Priti R. Patel

Health care-associated invasive MRSA infections, 2005-2008.

CONTEXT Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of public health importance; MRSA prevention programs that may affect MRSA transmission and infection are increasingly common in health care settings. Whether there have been changes in MRSA infection incidence as these programs become established is unknown; however, recent data have shown that rates of MRSA bloodstream infections (BSIs) in intensive care units are decreasing. OBJECTIVE To describe changes in rates of invasive health care-associated MRSA infections from 2005 through 2008 among residents of 9 US metropolitan areas. DESIGN, SETTING, AND PARTICIPANTS Active, population-based surveillance for invasive MRSA in 9 metropolitan areas covering a population of approximately 15 million persons. All reports of laboratory-identified episodes of invasive (from a normally sterile body site) MRSA infections from 2005 through 2008 were evaluated and classified based on the setting of the positive culture and the presence or absence of health care exposures. Health care-associated infections (ie, hospital-onset and health care-associated community-onset), which made up 82% of the total infections, were included in this analysis. MAIN OUTCOME MEASURES Change in incidence of invasive health care-associated MRSA infections and health care-associated MRSA BSIs using population of the catchment area as the denominator. RESULTS From 2005 through 2008, there were 21,503 episodes of invasive MRSA infection; 17,508 were health care associated. Of these, 15,458 were MRSA BSIs. The incidence rate of hospital-onset invasive MRSA infections was 1.02 per 10,000 population in 2005 and decreased 9.4% per year (95% confidence interval [CI], 14.7% to 3.8%; P = .005), and the incidence of health care-associated community-onset infections was 2.20 per 10,000 population in 2005 and decreased 5.7% per year (95% CI, 9.7% to 1.6%; P = .01). The decrease was most prominent for the subset of infections with BSIs (hospital-onset: -11.2%; 95% CI -15.9% to -6.3%; health care-associated community-onset: -6.6%; 95% CI -9.5% to -3.7%). CONCLUSION Over the 4-year period from 2005 through 2008 in 9 diverse metropolitan areas, rates of invasive health care-associated MRSA infections decreased among patients with health care-associated infections that began in the community and also decreased among those with hospital-onset invasive disease.

Emergency Department Visits for Antibiotic- Associated Adverse Events

BACKGROUND Drug-related adverse events are an under-appreciated consequence of antibiotic use, and the national magnitude and scope of these events have not been studied. Our objective was to estimate and compare the numbers and rates of emergency department (ED) visits for drug-related adverse events associated with systemic antibiotics in the United States by drug class, individual drug, and event type. METHODS We analyzed drug-related adverse events from the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project (2004-2006) and outpatient prescriptions from national sample surveys of ambulatory care practices, the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey (2004-2005). RESULTS On the basis of 6614 cases, an estimated 142,505 visits (95% confidence interval [CI], 116,506-168,504 visits) annually were made to US EDs for drug-related adverse events attributable to systemic antibiotics. Antibiotics were implicated in 19.3% of all ED visits for drug-related adverse events. Most ED visits for antibiotic-associated adverse events were for allergic reactions (78.7% of visits; 95% CI, 75.3%-82.1% of visits). One-half of the estimated ED visits were attributable to penicillins (36.9% of visits; 95% CI, 34.7%-39.2% of visits) and cephalosporins (12.2%; 95% CI, 10.9%-13.5%). Among commonly prescribed antibiotics, sulfonamides and clindamycin were associated with the highest rate of ED visits (18.9 ED visits per 10,000 outpatient prescription visits [95% CI, 13.1-24.7 ED visits per 10,000 outpatient prescription visits] and 18.5 ED visits per 10,000 outpatient prescription visits [95% CI, 12.1-25.0 ED visits per 10,000 outpatient prescription visits], respectively). Compared with all other antibiotic classes, sulfonamides were associated with a significantly higher rate of moderate-to-severe allergic reactions (4.3% [95% CI, 2.9%-5.8%] vs. 1.9 % [95% CI, 1.5%-2.3%]), and sulfonamides and fluoroquinolones were associated with a significantly higher rate of neurologic or psychiatric disturbances (1.4% [95% CI, 1.0%-1.7%] vs. 0.5% [95% CI, 0.4%-0.6%]). CONCLUSIONS Antibiotic-associated adverse events lead to many ED visits, and allergic reactions are the most common events. Minimizing unnecessary antibiotic use by even a small percentage could significantly reduce the immediate and direct risks of drug-related adverse events in individual patients.

Outbreak of Adverse Reactions Associated with Contaminated Heparin

BACKGROUND In January 2008, the Centers for Disease Control and Prevention began a nationwide investigation of severe adverse reactions that were first detected in a single hemodialysis facility. Preliminary findings suggested that heparin was a possible cause of the reactions. METHODS Information on clinical manifestations and on exposure was collected for patients who had signs and symptoms that were consistent with an allergic-type reaction after November 1, 2007. Twenty-one dialysis facilities that reported reactions and 23 facilities that reported no reactions were included in a case-control study to identify facility-level risk factors. Unopened heparin vials from facilities that reported reactions were tested for contaminants. RESULTS A total of 152 adverse reactions associated with heparin were identified in 113 patients from 13 states from November 19, 2007, through January 31, 2008. The use of heparin manufactured by Baxter Healthcare was the factor most strongly associated with reactions (present in 100.0% of case facilities vs. 4.3% of control facilities, P<0.001). Vials of heparin manufactured by Baxter from facilities that reported reactions contained a contaminant identified as oversulfated chondroitin sulfate (OSCS). Adverse reactions to the OSCS-contaminated heparin were often characterized by hypotension, nausea, and shortness of breath occurring within 30 minutes after administration. Of 130 reactions for which information on the heparin lot was available, 128 (98.5%) occurred in a facility that had OSCS-contaminated heparin on the premises. Of 54 reactions for which the lot number of administered heparin was known, 52 (96.3%) occurred after the administration of OSCS-contaminated heparin. CONCLUSIONS Heparin contaminated with OSCS was epidemiologically linked to adverse reactions in this nationwide outbreak. The reported clinical features of many of the cases further support the conclusion that contamination of heparin with OSCS was the cause of the outbreak.

Gadolinium-Containing Magnetic Resonance Imaging Contrast and Nephrogenic Systemic Fibrosis: A Case-Control Study

BACKGROUND Nephrogenic systemic fibrosis (NSF) is a newly described disorder occurring in persons with renal failure. Gadolinium-based contrast used in magnetic resonance imaging (MRI) has been suggested as a cause. A cluster of patients with NSF was investigated to identify risk factors. Limited preliminary findings from this investigation were presented in the Morbidity and Mortality Weekly Report. STUDY DESIGN Matched case-control. SETTING & PARTICIPANTS Dialysis patients with and without a diagnosis of NSF treated at an academic medical center. PREDICTOR Exposure to gadolinium-based contrast. OUTCOMES & MEASUREMENTS Laboratory and clinical characteristics of NSF. RESULTS 19 of 28 cases identified at the hospital from December 2002 to August 2006 met inclusion criteria and were matched to 57 controls. In univariate analysis, receipt of gadolinium-containing MRI contrast in the preceding year (odds ratio [OR], 7.99; 95% confidence interval, 2.22 to 28.8) was associated with NSF; the measure of association increased as cumulative dose increased. Gadodiamide exposure (OR, 9.83; 95% confidence interval, 2.09 to 46.2) was associated more strongly with NSF than gadoversetamide (OR, 1.82; 95% confidence interval, 0.33 to 10.2). Although not statistically significant, cases were more likely than controls to have undergone primarily peritoneal dialysis in the preceding 6 months. There was no significant difference in receipt of high-dose recombinant erythropoietin between cases and controls. In multivariable analysis, gadolinium contrast exposure (OR, 8.97; 95% confidence interval, 1.28 to 63.0) remained significantly associated with NSF. LIMITATIONS Retrospective design, small sample size, inability to completely evaluate erythropoietin. CONCLUSIONS Receipt of gadolinium-containing MRI contrast is associated with NSF in a dose-dependent manner. The risk associated with gadolinium may differ by contrast agent and dialysis modality. Use of gadolinium-based contrast agents should be avoided when possible in patients with renal failure.

Preventing Catheter-Related Bloodstream Infections outside the Intensive Care Unit: Expanding Prevention to New Settings

With the growing recognition of the preventability of catheter-related bloodstream infections (CRBSIs), reducing the number of CRBSIs acquired in health care facilities has become an important patient safety goal. To date, most prevention efforts have been conducted in intensive care units (ICUs); however, many central venous catheters (CVCs) are found outside the ICU, and rates of catheter-associated bloodstream infections in these settings appear to be similar to rates of these infections in ICUs. CVCs are also used in patients who primarily receive their care as outpatients, including those requiring hemodialysis, undergoing treatment for malignancies, and receiving parenteral nutrition. In some of these patients, CVCs might be used for extended periods, prolonging the patients time at risk for CRBSIs and highlighting the potential need to look beyond insertion-based interventions to prevent infections. To meet the goal of reducing the number of all CRBSIs associated with health care, further attention on CRBSIs occurring outside the ICU is needed; however, this effort will require a better understanding of the epidemiology and prevention of these infections.

Hepatitis C Virus Infections from Unsafe Injection Practices at an Endoscopy Clinic in Las Vegas, Nevada, 2007–2008

BACKGROUND In January 2008, 3 persons with acute hepatitis C who all underwent endoscopy at a single facility in Nevada were identified. METHOD We reviewed clinical and laboratory data from initially detected cases of acute hepatitis C and reviewed infection control practices at the clinic where case patients underwent endoscopy. Persons who underwent procedures on days when the case patients underwent endoscopy were tested for hepatitis C virus (HCV) infection and other bloodborne pathogens. Quasispecies analysis determined the relatedness of HCV in persons infected. RESULTS In addition to the 3 initial cases, 5 additional cases of clinic-acquired HCV infection were identified from 2 procedure dates included in this initial field investigation. Quasispecies analysis revealed 2 distinct clusters of clinic-acquired HCV infections and a source patient related to each cluster, suggesting separate transmission events. Of 49 HCV-susceptible persons whose procedures followed that of the source patient on 25 July 2007, 1 (2%) was HCV infected. Among 38 HCV-susceptible persons whose procedures followed that of another source patient on 21 September 2007, 7 (18%) were HCV infected. Reuse of syringes on single patients in conjunction with use of single-use propofol vials for multiple patients was observed during normal clinic operations. CONCLUSIONS Patient-to-patient transmission of HCV likely resulted from contamination of single-use medication vials that were used for multiple patients during anesthesia administration. The resulting public health notification of approximately 50,000 persons was the largest of its kind in United States health care. This investigation highlighted breaches in aseptic technique, deficiencies in oversight of outpatient settings, and difficulties in detecting and investigating such outbreaks.

Epidemiology, Surveillance, and Prevention of Bloodstream Infections in Hemodialysis Patients

Infections cause significant morbidity and mortality in patients undergoing hemodialysis. Bloodstream infections (BSIs) are particularly problematic, accounting for a substantial number of hospitalizations in these patients. Hospitalizations for BSI and other vascular access infections appear to have increased dramatically in hemodialysis patients since 1993. These infections frequently are related to central venous catheter (CVC) use for dialysis access. Regional initiatives that have shown successful decreases in catheter-related BSIs in hospitalized patients have generated interest in replicating this success in outpatient hemodialysis populations. Several interventions have been effective in preventing BSIs in the hemodialysis setting. Avoiding the use of CVCs in favor of access types with lower associated BSI risk is among the most important. When CVCs are used, adherence to evidence-based catheter insertion and maintenance practices can positively influence BSI rates. In addition, facility-level surveillance to detect BSIs and stimulate examination of vascular access use and care practices is essential to a comprehensive approach to prevention. This article describes the current epidemiology of BSIs in hemodialysis patients and effective prevention strategies to decrease the incidence of these devastating infections.

Epidemiology, Surveillance, and Prevention of Hepatitis C Virus Infections in Hemodialysis Patients

Hepatitis C virus (HCV) infection is the most common chronic blood-borne infection in the United States; the prevalence in maintenance hemodialysis patients substantially exceeds that in the general population. In hemodialysis patients, HCV infection has been associated with increased occurrence of cirrhosis and hepatocellular carcinoma and increased mortality. Injection drug use and receipt of blood transfusions before 1992 has accounted for most prevalent HCV infections in the United States. However, HCV transmission among patients undergoing hemodialysis has been documented frequently. Outbreak investigations have implicated lapses in infection control practices as the cause of HCV infections. Preventing these infections is an emerging priority for renal care providers, public health agencies, and regulators. Adherence to recommended infection control practices is effective in preventing HCV transmission in hemodialysis facilities. In addition, adoption of routine screening to facilitate the detection of incident HCV infections and hemodialysis-related transmission is an essential component of patient safety and infection prevention efforts. This article describes the current epidemiology of HCV infection in US maintenance hemodialysis patients and prevention practices to decrease its incidence and transmission.

Bloodstream Infection Rates in Outpatient Hemodialysis Facilities Participating in a Collaborative Prevention Effort: A Quality Improvement Report

BACKGROUND Bloodstream infections (BSIs) cause substantial morbidity in hemodialysis patients. In 2009, the US Centers for Disease Control and Prevention (CDC) sponsored a collaborative project to prevent BSIs in outpatient hemodialysis facilities. We sought to assess the impact of a set of interventions on BSI and access-related BSI rates in participating facilities using data reported to the CDCs National Healthcare Safety Network (NHSN). STUDY DESIGN Quality improvement project. SETTING & PARTICIPANTS Patients in 17 outpatient hemodialysis facilities that volunteered to participate. QUALITY IMPROVEMENT PLAN Facilities reported monthly event and denominator data to NHSN, received guidance from the CDC, and implemented an evidence-based intervention package that included chlorhexidine use for catheter exit-site care, staff training and competency assessments focused on catheter care and aseptic technique, hand hygiene and vascular access care audits, and feedback of infection and adherence rates to staff. OUTCOMES Crude and modeled BSI and access-related BSI rates. MEASUREMENTS Up to 12 months of preintervention (January 2009 through December 2009) and 15 months of intervention period (January 2010 through March 2011) data from participating centers were analyzed. Segmented regression analysis was used to assess changes in BSI and access-related BSI rates during the preintervention and intervention periods. RESULTS Most (65%) participating facilities were hospital based. Pooled mean BSI and access-related BSI rates were 1.09 and 0.73 events per 100 patient-months during the preintervention period and 0.89 and 0.42 events per 100 patient-months during the intervention period, respectively. Modeled rates decreased 32% (P = 0.01) for BSIs and 54% (P < 0.001) for access-related BSIs at the start of the intervention period. LIMITATIONS Participating facilities were not representative of all outpatient hemodialysis centers nationally. There was no control arm to this quality improvement project. CONCLUSIONS Facilities participating in a collaborative successfully decreased their BSI and access-related BSI rates. The decreased rates appeared to be maintained in the intervention period. These findings suggest that improved implementation of recommended practices can reduce BSIs in hemodialysis centers.

US Outbreak Investigations Highlight the Need for Safe Injection Practices and Basic Infection Control

Current understanding of viral hepatitis transmission in United States health care settings indicates progress over the past several decades with respect to the risks from transfusions or blood products. Likewise, risks to health care providers from sharps injuries and other blood and body fluid exposures have been reduced as a consequence of widespread hepatitis B vaccination and the adoption of safer work practices. Increasing recognition of outbreaks involving patient-to-patient spread of hepatitis B and hepatitis C virus infections, however, has uncovered a disturbing trend. This article highlights the importance of basic infection control and the need for increased awareness of safe injection practices.