Baddour, Larry M.

Abstract Objectives Antibiotic prophylaxis (AP) administration prior to invasive dental procedures has been a leading focus of infective endocarditis prevention. However, there have been long-standing concerns about the risk of adverse drug reactions as a result of this practice. The objective of this study was to identify the incidence and nature of adverse reactions to amoxicillin and clindamycin prophylaxis to prevent infective endocarditis. Methods We obtained AP prescribing data for England from January 2004 to March 2014 from the NHS Business Services Authority, and adverse drug reaction data from the Medicines and Healthcare Products Regulatory Agency's Yellow Card reporting scheme for prescriptions of the standard AP protocol of a single 3 g oral dose of amoxicillin or a single 600 mg oral dose of clindamycin for those allergic to penicillin. Results The reported adverse drug reaction rate for amoxicillin AP was 0 fatal reactions/million prescriptions (in fact 0 fatal reactions for nearly 3 million prescriptions) and 22.62 non-fatal reactions/million prescriptions. For clindamycin, it was 13 fatal and 149 non-fatal reactions/million prescriptions. Most clindamycin adverse drug reactions were Clostridium difficile infections. Conclusions AP adverse drug reaction reporting rates in England were low, particularly for amoxicillin, and lower than previous estimates. This suggests that amoxicillin AP is comparatively safe for patients without a history of amoxicillin allergy. The use of clindamycin AP was, however, associated with significant rates of fatal and non-fatal adverse drug reactions associated with C. difficile infections. These were higher than expected and similar to those for other doses, durations and routes of clindamycin administration.

Scopulariopsisis a genus of mold that is usually associated with onychomycosis and rarely causes complicated infection in immunocompetent persons. We describe a case of an immunocompetent 65-year-old male with a history of mitral valve repair with prosthetic ring placement who developed acute left posterior knee pain. Imaging showed a left popliteal artery aneurysm and thrombus, and further evaluation with transesophageal echocardiogram demonstrated two large, mobile mitral valve vegetations. He underwent debridement and replacement of the mitral valve, followed by debridement of the left popliteal artery with peroneal artery bypass. The intraoperative cultures grewScopulariopsis brevicaulis. Due to the resistant nature of the organism, he was initially treated with combination antifungals including liposomal amphotericin B, caspofungin, and voriconazole and was continued on chronic suppression with posaconazole with no evidence of recurrence.Scopulariopsisis a rare cause of fungal endocarditis. Treatment ofScopulariopsisendocarditis is challenging and is not well understood due to its rarity.

AbstractA 63-year-old man presented with generalized fatigue, chills, malaise, dyspnea, intermittent fevers, and 50-pound weight loss of 4 months′ duration. Blood cultures were positive for pan-sensitive Streptococcus anginosus. Transesophageal echocardiography showed an 11 mm × 3 mm mobile mass attached to the mitral valve, a 16 mm × 16 mm mobile mass attached to the pulmonary valve, and a small membranous ventricular septal defect. The patient received 12 weeks of intravenous (IV) antibiotics with eventual resolution of the masses. Multi-valve endocarditis involving both the left and right chambers is rarely reported without prior history of IV drug use or infective endocarditis. Our case emphasizes the importance of careful assessment for ventricular septal defects or extra-cardiac shunts in individuals who present with simultaneous right and left-sided endocarditis.

Background— Prompt recognition of underlying cardiovascular implantable electronic device (CIED) infection in patients presenting with Staphylococcus aureus bacteremia (SAB) is critical for optimal management of these cases. The goal of this study was to identify clinical predictors of CIED infection in patients presenting with SAB and no signs of pocket infection. Methods and Results— All cases of SAB in CIED recipients at Mayo Clinic from 2001 to 2011 were retrospectively reviewed. We identified 131 patients with CIED who presented with SAB and had no clinical signs of device pocket infection. Forty-five (34%) of these patients had underlying CIED infection based on clinical or echocardiographic criteria. The presence of a permanent pacemaker rather than an implantable cardioverter-defibrillator (odds ratio, 3.90; 95% confidence interval, 1.65–9.23; P =0.002), >1 device-related procedure (odds ratio, 3.30; 95% confidence interval, 1.23–8.86; P =0.018), and duration of SAB ≥4 days (odds ratio, 5.54; 95% confidence interval, 3.32–13.23; P <0.001) were independently associated with an increased risk of CIED infection in a multivariable model. The area under the receiver operating characteristics curve for the multivariable model was 0.79, indicating a good discriminatory capacity to distinguish SAB patients with and without CIED infection. Conclusions— Among patients presenting with SAB and no signs of pocket infection, the risk of underlying CIED infection can be calculated based on the type of device, number of device-related procedures, and duration of SAB. We propose that patients without any of these high-risk features have a low risk of underlying CIED infection and may be monitored closely without immediate device extraction. Prospective studies are needed to validate this risk prediction model.

SummaryBackgroundClostridium difficile infection (CDI) recurs in 20–30% of patients.AimTo describe the predictors of recurrence in out‐patients with CDI.MethodsOut‐patient cases of CDI in Olmsted County, MN residents diagnosed between 28 June 2007 and 25 June 2010 were identified. Recurrent CDI was defined as recurrence of diarrhoea with a positive C. difficile PCR test from 15 to 56 days after the initial diagnosis with interim resolution of symptoms. Patients who had two positive tests within 14 days were excluded. Cox proportional hazard models were used to assess the association of clinical variables with time to recurrence of CDI.ResultsThe cohort included 520 out‐patients; 104 had recurrent CDI (cumulative incidence of 17.5% by 30 days). Univariate analysis identified increasing age and antibiotic use to be associated with recurrent CDI. Severe CDI, peripheral leucocyte count and change in serum creatinine >1.5‐fold were not. In a multiple variable model, concomitant antibiotic use was associated with risk of recurrent CDI (HR = 5.4, 95% CI 1.6–17.5, P = 0.005), while age (HR per 10 year increase = 1.1, 95% CI 0.9–1.3, P = 0.22); peripheral leucocyte count >15 × 109/L (HR = 1.0, 95% CI 0.5–2.1, P = 0.92); and change in serum creatinine greater than 1.5‐fold (HR = 0.8, 95% CI 0.4–1.5, P = 0.44) were not.ConclusionsAntibiotic use was independently associated with a dramatic risk of recurrent Clostridium difficile infection in an out‐patient cohort. It is important to avoid unnecessary systemic antibiotics in patients with Clostridium difficile infection, and patients with ongoing antibiotic use should be monitored closely for recurrent infection.

Background Cardiovascular implantable electronic device (CIED) pocket infections are often related to recent CIED placement or manipulation, but these infections are not well characterized. The clinical presentation of CIED pocket infection, based on temporal onset related to last CIED procedure, deserves further study. Methods The MEDIC (Multicenter Electrophysiologic Device Infection Cohort) prospectively enrolled subjects with CIED infection. Subjects were stratified into those whose infection occurred <12 months (early) or ≥12 months (late) since their last CIED‐related procedure. Results There were 132 subjects in the early group and 106 in the late group. There were more females (P = 0.009) and anticoagulation use (P = 0.039) in the early group. Subjects with early infections were more likely to have had a generator change or lead addition as their last procedure (P = 0.03) and had more prior CIED procedures (P = 0.023). Early infections were more likely to present with pocket erythema (P < 0.001), swelling (P < 0.001), and pain (P = 0.007). Late infections were more likely to have pocket erosion (P = 0.005) and valvular vegetations (P = 0.009). In bacteremic subjects, early infections were more likely healthcare‐associated (P < 0.001). In‐hospital and 6‐month mortality were equivalent. Conclusion A total of 45% of patients with CIED pocket infection presented >12 months following their last CIED‐related procedure. Patients with early infection were more likely to be female, on anticoagulation, and present with localized inflammation, whereas those with late infection were more likely to have CIED erosion or valvular endocarditis.

Objectives Asthmatics have increased risks of airway-related infections. Little is known about whether this is true for non-airway-related serious infections such as Escherichia coli bloodstream infection (BSI). We assessed whether asthma is associated with a risk of developing community-acquired E coli BSI. Design The study was designed as a population-based retrospective case–control study. Setting This population-based study was conducted in Olmsted County, Minnesota. Participants The study included 259 all eligible community-acquired E coli BSI cases in Olmsted County, MN between 1998 and 2007 and 259 birthday-matched, gender-matched and residency-matched controls. Primary and secondary outcome measures Only community-acquired E coli BSI cases as the primary outcome was included. Asthma status as an exposure was ascertained by predetermined criteria. An adjusted OR and 95% CI for the association between asthma and risk of community-acquired E coli BSI was calculated using conditional logistic regression. Results Of 259 eligible cases, 179 (69%) were women and mean age was 61±22 years. Of the 259 cases 37 (14%) and 16 (6%) of 259 controls had a prior history of asthma (adjusted OR 2.74; 95% CI 1.11 to 6.76; p=0.029). The population attributable risk of asthma for community-acquired E coli BSI was 9%. Although not statistically significant, there was a borderline association between having a history of food allergy and increased risk of community-acquired E coli BSI (6% vs 2%; adjusted OR 3.51; 95% CI 0.94 to 13.11; p=0.062). Conclusions Based on the findings of the current population-based, case–control investigation, a history of asthma may be associated with risk of community-acquired E coli BSI. The impact of asthma on risk of microbial infections may go beyond airways.

BackgroundMost patients with left ventricular assist devices (LVADs) have concomitant cardiovascular implantable electronic devices (CIEDs). However, clinical presentation and outcome of CIED infection in the setting of LVAD has not been previously described.MethodsWe retrospectively reviewed 247 patients who underwent LVAD implantation at Mayo Clinic campuses in Minnesota, Arizona, and Florida, from January 2005 to December 2011. Demographic and clinical data of patients who met criteria for CIED infection were extracted.ResultsOf 247 patients with LVADs, 215 (87%) had CIED at the time of LVAD implantation and six (2.8%) subsequently developed CIED infections. Three patients developed CIED lead‐related endocarditis and the other three had pocket infection. All three instances of CIED pocket infection were preceded by device generator exchange, whereas all three patients with CIED lead‐related endocarditis had prior LVAD‐related infections. Causative pathogens included Pseudomonas aeruginos (1), coagulase‐negative staphylococci (2), methicillin‐resistant Staphylococcus aureus (1), a gram‐positive bacillus (1), and culture negative (2). All patients underwent complete CIED removal along with antimicrobial therapy. The three patients with CIED lead‐related endocarditis and prior LVAD infections received chronic suppressive antibiotic therapy, and one patient had LVAD exchange. All but one remained alive at the last follow‐up with a median duration of 15 months (7–46 months) from the time of CIED infection.ConclusionPatients who are receiving LVAD therapy and develop CIED infection should be managed with complete CIED removal. Chronic suppressive antibiotic therapy is warranted in cases that have concomitant LVAD infection.

ABSTRACT Microbiological diagnosis is pivotal to the appropriate management and treatment of infective endocarditis. We evaluated PCR-electrospray ionization mass spectrometry (PCR/ESI-MS) for bacterial and candidal detection using 83 formalin-fixed paraffin-embedded heart valves from subjects with endocarditis who had positive valve and/or blood cultures, 63 of whom had positive valvular Gram stains. PCR/ESI-MS yielded 55% positivity with concordant microbiology at the genus/species or organism group level (e.g., viridans group streptococci), 11% positivity with discordant microbiology, and 34% with no detection. PCR/ESI-MS detected all antimicrobial resistance encoded by mecA or vanA / B and identified a case of Tropheryma whipplei endocarditis not previously recognized.