SAN FRANCISCO – Symptoms of acute respiratory infections occur in 22% of health care providers during the respiratory viral season, and almost as many have asymptomatic infection, according to findings from the Respiratory Protection Effectiveness Clinical Trial.
Mandatory influenza vaccination may help reduce absenteeism resulting from flulike symptoms, according to a separate report from the same study.
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Mandatory influenza vaccination may help reduce absenteeism resulting from flulike symptoms.
The Respiratory Protection Effectiveness Clinical Trial (ResPECT) is an ongoing cluster randomized trial taking place at 99 outpatient departments and emergency departments in seven locations across the United States. The current analyses are based on data collected during 12 weeks of the 2011-12 and 2012-13 respiratory seasons.
For one analysis, 1,686 health care providers were surveyed for signs and symptoms of acute respiratory infection (ARI). Cultures from swabs obtained from those with symptoms, as well as paired blood samples obtained at the start of the intervention and 2 weeks later, revealed that the most common viral isolates were for coronavirus (34%), followed by influenza A and B (32% combined), and rhinovirus (17%), Dr. Trish M. Perl of Johns Hopkins University, Baltimore, reported at an annual scientific meeting on infectious diseases.
Of the 22% of health care providers with ARI symptoms, 28% had identifiable viral causes. Nearly 20% of the providers were asymptomatic but were found to have an identifiable viral infection.
Interestingly, the same three viruses – coronavirus, influenza, and rhinovirus – topped the list of isolates in both symptomatic and asymptomatic patients, Dr. Perl noted.
Also of note, 9 of the 10 patients with influenza in the 2011-12 study period had been vaccinated. The data on influenza among vaccinated individuals were not available for the 2012-13 study period, she said.
At least some of the effect of ARI exposures among providers might be attenuated by a mandatory vaccine program, according to another report from ResPECT.
Of 1,077 health care providers included in that analysis, 64% were from private sites with mandatory vaccine policies and 36% were from Veterans Affairs sites and private sites without a mandatory vaccine policy. Those from sites with mandatory vaccination had significantly higher mean influenza vaccination rates (88% vs. 59%) and a lower mean sick day ratio, defined as symptomatic absenteeism/number of participants (0.56 vs. 0.90), said John Frederick of New York Harbor Healthcare System, New York.
Hand hygiene compliance rates did not differ significantly between the private site and VA site participants (33.1% vs. 33.8%, respectively), and facial protective equipment compliance differed only marginally during respiratory illness exposures (24.7% vs. 19.8%), despite a significantly greater exposure rate among the VA site subjects (11.1% vs. 6.7%), Mr. Frederick noted.
Furthermore, institutional impact of influenza was higher in systems with mandatory vaccine policies and lower sick day ratios.
"So this would suggest that, even in the face of increased influenza rates – an increased burden of disease – increased vaccination rates can actually provide a protective effect to health care personnel, and vaccination rates may very well be the driving differential force," he said.
Though limited by certain factors, such as the use of observational and self-reported data, and possible variability in how participants define ARI symptoms, it still is possible to draw some important conclusions from the findings, he said at the conference, part of the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
"Mandating vaccination does indeed appear to increase vaccination rates, and increasing vaccination rates does appear to decrease symptomatic absenteeism. So, combining those two, it appears that mandating vaccination does indeed decrease symptomatic absenteeism among health care personnel during viral respiratory season, even in the face of higher influenza rates," he concluded, adding that other factors, such as sick-leave policies, may certainly be in play as well, and that future studies should focus on these.
Dr. Perl and Mr. Frederick reported having no disclosures. The ResPECT trial is supported by Johns Hopkins University, the Centers for Disease Control and Prevention, the Department of Veterans Affairs, and the National Institute for Occupational Safety and Health.