Respiratory illnesses in Canadian health care workers: a pilot study of influenza vaccine and oseltamivir prophylaxis during the 2007/2008 influenza season

Abstract

Please cite this paper as: Coleman et al. (2011) Respiratory illnesses in Canadian health care workers: a pilot study of influenza vaccine and oseltamivir prophylaxis during the 2007/2008 influenza season. Influenza and Other Respiratory Viruses 5(6), 404–408. Background Data regarding both rates of acute respiratory illness in health care workers and experience with long‐term antiviral prophylaxis are sparse. Objective To determine the efficacy and tolerability of oseltamivir prophylaxis versus seasonal influenza vaccine for the prevention of influenza among health care workers. Methods We conducted a pilot, randomized control study during the 2007/2008 influenza season in a tertiary care setting. Adult health care workers 18–69 years of age were recruited and randomly assigned in a 4:1 ratio to receive either oseltamivir (Tamiflu®; Roche) 75 mg once daily prophylaxis or seasonal influenza (Fluviral®) vaccine. Results Of 56 adults enrolled, 12 received vaccine and 44 received prophylaxis. Incidence of symptomatic laboratory‐confirmed influenza was similar for participants in the vaccine and prophylaxis arms (17% and 24%, respectively; P = 0·71). Participants who developed an acute respiratory illness during the study period reported working 85% of scheduled work days, and 29% stated that they worked despite feeling miserable because they were too busy to stay home. Of 42 participants who initiated oseltamivir prophylaxis, four discontinued it owing to side effects. Median duration of oseltamivir prophylaxis was 121 days, with 34 (81%) continuing ≥12 weeks. Conclusions During an extended season of suboptimal vaccine match, 22% of health care workers receiving antiviral prophylaxis or seasonal influenza vaccine developed symptomatic laboratory‐confirmed influenza. Long‐term antiviral prophylaxis against influenza was generally well tolerated with good compliance.

A systematic review of factors affecting intended and actual adherence with antiviral medication as treatment or prophylaxis in seasonal and pandemic flu

“…All but three studies investigated pandemic influenza (actual influenza A(H1N1)pdm09 or hypothetical scenarios), with other studies investigating influenza H5N1, H7N3 and seasonal influenza . The majority of studies were cross‐sectional, with one RCT, and two qualitative studies . All but one study investigated adherence with antivirals via self‐report.…”

“…The majority of studies were cross‐sectional, with one RCT, and two qualitative studies . All but one study investigated adherence with antivirals via self‐report. All studies investigated predictors of actual or intended adherence to oseltamivir; no studies included in the review investigated predictors of adherence to zanamivir (trade name “Relenza”) or other antivirals such as amantadine.…”

“…Many studies did not clearly report response rates or eligibility criteria to ensure that the sample was representative . Additionally, four studies had small sample sizes . Multiple studies lacked clearly defined outcomes and all but two studies lacked valid and reliable methods of outcome measures, both factors contributing to higher potential detection bias.…”

“…Other sources of bias included the fact that none of the studies reported a sample size calculation. Main potential confounders were not taken into account in ten studies . Fourteen studies also did not address appropriate or clearly focused questions …”

Oseltamivir and inhaled zanamivir as influenza prophylaxis in Thai health workers: a randomized, double-blind, placebo-controlled safety trial over 16 weeks

“…Breakthrough, laboratory-confirmed influenza was observed in 24% and 17% of oseltamivir and influenza vaccine recipients, respectively (not significantly different). 33 …”