Table 2.

The summary of studies on the effectiveness of face masks for SARS-CoV-2 infection.

Study	Country	Population	Study design	The type of mask	Other preventive applications	Results
Wang et al.2020	China	Healthy workers (doctors and nurses)	Retrospective	N95	Disinfection and hand washing	Reduction in the infectious risk of 2019-nCoV in doctors and nurses
Bundgaard et al.2020	Denmark	Adults outdoor more than 3 h per day without occupational mask use	Randomized controlled trial	Surgicalmask	-	Surgical masks in addition with other public measures did not reduce the SARS-CoV-2 infection rate
Ma et al.2020	China	Experimental	Researcharticle	N95, surgical mask, cotton mask	Hand hygiene	Wearing effective masks and hand hygiene, may slow therapid spread of the virus
Fan et al.2020	China	Chinese citizensliving in Iranand subsequently evacuated	Cohort	Surgicalmask	Travel restrictions	Restricting gatherings and wearing facemasks can decrease transmission of COVID-19
Doung-ngern et al.2020	Thailand	Asymptomatic contacts ofCOVID-19 patients	Case control	Surgicalmask	Handwashingand social distancing	Wearing masks, handwashing, and social distancing in public is suggested to protect against COVID-19
Mboowa et al.2021	Uganda	High risk individuals (polices, market workers, healthcare workers)	Retrospective Cross sectional	Face mask	Health education programs	Face masks in healthcare and community settings prevent the transmission of COVID-19
Natnael et al.2021	Ethiopia	Taxi drivers	Cross sectional	N95, surgical mask, cotton mask	-	Prevalence of mask wearing among taxi drivers was low. The significantly associated factors were determined