To determine the relationship between severe acute respiratory syndrome coronavirus 2 infection, hospital-acquired infections (HAIs), and mortality.

Retrospective cohort.

Three St. Louis, MO hospitals.

Adults admitted ≥48 hours from January 1, 2017 to August 31, 2020.

Hospital-acquired infections were defined as those occurring ≥48 hours after admission and were based on positive urine, respiratory, and blood cultures. Poisson interrupted time series compared mortality trajectory before (beginning January 1, 2017) and during the first 6 months of the pandemic. Multivariable logistic regression models were fitted to identify risk factors for mortality in patients with an HAI before and during the pandemic. A time-to-event analysis considered time to death and discharge by fitting Cox proportional hazards models.

Among 6,447 admissions with subsequent HAIs, patients were predominantly White (67.9%), with more females (50.9% vs 46.1%, P = .02), having slightly lower body mass index (28 vs 29, P = .001), and more having private insurance (50.6% vs 45.7%, P = .01) in the pre-pandemic period. In the pre-pandemic era, there were 1,000 (17.6%) patient deaths, whereas there were 160 deaths (21.3%, P = .01) during the pandemic. A total of 53 (42.1%) coronavirus disease 2019 (COVID-19) patients died having an HAI. Age and comorbidities increased the risk of death in patients with COVID-19 and an HAI. During the pandemic, Black patients with an HAI and COVID-19 were more likely to die than White patients with an HAI and COVID-19.

In three Midwestern hospitals, patients with concurrent HAIs and COVID-19 were more likely to die if they were Black, elderly, and had certain chronic comorbidities.

To determine the prevalence of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) IgG nucleocapsid (N) antibodies among healthcare personnel (HCP) with no prior history of COVID-19 and to identify factors associated with seropositivity.

Prospective cohort study.

An academic, tertiary-care hospital in St. Louis, Missouri.

The study included 400 HCP aged ≥18 years who potentially worked with coronavirus disease 2019 (COVID-19) patients and had no known history of COVID-19; 309 of these HCP also completed a follow-up visit 70–160 days after enrollment. Enrollment visits took place between September and December 2020. Follow-up visits took place between December 2020 and April 2021.

At each study visit, participants underwent SARS-CoV-2 IgG N-antibody testing using the Abbott SARS-CoV-2 IgG assay and completed a survey providing information about demographics, job characteristics, comorbidities, symptoms, and potential SARS-CoV-2 exposures.

Participants were predominately women (64%) and white (79%), with median age of 34.5 years (interquartile range [IQR], 30–45). Among the 400 HCP, 18 (4.5%) were seropositive for IgG N-antibodies at enrollment. Also, 34 (11.0%) of 309 were seropositive at follow-up. HCP who reported having a household contact with COVID-19 had greater likelihood of seropositivity at both enrollment and at follow-up.

In this cohort of HCP during the first wave of the COVID-19 pandemic, ∼1 in 20 had serological evidence of prior, undocumented SARS-CoV-2 infection at enrollment. Having a household contact with COVID-19 was associated with seropositivity.

We compared the individual-level risk of hospital-onset infections with multidrug-resistant organisms (MDROs) in hospitalized patients prior to and during the coronavirus disease 2019 (COVID-19) pandemic. We also quantified the effects of COVID-19 diagnoses and intrahospital COVID-19 burden on subsequent MDRO infection risk.

Multicenter, retrospective, cohort study.

Patient admission and clinical data were collected from 4 hospitals in the St. Louis area.

Data were collected for patients admitted between January 2017 and August 2020, discharged no later than September 2020, and hospitalized ≥48 hours.

Mixed-effects logistic regression models were fit to the data to estimate patients’ individual-level risk of infection with MDRO pathogens of interest during hospitalization. Adjusted odds ratios were derived from regression models to quantify the effects of the COVID-19 period, COVID-19 diagnosis, and hospital-level COVID-19 burden on individual-level hospital-onset MDRO infection probabilities.

We calculated adjusted odds ratios for COVID-19–era hospital-onset Acinetobacter spp., P. aeruginosa and Enterobacteriaceae spp infections. Probabilities increased 2.64 (95% confidence interval [CI], 1.22–5.73) times, 1.44 (95% CI, 1.03–2.02) times, and 1.25 (95% CI, 1.00–1.58) times relative to the prepandemic period, respectively. COVID-19 patients were 4.18 (95% CI, 1.98–8.81) times more likely to acquire hospital-onset MDRO S. aureus infections.

Our results support the growing body of evidence indicating that the COVID-19 pandemic has increased hospital-onset MDRO infections.

To use interrupted time-series analyses to investigate the impact of the coronavirus disease 2019 (COVID-19) pandemic on healthcare-associated infections (HAIs). We hypothesized that the pandemic would be associated with higher rates of HAIs after adjustment for confounders.

We conducted a cross-sectional study of HAIs in 3 hospitals in Missouri from January 1, 2017, through August 31, 2020, using interrupted time-series analysis with 2 counterfactual scenarios.

The study was conducted at 1 large quaternary-care referral hospital and 2 community hospitals.

All adults ≥18 years of age hospitalized at a study hospital for ≥48 hours were included in the study.

In total, 254,792 admissions for ≥48 hours occurred during the study period. The average age of these patients was 57.6 (±19.0) years, and 141,107 (55.6%) were female. At hospital 1, 78 CLABSIs, 33 CAUTIs, and 88 VAEs were documented during the pandemic period. Hospital 2 had 13 CLABSIs, 6 CAUTIs, and 17 VAEs. Hospital 3 recorded 11 CLABSIs, 8 CAUTIs, and 11 VAEs. Point estimates for hypothetical excess HAIs suggested an increase in all infection types across facilities, except for CLABSIs and CAUTIs at hospital 1 under the “no pandemic” scenario.

The COVID-19 era was associated with increases in CLABSIs, CAUTIs, and VAEs at 3 hospitals in Missouri, with variations in significance by hospital and infection type. Continued vigilance in maintaining optimal infection prevention practices to minimize HAIs is warranted.

Few data are available to quantify the Clostridioides difficile infection (CDI) burden in US adults depending on Medicaid insurance status; thus, we sought to contribute to this body of information.

Retrospective cohort study to identify adults with codes for CDI from 2011 to 2017 in MarketScan commercial and Medicaid databases (for those aged 25–64 years) and the CMS Medicare database (for those aged ≥65 years). CDI was categorized as healthcare-facility–associated (HCA-CDI) and community-associated CDI (CA-CDI). CDI incidence rates were compared by year, insurer, and age group.

The overall CDI incidence in the elderly was 3.1-fold higher in persons insured by Medicare plus Medicaid than in those insured by Medicare only (1,935 vs 618 per 100,000 person years (PY)), and the CDI incidence was 2.7-fold higher in younger adults with Medicaid compared to commercial insurance (195 vs 73 per 100,000 PY). From 2011 to 2017, HCA-CDI rates declined in the younger Medicaid population (124.0 to 95.2 per 100,000 PY; P < .001) but were stable in those commercially insured (25.9 to 24.8 per 100,000 PY; P = .33). In the elderly HCA-CDI rates declined from 2011 to 2017 in the Medicare-only population (403 to 318 per 100,000 PY; P < .001) and the Medicare plus Medicaid population (1,770 to 1,163 per 100,000 PY; P < .002). Persons with chronic medical conditions and those with immunocompromising conditions insured by Medicaid had 2.8- and 2.7-fold higher CDI incidence compared to the commercially insured population, respectively. The incidence of CDI was lowest in Medicaid and commercially insured younger adults without chronic medical or immunosuppressive conditions (67.5 and 45.6 per 100,000 PY, respectively).

Although HCA-CDI incidence decreased from 2011 to 2017 in elderly and younger adults insured by Medicaid, the burden of CDI remains much higher in low-income adults insured by Medicaid.

To identify characteristics associated with positive severe acute respiratory coronavirus virus 2 (SARS-CoV-2) polymerase chain reaction (PCR) tests in healthcare personnel.

Retrospective cohort study.

A multihospital healthcare system.

Employees who reported SARS-CoV-2 exposures and/or symptoms of coronavirus disease 2019 (COVID-19) between March 30, 2020, and September 20, 2020, and were subsequently referred for SARS-CoV-2 PCR testing.

Data from exposure and/or symptom reports were linked to the corresponding SARS-CoV-2 PCR test result. Employee demographic characteristics, occupational characteristics, SARS-CoV-2 exposure history, and symptoms were evaluated as potential risk factors for having a positive SARS-CoV-2 PCR test.

Among 6,289 employees who received SARS-CoV-2 PCR testing, 873 (14%) had a positive test. Independent risk factors for a positive PCR included: working in a patient care area (relative risk [RR], 1.82; 95% confidence interval [CI], 1.37–2.40), having a known SARS-CoV-2 exposure (RR, 1.20; 95% CI, 1.04–1.37), reporting a community versus an occupational exposure (RR, 1.87; 95% CI, 1.49–2.34), and having an infected household contact (RR, 2.47; 95% CI, 2.11–2.89). Nearly all HCP (99%) reported symptoms. Symptoms associated with a positive PCR in a multivariable analysis included loss of sense of smell (RR, 2.60; 95% CI, 2.09–3.24) or taste (RR, 1.75; 95% CI, 1.40–2.20), cough (RR, 1.95; 95% CI, 1.40–2.20), fever, and muscle aches.

In this cohort of >6,000 healthcare system and academic medical center employees early in the pandemic, community exposures, and particularly household exposures, were associated with greater risk of SARS-CoV-2 infection than occupational exposures. This work highlights the importance of COVID-19 prevention in the community and in healthcare settings to prevent COVID-19.

Patients on dialysis are at high risk for severe COVID-19 and associated morbidity and mortality. We examined the humoral response to SARS-CoV-2 mRNA vaccine BNT162b2 in a maintenance dialysis population.

Single-center cohort study.

Adult maintenance dialysis patients at 3 outpatient dialysis units of a large academic center.

Participants were vaccinated with 2 doses of BNT162b2, 3 weeks apart. We assessed anti–SARS-CoV-2 spike antibodies (anti-S) ∼4–7 weeks after the second dose and evaluated risk factors associated with insufficient response. Definitions of antibody response are as follows: nonresponse (anti-S level, <50 AU/mL), low response (anti-S level, 50–839 AU/mL), and sufficient response (anti-S level, ≥840 AU/mL).

Among the 173 participants who received 2 vaccine doses, the median age was 60 years (range, 28–88), 53.2% were men, 85% were of Black race, 86% were on in-center hemodialysis and 14% were on peritoneal dialysis. Also, 7 participants (4%) had no response, 27 (15.6%) had a low response, and 139 (80.3%) had a sufficient antibody response. In multivariable analysis, factors significantly associated with insufficient antibody response included end-stage renal disease comorbidity index score ≥5 and absence of prior hepatitis B vaccination response.

Although most of our study participants seroconverted after 2 doses of BNT162b2, 20% of our cohort did not achieve sufficient humoral response. Our findings demonstrate the urgent need for a more effective vaccine strategy in this high-risk patient population and highlight the importance of ongoing preventative measures until protective immunity is achieved.

To determine the 180-day cumulative incidence of culture-confirmed Staphylococcus aureus infections after elective pediatric surgeries.

Retrospective cohort study utilizing the Premier Healthcare database (PHD).

Inpatient and hospital-based outpatient elective surgical discharges.

Pediatric patients <18 years who underwent surgery during elective admissions between July 1, 2010, and June 30, 2015, at any of 181 PHD hospitals reporting microbiology results.

In total, 74 surgical categories were defined using ICD-9-CM and CPT procedure codes. Microbiology results and ICD-9-CM diagnosis codes defined S. aureus infection types: bloodstream infection (BSI), surgical site infection (SSI), and other types (urinary tract, respiratory, and all other). Cumulative postsurgical infection incidence was calculated as the number of infections divided by the number of discharges with qualifying elective surgeries.

Among 11,874 inpatient surgical discharges, 180-day S. aureus infection incidence was 1.79% overall (1.00% SSI, 0.35% BSI, 0.45% other). Incidence was highest among children <2 years of age (2.76%) and lowest for those 10–17 years (1.49%). Among 50,698 outpatient surgical discharges, incidence was 0.36% overall (0.23% SSI, 0.05% BSI, 0.08% others); it was highest among children <2 years of age (0.57%) and lowest for those aged 10–17 years (0.30%). MRSA incidence was significantly higher after inpatient surgeries (0.68%) than after outpatient surgeries (0.14%; P < .0001). Overall, the median days to S. aureus infection was longer after outpatient surgery than after inpatient surgery (39 vs. 31 days; P = .0116).

These findings illustrate the burden of postoperative S. aureus infections in the pediatric population, particularly among young children. These results underscore the need for continued infection prevention efforts and longer-term surveillance after surgery.

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.

To assess the 180-day incidence of Staphylococcus aureus infections following orthopedic surgeries using microbiology cultures.

Retrospective observational epidemiology study.

National administrative hospital database.

Adult patients with an elective admission undergoing orthopedic surgeries in the inpatient and hospital-based outpatient settings discharged between July 1, 2010, and June 30, 2015.

Patients were identified from 181 hospitals reporting microbiology results to the Premier Healthcare Database. Orthopedic surgeries were defined using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) procedure and current procedural terminology (CPT) codes. Microbiology cultures and ICD-9/10 diagnosis codes identified surgical site infections (SSIs), bloodstream infections (BSIs), and other infections associated postoperatively (eg, respiratory and urinary tract infections).

Among 359,268 inpatient orthopedic surgical encounters, the S. aureus infection incidence was 1.13%: SSI, 0.68%; BSI, 0.28%; and other types, 0.17%. Among 292,011 outpatient encounters, the S. aureus incidence was 0.78%: SSI, 0.55%; BSI, 0.12%; and other types, 0.11%. Methicillin-resistant S. aureus (MRSA) infections accounted for 46% and 44% in the respective settings. Plastic/hand-limb reattachment and amputation had the highest overall S. aureus incidence in both settings. S. aureus was the most commonly isolated microorganism among culture-confirmed SSIs (48.0%) and BSIs (35.0%), followed by other Enterobacteriaceae (14.0%) for SSIs and Escherichia spp (12.5%) for BSIs.

These findings suggest that S. aureus infections continue to be an important contributor to the burden of postoperative infections after inpatient and outpatient orthopedic procedures.

To examine rural–urban differences in temporal trends and risk of inappropriate antibiotic use by agent and duration among women with uncomplicated urinary tract infection (UTI).

Observational cohort study.

Using the IBM MarketScan Commercial Database (2010–2015), we identified US commercially insured women aged 18–44 years coded for uncomplicated UTI and prescribed an oral antibiotic agent. We classified antibiotic agents and durations as appropriate versus inappropriate based on clinical guidelines. Rural–urban status was defined by residence in a metropolitan statistical area. We used modified Poisson regression to determine the association between rural–urban status and inappropriate antibiotic receipt, accounting for patient- and provider-level characteristics. We used multivariable logistic regression to estimate trends in antibiotic use by rural–urban status.

Of 670,450 women with uncomplicated UTI, a large proportion received antibiotic prescriptions for inappropriate agents (46.7%) or durations (76.1%). Compared to urban women, rural women were more likely to receive prescriptions with inappropriately long durations (adjusted risk ratio 1.10, 95% CI, 1.10–1.10), which was consistent across subgroups. From 2011 to 2015, there was slight decline in the quarterly proportion of patients who received inappropriate agents (48.5% to 43.7%) and durations (78.3% to 73.4%). Rural–urban differences varied over time by agent (duration outcome only), geographic region, and provider specialty.

Inappropriate antibiotic prescribing is quite common for the treatment of uncomplicated UTI. Rural women are more likely to receive inappropriately long antibiotic durations. Antimicrobial stewardship interventions are needed to improve outpatient UTI antibiotic prescribing and to reduce unnecessary exposure to antibiotics, particularly in rural settings.

Despite recommendations to discontinue prophylactic antibiotics after incision closure or <24 hours after surgery, prophylactic antibiotics are continued after discharge by some clinicians. The objective of this study was to determine the prevalence and factors associated with postdischarge prophylactic antibiotic use after spinal fusion.

Multicenter retrospective cohort study.

This study included patients aged ≥18 years undergoing spinal fusion or refusion between July 2011 and June 2015 at 3 sites. Patients with an infection during the surgical admission were excluded.

Prophylactic antibiotics were identified at discharge. Factors associated with postdischarge prophylactic antibiotic use were identified using hierarchical generalized linear models.

In total, 8,652 spinal fusion admissions were included. Antibiotics were prescribed at discharge in 289 admissions (3.3%). The most commonly prescribed antibiotics were trimethoprim/sulfamethoxazole (22.1%), cephalexin (18.8%), and ciprofloxacin (17.1%). Adjusted for study site, significant factors associated with prophylactic discharge antibiotics included American Society of Anesthesiologists (ASA) class ≥3 (odds ratio [OR], 1.31; 95% CI, 1.00–1.70), lymphoma (OR, 2.57; 95% CI, 1.11–5.98), solid tumor (OR, 3.63; 95% CI, 1.62–8.14), morbid obesity (OR, 1.64; 95% CI, 1.09–2.47), paralysis (OR, 2.38; 95% CI, 1.30–4.37), hematoma/seroma (OR, 2.93; 95% CI, 1.17–7.33), thoracic surgery (OR, 1.39; 95% CI, 1.01–1.93), longer length of stay, and intraoperative antibiotics.

Postdischarge prophylactic antibiotics were uncommon after spinal fusion. Patient and perioperative factors were associated with continuation of prophylactic antibiotics after hospital discharge.

In this study, we aimed to quantify short- and long-term outcomes of Clostridium difficile infection (CDI) in the elderly, including all-cause mortality, transfer to a facility, and hospitalizations.

Retrospective study using 2011 Medicare claims data, including all elderly persons coded for CDI and a sample of uninfected persons. Analysis of propensity score-matched pairs and the entire population stratified by the propensity score was used to determine the risk of all-cause mortality, new transfer to a long-term care facility (LTCF), and short-term skilled nursing facility (SNF), and subsequent hospitalizations within 30, 90, and 365 days.

The claims records of 174,903 patients coded for CDI were compared with those of 1,318,538 control patients. CDI was associated with increased risk of death (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.74–1.81; attributable mortality, 10.9%), new LTCF transfer (OR, 1.74; 95% CI, 1.67–1.82), and new SNF transfer (OR, 2.52; 95% CI, 2.46–2.58) within 30 days in matched-pairs analyses. In a stratified analysis, CDI was associated with greatest risk of 30-day all-cause mortality in persons with lowest baseline probability of CDI (hazard ratio [HR], 3.04; 95% CI, 2.83–3.26); the risk progressively decreased as the baseline probability of CDI increased. CDI was also associated with increased risk of subsequent 30-day, 90-day, and 1-year hospitalization.

CDI was associated with increased risk of short- and long-term adverse outcomes, including transfer to short- and long-term care facilities, hospitalization, and all-cause mortality. The magnitude of mortality risk varied depending on baseline probability of CDI, suggesting that even lower-risk patients may benefit from interventions to prevent CDI.