To determine whether HCP were at higher risk than adults working in nonhealthcare roles (non-HCP).

Prospective cohort study.

Acute-care hospitals and other businesses in Toronto, Ontario, Canada.

Adults aged 18–69 years were enrolled for 1 or more of the 2010/2011, 2011/2012, and 2012/2013 influenza seasons. Swabs collected during acute respiratory illnesses were tested for influenza and pre- and postseason blood samples were tested for influenza-specific immune response.

The adjusted odds of influenza were similar for HCP and non-HCP (odds ratio [OR], 1.29; 95% confidence interval [CI], 0.63–2.63). Older adults and those vaccinated against influenza had lower odds, and those who shared their workspace and who used corrective eyewear had higher odds of influenza.

HCP and other working adults are at similar risk of influenza infection.

Healthcare workers (HCWs) are at risk of acquiring and transmitting respiratory viruses while working in healthcare settings.

To investigate the incidence of and factors associated with HCWs working during an acute respiratory illness (ARI).

HCWs from 9 Canadian hospitals were prospectively enrolled in active surveillance for ARI during the 2010–2011 to 2013–2014 influenza seasons. Daily illness diaries during ARI episodes collected information on symptoms and work attendance.

At least 1 ARI episode was reported by 50.4% of participants each study season. Overall, 94.6% of ill individuals reported working at least 1 day while symptomatic, resulting in an estimated 1.9 days of working while symptomatic and 0.5 days of absence during an ARI per participant season. In multivariable analysis, the adjusted relative risk of working while symptomatic was higher for physicians and lower for nurses relative to other HCWs. Participants were more likely to work if symptoms were less severe and on the illness onset date compared to subsequent days. The most cited reason for working while symptomatic was that symptoms were mild and the HCW felt well enough to work (67%). Participants were more likely to state that they could not afford to stay home if they did not have paid sick leave and were younger.

HCWs worked during most episodes of ARI, most often because their symptoms were mild. Further data are needed to understand how best to balance the costs and risks of absenteeism versus those associated with working while ill.

To measure transmission frequencies and risk factors for household acquisition of community-associated and healthcare-associated (HA-) methicillin-resistant Staphylococcus aureus (MRSA).

Prospective cohort study from October 4, 2008, through December 3, 2012.

Seven acute care hospitals in or near Toronto, Canada.

Total of 99 MRSA-colonized or MRSA-infected case patients and 183 household contacts.

Baseline interviews were conducted, and surveillance cultures were collected monthly for 3 months from household members, pets, and 8 prespecified high-use environmental locations. Isolates underwent pulsed-field gel electrophoresis and staphylococcal cassette chromosome mec typing.

Overall, of 183 household contacts 89 (49%) were MRSA colonized, with 56 (31%) detected at baseline. MRSA transmission from index case to contacts negative at baseline occurred in 27 (40%) of 68 followed-up households. Strains were identical within households. The transmission risk for HA-MRSA was 39% compared with 40% (P=.95) for community-associated MRSA. HA-MRSA index cases were more likely to be older and not practice infection control measures (P=.002–.03). Household acquisition risk factors included requiring assistance and sharing bath towels (P=.001–.03). Environmental contamination was identified in 78 (79%) of 99 households and was more common in HA-MRSA households.

Household transmission of community-associated and HA-MRSA strains was common and the difference in transmission risk was not statistically significant.

Infect Control Hosp Epidemiol 2016;1–7

Bloodstream infection (BSI) due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with considerable morbidity and mortality.

To determine the incidence of MRSA BSI in Canadian hospitals and to identify variables associated with increased mortality.

Prospective surveillance for MRSA BSI conducted in 53 Canadian hospitals from January 1, 2008, through December 31, 2012. Thirty-day all-cause mortality was determined, and logistic regression analysis was used to identify variables associated with mortality.

A total of 1,753 patients with MRSA BSI were identified (incidence, 0.45 per 1,000 admissions). The most common sites presumed to be the source of infection were skin/soft tissue (26.6%) and an intravascular catheter (22.0%). The most common spa types causing MRSA BSI were t002 (USA100/800; 55%) and t008 (USA300; 29%). Thirty-day all-cause mortality was 23.8%. Mortality was associated with increasing age (odds ratio, 1.03 per year [95% CI, 1.02–1.04]), the presence of pleuropulmonary infection (2.3 [1.4–3.7]), transfer to an intensive care unit (3.2 [2.1–5.0]), and failure to receive appropriate antimicrobial therapy within 24 hours of MRSA identification (3.2 [2.1–5.0]); a skin/soft-tissue source of BSI was associated with decreased mortality (0.5 [0.3–0.9]). MRSA genotype and reduced susceptibility to vancomycin were not associated with risk of death.

This study provides additional insight into the relative impact of various host and microbial factors associated with mortality in patients with MRSA BSI. The results emphasize the importance of ensuring timely receipt of appropriate antimicrobial agents to reduce the risk of an adverse outcome.

Infect. Control Hosp. Epidemiol. 2016;37(4):390–397

To examine the prevalence of the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and the A2756G polymorphism of methionine synthase (MS), and their impact on antidepressant response.

We screened 224 subjects (52% female, mean age 39 ± 11 years) with SCID-diagnosed major depressive disorder (MDD), and obtained 194 genetic samples. 49 subjects (49% female, mean age 36 ± 11 years) participated in a 12-week open clinical trial of fluoxetine 20–60 mg/day. Association between clinical response and C677T and A2756G polymorphisms, folate, B12, and homocysteine was examined.

Prevalence of the C677T and A2756G polymorphisms was consistent with previous reports (C/C = 41%, C/T = 47%, T/T = 11%, A/A = 66%, A/G = 29%, G/G = 4%). In the fluoxetine-treated subsample (n = 49), intent-to-treat (ITT) response rates were 47% for C/C subjects and 46% for pooled C/T and T/T subjects (nonsignificant). ITT response rates were 38% for A/A subjects and 60% for A/G subjects (nonsignificant), with no subjects exhibiting the G/G homozygote. Mean baseline plasma B12 was significantly lower in A/G subjects compared to A/A, but folate and homocysteine levels were not affected by genetic status. Plasma folate was negatively associated with treatment response.

The C677T and A2756G polymorphisms did not significantly affect antidepressant response. These preliminary findings require replication in larger samples.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), which is caused primarily by the Canadian methicillin-resistant Staphylococcus aureus-10 (CMRSA-10) strain (also known as the USA300 strain) has emerged rapidly in the United States and is now emerging in Canada. We assessed the prevalence, risk factors, microbiological characteristics and outcomes of CA-MRSA in patients with purulent skin and soft tissue infections (SSTIs) presenting to emergency departments (EDs) in the Greater Toronto Area.

Patients with Staphylococcus aureus SSTIs who presented to 7 EDs between Mar. 1 and Jun. 30, 2007, were eligible for inclusion in this study. Antimicrobial susceptibilities and molecular characteristics of MRSA strains were identified. Demographic, risk factor and clinical data were collected through telephone interviews.

MRSA was isolated from 58 (19%) of 299 eligible patients. CMRSA-10 was identified at 6 of the 7 study sites and accounted for 29 (50%) of all cases of MRSA. Telephone interviews were completed for 161 of the eligible patients. Individuals with CMRSA-10 were younger (median 34 v. 63 yr, p = 0.002), less likely to report recent antibiotic use (22% v. 67%, p = 0.046) or health care–related risk factors (33% v. 72%, p = 0.097) and more likely to report community-related risk factors (56% v. 6%, p = 0.008) than patients with other MRSA strains. CMRSA-10 SSTIs were treated with incision and drainage (1 patient), antibiotic therapy (3 patients) or both (5 patients), and all resolved. CMRSA-10 isolates were susceptible to clindamycin, tetracycline and trimethoprimsulfamethoxazole.

CA-MRSA is a significant cause of SSTIs in the Greater Toronto Area, and can affect patients without known community-related risk factors. The changing epidemiology of CA-MRSA necessitates further surveillance to inform prevention strategies and empiric treatment guidelines.

To describe the use of laminar airflow, body exhaust, and ultraviolet lights during total knee replacement (TKR) in four U.S. states.

Survey of healthcare facilities.

Hospitals in Illinois, North Carolina, Ohio, and Tennessee that performed TKR during 2000 as identified by Medicare claims data.

Hospitals responding to a mailed questionnaire.

Two hundred ninety-five (73%) of 405 eligible hospitals that performed 18,374 primary and revision TKR procedures responded to the questionnaire. Among responding hospitals, 30% reported regular use (for > 75% of procedures) of laminar airflow, 42% reported regular use of body exhaust, and 5% reported regular use of ultraviolet lights. Among hospitals providing complete data, 150 (58%) performing 66% of procedures reported regular use of at least one of these techniques. On regression analyses, laminar airflow was used more often by hospitals with a TKR volume greater than 25 procedures per year (odds ratio [OR], 2.0; 95% confidence interval [CI95], 1.1-3.7) and orthopedic residency programs (OR, 2.8; CI95,1.3-6.3), but its use was not significantly related to hospital setting or ownership status.

Although these clean air practices are not recommended by any U.S. governmental or professional organization, they are used in nearly two-thirds of TKR procedures. Better information about their impact on current practice and more explicit guidelines may aid decisions about the use of these resource-intensive infection control practices.