporadically on 6 occasions. A changing CDI molecular epidemiology should be expected in the future.
Belmares
Jaime
J
Division of Infectious Diseases, Loyola University Chicago Medical Center, Maywood 60153, USA. jbelmares@lumc.edu
Johnson
Stuart
S
Parada
Jorge P
JP
Olson
Mary M
MM
Clabots
Connie R
CR
Bettin
Kristine M
KM
Peterson
Lance R
LR
Gerding
Dale N
DN
D015373:Bacterial Typing Techniques; D016360:Clostridioides difficile / Q000145:classification* / Q000302:isolation & purification; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D015247:Deoxyribonuclease HindIII / Q000378:metabolism; D004761:Enterocolitis, Pseudomembranous / Q000453:epidemiology* / Q000382:microbiology; D005838:Genotype; D006801:Humans; D008910:Minnesota; D017720:Molecular Epidemiology; D012150:Polymorphism, Restriction Fragment Length; D000091402:Prohibitins
D004269:DNA, Bacterial; C000717331:PHB2 protein, human; D000091402:Prohibitins; D015247:Deoxyribonuclease HindIII