Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis

Liang, M. (2020). Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis.



Conflicting recommendations exist related to whether masks have a protective effect on the spread of respiratory viruses.


The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement was consulted to report this systematic review. Relevant articles were retrieved from PubMed, Web of Science, ScienceDirect, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI), VIP (Chinese) database.


A total of 21 studies met our inclusion criteria. Meta-analyses suggest that mask use provided a significant protective effect (OR = 0.35 and 95% CI = 0.24–0.51). Use of masks by healthcare workers (HCWs) and non-healthcare workers (Non-HCWs) can reduce the risk of respiratory virus infection by 80% (OR = 0.20, 95% CI = 0.11–0.37) and 47% (OR = 0.53, 95% CI = 0.36–0.79). The protective effect of wearing masks in Asia (OR = 0.31) appeared to be higher than that of Western countries (OR = 0.45). Masks had a protective effect against influenza viruses (OR = 0.55), SARS (OR = 0.26), and SARS-CoV-2 (OR = 0.04). In the subgroups based on different study designs, protective effects of wearing mask were significant in cluster randomized trials and observational studies.


This study adds additional evidence of the enhanced protective value of masks, we stress that the use masks serve as an adjunctive method regarding the COVID-19 outbreak.

Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis

 Compliance with hand hygiene in emergency medical services: an international observational study

Vikke, H.S. et al | 2019| Compliance with hand hygiene in emergency medical services: an international observational study |

An observational study, published in the Emergency Medicine Journal, identified sub-optimal levels of hand hygiene compliance among emergency medical service indications. 

The study’s results indicate a tendency to self-protection and over-reliance on gloves among emergency medical service providers (less than or equal to 15 per cent).

The research team found average hand hygiene compliance was low (3 per cent) before touching the patient and less than a fifth (19 per cent)  after having touched the patient. Gloves were worn  in more than half (54 per cent) of all hand hygiene indications.



Introduction Healthcare-associated infection caused by insufficient hygiene is associated with mortality, economic burden, and suffering for the patient. Emergency medical service (EMS) providers encounter many patients in different surroundings and are thus at risk of posing a source of microbial transmission. Hand hygiene (HH), a proven infection control intervention, has rarely been studied in the EMS.

Methods A multicentre prospective observational study was conducted from December 2016 to May 2017 in ambulance services from Finland, Sweden, Australia and Denmark. Two observers recorded the following parameters: HH compliance according to WHO guidelines (before patient contact, before clean/aseptic procedures, after risk of body fluids, after patient contact and after contact with patient surroundings). Glove use and basic parameters such as nails, hair and use of jewellery were also recorded.

Results Sixty hours of observation occurred in each country, for a total of 87 patient encounters. In total, there were 1344 indications for HH. Use of hand rub or hand wash was observed: before patient contact, 3%; before clean/aseptic procedures, 2%; after the risk of body fluids, 8%; after patient contact, 29%; and after contact with patient-related surroundings, 38%. Gloves were worn in 54% of all HH indications. Adherence to short or up done hair, short, clean nails without polish and no jewellery was 99%, 84% and 62%, respectively. HH compliance was associated with wearing gloves, but not associated with gender.

Conclusion HH compliance among EMS providers was remarkably low, with higher compliance after patient contacts compared with before patient contacts, and an over-reliance on gloves. We recommend further research on contextual challenges and hygiene perceptions among EMS providers to clarify future improvement strategies.

The full open-access article is available to download from the BMJ

Membrane charge and lipid packing determine polymyxin-induced membrane damage

Khondker, A. et al | 2019 | Membrane charge and lipid packing determine polymyxin-induced membrane damage | Communications Biology |10.1038/s42003-019-0297-6.

A paper published in the journal Communications Biology indicates that bacteria- as they become resistant to antibiotics- are able to produce stronger cell walls  which enables them to repel antibiotics and prevents effective treatment.

With the advent of polymyxin B (PmB) resistance in bacteria, the mechanisms for mcr-1 resistance are of crucial importance in the design of novel therapeutics. The mcr-1 phenotype is known to decrease membrane charge and increase membrane packing by modification of the bacterial outer membrane. We used X-ray diffraction, Molecular Dynamics simulations, electrochemistry, and leakage assays to determine the location of PmB in different membranes and assess membrane damage. By varying membrane charge and lipid tail packing independently, we show that increasing membrane surface charge promotes penetration of PmB and membrane damage, whereas increasing lipid packing decreases penetration and damage. The penetration of the PmB molecules is well described by a phenomenological model that relates an attractive electrostatic and a repulsive force opposing insertion due to increased membrane packing. The model applies well to several gram-negative bacterial strains and may be used to predict resistance strength (Source: Khondker et al).

Membrane charge and lipid packing determine polymyxin-induced membrane damage

In the news:

The Telegraph Bacteria develop tougher membranes to resist antibiotics, report into superbugs finds

Association of Corticosteroid Treatment With Outcomes in Adult Patients With Sepsis A Systematic Review and Meta-analysis

Fang, F. et al| 2018| Association of Corticosteroid Treatment With Outcomes in Adult Patients With SepsisA Systematic Review and Meta-analysis|  JAMA Intern Med| Published online December 21, 2018|  doi:10.1001/jamainternmed.2018.5849

This systematic review with meta-analysis of 37 RCTs considers the research question: Are corticosteroids associated with a reduction in 28-day mortality in patients with sepsis? 

It reports in its study of over 9500 patients with sepsis, that the administration of arteriosclerosis was  associated with reduced 28-day mortality. Administration of corticosteroids were also linked to a increased shock reversal at day 7, as well as vasopressor-free days and with decreased intensive care unit length of stay. 


The authors of the research suggest that administration of corticosteroid treatment in patients with sepsis is associated with significant improvement in health care outcomes and thus with reduced 28-day mortality.


Importance  Although corticosteroids are widely used for adults with sepsis, both the overall benefit and potential risks remain unclear.

Objective  To conduct a systematic review and meta-analysis of the efficacy and safety of corticosteroids in patients with sepsis.

Data Sources and Study Selection  MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception until March 20, 2018, and updated on August 10, 2018. The terms corticosteroidssepsisseptic shockhydrocortisonecontrolled trials, and randomized controlled trialwere searched alone or in combination. Randomized clinical trials (RCTs) were included that compared administration of corticosteroids with placebo or standard supportive care in adults with sepsis.

Data Extraction and Synthesis  Meta-analyses were conducted using a random-effects model to calculate risk ratios (RRs) and mean differences (MDs) with corresponding 95% CIs. Two independent reviewers completed citation screening, data abstraction, and risk assessment.

Main Outcomes and Measures  Twenty-eight–day mortality.

Results  This meta-analysis included 37 RCTs (N = 9564 patients). Eleven trials were rated as low risk of bias. Corticosteroid use was associated with reduced 28-day mortality  and intensive care unit (ICU) mortality. Corticosteroids were significantly associated with increased shock reversal at day 7 and vasopressor-free days ( and with ICU length of stay, the sequential organ failure assessment score at day 7, and time to resolution of shock. However, corticosteroid use was associated with increased risk of hyperglycemia  and hypernatremia.

Conclusions and Relevance  The findings suggest that administration of corticosteroids is associated with reduced 28-day mortality compared with placebo use or standard supportive care. More research is needed to associate personalized medicine with the corticosteroid treatment to select suitable patients who are more likely to show a benefit.

This article is available to Rotherham NHS staff through NHS Athens (one month embargo) or a paper copy of this article is available in the Library

Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study

Best, E., |2018|  Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study|  Journal of Hospital Infection| 100| 4| P. 469-475.

A new article in the Journal of Hospital Infection considers the importance of hand- drying, it is the largest study of its type to examine whether hand-drying method, in healthcare settings, affects the extent of environmental contamination by potential bacterial pathogens. 




Hand hygiene is a fundamental component of infection prevention, but few studies have examined whether hand-drying method affects the risk of dissemination of potential pathogens.


To perform a multi-centre, internal-crossover study comparing bacterial contamination levels in washrooms with hand-drying by either paper towels (PT) or jet air dryer (JAD; Dyson).


A total of 120 sampling sessions occurred over 12 weeks in each of three hospitals (UK, France, Italy). Bacteria were cultured from air, multiple surfaces, and dust. Washroom footfall (patients/visitors/staff) was monitored externally.


Footfall was nine times higher in UK washrooms. Bacterial contamination was lower in PT versus JAD washrooms; contamination was similar in France and the UK, but markedly lower in Italian washrooms. Total bacterial recovery was significantly greater from JAD versus PT dispenser surfaces at all sites. In the UK and France, significantly more bacteria were recovered from JAD washroom floors (median: 24 vs 191 cfu, P less than 0.00001). UK meticillin-susceptible Staphylococcus aureus recovery was three times more frequent and six-fold higher for JAD vs PT surfaces (both P less than  0.0001). UK meticillin-resistant S. aureus recovery was three times more frequent (21 vs 7 cfu) from JAD versus PT surfaces or floors. Significantly more enterococci and extended-spectrum β-lactamase (ESBL)-producing bacteria were recovered from UK JAD versus PT washroom floors (P less than 0.0001). In France, ESBL-producing bacteria were recovered from dust twice as often during JAD versus PT use.


Multiple examples of significant differences in surface bacterial contamination, including by faecal and antibiotic-resistant bacteria, were observed, with higher levels in JAD versus PT washrooms. Hand-drying method affects the risk of (airborne) dissemination of bacteria in real-world settings.

Read the full article at the Journal of Hospital Infection or download