Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review

Abstract

Objective To review systematically the evidence of effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. Data sources Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without restrictions on language or publication. Data selection Studies of any intervention to prevent the transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). A search of study designs included randomised trials, cohort, case-control, crossover, before and after, and time series studies. After scanning of the titles, abstracts and full text articles as a first filter, a standardised form was used to assess the eligibility of the remainder. Risk of bias of randomised studies was assessed for generation of the allocation sequence, allocation concealment, blinding, and follow-up. Nonrandomised studies were assessed for the presence of potential confounders and classified as being at low, medium, or high risk of bias. Data synthesis 58 papers of 59 studies were included. The quality of the studies was poor for all four randomised controlled trials and most cluster randomised controlled trials; the observational studies were of mixed quality. Meta-analysis of six case-control studies suggested that physical measures are highly effective in preventing the spread of severe acute respiratory syndrome: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52), wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03), wearing N95 masks (0.09, 0.03 to 0

Attitudes of influenza-vaccinated health care workers toward masks to prevent nosocomial transmission of influenza

“…A recently published US study demonstrated that a large percentage of HCWs were unwilling to wear N95 respirators for an entire 8‐hour work shift because of facial heat and pressure as well as communication interference 23 . Beyond that, N95 masks might cause skin irritations such as rash and acne, further limiting the compliance of HCWs 9 . In our survey, over 70% of participants stated that the infection control recommendation “wearing a surgical mask” was appropriate.…”

“…There are only a few studies that compare surgical masks with FFP2 masks (equivalent to a N95 respirator). The efficacy of these different mask types is being controversially discussed 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . Surgical masks are designed to trap respiratory secretions expelled by the wearer.…”

Polyacrylonitrile/silver nanoparticle electrospun nanocomposite matrix for bacterial filtration

“…In 20th century, presence and role of disease transmission by bacteria in the form of droplets from nose and mouth by human activities was discovered [1]. Jones and Cookson studied about ambient outdoor air of a suburban area and showed that 34 % of bacteria are present as airborne microbiological particles in the respirable fraction [2].…”

Possible Role of Aerosol Transmission in a Hospital Outbreak of Influenza

“…Lack of preexisting immunity toward the recently emerged pandemic influenza H1N1 virus and its potential to cause serious disease in both young and older adults have further raised the importance of hospital infection control [7][8][9]. However, how influenza is transmitted in the health care setting and what control measures are effective have remained largely unclear [2,[8][9][10][11][12].…”