One in six nursing home residents and staff with positive SARS-CoV-2 tests 90 days after initial infection had specimen cycle thresholds (Ct) <30. Individuals with specimen Ct<30 were more likely to report symptoms but were not different from individuals with high Ct value specimens by other clinical and testing data.

CONTEXT: Between April 2020 and May 2021, the Centers for Disease Control and Prevention (CDC) awarded more than $40 billion to health departments nationwide for COVID-19 prevention and response activities. One of the identified priorities for this investment was improving infection prevention and control (IPC) in nursing homes. PROGRAM: CDC developed a virtual course to train new and less experienced public health staff in core healthcare IPC principles and in the application of CDC COVID-19 healthcare IPC guidance for nursing homes. IMPLEMENTATION: From October 2020 to August 2021, the CDC led training sessions for 12 cohorts of public health staff using pretraining reading materials, case-based scenarios, didactic presentations, peer-learning opportunities, and subject matter expert-led discussions. Multiple electronic assessments were distributed to learners over time to measure changes in self-reported knowledge and confidence and to collect feedback on the course. Participating public health programs were also assessed to measure overall course impact. EVALUATION: Among 182 enrolled learners, 94% completed the training. Most learners were infection preventionists (42%) or epidemiologists (38%), had less than 1 year of experience in their health department role (75%), and had less than 1 year of subject matter experience (54%). After training, learners reported increased knowledge and confidence in applying the CDC COVID-19 healthcare IPC guidance for nursing homes (≥81%) with the greatest increase in performing COVID-19 IPC consultations and assessments (87%). The majority of participating programs agreed that the course provided an overall benefit (88%) and reduced training burden (72%). DISCUSSION: The CDC's virtual course was effective in increasing public health capacity for COVID-19 healthcare IPC in nursing homes and provides a possible model to increase IPC capacity for other infectious diseases and other healthcare settings. Future virtual healthcare IPC courses could be enhanced by tailoring materials to health department needs, reinforcing training through applied learning experiences, and supporting mechanisms to retain trained staff.

In March 2018, the US Food and Drug Administration (FDA), US Centers for Disease Control and Prevention, California Department of Public Health, Los Angeles County Department of Public Health and Pennsylvania Department of Health initiated an investigation of an outbreak of Burkholderia cepacia complex (Bcc) infections. Sixty infections were identified in California, New Jersey, Pennsylvania, Maine, Nevada and Ohio. The infections were linked to a no-rinse cleansing foam product (NRCFP), produced by Manufacturer A, used for skin care of patients in healthcare settings. FDA inspected Manufacturer A's production facility (manufacturing site of over-the-counter drugs and cosmetics), reviewed production records and collected product and environmental samples for analysis. FDA's inspection found poor manufacturing practices. Analysis by pulsed-field gel electrophoresis confirmed a match between NRCFP samples and clinical isolates. Manufacturer A conducted extensive recalls, FDA issued a warning letter citing the manufacturer's inadequate manufacturing practices, and federal, state and local partners issued public communications to advise patients, pharmacies, other healthcare providers and healthcare facilities to stop using the recalled NRCFP. This investigation highlighted the importance of following appropriate manufacturing practices to minimize microbial contamination of cosmetic products, especially if intended for use in healthcare settings.

The purpose of this document is to highlight practical recommendations to assist acute care hospitals to prioritize and implement strategies to prevent ventilator-associated pneumonia (VAP), ventilator-associated events (VAE), and non-ventilator hospital-acquired pneumonia (NV-HAP) in adults, children, and neonates. This document updates the Strategies to Prevent Ventilator-Associated Pneumonia in Acute Care Hospitals published in 2014. This expert guidance document is sponsored by the Society for Healthcare Epidemiology (SHEA), and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America, the American Hospital Association, the Association for Professionals in Infection Control and Epidemiology, and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

BACKGROUND: In 2015, an international outbreak of Mycobacterium chimaera infections among patients undergoing cardiothoracic surgeries was associated with exposure to contaminated LivaNova 3T heater-cooler devices (HCDs). From June 2017 to October 2020, the Centers for Disease Control and Prevention was notified of 18 patients with M. chimaera infections who had undergone cardiothoracic surgeries at 2 hospitals in Kansas (14 patients) and California (4 patients); 17 had exposure to 3T HCDs. Whole-genome sequencing of the clinical and environmental isolates matched the global outbreak strain identified in 2015. METHODS: Investigations were conducted at each hospital to determine the cause of ongoing infections. Investigative methods included query of microbiologic records to identify additional cases, medical chart review, observations of operating room setup, HCD use and maintenance practices, and collection of HCD and environmental samples. RESULTS: Onsite observations identified deviations in the positioning and maintenance of the 3T HCDs from the US Food and Drug Administration (FDA) recommendations and the manufacturer's updated cleaning and disinfection protocols. Additionally, most 3T HCDs had not undergone the recommended vacuum and sealing upgrades by the manufacturer to decrease the dispersal of M. chimaera-containing aerosols into the operating room, despite hospital requests to the manufacturer. CONCLUSIONS: These findings highlight the need for continued awareness of the risk of M. chimaera infections associated with 3T HCDs, even if the devices are newly manufactured. Hospitals should maintain vigilance in adhering to FDA recommendations and the manufacturer's protocols and in identifying patients with potential M. chimaera infections with exposure to these devices.

In 2020 a group of U.S. healthcare leaders formed the National Organization to Prevent Hospital-Acquired Pneumonia (NOHAP) to issue a call to action to address non-ventilator-associated hospital-acquired pneumonia (NVHAP). NVHAP is one of the most common and morbid healthcare-associated infections, but it is not tracked, reported, or actively prevented by most hospitals. This national call to action includes (1) launching a national healthcare conversation about NVHAP prevention; (2) adding NVHAP prevention measures to education for patients, healthcare professionals, and students; (3) challenging healthcare systems and insurers to implement and support NVHAP prevention; and (4) encouraging researchers to develop new strategies for NVHAP surveillance and prevention. The purpose of this document is to outline research needs to support the NVHAP call to action. Primary needs include the development of better models to estimate the economic cost of NVHAP, to elucidate the pathophysiology of NVHAP and identify the most promising pathways for prevention, to develop objective and efficient surveillance methods to track NVHAP, to rigorously test the impact of prevention strategies proposed to prevent NVHAP, and to identify the policy levers that will best engage hospitals in NVHAP surveillance and prevention. A joint task force developed this document including stakeholders from the Veterans' Health Administration (VHA), the U.S. Centers for Disease Control and Prevention (CDC), The Joint Commission, the American Dental Association, the Patient Safety Movement Foundation, Oral Health Nursing Education and Practice (OHNEP), Teaching Oral-Systemic Health (TOSH), industry partners and academia.

Objectives. To assess SARS-CoV-2 transmission within a correctional facility and recommend mitigation strategies.Methods. From April 29 to May 15, 2020, we established the point prevalence of COVID-19 among incarcerated persons and staff within a correctional facility in Arkansas. Participants provided respiratory specimens for SARS-CoV-2 testing and completed questionnaires on symptoms and factors associated with transmission.Results. Of 1647 incarcerated persons and 128 staff tested, 30.5% of incarcerated persons (range by housing unit = 0.0%-58.2%) and 2.3% of staff tested positive for SARS-CoV-2. Among those who tested positive and responded to symptom questions (431 incarcerated persons, 3 staff), 81.2% and 33.3% were asymptomatic, respectively. Most incarcerated persons (58.0%) reported wearing cloth face coverings 8 hours or less per day, and 63.3% reported close contact with someone other than their bunkmate.Conclusions. If testing remained limited to symptomatic individuals, fewer cases would have been detected or detection would have been delayed, allowing transmission to continue. Rapid implementation of mass testing and strict enforcement of infection prevention and control measures may be needed to mitigate spread of SARS-CoV-2 in this setting. (Am J Public Health. Published online ahead of print March 18, 2021: e1-e10. https://doi.org/10.2105/AJPH.2020.306117).

The drivers and patterns of zoonotic virus emergence in the human population are poorly understood. The mosquito Aedes aegypti is a major arbovirus vector native to Africa that invaded most of the world's tropical belt over the past four centuries, after the evolution of a "domestic" form that specialized in biting humans and breeding in water storage containers. Here, we show that human specialization and subsequent spread of A. aegypti out of Africa were accompanied by an increase in its intrinsic ability to acquire and transmit the emerging human pathogen Zika virus. Thus, the recent evolution and global expansion of A. aegypti promoted arbovirus emergence not solely through increased vector-host contact but also as a result of enhanced vector susceptibility.

BACKGROUND: Burkholderia cepacia complex (Bcc) has caused healthcare-associated outbreaks, often in association with contaminated products. The identification of 4 Bcc bloodstream infections in patients residing at a single skilled nursing facility (SNF) within 1 week led to an epidemiological investigation to identify additional cases and the outbreak source. METHODS: A case was initially defined via a blood culture yielding Bcc in a SNF resident receiving intravenous therapy after 1 August 2016. Multistate notifications were issued to identify additional cases. Public health authorities performed site visits at facilities with cases to conduct chart reviews and identify possible sources. Pulsed-field gel electrophoresis (PFGE) was performed on isolates from cases and suspect products. Facilities involved in manufacturing suspect products were inspected to assess possible root causes. RESULTS: An outbreak of 162 Bcc bloodstream infections across 59 nursing facilities in 5 states occurred during September 2016-January 2017. Isolates from patients and pre-filled saline flush syringes were closely related by PFGE, identifying contaminated flushes as the outbreak source and prompting a nationwide recall. Inspections of facilities at the saline flush manufacturer identified deficiencies that might have led to the failure to sterilize a specific case containing a partial lot of the product. CONCLUSIONS: Communication and coordination among key stakeholders, including healthcare facilities, public health authorities, and state and federal agencies, led to the rapid identification of an outbreak source and likely prevented many additional infections. Effective processes to ensure the sterilization of injectable products are essential to prevent similar outbreaks in the future.

CONTEXT: The Centers for Disease Control and Prevention awarded $85 million to health care-associated infection and antibiotic resistance (HAI/AR) programs in March 2015 as part of Infection Control Assessment and Response (ICAR) activities in the Epidemiology and Laboratory Capacity cooperative agreement Domestic Ebola Supplement. PROGRAM: One goal of this funding was to assess and improve program capacity to respond to potential health care outbreaks (eg, HAI clusters). All 55 funded programs (in 49 state and 6 local health departments) participated. IMPLEMENTATION: The Centers for Disease Control and Prevention developed guidance and tools for HAI/AR programs to document relevant response capacities, assess policies, and measure progress. HAI/AR programs completed an interim assessment in 2016 and a final progress report in 2017. EVALUATION: During the project period, 78% (n = 43) of the programs developed new investigation tools, 85% (n = 47) trained staff on outbreak response, and 96% (n = 53) of the programs reported hiring staff to assist with outbreak response activities. Staffing and expertise to support HAI outbreak response increased substantially among awardees reporting staffing limitations on the interim assessment, including in domains such as on-site infection control assessment (n = 20; 83%), laboratory capacity (n = 20; 91%), and data management/analytics (n = 14; 67%). By 2017, reporting requirements in 100% of the programs addressed possible HAI/AR outbreaks; 93% (n = 51) also addressed sentinel events such as identification of novel AR threats. More than 90% (n = 50) of programs enhanced capacities for tracking response activities; in 2016, these systems captured 6665 events (range, 3-1379; median = 46). Health departments also reported wide-ranging efforts to engage regulatory, public health, and health care partners to improve HAI/AR outbreak reporting and investigation. DISCUSSION: Broad capacity for responding to HAI/AR outbreaks was enhanced using Ebola ICAR supplemental funding. As response activities expand, health department programs will be challenged to continue building expertise, reporting infrastructure, investigation resources, and effective relations with health care partners.

BACKGROUND: Despite large reductions from 2005-2012, hospital-onset methicillin-resistant Staphylococcus aureus bloodstream infections (HO MRSA BSIs) continue be a major source of morbidity and mortality. AIM: To describe risk factors for and underlying sources of HO MRSA BSIs. METHODS: We investigated HO MRSA BSIs at eight high-burden short-stay acute care hospitals. A case was defined as first isolation of MRSA from a blood specimen collected in 2016 on hospital day >/=4 from a patient without an MRSA-positive blood culture in the 14 days prior. We reviewed case-patient demographics and risk factors by medical record abstraction. The potential clinical source(s) of infection were determined by consensus by a clinician panel. FINDINGS: Of the 195 eligible cases, 186 were investigated. Case-patients were predominantly male (63%); median age was 57 years (range 0-92). In the two weeks prior to the BSI, 88% of case-patients had indwelling devices, 31% underwent a surgical procedure, and 18% underwent dialysis. The most common locations of attribution were intensive care units (ICUs) (46%) and step-down units (19%). The most commonly identified non-mutually exclusive clinical sources were CVCs (46%), non-surgical wounds (17%), surgical site infections (16%), non-ventilator healthcare-associated pneumonia (13%), and ventilator-associated pneumonia (11%). CONCLUSIONS: Device-and procedure-related infections were common sources of HO MRSA BSIs. Prevention strategies focused on improving adherence to existing prevention bundles for device-and procedure-associated infections and on source control for ICU patients, patients with certain indwelling devices, and patients undergoing certain high-risk surgeries are being pursued to decrease HO MRSA BSI burden at these facilities.

BACKGROUND: In July 2018, the Arkansas Department of Health (ADH) was notified by Hospital A of three patients with bloodstream infections (BSIs) with a rapidly growing, nontuberculous Mycobacterium (NTM) species; on September 5, 2018, six additional BSIs were reported. All were among oncology patients at Clinic A. We investigated to identify sources and to prevent further infections. METHODS: ADH performed an onsite investigation at Clinic A on September 7, 2018 and reviewed patient charts, obtained environmental samples, and cultured isolates. Isolates were sequenced (whole genome, 16S, rpoB) by the Centers for Disease Control and Prevention to determine species identity and relatedness. RESULTS: By December 31, 2018, 52 (34%) of 151 oncology patients with chemotherapy ports accessed at Clinic A during March 22-September 12, 2018 had NTM BSIs. Infected patients received significantly more saline flushes than uninfected patients (P <0.001) during the risk period. NTM grew from 6 unused saline flushes compounded by Clinic A. The identified species was novel and designated Mycobacterium FVL 201832. Isolates from patients and saline flushes were highly related by whole-genome sequencing, indicating a common source. Clinic A changed to prefilled saline flushes on September 12 as recommended. CONCLUSIONS: Mycobacterium FVL 201832 caused BSIs in oncology clinic patients. Laboratory data allowed investigators to rapidly link infections to contaminated saline flushes; cooperation between multiple institutions resulted in timely outbreak resolution. New state policies being considered because of this outbreak include adding extrapulmonary NTM to ADH's reportable disease list and providing more oversight to outpatient oncology clinics.

A surgical heater-cooler unit has been implicated as the source for Mycobacterium chimaera infections among cardiac surgery patients in several countries. We isolated M. chimaera from heater-cooler units and patient infections in the United States. Whole-genome sequencing corroborated a risk for these units acting as a reservoir for this pathogen.

Nontuberculous mycobacteria (NTM), ubiquitous in soil and water, usually infect immunocompromised persons. However, even healthy persons are susceptible to infection through percutaneous inoculation. Although 77% of NTM diseases manifest as primarily pulmonary illnesses (1), NTM also infect skin, bones, joints, the lymphatic system, and soft tissue. NTM infections can have incubation periods that exceed 5 years (2), often require prolonged treatment, and can lead to sepsis and death. Extrapulmonary NTM outbreaks have been reported in association with contaminated surgical gentian violet (3), nail salon pedicures (4), and tattoos received at tattoo parlors (5), although few surveillance data have been available for estimating the public health burden of NTM.* On January 1, 2014, the Oregon Health Authority designated extrapulmonary NTM disease a reportable condition. To characterize extrapulmonary NTM infection, estimate resources required for surveillance, and assess the usefulness of surveillance in outbreak detection and investigation, 2014-2016 extrapulmonary NTM surveillance data were reviewed, and interviews with stakeholders were conducted. During 2014-2016, 134 extrapulmonary NTM cases (11 per 1 million persons per year) were reported in Oregon. The age distribution was bimodal, with highest incidence among persons aged <10 years (20 per 1 million persons per year) and persons aged 60-69 years (18 per 1 million persons per year). The most frequently reported predisposing factors (occurring within 14-70 days of symptom onset) were soil exposure (41/98; 42%), immunocompromised condition (42/124; 34%), and surgery (32/120; 27%). Overall, 43 (33%) patients were hospitalized, 18 (15%) developed sepsis, and one (0.7%) died. Surveillance detected or helped to control two outbreaks at low cost. Jurisdictions interested in implementing extrapulmonary NTM surveillance can use the Council of State and Territorial Epidemiologists (CSTE) standardized case definition (6) for extrapulmonary NTM reporting or investigative guidelines maintained by the Oregon Health Authority (7).

BACKGROUND: Outbreaks of health care-associated infections (HAIs) caused by Burkholderia cepacia complex (Bcc) have been associated with medical devices and water-based products. Water is the most common raw ingredient in nonsterile liquid drugs, and the significance of organisms recovered from microbiologic testing during manufacturing is assessed using a risk-based approach. This incident demonstrates that lapses in manufacturing practices and quality control of nonsterile liquid drugs can have serious unintended consequences. METHODS: An epidemiologic and laboratory investigation of clusters of Bcc HAIs that occurred among critically ill, hospitalized, adult and pediatric patients was performed between January 1, 2016, and October 31, 2016. RESULTS: One hundred and eight case patients with Bcc infections at a variety of body sites were identified in 12 states. Two distinct strains of Bcc were obtained from patient clinical cultures. These strains were found to be indistinguishable or closely related to 2 strains of Bcc obtained from cultures of water used in the production of liquid docusate, and product that had been released to the market by manufacturer X. CONCLUSIONS: This investigation highlights the ability of bacteria present in nonsterile, liquid drugs to cause infections or colonization among susceptible patients. Prompt reporting and thorough investigation of potentially related infections may assist public health officials in identifying and removing contaminated products from the market when lapses in manufacturing occur.

An atypically large outbreak of Elizabethkingia anophelis infections occurred in Wisconsin. Here we show that it was caused by a single strain with thirteen characteristic genomic regions. Strikingly, the outbreak isolates show an accelerated evolutionary rate and an atypical mutational spectrum. Six phylogenetic sub-clusters with distinctive temporal and geographic dynamics are revealed, and their last common ancestor existed approximately one year before the first recognized human infection. Unlike other E. anophelis, the outbreak strain had a disrupted DNA repair mutY gene caused by insertion of an integrative and conjugative element. This genomic change probably contributed to the high evolutionary rate of the outbreak strain and may have increased its adaptability, as many mutations in protein-coding genes occurred during the outbreak. This unique discovery of an outbreak caused by a naturally occurring mutator bacterial pathogen provides a dramatic example of the potential impact of pathogen evolutionary dynamics on infectious disease epidemiology.

In October 2015, the Texas Department of State Health Services (DSHS) was notified that a hospital telemetry unit nurse had been reusing saline flush prefilled syringes in the intravenous (IV) lines of multiple patients, a risk factor for patient-to-patient transmission of bloodborne pathogens (1).* This practice was discovered through an investigation undertaken by the hospital after the nurse was observed to frequently leave a partially filled syringe near a computer work station. State, regional, and local health departments, with consultation from CDC, collaborated with the hospital to investigate infection prevention lapses, assess risk to patients, perform patient notification, and provide bloodborne pathogen testing.† | Upon interview, the nurse reported reusing syringes during the previous 6 months, erroneously believing that this was a safe, cost-saving measure if no fluids were withdrawn into the syringe before injection of the saline flush (1,2). The nurse had been working in this unit for 18 months, had not worked at another health care facility before or during employment at the hospital, and reported that this practice was not taught by the hospital. The hospital voluntarily notified patients and offered bloodborne pathogen screening to patients who might have been cared for by the nurse during employment from April 2014 to October 2015, when the practice was recognized and corrected (3). Because all telemetry unit patients were required to have IV access, all patients cared for on the unit during shifts worked by the nurse were included in the notification.

Nontuberculous mycobacteria (NTM) are opportunistic pathogens that have a strong affinity for healthcare. As illustrated in a report by Baker et al in this issue of Clinical Infectious Diseases, NTM are capable of exploiting myriad pathways to expose and infect patients [1]. NTM occur naturally in the environment and can be found in soil and water, including the potable water systems that supply many US healthcare facilities. There, in hospitals and clinics alike, they find opportunities to take advantage of immunocompromised hosts, breaches in host defenses, and novel technologies including medical devices. | Baker et al describe a bimodal or “2-phase” outbreak of Mycobacterium abscessus. Phase 1 primarily involved pulmonary infections among lung transplant patients. Phase 2 primarily involved patients exposed to heater-cooler devices (HCDs) during open-chest cardiac surgery. The phases were not completely distinct, which added to the challenge of investigating what unfolded as a large outbreak involving multiple modes of transmission. The investigation and comprehensive mitigation measures described in this report offer important lessons regarding transmission and prevention of healthcare-associated NTM.

In the spring of 2015, investigators in Switzerland reported a cluster of six patients with invasive infection with Mycobacterium chimaera, a species of nontuberculous mycobacterium ubiquitous in soil and water. The infected patients had undergone open-heart surgery that used contaminated heater-cooler devices during extracorporeal circulation (1). In July 2015, a Pennsylvania hospital also identified a cluster of invasive nontuberculous mycobacterial infections among open-heart surgery patients. Similar to the Swiss report, a field investigation by the Pennsylvania Department of Health, with assistance from CDC, used both epidemiologic and laboratory evidence to identify an association between invasive Mycobacterium avium complex, including M. chimaera, infections and exposure to contaminated Stockert 3T heater-cooler devices, all manufactured by LivaNova PLC (formerly Sorin Group Deutschland GmbH) (2). M. chimaera was described as a distinct species of M. avium complex in 2004 (3). The results of the field investigation prompted notification of approximately 1,300 potentially exposed patients.* Although heater-cooler devices are used to regulate patients' blood temperature during cardiopulmonary bypass through water circuits that are closed, these reports suggest that aerosolized M. chimaera from the devices resulted in the invasive infections (1,2). The Food and Drug Administration (FDA) and CDC have issued alerts regarding the need to follow updated manufacturer's instructions for use of the devices, evaluate the devices for contamination, remain vigilant for new infections, and continue to monitor reports from the United States and overseas (2).

Since the publication of "A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals" in 2008, prevention of healthcare-associated infections (HAIs) has become a national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. They are the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS).

Since the publication of "A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals" in 2008, prevention of healthcare-associated infections (HAIs) has become a national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. It is the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS).

BACKGROUND: Group A Streptococcus (GAS) is an important bacterial cause of life-threatening illness among the elderly. Public health officials investigated a protracted GAS outbreak in a skilled nursing facility in Georgia housing patients requiring 24-hour nursing or rehabilitation, to prevent additional cases. METHODS: We defined a case as illness in a skilled nursing facility resident with onset after January 2009 with GAS isolated from a usually sterile (invasive) or nonsterile site (noninvasive). Cases were "recurrent" if >1 month elapsed between episodes. We evaluated infection control practices, performed a GAS carriage study, emm-typed available GAS isolates, and conducted a case-control study of risk factors for infection. RESULTS: Three investigations, spanning 36 months, identified 19 residents with a total of 24 GAS infections: 15 invasive (3 recurrent) and 9 noninvasive (2 recurrent) episodes. All invasive cases required hospitalization; 4 patients died. Seven residents were GAS carriers. All invasive cases and resident carrier isolates were type emm 11.0. We observed hand hygiene lapses, inadequate infection documentation, and more frequent wound care staff turnover on wing A versus wing B. Risk factors associated with infection in multivariable analysis included living on wing A (odds ratio [OR], 3.4; 95% confidence interval [CI], .9-16.4) and having an indwelling line (OR, 5.6; 95% CI, 1.2-36.4). Cases ceased following facility-wide chemoprophylaxis in July 2012. CONCLUSIONS: Staff turnover, compromised skin integrity in residents, a suboptimal infection control program, and lack of awareness of infections likely contributed to continued GAS transmission. In widespread, prolonged GAS outbreaks in skilled nursing facilities, facility-wide chemoprophylaxis may be necessary to prevent sustained person-to-person transmission.