Duration of Colonization and Determinants of Earlier Clearance of Colonization With Methicillin-Resistant Staphylococcus aureus.

BACKGROUND: The duration of colonization and factors associated with clearance of methicillin-resistant Staphylococcus aureus (MRSA) after community-onset MRSA skin and soft-tissue infection (SSTI) remain unclear. METHODS: We conducted a prospective cohort study of patients with acute MRSA SSTI presenting to 5 adult and pediatric academic hospitals from 1 January 2010 through 31 December 2012. Index patients and household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as negative MRSA surveillance cultures during 2 consecutive sampling periods. A Cox proportional hazards regression model was developed to identify determinants of clearance of colonization. RESULTS: Two hundred forty-three index patients were included. The median duration of MRSA colonization after SSTI diagnosis was 21 days (95% confidence interval [CI], 19-24), and 19.8% never cleared colonization. Treatment of the SSTI with clindamycin was associated with earlier clearance (hazard ratio [HR], 1.72; 95% CI, 1.28-2.30; P < .001). Older age (HR, 0.99; 95% CI, .98-1.00; P = .01) was associated with longer duration of colonization. There was a borderline significant association between increased number of household members colonized with MRSA and later clearance of colonization in the index patient (HR, 0.85; 95% CI, .71-1.01; P = .06). CONCLUSIONS: With a systematic, regular sampling protocol, duration of MRSA colonization was noted to be shorter than previously reported, although 19.8% of patients remained colonized at 6 months. The association between clindamycin and shorter duration of colonization after MRSA SSTI suggests a possible role for the antibiotic selected for treatment of MRSA infection.

Baricitinib Treatment of Coronavirus Disease 2019 Is Associated With a Reduction in Secondary Infections.

We performed a secondary analysis of the National Institutes of Health-sponsored Adaptive COVID-19 Treatment Trial (ACTT-2) randomized controlled trial and found that baricitinib was associated with a 50% reduction in secondary infections after controlling for baseline and postrandomization patient characteristics. This finding provides a novel mechanism of benefit for baricitinib and supports the safety profile of this immunomodulator for the treatment of coronavirus disease 2019.

Baricitinib versus dexamethasone for adults hospitalised with COVID-19 (ACTT-4): a randomised, double-blind, double placebo-controlled trial.

BACKGROUND: Baricitinib and dexamethasone have randomised trials supporting their use for the treatment of patients with COVID-19. We assessed the combination of baricitinib plus remdesivir versus dexamethasone plus remdesivir in preventing progression to mechanical ventilation or death in hospitalised patients with COVID-19. METHODS: In this randomised, double-blind, double placebo-controlled trial, patients were enrolled at 67 trial sites in the USA (60 sites), South Korea (two sites), Mexico (two sites), Singapore (two sites), and Japan (one site). Hospitalised adults (≥18 years) with COVID-19 who required supplemental oxygen administered by low-flow (≤15 L/min), high-flow (>15 L/min), or non-invasive mechanical ventilation modalities who met the study eligibility criteria (male or non-pregnant female adults ≥18 years old with laboratory-confirmed SARS-CoV-2 infection) were enrolled in the study. Patients were randomly assigned (1:1) to receive either baricitinib, remdesivir, and placebo, or dexamethasone, remdesivir, and placebo using a permuted block design. Randomisation was stratified by study site and baseline ordinal score at enrolment. All patients received remdesivir (≤10 days) and either baricitinib (or matching oral placebo) for a maximum of 14 days or dexamethasone (or matching intravenous placebo) for a maximum of 10 days. The primary outcome was the difference in mechanical ventilation-free survival by day 29 between the two treatment groups in the modified intention-to-treat population. Safety analyses were done in the as-treated population, comprising all participants who received one dose of the study drug. The trial is registered with ClinicalTrials.gov, NCT04640168. FINDINGS: Between Dec 1, 2020, and April 13, 2021, 1047 patients were assessed for eligibility. 1010 patients were enrolled and randomly assigned, 516 (51%) to baricitinib plus remdesivir plus placebo and 494 (49%) to dexamethasone plus remdesivir plus placebo. The mean age of the patients was 58·3 years (SD 14·0) and 590 (58%) of 1010 patients were male. 588 (58%) of 1010 patients were White, 188 (19%) were Black, 70 (7%) were Asian, and 18 (2%) were American Indian or Alaska Native. 347 (34%) of 1010 patients were Hispanic or Latino. Mechanical ventilation-free survival by day 29 was similar between the study groups (Kaplan-Meier estimates of 87·0% [95% CI 83·7 to 89·6] in the baricitinib plus remdesivir plus placebo group and 87·6% [84·2 to 90·3] in the dexamethasone plus remdesivir plus placebo group; risk difference 0·6 [95% CI -3·6 to 4·8]; p=0·91). The odds ratio for improved status in the dexamethasone plus remdesivir plus placebo group compared with the baricitinib plus remdesivir plus placebo group was 1·01 (95% CI 0·80 to 1·27). At least one adverse event occurred in 149 (30%) of 503 patients in the baricitinib plus remdesivir plus placebo group and 179 (37%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 7·5% [1·6 to 13·3]; p=0·014). 21 (4%) of 503 patients in the baricitinib plus remdesivir plus placebo group had at least one treatment-related adverse event versus 49 (10%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 6·0% [2·8 to 9·3]; p=0·00041). Severe or life-threatening grade 3 or 4 adverse events occurred in 143 (28%) of 503 patients in the baricitinib plus remdesivir plus placebo group and 174 (36%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 7·7% [1·8 to 13·4]; p=0·012). INTERPRETATION: In hospitalised patients with COVID-19 requiring supplemental oxygen by low-flow, high-flow, or non-invasive ventilation, baricitinib plus remdesivir and dexamethasone plus remdesivir resulted in similar mechanical ventilation-free survival by day 29, but dexamethasone was associated with significantly more adverse events, treatment-related adverse events, and severe or life-threatening adverse events. A more individually tailored choice of immunomodulation now appears possible, where side-effect profile, ease of administration, cost, and patient comorbidities can all be considered. FUNDING: National Institute of Allergy and Infectious Diseases.

Long-term follow-up of post-cardiac surgery Mycobacterium chimaera infections: A 5-center case series.

OBJECTIVES: In multiple countries, endovascular/disseminated Mycobacterium chimaera infections have occurred in post-cardiac surgery patients in association with contaminated, widely-distributed cardiac bypass heater-cooler devices. To contribute to long-term characterization of this recently recognized infection, we describe the clinical course of 28 patients with 3-7 years of follow-up for survivors. METHODS: Identified at five hospitals in the United States 2010-2016, post-cardiac surgery patients in the cohort had growth of Mycobacterium avium complex (MAC)/M. chimaera from a sterile site or surgical wound, or a clinically compatible febrile illness with granulomatous inflammation on biopsy. Case follow-up was conducted in May 2019. RESULTS: Of 28 patients, infection appeared to be localized to the sternum in four patients. Among 18 with endovascular/disseminated infection who received combination anti-mycobacterial treatment and had sufficient follow-up, 39% appeared to have controlled infection (>12 months), 56% died, and one patient is alive with relapsed bacteremia. While the number of patients is small and interpretation is limited, four (67%) of six patients who had cardiac prosthesis removal/replacement appeared to have controlled infection compared to three (25%) of 12 with retained cardiac prosthesis (p >0.14; Fisher's exact test). CONCLUSIONS: Given poor response to treatment and potential for delayed relapses, post-cardiac surgery M. chimaera infection warrants aggressive treatment and long-term monitoring.

First year of mandatory reporting of healthcare-associated infections, Pennsylvania: an infection control-chart abstractor collaboration.

BACKGROUND: In 2004, the Commonwealth of Pennsylvania mandated hospitals to report healthcare-associated infections (HAIs). The increased workload led our Infection Control staff to collaborate with Atlas, a group of chart abstractors. OBJECTIVE: The objective of this study was to assess our first year of experience with mandatory reporting of HAIs--specifically, to assess Atlas' contribution to surveillance. DESIGN: Cases were selected if they had 1 or more of the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes designated by Pennsylvania as a possible HAI. After training by the Infection Control staff, Atlas applied National Nosocomial Infection Surveillance (NNIS) system case definitions for catheter-associated urinary tract infections (UTIs) and surgical site infections (SSIs), and they applied NNIS chest imaging criteria to eliminate cases that were not ventilator-associated pneumonia (VAP). To assess Atlas' performance, Infection Control staff conducted a parallel review. RESULTS: For discharges from the hospital during the fourth quarter of 2004, a total of 410 UTIs, 59 SSIs, and 56 VAPs were identified on the basis of state-designated ICD-9-CM codes; review by Atlas/Infection Control determined that 15%, 15%, and 16% of cases met case definitions, respectively. Of cases reviewed by both Infection Control and Atlas, 87% of the assessments made by Atlas were correct for UTI, and 96% were correct for SSI. For VAP, Infection Control concluded that 39% of cases could be ruled out on the basis of chest imaging criteria; Atlas correctly dismissed these 12 cases but incorrectly dismissed an additional 6 (error, 19%). Surveillance was not timely: 1-2 months elapsed between the time of HAI onset and the earliest case review. CONCLUSIONS: With ongoing training by Infection Control, Atlas successfully demonstrated a role in retrospective HAI surveillance. However, despite a major effort to comply with mandates, time lags and other design limitations rendered the data of low utility for Infection Control. States that are planning HAI-reporting programs should standardize an efficient surveillance methodology that yields data capable of guiding interventions to prevent HAI.

The Effect of Total Household Decolonization on Clearance of Colonization With Methicillin-Resistant Staphylococcus aureus.

OBJECTIVE To determine the impact of total household decolonization with intranasal mupirocin and chlorhexidine gluconate body wash on recurrent methicillin-resistant Staphylococcus aureus (MRSA) infection among subjects with MRSA skin and soft-tissue infection. DESIGN Three-arm nonmasked randomized controlled trial. SETTING Five academic medical centers in Southeastern Pennsylvania. PARTICIPANTS Adults and children presenting to ambulatory care settings with community-onset MRSA skin and soft-tissue infection (ie, index cases) and their household members. INTERVENTION Enrolled households were randomized to 1 of 3 intervention groups: (1) education on routine hygiene measures, (2) education plus decolonization without reminders (intranasal mupirocin ointment twice daily for 7 days and chlorhexidine gluconate on the first and last day), or (3) education plus decolonization with reminders, where subjects received daily telephone call or text message reminders. MAIN OUTCOME MEASURES Owing to small numbers of recurrent infections, this analysis focused on time to clearance of colonization in the index case. RESULTS Of 223 households, 73 were randomized to education-only, 76 to decolonization without reminders, 74 to decolonization with reminders. There was no significant difference in time to clearance of colonization between the education-only and decolonization groups (log-rank P=.768). In secondary analyses, compliance with decolonization was associated with decreased time to clearance (P=.018). CONCLUSIONS Total household decolonization did not result in decreased time to clearance of MRSA colonization among adults and children with MRSA skin and soft-tissue infection. However, subjects who were compliant with the protocol had more rapid clearance Trial registration. ClinicalTrials.gov identifier: NCT00966446 Infect Control Hosp Epidemiol 2016;1-8.

Actinomyces viscosus endocarditis requiring aortic valve replacement.

We report a case of primary Actinomyces viscosus endocarditis, an unusual manifestation of actinomycosis, in a 43-year-old farmer with an indolent febrile illness. As has occurred in previous cases, diagnosis was delayed in part because blood isolates were misidentified. Months later when she required aortic valve and root replacement, histologic exam of the diseased valve revealed branching filamentous organisms and the original blood isolates were retrospectively confirmed to be Actinomyces viscosus.

Patients' request for and emergency physicians' prescription of antimicrobial prophylaxis for anthrax during the 2001 bioterrorism-related outbreak.

BACKGROUND: Inappropriate use of antibiotics by individuals worried about biological agent exposures during bioterrorism events is an important public health concern. However, little is documented about the extent to which individuals with self-identified risk of anthrax exposure approached physicians for antimicrobial prophylaxis during the 2001 bioterrorism attacks in the United States. METHODS: We conducted a telephone survey of randomly selected members of the Pennsylvania Chapter of the American College of Emergency Physicians to assess patients' request for and emergency physicians' prescription of antimicrobial agents during the 2001 anthrax attacks. RESULTS: Ninety-seven physicians completed the survey. Sixty-four (66%) respondents had received requests from patients for anthrax prophylaxis; 16 (25%) of these physicians prescribed antibiotics to a total of 23 patients. Ten physicians prescribed ciprofloxacin while 8 physicians prescribed doxycycline. CONCLUSION: During the 2001 bioterrorist attacks, the majority of the emergency physicians we surveyed encountered patients who requested anthrax prophylaxis. Public fears may lead to a high demand for antibiotic prophylaxis during bioterrorism events. Elucidation of the relationship between public health response to outbreaks and outcomes would yield insights to ease burden on frontline clinicians and guide strategies to control inappropriate antibiotic allocation during bioterrorist events.

Risk factors for recurrent colonization with methicillin-resistant Staphylococcus aureus in community-dwelling adults and children.

OBJECTIVE To identify risk factors for recurrent methicillin-resistant Staphylococcus aureus (MRSA) colonization. DESIGN Prospective cohort study conducted from January 1, 2010, through December 31, 2012. SETTING Five adult and pediatric academic medical centers. PARTICIPANTS Subjects (ie, index cases) who presented with acute community-onset MRSA skin and soft-tissue infection. METHODS Index cases and all household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as 2 consecutive sampling periods with negative surveillance cultures. Recurrent colonization was defined as any positive MRSA surveillance culture after clearance. Index cases with recurrent MRSA colonization were compared with those without recurrence on the basis of antibiotic exposure, household demographic characteristics, and presence of MRSA colonization in household members. RESULTS The study cohort comprised 195 index cases; recurrent MRSA colonization occurred in 85 (43.6%). Median time to recurrence was 53 days (interquartile range, 36-84 days). Treatment with clindamycin was associated with lower risk of recurrence (odds ratio, 0.52; 95% CI, 0.29-0.93). Higher percentage of household members younger than 18 was associated with increased risk of recurrence (odds ratio, 1.01; 95% CI, 1.00-1.02). The association between MRSA colonization in household members and recurrent colonization in index cases did not reach statistical significance in primary analyses. CONCLUSION A large proportion of patients initially presenting with MRSA skin and soft-tissue infection will have recurrent colonization after clearance. The reduced rate of recurrent colonization associated with clindamycin may indicate a unique role for this antibiotic in the treatment of such infection.

Early season crow mortality as a sentinel for West Nile virus disease in humans, northeastern United States.

The 1999 New York epidemic of human West Nile virus (WN) encephalitis and meningitis was preceded by a crow die-off also caused by WN infection. As one component of the subsequently developed national surveillance system, crow mortality data were collected to detect WN activity before humans might become infected. However, predicting areas at risk for human WN disease likely requires assessment of multiple factors, including the intensity and timing of crow epizootics. To identify early season measures of WN activity in crows associated with subsequent WN disease in humans, county-level crow mortality data from seven northeastern states were analyzed. A predictive model was developed based on analysis of 2000 surveillance data and then assessed for 2001. To characterize the intensity of early season WN activity in crows, 15 variables were constructed from surveillance data of 52 counties that tested at least four crows during the early season (defined as June 17-July 28, 2000). County values for each variable were dichotomized at the 75th percentile into "high" and "low" activity. Multivariate analysis indicated that "high" early season activity of two variables-density of reported dead crow sightings (reported dead crows/area) and [(WN-infected crows/tested crows) x (human population)]--were associated with report of at least one human WN disease case (for each variable: adjusted odds ratio, 6.9; 95% confidence interval, 1.2-40.6). An assessment of this model using 2001 surveillance data from 61 counties yielded similar findings. With emphasis on early season WN activity, crow surveillance may allow timely targeting of interventions to protect the public health.

Household risk factors for colonization with multidrug-resistant Staphylococcus aureus isolates.

Antimicrobial resistance, particularly in pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), limits treatment options and increases healthcare costs. To understand patient risk factors, including household and animal contact, potentially associated with colonization with multidrug-resistant MRSA isolates, we performed a prospective study of case patients colonized with MRSA on admission to a rural tertiary care hospital. Patients were interviewed and antimicrobial resistance patterns were tested among isolates from admitted patients colonized with MRSA in 2009-10. Prevalence of resistance was compared by case-patient risk factors and length-of-stay outcome among 88 MRSA case patients. Results were compared to NHANES 2003-04. Overall prevalence of multidrug resistance (non-susceptibility to ≥ four antimicrobial classes) in MRSA nasal isolates was high (73%) and was associated with a 1.5-day increase in subsequent length of stay (p = 0.008). History of hospitalization within the past six months, but not antimicrobial use in the same time period, was associated with resistance patterns. Within a subset of working-age case patients without recent history of hospitalization, animal contact was potentially associated with multidrug resistance. History of hospitalization, older age, and small household size were associated with multidrug resistance in NHANES data. In conclusion, recent hospitalization of case patients was predictive of antimicrobial resistance in MRSA isolates, but novel risk factors associated with the household may be emerging in CA-MRSA case patients. Understanding drivers of antimicrobial resistance in MRSA isolates is important to hospital infection control efforts, relevant to patient outcomes and to indicators of the economic burden of antimicrobial resistance.

Risk of methicillin-resistant Staphylococcus aureus surgical site infection in patients with nasal MRSA colonization.

BACKGROUND: Patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) are at increased risk for invasive infection compared with noncolonized patients; however, the magnitude of risk for MRSA surgical site infection (SSI) is unclear. To aid in planning of infection prevention strategies, we sought to assess the incidence of MRSA SSI in MRSA carriers. METHODS: We conducted a retrospective cohort study at our tertiary care center of inpatients who underwent MRSA polymerase chain reaction (PCR) screen of the nares within 30 days before a National Healthcare Safety Network principal procedure between April 2008 and July 2010. RESULTS: The rate of MRSA SSI was 1.86% in the MRSA PCR-positive group (n = 431) and 0.20% in the MRSA PCR-negative group (n = 9432). Multivariate analysis identified MRSA PCR-positive status as an independent risk factor for MRSA SSI (odds ratio, 9.20; 95% confidence interval, 3.81-20.47; P < .0001); other risk factors included duration of surgery ≥137 minutes, American Society of Anesthesiologists score ≥3, and abdominal surgery. CONCLUSIONS: Surgical patients with a positive nasal MRSA PCR screen had a 9-fold greater odds of developing a subsequent MRSA SSI compared with patients with a negative nasal MRSA PCR screen. The incidence of MRSA SSI in PCR-positive patients was low (1.86%), however, and identifying subsets of patients at greatest risk for SSI may help target decolonization and other interventions.

Molecular and phenotypic characteristics of healthcare- and community-associated methicillin-resistant Staphylococcus aureus at a rural hospital.

BACKGROUND: While methicillin-resistant Staphylococcus aureus (MRSA) originally was associated with healthcare, distinct strains later emerged in patients with no prior hospital contact. The epidemiology of MRSA continues to evolve. METHODS: To characterize the current epidemiology of MRSA-colonized patients entering a hospital serving both rural and urban communities, we interviewed patients with MRSA-positive admission nasal swabs between August 2009 and March 2010. We applied hospitalization risk factor, antimicrobial resistance phenotype, and multi-locus sequence genotype (MLST) classification schemes to 94 case-patients. RESULTS: By MLST analysis, we identified 15 strains with two dominant clonal complexes (CCs)-CC5 (51 isolates), historically associated with hospitals, and CC8 (27 isolates), historically of community origin. Among patients with CC5 isolates, 43% reported no history of hospitalization within the past six months; for CC8, 67% reported the same. Classification by hospitalization risk factor did not correlate strongly with genotypic classification. Sensitivity of isolates to ciprofloxacin, clindamycin, or amikacin was associated with the CC8 genotype; however, among CC8 strains, 59% were resistant to ciprofloxacin, 15% to clindamycin, and 15% to amikacin. CONCLUSIONS: Hospitalization history was not a strong surrogate for the CC5 genotype. Conversely, patients with a history of hospitalization were identified with the CC8 genotype. Although ciprofloxacin, clindamycin, and amikacin susceptibility distinguished CC8 strains, the high prevalence of ciprofloxacin resistance limited its predictive value. As CC8 strains become established in healthcare settings and CC5 strains disseminate into the community, community-associated MRSA definitions based on case-patient hospitalization history may prove less valuable in tracking community MRSA strains.

Hospital costs associated with surgical site infections in general and vascular surgery patients.

BACKGROUND: Although much has been written about excess cost and duration of stay (DOS) associated with surgical site infections (SSIs) after cardiothoracic surgery, less has been reported after vascular and general surgery. We used data from the National Surgical Quality Improvement Program (NSQIP) to estimate the total cost and DOS associated with SSIs in patients undergoing general and vascular surgery. METHODS: Using standard NSQIP practices, data were collected on patients undergoing general and vascular surgery at a single academic center between 2007 and 2009 and were merged with fully loaded operating costs obtained from the hospital accounting database. Logistic regression was used to determine which patient and preoperative variables influenced the occurrence of SSIs. After adjusting for patient characteristics, costs and DOS were fit to linear regression models to determine the effect of SSIs. RESULTS: Of the 2,250 general and vascular surgery patients sampled, SSIs were observed in 186 inpatients. Predisposing factors of SSIs were male sex, insulin-dependent diabetes, steroid use, wound classification, and operative time (P < .05). After adjusting for those characteristics, the total excess cost and DOS attributable to SSIs were $10,497 (P < .0001) and 4.3 days (P < .0001), respectively. CONCLUSION: SSIs complicating general and vascular surgical procedures share many risk factors with SSIs after cardiothoracic surgery. Although the excess costs and DOS associated with SSIs after general and vascular surgery are somewhat less, they still represent substantial financial and opportunity costs to hospitals and suggest, along with the implications for patient care, a continuing need for cost-effective quality improvement and programs of infection prevention.

Molecular and epidemiologic characteristics of linezolid-resistant coagulase-negative staphylococci at a tertiary care hospital.

We investigated emergence of linezolid resistance among coagulase-negative staphylococci at our tertiary care center in 2007. All 17 cases were healthcare associated, and prior administration of linezolid was documented

Outcomes from pandemic influenza A H1N1 infection in recipients of solid-organ transplants: a multicentre cohort study.

BACKGROUND: There are few data on the epidemiology and outcomes of influenza infection in recipients of solid-organ transplants. We aimed to establish the outcomes of pandemic influenza A H1N1 and factors leading to severe disease in a cohort of patients who had received transplants. METHODS: We did a multicentre cohort study of adults and children who had received organ transplants with microbiological confirmation of influenza A infection from April to December, 2009. Centres were identified through the American Society of Transplantation Influenza Collaborative Study Group. Demographics, clinical presentation, treatment, and outcomes were assessed. Severity of disease was measured by admission to hospital and intensive care units (ICUs). The data were analysed with descriptive statistics. Proportions were compared by use of chi(2) tests. We used univariate analysis to identify factors leading to pneumonia, admission to hospital, and admission to an ICU. Multivariate analysis was done by use of a stepwise logistic regression model. We analysed deaths with Kaplan-Meier survival analysis. FINDINGS: We assessed 237 cases of medically attended influenza A H1N1 reported from 26 transplant centres during the study period. Transplant types included kidney, liver, heart, lung, and others. Both adults (154 patients; median age 47 years) and children (83; 9 years) were assessed. Median time from transplant was 3.6 years. 167 (71%) of 237 patients were admitted to hospital. Data on complications were available for 230 patients; 73 (32%) had pneumonia, 37 (16%) were admitted to ICUs, and ten (4%) died. Antiviral treatment was used in 223 (94%) patients (primarily oseltamivir monotherapy). Seven (8%) patients given antiviral drugs within 48 h of symptom onset were admitted to an ICU compared with 28 (22.4%) given antivirals later (p=0.007). Children who received transplants were less likely to present with pneumonia than adults, but rates of admission to hospital and ICU were similar. INTERPRETATION: Influenza A H1N1 caused substantial morbidity in recipients of solid-organ transplants during the 2009-10 pandemic. Starting antiviral therapy early is associated with clinical benefit as measured by need for ICU admission and mechanical ventilation. FUNDING: None.