Trends in antiviral therapy of adults hospitalized with influenza in Canada since the end of the 2009 pandemic.

BACKGROUND: Multiple observational studies have associated antiviral treatment of patients hospitalized with influenza with improved outcome, including reduced mortality. During the 2009-2010 H1N1 pandemic increased use of antiviral treatment of hospital patients was reported. We have carried out prospective surveillance for influenza in patients in a large network of Canadian hospitals since 2006. We wished to assess trends in antiviral use in the two seasons (2010-2011 and 2011-2012) since the end of the pandemic. FINDINGS: Adults (>16 years) testing positive for influenza at the time of or during admission to participating Canadian hospitals were prospectively reviewed. In 2009-2010 there were 1132 confirmed cases, 1107 in 2010-2011 and 631 in 2011-2012. Information on antiviral therapy was available in >95% in each year. Rising to 89.6% in 2009, the proportion of adult patients treated with antiviral therapy fell to 79.9% and 65.7% in the two subsequent seasons (p < 0.001). Oseltamivir was the antiviral agent used in >98% of cases in each year. The median time from onset of symptoms to initiation of antiviral therapy was three days. The treatment proportion fell across all age groups, co-morbid conditions and disease severity. CONCLUSION: Despite evidence for benefit of antiviral therapy, and clinical practice guidelines recommending treatment of this population, antiviral therapy of Canadian adults hospitalized with influenza has progressively fallen in the two seasons since the end of the 2009-2010 influenza pandemic.

Healthcare-associated influenza in Canadian hospitals from 2006 to 2012.

OBJECTIVE: To determine trends, patient characteristics, and outcome of patients with healthcare-associated influenza in Canadian hospitals. DESIGN: Prospective surveillance of laboratory-confirmed influenza among hospitalized adults was conducted from 2006 to 2012. Adults with positive test results at or after admission to the hospital were assessed. Influenza was considered to be healthcare associated if symptom onset was equal to or more than 96 hours after admission to a facility or if a patient was readmitted less than 96 hours after discharge or admitted less than 96 hours after transfer from another facility. Baseline characteristics of influenza patients were collected. Patients were reassessed at 30 days to determine the outcome. SETTING: Acute care hospitals participating in the Canadian Nosocomial Infection Surveillance Program. RESULTS: A total of 570 (17.3%) of 3,299 influenza cases were healthcare associated; 345 (60.5%) were acquired in a long-term care facility (LTCF), and 225 (39.5%) were acquired in an acute care facility (ACF). There was year-to-year variability in the rate and proportion of cases that were healthcare associated and variability in the proportion that were acquired in a LTCF versus an ACF. Patients with LTCF-associated cases were older, had a higher proportion of chronic heart disease, and were less likely to be immunocompromised compared with patients with ACF-associated cases; there was no significant difference in 30-day all-cause and influenza-specific mortality. CONCLUSIONS: Healthcare-associated influenza is a major component of the burden of disease from influenza in hospitals, but the proportion of cases that are healthcare associated varies markedly from year to year, as does the proportion of healthcare-associated infections that are acquired in an ACF versus an LTCF.

Understanding the burden of influenza infection among adults in Canadian hospitals: a comparison of the 2009-2010 pandemic season with the prepandemic and postpandemic seasons.

BACKGROUND: The degree to which the 2009-2010 influenza pandemic season differed from previous and subsequent influenza seasons in Canadian hospitals has not yet been assessed. METHODS: Surveillance for laboratory-confirmed influenza among adults in 51 Canadian Nosocomial Infection Surveillance Program hospitals was conducted between November 1, 2006, and May 31, 2011. Inpatient characteristics, treatment, and outcomes of influenza cases in the pandemic season (2009-2010) were compared with those in the prepandemic (2006-2007 to 2008-2009) and postpandemic (2010-2011) seasons. RESULTS: The incidence of influenza infection was lower in the postpandemic season (1.59/1,000 admissions) compared with the prepandemic seasons (2.00/1,000 admissions; P < .001) and the pandemic season (1.80/1,000 admissions; P < .001). The proportion of cases classified as health care-associated was much smaller during the pandemic season (6.6%) than in either the prepandemic season (23.2%; P < .001) or the postpandemic season (23.6%; P < .001). Inpatients in the pandemic season were significantly younger compared with those in the prepandemic and postpandemic seasons (P < .001). Inpatients in the pandemic season were less likely to have been vaccinated (P < .001), but more likely to be treated with antiviral agents (P < .001), than inpatients in both the prepandemic and postpandemic seasons. Intensive care unit admission was greater during the pandemic season, but there were no significant differences in 30-day mortality among the seasons. CONCLUSIONS: Among adult inpatients, the pH1N1 pandemic season differed from seasonal influenza in terms of age, vaccination status, antiviral use, and intensive care unit admission, but not in terms of 30-day mortality.

Laboratory-confirmed pandemic h1n1 influenza in hospitalized adults: findings from the Canadian Nosocomial Infections Surveillance Program, 2009-2010.

Surveillance for pandemic H1N1 influenza was conducted between June 1, 2009, and May 31, 2010, among adults at 40 participating hospitals in the Canadian Nosocomial Infection Surveillance Program. The first wave was characterized by a higher proportion of Aboriginals and pregnant women as well as severe outcomes, compared to the second wave.

Infection control and antimicrobial restriction practices for antimicrobial-resistant organisms in Canadian tertiary care hospitals.

In 2003, a survey examining infection control and antimicrobial restriction policies and practices for preventing the emergence and transmission of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and extended spectrum beta-lactamase (ESBL) was performed within Canadian teaching hospitals as part of the Canadian Nosocomial Infection Surveillance Program. Twenty-eight of 29 questionnaires were returned. The majority of facilities conducted admission screening for MRSA (96.4%) and VRE (89.3%) but only 1 site screened for ESBL/AmpC. Rates of MRSA, VRE, and ESBL remain low in Canada. It is believed that these lower rates may be due to intense admission screening protocols and stringent infection control policies for antimicrobial-resistant organisms (AROs) within Canadian institutions. Few (MRSA: 14.8%; VRE: 12.0%) recorded the number of patients screened. Regular prevalence surveys were done for MRSA (21.4%), VRE (35.7%), and ESBL/AmpC (3.8%). Pre-emptive precautions were applied for MRSA by 60.7% and for VRE by 75.0% of facilities. All facilities flagged patients previously identified with MRSA and VRE but only 46.2% flagged ESBL and 15.4% flagged AmpC patients. Barrier precautions varied by ARO and patient-care setting. In the inpatient non-ICU setting, more than 90% wore gowns and gloves for MRSA and VRE but only 50% for ESBL; and 57.1% wore masks for MRSA. Attempts to decolonize MRSA patients had been made by 82.1%, largely in order to place them in another facility. Policies restricting antimicrobial prescribing were reported by 21 facilities (75.0%). Further studies examining hospital infection control policies and corresponding rates of ARO infections would help in identifying and refining best practice guidelines within Canadian institutions.