Vancomycin-resistant Staphylococcus aureus (VRSA) is a rare but serious public health concern. We describe a VRSA case in North Carolina, USA. The isolate from the case belonged to the USA600 lineage and clonal complex 45. No transmission was identified. Confirmed VRSA cases should include a thorough investigation and public health response.

SARS-CoV-2 infections among vaccinated nursing home residents increased after the Omicron variant emerged. Data on booster dose effectiveness in this population are limited. During July 2021-March 2022, nursing home outbreaks in 11 US jurisdictions involving >3 infections within 14 days among residents who had received at least the primary COVID-19 vaccine(s) were monitored. Among 2,188 nursing homes, 1,247 outbreaks were reported in the periods of Delta (n = 356, 29%), mixed Delta/Omicron (n = 354, 28%), and Omicron (n = 536, 43%) predominance. During the Omicron-predominant period, the risk for infection within 14 days of an outbreak start was lower among boosted residents than among residents who had received the primary vaccine series alone (risk ratio [RR] 0.25, 95% CI 0.19-0.33). Once infected, boosted residents were at lower risk for all-cause hospitalization (RR 0.48, 95% CI 0.40-0.49) and death (RR 0.45, 95% CI 0.34-0.59) than primary vaccine-only residents.

OBJECTIVES: On September 23, 2019, the North Carolina Division of Public Health identified a legionellosis increase in western North Carolina; most patients had recently attended the North Carolina Mountain State Fair. We conducted a source investigation. METHODS: Cases were fair attendees with laboratory-confirmed legionellosis and symptom onset within 2 to 14 days (Legionnaires' disease) or ≤3 days (Pontiac fever). We conducted a case-control study matching cases to non-ill fair attendees as control participants and an environmental investigation, and we performed laboratory testing (Legionella bacteria culture and polymerase chain reaction) of 27 environmental samples from fairgrounds and hot tubs and 14 specimens from case patients. We used multivariable unconditional logistic regression models to calculate adjusted odds ratios for potential Legionella exposure sources and risk factors. RESULTS: Of 136 people identified with fair-associated legionellosis, 98 (72%) were hospitalized and 4 (3%) died. Case patients were more likely than control participants to report walking by hot tub displays (adjusted odds ratio = 10.0; 95% CI, 4.2-24.1). Complete hot tub water treatment records were not kept, precluding evaluation of water maintenance conducted on display hot tubs. Legionella pneumophila sequence types (STs) were consistent among 10 typed clinical specimens (ST224) but distinct from the only positive environmental sample from the fair (ST7 and ST8). CONCLUSIONS: Hot tub displays were identified as the most likely outbreak source, making this the largest hot tub-associated Legionnaires' disease outbreak worldwide. Following the investigation, the North Carolina Division of Public Health and the Centers for Disease Control and Prevention released guidance on mitigating risk of Legionella exposure from hot tub displays. Results highlight the importance of properly maintaining equipment that aerosolizes water, including hot tubs intended for display purposes only.

Among nursing home outbreaks of coronavirus disease 2019 (COVID-19) with ≥3 breakthrough infections when the predominant severe acute respiratory coronavirus virus 2 (SARS-CoV-2) variant circulating was the SARS-CoV-2 δ (delta) variant, fully vaccinated residents were 28% less likely to be infected than were unvaccinated residents. Once infected, they had approximately half the risk for all-cause hospitalization and all-cause death compared with unvaccinated infected residents.

Antibiotic exposure can lead to unintended outcomes, including drug-drug interactions, adverse drug events, and healthcare-associated infections like Clostridioides difficile infection (CDI). Improving antibiotic use is critical to reduce an individual's CDI risk. Antibiotic stewardship initiatives can reduce inappropriate antibiotic prescribing (e.g., unnecessary antibiotic prescribing, inappropriate antibiotic selection), impacting both hospital (healthcare)-onset (HO)-CDI and community-associated (CA)-CDI. Previous computational and mathematical modeling studies have demonstrated a reduction in CDI incidence associated with antibiotic stewardship initiatives in hospital settings. Although the impact of antibiotic stewardship initiatives in long-term care facilities (LTCFs), including nursing homes, and in outpatient settings have been documented, the effects of specific interventions on CDI incidence are not well understood. We examined the relative effectiveness of antibiotic stewardship interventions on CDI incidence using a geospatially explicit agent-based model of a regional healthcare network in North Carolina. We simulated reductions in unnecessary antibiotic prescribing and inappropriate antibiotic selection with intervention scenarios at individual and network healthcare facilities, including short-term acute care hospitals (STACHs), nursing homes, and outpatient locations. Modeled antibiotic prescription rates were calculated using patient-level data on antibiotic length of therapy for the 10 modeled network STACHs. By simulating a 30% reduction in antibiotics prescribed across all inpatient and outpatient locations, we found the greatest reductions on network CDI incidence among tested scenarios, namely a 17% decrease in HO-CDI incidence and 7% decrease in CA-CDI. Among intervention scenarios of reducing inappropriate antibiotic selection, we found a greater impact on network CDI incidence when modeling this reduction in nursing homes alone compared to the same intervention in STACHs alone. These results support the potential importance of LTCF and outpatient antibiotic stewardship efforts on network CDI burden and add to the evidence that a coordinated approach to antibiotic stewardship across multiple facilities, including inpatient and outpatient settings, within a regional healthcare network could be an effective strategy to reduce network CDI burden.

Agent-based models (ABMs) describe and simulate complex systems comprising unique agents, or individuals, while accounting for geospatial and temporal variability among dynamic processes. ABMs are increasingly used to study healthcare-associated infections (ie, infections acquired during admission to a healthcare facility), including Clostridioides difficile infection, currently the most common healthcare-associated infection in the United States. The overall burden and transmission dynamics of healthcare-associated infections, including C difficile infection, may be influenced by community sources and movement of people among healthcare facilities and communities. These complex dynamics warrant geospatially explicit ABMs that extend beyond single healthcare facilities to include entire systems (eg, hospitals, nursing homes and extended care facilities, the community). The agents in ABMs can be built on a synthetic population, a model-generated representation of the actual population with associated spatial (eg, home residence), temporal (eg, change in location over time), and nonspatial (eg, sociodemographic features) attributes. We describe our methods to create a geospatially explicit ABM of a major regional healthcare network using a synthetic population as microdata input. We illustrate agent movement in the healthcare network and the community, informed by patient-level medical records, aggregate hospital discharge data, healthcare facility licensing data, and published literature. We apply the ABM output to visualize agent movement in the healthcare network and the community served by the network. We provide an application example of the ABM to C difficile infection using a natural history submodel. We discuss the ABM's potential to detect network areas where disease risk is high; simulate and evaluate interventions to protect public health; adapt to other geographic locations and healthcare-associated infections, including emerging pathogens; and meaningfully translate results to public health practitioners, healthcare providers, and policymakers.

We describe an outbreak of imipenemase metallo-beta-lactamase-producing organisms in a long-term-care facility (LTCF) amid a larger community outbreak of extended-spectrum beta-lactamase-producing organisms. Transmission was propagated by inadequate infection prevention practices. We provided infection prevention recommendations and education, facilitated colonization screening, and increased interfacility communication. This outbreak demonstrates the unmet need for infection prevention education in long-term-care facilities and the importance of prompt public health response to ensure appropriate identification, containment, and prevention of emerging resistance.

On July 2, 2018, the North Carolina Division of Public Health was notified that approximately three dozen members of an ethnic Nepali refugee community had been transported to area hospitals for severe gastrointestinal illness after attending a potluck party on June 30. The North Carolina Division of Public Health partnered with the local health department and CDC to investigate the outbreak, identify the cause, and prevent further transmission. The investigation included molecular-guided laboratory testing of clinical specimens by CDC, which determined that this was the first confirmed U.S. outbreak of enteroinvasive Escherichia coli (EIEC) in 47 years.

In this report, we summarize the results of surveillance, on-site assessments, and molecular analysis conducted as part of a group A Streptococcus outbreak investigation in 2 skilled nursing facilities. We identified cases in 24 individuals (6 deaths) and infection prevention deficiencies. Isolates from 14 individuals represented the globally emergent clade 3 emm89 strain. Molecular analysis suggests that the 2 outbreaks were related. Wound care practices and 1 symptomatic shared employee may have facilitated transmission. Strict adherence to infection prevention practices is needed to prevent group A Streptococcus transmission.

OBJECTIVE: In 2016, North Carolina blood lead level (BLL) surveillance activities identified elevated BLLs among 3 children exposed to take-home lead by household members employed at a lead oxide manufacturing facility. We characterized BLLs among employees and associated children and identified risk factors for occupational and take-home lead exposure. METHODS: We reviewed BLL surveillance data for 2012-2016 to identify facility employees and associated children. We considered a BLL >/=5 mug/dL elevated for adults and children and compared adult BLLs with regulatory limits and recommended health-based thresholds. We also conducted an environmental investigation and interviewed current employees about exposure controls and cleanup procedures. RESULTS: During 2012-2016, 5 children associated with facility employees had a confirmed BLL >/=5 mug/dL. Among 77 people employed during 2012-2016, median BLLs increased from 22 mug/dL (range, 4-45 mug/dL) in 2012 to 37 mug/dL (range, 16-54 mug/dL) in 2016. All employee BLLs were <60 mug/dL, the national regulatory threshold for immediate medical removal from lead exposure; however, 55 (71%) had a BLL >/=20 mug/dL, a recommended health-based threshold for removal from lead exposure. Because of inadequate controls in the facility, areas considered clean were visibly contaminated with lead dust. Employees reported bringing personal items to work and then into their cars and homes, resulting in take-home lead exposure. CONCLUSIONS: Integration of child and adult BLL surveillance activities identified an occupational source of lead exposure among workers and associated children. Our findings support recent recommendations that implementation of updated lead standards will support better control of lead in the workplace and prevent lead from being carried home.

In November 2016, hospital A notified the North Carolina Division of Public Health (NCDPH) that annual tuberculosis screening of neonatal intensive care unit (NICU) staff members identified six health care staff members with newly positive tuberculin skin tests (TSTs). All six staff members had cared for an infant in whom a diagnosis of congenital tuberculosis was made after death. NCDPH worked with county health departments and hospital A to conduct a contact investigation.

During November 2015, the North Carolina Division of Public Health was notified by the Pitt County Health Department (PCHD) that approximately 40 persons who attended a catered company Thanksgiving lunch the previous day were ill with diarrhea and abdominal pain. The North Carolina Division of Public Health and PCHD worked together to investigate the source of illness and implement control measures. Within hours of notification, investigators developed and distributed an online survey to all lunch attendees regarding symptoms and foods consumed and initiated a cohort study. A case of illness was defined as abdominal pain or diarrhea in a lunch attendee with illness onset <24 hours after the event. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated for all menu items. Among 80 attendees, 58 (73%) completed the survey, including 44 respondents (76%) who reported illnesses meeting the case definition; among these, 41 (93%) reported diarrhea, and 40 (91%) reported abdominal pain. There were no hospitalizations. Symptom onset began a median of 13 hours after lunch (range = 1-22 hours). Risk for illness among persons who ate turkey or stuffing (38 of 44; 86%), which were plated and served together, was significantly higher than risk for illness among those who did not eat turkey or stuffing (six of 14; 43%) (RR = 2.02; 95% CI = 1.09-3.73).

Zika virus is a cause of microcephaly and brain abnormalities (1), and it is the first known mosquito-borne infection to cause congenital anomalies in humans. The establishment of a comprehensive surveillance system to monitor pregnant women with Zika virus infection will provide data to further elucidate the full range of potential outcomes for fetuses and infants of mothers with asymptomatic and symptomatic Zika virus infection during pregnancy. In February 2016, Zika virus disease and congenital Zika virus infections became nationally notifiable conditions in the United States (2). Cases in pregnant women with laboratory evidence of Zika virus infection who have either 1) symptomatic infection or 2) asymptomatic infection with diagnosed complications of pregnancy can be reported as cases of Zika virus disease to ArboNET* (2), CDC's national arboviral diseases surveillance system. Under existing interim guidelines from the Council for State and Territorial Epidemiologists (CSTE), asymptomatic Zika virus infections in pregnant women who do not have known pregnancy complications are not reportable. ArboNET does not currently include pregnancy surveillance information (e.g., gestational age or pregnancy exposures) or pregnancy outcomes. To understand the full impact of infection on the fetus and neonate, other systems are needed for reporting and active monitoring of pregnant women with laboratory evidence of possible Zika virus infection during pregnancy. Thus, in collaboration with state, local, tribal, and territorial health departments, CDC established two surveillance systems to monitor pregnancies and congenital outcomes among women with laboratory evidence of Zika virus infection(dagger) in the United States and territories: 1) the U.S. Zika Pregnancy Registry (USZPR),( section sign) which monitors pregnant women residing in U.S. states and all U.S. territories except Puerto Rico, and 2) the Zika Active Pregnancy Surveillance System (ZAPSS), which monitors pregnant women residing in Puerto Rico. As of May 12, 2016, the surveillance systems were monitoring 157 and 122 pregnant women with laboratory evidence of possible Zika virus infection from participating U.S. states and territories, respectively. Tracking and monitoring clinical presentation of Zika virus infection, all prenatal testing, and adverse consequences of Zika virus infection during pregnancy are critical to better characterize the risk for congenital infection, the performance of prenatal diagnostic testing, and the spectrum of adverse congenital outcomes. These data will improve clinical guidance, inform counseling messages for pregnant women, and facilitate planning for clinical and public health services for affected families.

In March 2013, public health authorities were notified of a new hepatitis B virus (HBV) infection in a patient receiving hemodialysis. We investigated to identify the source and prevent additional infections. We reviewed medical records, interviewed the index patient regarding hepatitis B risk factors, performed HBV molecular analysis, and observed infection control practices at the outpatient hemodialysis facility where she received care. The index patient's only identified hepatitis B risk factor was hemodialysis treatment. The facility had no other patients with known active HBV infection. One patient had evidence of a resolved HBV infection. Investigation of this individual, who was identified as the source patient, indicated that HBV reverse seroconversion and reactivation had occurred in the setting of HIV (human immunodeficiency virus) infection and a failed kidney transplant. HBV whole genome sequences analysis from the index and source patients indicated 99.9% genetic homology. Facility observations revealed multiple infection control breaches. Inadequate dilution of the source patient's sample during HBV testing might have led to a false-negative result, delaying initiation of hemodialysis in isolation. In conclusion, HBV transmission occurred after an HIV-positive hemodialysis patient with transplant-related immunosuppression experienced HBV reverse seroconversion and reactivation. Providers should be aware of this possibility, especially among severely immunosuppressed patients, and maintain stringent infection control.

BACKGROUND: Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning. METHODS: A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by "Company A," purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available. RESULTS: The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 microg/d (recommended dietary allowance is 55 microg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 microg/L (reference range, < or =125 microg/L). The mean initial urine selenium concentration of 7 patients was 166 microg/24 h (reference range, < or =55 microg/24 h). CONCLUSIONS: Toxic concentrations of selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented.

BACKGROUND: In September 2007, the Tennessee Department of Health was notified of a cluster of late-onset group B streptococcal (GBS) infections in a neonatal intensive care unit (NICU). Outbreaks of late-onset GBS are rare. METHODS: A case was defined as culture-confirmed invasive GBS infection in a neonate aged ≥7 days, identified in hospital A during August 23 to September 6, 2007. We reviewed medical records; examined NICU microbiology reports; and performed serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) on invasive isolates. Maternal GBS screening, prophylaxis, and infection control policies were reviewed and staff practices observed. RESULTS: Five cases of late-onset GBS were identified. None of the mothers of the infants received optimal GBS prophylaxis. Patient isolates were of 2 serotypes, 3 PFGE patterns, and 2 MLST patterns. Three isolates were indistinguishable on subtyping. These 3 cases were clustered in time. No common health care providers were identified. Infection control deviations in the NICU were observed. CONCLUSION: We identified a multiclonal cluster of 5 late-onset GBS cases. Multiple factors likely contributed to the outbreak, including nosocomial transmission of GBS. Further efforts to prevent late-onset GBS disease are necessary.