2012. 11. 20 Journal Watch Hospital Medicine（英文）
【原題】Minimizing Antibiotic Dental Prophylaxis
※Journal WatchはNew England Journal of Medicineの発行元であるMassachusetts Medical Societyが発行する医学ニューズレターです。
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Mouth flora—related infective endocarditis did not rise after drastic reductions in antibiotic use for dental procedures.（歯科処置時の抗生物質使用の大幅な縮小の後に、口腔細菌に関連する感染性心内膜炎の発症は増えず）
Invasive dental procedures have long been suggested as a cause of infective endocarditis （IE），because oral streptococci have been implicated in many cases of IE. Antibiotic prophylaxis for dental procedures has been recommended by the American Heart Association and other groups for decades，especially in patients at particular risk for IE. In 2002 in France （2007 in the U.S.； 2008 in the U.K.），guidelines were altered to drastically lower the indications for such prophylaxis.
A study conducted in England showed no appreciable increase in viridans group streptococcal endocarditis （VGS−IE） during the years following antibiotic prophylaxis restriction （BMJ 2011； 342：d2392）. Now，researchers have reported the results of two additional population−based studies on the topic.
Using the Mayo Clinic's Endocarditis Registry，DeSimone and colleagues assessed the incidence of VGS−IE among adults in Olmsted County，Minnesota，from 1999 （before restriction） through 2010 （3 years after restriction）. Over this 12−year period，only 22 cases of VGS−IE were identified. The age− and sex−adjusted incidence per 100，000 person−years were 3.19 （95％ confidence interval，1.20—5.17） for 1999—2002，2.48 （95％ CI，0.85—4.10） for 2003—2006，and 0.77 （95％ CI，0.00— 1.64） for 2007—2010. The nationwide incidence of VGS−IE，derived from the Nationwide Inpatient Sample database，also remained stable during this period. Of the three cases identified in Olmsted County between 2007 and 2010，two patients had undergone no dental work during the preceding 6 months； the third had received clindamycin prophylaxis.
Duval and colleagues conducted three 1−year population−based surveys in three regions of France encompassing 11 million inhabitants aged ≧20. All IE cases were validated by a panel of experts. The number of patients with definite，probable，or possible IE remained stable over time — 323 in 1991，331 in 1999，and 339 in 2008. No increase was seen in VGS−IE incidence after publication of the more restrictive guidelines. However，the incidence of staphylococcal IE rose，especially among patients without previously known native valve disease.
Clearly，lower use of dental antibiotic prophylaxis in the three populations studied has not resulted in more IE cases caused by oral bacteria. That such prophylaxis has never been helpful cannot be proven. But given the current findings and the fact that antimicrobial resistance is a major health problem，it seems prudent to reinforce guidelines that restrict antibiotic overuse.
— Stephen G. Baum，MD，Journal Watch Infectious Diseases
Larry Baddour，an author on the study conducted in Minnesota，is the Editor−in−Chief of Journal Watch Infectious Diseases. Dr. Baddour had no role in the writing or review of this summary.
DeSimone DC et al. Incidence of infective endocarditis caused by viridans group streptococci before and after publication of the 2007 American Heart Association's endocarditis prevention guidelines. Circulation 2012 Jul 3； 126：60.
Duval X et al. Temporal trends in infective endocarditis in the context of prophylaxis guideline modifications： Three successive population−based surveys. J Am Coll Cardiol 2012 May 29； 59：1968.