To evaluate the prevalence of hospital-onset bacteremia and fungemia (HOB), identify hospital-level predictors, and to evaluate the feasibility of an HOB metric.

We analyzed 9,202,650 admissions from 267 hospitals during 2015–2020. An HOB event was defined as the first positive blood-culture pathogen on day 3 of admission or later. We used the generalized linear model method via negative binomial regression to identify variables and risk markers for HOB. Standardized infection ratios (SIRs) were calculated based on 2 risk-adjusted models: a simple model using descriptive variables and a complex model using descriptive variables plus additional measures of blood-culture testing practices. Performance of each model was compared against the unadjusted rate of HOB.

Overall median rate of HOB per 100 admissions was 0.124 (interquartile range, 0.00–0.22). Facility-level predictors included bed size, sex, ICU admissions, community-onset (CO) blood culture testing intensity, and hospital-onset (HO) testing intensity, and prevalence (all P < .001). In the complex model, CO bacteremia prevalence, HO testing intensity, and HO testing prevalence were the predictors most associated with HOB. The complex model demonstrated better model performance; 55% of hospitals that ranked in the highest quartile based on their raw rate shifted to a lower quartile when the SIR from the complex model was applied.

Hospital descriptors, aggregate patient characteristics, community bacteremia and/or fungemia burden, and clinical blood-culture testing practices influence rates of HOB. Benchmarking an HOB metric is feasible and should endeavor to include both facility and clinical variables.

To assess preventability of hospital-onset bacteremia and fungemia (HOB), we developed and evaluated a structured rating guide accounting for intrinsic patient and extrinsic healthcare-related risks.

HOB preventability rating guide was compared against a reference standard expert panel.

A 10-member panel of clinical experts was assembled as the standard of preventability assessment, and 2 physician reviewers applied the rating guide for comparison.

The expert panel independently rated 82 hypothetical HOB scenarios using a 6-point Likert scale collapsed into 3 categories: preventable, uncertain, or not preventable. Consensus was defined as concurrence on the same category among ≥70% experts. Scenarios without consensus were deliberated and followed by a second round of rating.

Two reviewers independently applied the rating guide to adjudicate the same 82 scenarios in 2 rounds, with interim revisions. Interrater reliability was evaluated using the κ (kappa) statistic.

Expert panel consensus criteria were met for 52 scenarios (63%) after 2 rounds.

After 2 rounds, guide-based rating matched expert panel consensus in 40 of 52 (77%) and 39 of 52 (75%) cases for reviewers 1 and 2, respectively. Agreement rates between the 2 reviewers were 84% overall (κ, 0.76; 95% confidence interval [CI], 0.64–0.88]) and 87% (κ, 0.79; 95% CI, 0.65–0.94) for the 52 scenarios with expert consensus.

Preventability ratings of HOB scenarios by 2 reviewers using a rating guide matched expert consensus in most cases with moderately high interreviewer reliability. Although diversity of expert opinions and uncertainty of preventability merit further exploration, this is a step toward standardized assessment of HOB preventability.

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.

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.

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.

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.

We investigated the quality of life (QoL) of patients hospitalized with C. difficile infection (CDI).

Prospective survey study.

US tertiary-care referral center, acute-care setting.

Adults hospitalized with a diagnosis of CDI, defined as ≥3 episodes of unformed stool in 24 hours and a positive laboratory test for C. difficile.

We surveyed patients from July 2019 to March 2020 using the disease-specific Cdiff32 questionnaire and the generic PROMIS GH survey. We compared differences in Cdiff32 scores among demographic and clinical subgroups (including CDI severity, CDI recurrence, and various comorbidities) using 2-sample t tests. We compared PROMIS GH scores to the general population T score of 50 using 1-sample t tests. We performed multivariable linear regression to identify predictors of Cdiff32 scores.

In total, 100 inpatients (mean age, 58.6 ±17.1 years; 53.0% male; 87.0% white) diagnosed with CDI completed QoL surveys. PROMIS GH physical health summary scores (T = 37.3; P < .001) and mental health summary scores (T = 43.4; P < .001) were significantly lower than those of the general population. In bivariate analysis, recurrent CDI, severe CDI, and number of stools were associated with lower Cdiff32 scores. In multivariable linear regression, recurrent CDI, severe CDI, and each additional stool in the previous 24 hours were associated with significantly decreased Cdiff32 scores.

Patients hospitalized with CDI reported low scores on the Cdiff32 and PROMIS GH, demonstrating a negative impact of CDI on QoL in multiple health domains. The Cdiff32 questionnaire is particularly sensitive to QoL changes in patients with recurrent or severe disease.

To determine the impact of clinical decision support on guideline-concordant Clostridioides difficile infection (CDI) treatment.

Quasi-experimental study in >50 ambulatory clinics.

Primary, specialty, and urgent-care clinics.

Adult patients were eligible for inclusion if they were diagnosed with and treated for a first episode of symptomatic CDI at an ambulatory clinic between November 1, 2019, and November 30, 2020.

An outpatient best practice advisory (BPA) was implemented to notify prescribers that “vancomycin or fidaxomicin are preferred over metronidazole for C.difficile infection” when metronidazole was prescribed to a patient with CDI.

In total, 189 patients were included in the study: 92 before the BPA and 97 after the BPA. Their median age was 59 years; 31% were male; 75% were white; 30% had CDI-related comorbidities; 35% had healthcare exposure; 65% had antibiotic exposure; 44% had gastric acid suppression therapy within 90 days of CDI diagnosis. The BPA was accepted 23 of 26 times and was used to optimize the therapy of 16 patients in 6 months. Guideline-concordant therapy increased after implementation of the BPA (72% vs 91%; P = .001). Vancomycin prescribing increased and metronidazole prescribing decreased after the BPA. There was no difference in clinical response or unplanned encounter within 14 days after treatment initiation. Fewer patients after the BPA had CDI recurrence within 14–56 days of the initial episode (27% vs 7%; P < .001).

Clinical decision support increased prescribing of guideline-concordant CDI therapy in the outpatient setting. A targeted BPA is an effective stewardship intervention and may be especially useful in settings with limited antimicrobial stewardship resources.

Intensive care unit (ICU)–acquired infections with antibiotic-resistant bacteria have been associated with substantial health and economic costs. Moreover, southern Europe has historically reported high levels of antimicrobial resistance.

We estimated the attributable economic burden of ICU-acquired infections due to resistant bacteria based upon hospital excess length of stay (LOS) in a selected sample of southern European countries.

We studied a cohort of adult patients admitted to the ICU who developed an ICU-acquired infection related to an invasive procedure in a sample of Spanish, Italian, and Portuguese hospitals between 2008 and 2016, using data from The European Surveillance System (TESSy) released by the European Centers for Disease Control (ECDC). We analyzed the association between infections with selected antibiotic-resistant bacteria of public health importance and excess LOS using regression, matching, and time-to-event methods. We controlled for several confounding factors as well as time-dependent biases. We also computed the associated economic burden of excess resource utilization for each selected country.

In total, 13,441 patients with at least 1 ICU-acquired infection were included in the analysis: 4,106 patients (30.5%) were infected with antimicrobial-resistant bacteria, whereas 9,335 patients (69.5%) were infected with susceptible bacteria. The unadjusted association between resistance status and excess LOS was 7 days (95% CI, 6.13–7.87; P < .001). Fully adjusted models yielded significantly lower estimates: 2.76 days (95% CI, 1.98–3.54; P < .001) in the regression model, 2.60 days (95% CI, 1.66–3.55; P < .001) in the genetic matching model, and a hazard ratio of 1.15 (95% CI, 1.11–1.19; P < .001) in the adjusted Cox regression model. These estimates, alongside the prevalence of resistance, translated into direct hospitalization attributable costs per ICU-acquired infection of 5,224€ (95% CI, 3,691–6,757) for Spain, 4,461€ (95% CI, 1,948–6,974) for Portugal, and 4,320€ (95% CI, 1,662–6,977) for Italy.

ICU-acquired infections associated with antibiotic-resistant bacteria are substantially associated with a 15% increase in excess LOS and resource utilization in 3 southern European countries. However, failure to appropriately control for significant confounders inflates estimates by ∼2.5-fold.

To evaluate the attitudes of infectious diseases (ID) and critical care physicians toward antimicrobial stewardship in the intensive care unit (ICU).

Anonymous, cross-sectional, web-based surveys.

Surveys were completed in March–November 2017, and data were analyzed from December 2017 to December 2019.

ID and critical care fellows and attending physicians.

We included 10 demographic and 17 newly developed, 5-point, Likert-scaled items measuring attitudes toward ICU antimicrobial stewardship and transdisciplinary collaboration. Exploratory principal components analysis (PCA) was used for data reduction. Multivariable linear regression models explored demographic and attitudinal variables.

Of 372 respondents, 315 physicians had complete data (72% attendings, 28% fellows; 63% ID specialists, and 37% critical care specialists). Our PCA yielded a 3-item factor measuring which specialty should assume ICU antimicrobial stewardship (Cronbach standardized α = 0.71; higher scores indicate that ID physicians should be stewards), and a 4-item factor measuring value of ICU transdisciplinary collaborations (α = 0.62; higher scores indicate higher value). In regression models, ID physicians (vs critical care physicians), placed higher value on ICU collaborations and expressed discomfort with uncertain diagnoses. These factors were independently associated with stronger agreement that ID physicians should be ICU antimicrobial stewards. The following factors were independently associated with higher value of transdisciplinary collaboration: female sex, less discomfort with uncertain diagnoses, and stronger agreement with ID physicians as ICU antimicrobial stewards.

ID and critical care physicians endorsed their own group for antimicrobial stewardship, but both groups placed high value on ICU transdisciplinary collaborations. Physicians who were more uncomfortable with uncertain diagnoses reported preference for ID physicians to coordinate ICU antimicrobial stewardship; however, physicians who were less uncomfortable with uncertain diagnoses placed greater value on ICU collaborations.

To evaluate the change in vancomycin days of therapy (DOT) and vancomycin-associated acute kidney injury (AKI) after an antimicrobial stewardship program (ASP) intervention to decrease vancomycin use in stable patients after hematopoietic stem cell transplantation (HSCT).

Retrospective cohort study and quasi-experimental interrupted time series analysis. Change in unit-level vancomycin DOT per 1,000 inpatient days after the intervention was assessed using segmented Poisson regression. Subject-specific risk of vancomycin-associated AKI was evaluated using a random intercept logistic regression model with mediation analysis.

HSCT unit at a single quaternary-care pediatric hospital.

Inpatients aged 3 months and older who underwent HSCT between January 1, 2015, and March 31, 2019 (27 months before and after the intervention) who received any dose of vancomycin.

An ASP intervention in April 2017 creating a new practice guideline to decrease prolonged (>72 hours) vancomycin courses for stable HSCT patients with febrile neutropenia.

Overall, 439 vancomycin exposures (234 before the intervention and 205 after the intervention) occurring across 300 transplants and 259 subjects were included. The mean vancomycin DOT was 307 per 1,000 inpatient days (95% confidence interval [CI], 272–342) and decreased after the intervention to 207 per 1,000 inpatient days (95% CI, 173–240). In multivariable analyses, the odds of AKI in the postintervention period were 37% lower than in the preintervention period (adjusted OR, 0.63; 95% CI, 0.42–0.95; P = .0268); 56% of the excess risk was mediated by vancomycin DOT.

An ASP intervention successfully decreased vancomycin use after HSCT and resulted in a decrease in AKI. Reducing empiric antibiotic exposure for stable patients after HSCT can improve clinical outcomes.

Prophylactic antibiotics are commonly prescribed at discharge for mastectomy, despite guidelines recommending against this practice. We investigated factors associated with postdischarge prophylactic antibiotic use after mastectomy with and without immediate reconstruction and the impact on surgical-site infection (SSI).

We studied a cohort of women aged 18–64 years undergoing mastectomy between January 1, 2010, and June 30, 2015, using the MarketScan commercial database. Patients with nonsurgical perioperative infections were excluded. Postdischarge oral antibiotics were identified from outpatient drug claims. SSI was defined using International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnosis codes. Generalized linear models were used to determine factors associated with postdischarge prophylactic antibiotic use and SSI.

The cohort included 38,793 procedures; 24,818 (64%) with immediate reconstruction. Prophylactic antibiotics were prescribed after discharge after 2,688 mastectomy-only procedures (19.2%) and 17,807 mastectomies with immediate reconstruction (71.8%). The 90-day incidence of SSI was 3.5% after mastectomy only and 8.8% after mastectomy with immediate reconstruction. Antibiotics with anti–methicillin-sensitive Staphylococcus aureus (MSSA) activity were associated with decreased SSI risk after mastectomy only (adjusted relative risk [aRR], 0.74; 95% confidence interval [CI], 0.55–0.99) and mastectomy with immediate reconstruction (aRR, 0.80; 95% CI, 0.73–0.88), respectively. The numbers needed to treat to prevent 1 additional SSI were 107 and 48, respectively.

Postdischarge prophylactic antibiotics were common after mastectomy. Anti-MSSA antibiotics were associated with decreased risk of SSI for patients who had mastectomy only and those who had mastectomy with immediate reconstruction. The high numbers needed to treat suggest that potential benefits of postdischarge antibiotics should be weighed against potential harms associated with antibiotic overuse.

The Core Elements of Outpatient Antibiotic Stewardship provides a framework to improve antibiotic use, but cost-effectiveness data on implementation of outpatient antibiotic stewardship interventions are limited. We evaluated the cost-effectiveness of Core Element implementation in the outpatient setting.

An economic simulation model from the health-system perspective was developed for patients presenting to outpatient settings with uncomplicated acute respiratory tract infections (ARI). Effectiveness was measured as quality-adjusted life years (QALYs). Cost and utility parameters for antibiotic treatment, adverse drug events (ADEs), and healthcare utilization were obtained from the literature. Probabilities for antibiotic treatment and appropriateness, ADEs, hospitalization, and return ARI visits were estimated from 16,712 and 51,275 patient visits in intervention and control sites during the pre- and post-implementation periods, respectively. Data for materials and labor to perform the stewardship activities were used to estimate intervention cost. We performed a one-way and probabilistic sensitivity analysis (PSA) using 1,000,000 second-order Monte Carlo simulations on input parameters.

The proportion of ARI patient-visits with antibiotics prescribed in intervention sites was lower (62% vs 74%) and appropriate treatment higher (51% vs 41%) after implementation, compared to control sites. The estimated intervention cost over a 2-year period was $133,604 (2018 US dollars). The intervention had lower mean costs ($528 vs $565) and similar mean QALYs (0.869 vs 0.868) per patient compared to usual care. In the PSA, the intervention was dominant in 63% of iterations.

Implementation of the CDC Core Elements in the outpatient setting was a cost-effective strategy.

To assess current resources, interventions, and obstacles of pediatric outpatient antimicrobial stewardship programs (ASP).

Cross-sectional study.

Institutions from the Sharing Antimicrobial Reports for Pediatric Stewardship OutPatient collaborative (SHARPS-OP).

Antimicrobial stewardship leaders from the above institutions.

An investigator-developed survey was deployed online in September 2020 to antimicrobial stewardship leaders in SHARPS-OP institutions. The survey was divided into 4 sections: (1) basic information, (2) status of pediatric outpatient ASP in the institutions including financial support, (3) outpatient ASP interventions undertaken by the institutions, and (4) needs and SHARPS-OP collaborative goals.

Of 56 invited institutions, 45 participated, achieving an 80% response rate. Only 5 sites (11%) had allocated financial support for an outpatient ASP, compared to 42 (95.6%) for their inpatient ASP. The most widely used outpatient ASP interventions included antimicrobial guidance (57.8%), education (46.7%), and quality improvement projects (37.8%). Time was identified as the biggest barrier to expanding outpatient ASPs (91.1%), followed by financial support (53.3%), development of meaningful reports (51.1%), and administrative support (44.4%). Important goals of the collaborative included seeking learning opportunities and developing clear metrics for pediatric outpatient ASP benchmarking. Program needs included securing operational support (35.8%) and strengthening data analysis (31.6%).

Very few pediatric institutions with robust inpatient ASPs have devoted time and financial support to advance outpatient efforts. To promote appropriate antibiotic prescribing in the outpatient arena, time and resource funding by administrative leaders are necessary to develop a robust, sustainable stewardship infrastructure.

Effective infection prevention and control (IPC) measures are key for protecting patients from nosocomial infections and require knowledge of transmission mechanisms in different settings. We performed a detailed outbreak analysis of the transmission and outcome of coronavirus disease 2019 (COVID-19) in a geriatric ward by combining whole-genome sequencing (WGS) with epidemiological data.

Retrospective cohort study.

Tertiary-care hospital.

Patients and healthcare workers (HCWs) from the ward with a nasopharyngeal sample (NPS) positive for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) RNA during the outbreak period.

Patient data regarding clinical characteristics, exposure and outcome were collected retrospectively from medical records. Stored NPSs from 32 patients and 15 HCWs were selected for WGS and phylogenetic analysis.

The median patient age was 84 years and 17 (53%) of 32 were male. Also, 14 patients (44%) died within 30 days of sampling. Viral loads were significantly higher among the deceased. WGS was successful in 28 (88%) of 32 patient samples and 14 (93%) of 15 HCW samples. Moreover, 3 separate viral clades were identified: 1 clade and 2 subclades among both patient and HCW samples. Integrated epidemiological and genetic analyses revealed 6 probable transmission events between patients and supported hospital-acquired COVID-19 among 25 of 32 patients.

WGS provided an insight into the outbreak dynamics and true extent of nosocomial COVID-19. The extensive transmission between patients and HCWs indicated that current IPC measures were insufficient. We recommend increased use of WGS in outbreak investigations to identify otherwise unknown transmission links and to evaluate IPC measures.

To identify the impact of universal masking on COVID-19 incidence and putative SARS-CoV-2 transmissions events among children’s hospital healthcare workers (HCWs).

Quasi-experimental study.

Single academic free-standing children’s hospital.

We performed whole-genome sequencing of SARS-CoV-2- PCR-positive samples collected from HCWs 3 weeks before and 6 weeks after implementing a universal masking policy. Phylogenetic analyses were performed to identify clusters of clonally related SARS-CoV-2 indicative of putative transmission events. We measured COVID-19 incidence, SARS-CoV-2 test positivity rates, and frequency of putative transmission events before and after the masking policy was implemented.

HCW COVID-19 incidence and test positivity declined from 14.3 to 4.3 cases per week, and from 18.4% to 9.0%, respectively. Putative transmission events were only identified prior to universal masking.

A universal masking policy was associated with reductions in HCW COVID-19 infections and occupational acquisition of SARS-CoV-2.

We compared the rates of hospital-onset secondary bacterial infections in patients with coronavirus disease 2019 (COVID-19) with rates in patients with influenza and controls, and we investigated reports of increased incidence of Enterococcus infections in patients with COVID-19.

Retrospective cohort study.

An academic quaternary-care hospital in San Francisco, California.

Patients admitted between October 1, 2019, and October 1, 2020, with a positive SARS-CoV-2 PCR (N = 314) or influenza PCR (N = 82) within 2 weeks of admission were compared with inpatients without positive SARS-CoV-2 or influenza tests during the study period (N = 14,332).

National Healthcare Safety Network definitions were used to identify infection-related ventilator-associated complications (IVACs), probable ventilator-associated pneumonia (PVAP), bloodstream infections (BSIs), and catheter-associated urinary tract infections (CAUTIs). A multiple logistic regression model was used to control for likely confounders.

COVID-19 patients had significantly higher rates of IVAC and PVAP compared to controls, with adjusted odds ratios of 4.7 (95% confidence interval [CI], 1.7–13.9) and 10.4 (95 % CI, 2.1–52.1), respectively. COVID-19 patients had higher incidence of BSI due to Enterococcus but not BSI generally, and whole-genome sequencing of Enterococcus isolates demonstrated that nosocomial transmission did not explain the increased rate. Subanalyses of patients admitted to the intensive care unit and patients who required mechanical ventilation revealed similar findings.

COVID-19 is associated with an increased risk of IVAC, PVAP, and Enterococcus BSI compared with hospitalized controls, which is not fully explained by factors such as immunosuppressive treatments and duration of mechanical ventilation. The mechanism underlying increased rates of Enterococcus BSI in COVID-19 patients requires further investigation.

To evaluate coronavirus disease 2019 (COVID-19) vaccine hesitancy among healthcare personnel (HCP) with significant clinical exposure to COVID-19 at 2 large, academic hospitals in Philadelphia, Pennsylvania.

HCP were surveyed in November–December 2020 about their intention to receive the COVID-19 vaccine.

The survey measured the intent among HCP to receive a COVID-19 vaccine, timing of vaccination, and reasons for or against vaccination. Among patient-facing HCP, multivariate regression evaluated the associations between healthcare positions (medical doctor, nurse practitioner or physician assistant, and registered nurse) and vaccine hesitancy (intending to decline, delay, or were unsure about vaccination), adjusting for demographic characteristics, reasons why or why not to receive the vaccine, and prior receipt of routine vaccines.

Among 5,929 HCP (2,253 medical doctors [MDs] and doctors of osteopathy [DOs], 582 nurse practitioners [NPs], 158 physician assistants [PAs], and 2,936 nurses), a higher proportion of nurses (47.3%) were COVID-vaccine hesitant compared with 30.0% of PAs and NPs and 13.1% of MDs and DOs. The most common reasons for vaccine hesitancy included concerns about side effects, the newness of the vaccines, and lack of vaccine knowledge. Regardless of position, Black HCP were more hesitant than White HCP (odds ratio [OR], ∼5) and females were more hesitant than males (OR, ∼2).

Although most clinical HCP intended to receive a COVID-19 vaccine, intention varied by healthcare position. Consistent with other studies, hesitancy was also significantly associated with race or ethnicity across all positions. These results highlight the importance of understanding and effectively addressing reasons for hesitancy, especially among frontline HCP who are at increased risk of COVID exposure and play a critical role in recommending vaccines to patients.

To assess reasons for noncompliance with COVID-19 vaccination among healthcare workers (HCWs).

Cohort observational and surveillance study.

Sheba Medical Center, a 1,600-bed tertiary-care medical center in Israel.

The study included 10,888 HCWs including all employees, students, and volunteers.

The BNT162b2 mRNA COVID-19 vaccine was offered to all HCWs of the hospital. Noncompliance was assessed, and pre-rollout and post-rollout surveys were conducted. Data regarding uptake of the vaccine as well as demographic data and compliance with prior influenza vaccination were collected, and 2 surveys were distributed. The survey before the rollout pertained to the intention to receive the vaccine, and the survey after the rollout pertained to all unvaccinated HCWs regarding causes of hesitancy.

In the pre-rollout survey, 1,673 (47%) of 3,563 HCWs declared their intent to receive the vaccine. Overall, 8,108 (79%) HCWs received the COVID-19 vaccine within 40 days of rollout. In a multivariate logistic regression model, the factors that were significant predictors of vaccine uptake were male sex, age 40–59 years, occupation (paramedical professionals and doctors), high socioeconomic level, and compliance with flu vaccine. Among 425 unvaccinated HCWs who answered the second survey, the most common cause for hesitancy was the risk during pregnancy (31%).

Although vaccine uptake among HCWs was higher than expected, relatively low uptake was observed among young women and those from lower socioeconomic levels and educational backgrounds. Concerns regarding vaccine safety during pregnancy were common and more data about vaccine safety, especially during pregnancy, might improve compliance.

To describe the incidence of systemic overlap and typical coronavirus disease 2019 (COVID-19) symptoms in healthcare personnel (HCP) following COVID-19 vaccination and association of reported symptoms with diagnosis of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection in the context of public health recommendations regarding work exclusion.

This prospective cohort study was conducted between December 16, 2020, and March 14, 2021, with HCP who had received at least 1 dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine.

Large healthcare system in New England.

HCP were prompted to complete a symptom survey for 3 days after each vaccination. Reported symptoms generated automated guidance regarding symptom management, SARS-CoV-2 testing requirements, and work restrictions. Overlap symptoms (ie, fever, fatigue, myalgias, arthralgias, or headache) were categorized as either lower or higher severity. Typical COVID-19 symptoms included sore throat, cough, nasal congestion or rhinorrhea, shortness of breath, ageusia and anosmia.

Among 64,187 HCP, a postvaccination electronic survey had response rates of 83% after dose 1 and 77% after dose 2. Report of ≥3 lower-severity overlap symptoms, ≥1 higher-severity overlap symptoms, or at least 1 typical COVID-19 symptom after dose 1 was associated with increased likelihood of testing positive. HCP with prior COVID-19 infection were significantly more likely to report severe overlap symptoms after dose 1.

Reported overlap symptoms were common; however, only report of ≥3 low-severity overlap symptoms, at least 1 higher-severity overlap symptom, or any typical COVID-19 symptom were associated with infection. Work-related restrictions for overlap symptoms should be reconsidered.

To estimate population-based rates and to describe clinical characteristics of hospital-acquired (HA) influenza.

Cross-sectional study.

US Influenza Hospitalization Surveillance Network (FluSurv-NET) during 2011–2012 through 2018–2019 seasons.

Patients were identified through provider-initiated or facility-based testing. HA influenza was defined as a positive influenza test date and respiratory symptom onset >3 days after admission. Patients with positive test date >3 days after admission but missing respiratory symptom onset date were classified as possible HA influenza.

Among 94,158 influenza-associated hospitalizations, 353 (0.4%) had HA influenza. The overall adjusted rate of HA influenza was 0.4 per 100,000 persons. Among HA influenza cases, 50.7% were 65 years of age or older, and 52.0% of children and 95.7% of adults had underlying conditions; 44.9% overall had received influenza vaccine prior to hospitalization. Overall, 34.5% of HA cases received ICU care during hospitalization, 19.8% required mechanical ventilation, and 6.7% died. After including possible HA cases, prevalence among all influenza-associated hospitalizations increased to 1.3% and the adjusted rate increased to 1.5 per 100,000 persons.

Over 8 seasons, rates of HA influenza were low but were likely underestimated because testing was not systematic. A high proportion of patients with HA influenza were unvaccinated and had severe outcomes. Annual influenza vaccination and implementation of robust hospital infection control measures may help to prevent HA influenza and its impacts on patient outcomes and the healthcare system.