Table 2.

Evidence for factors related to transmission by Mycobacterium tuberculosis and SARS-CoV-2

	Mycobacterium tuberculosis	SARS-CoV-2
Transmission by small aerosol particles	Strong	Strong
Transmission by large aerosol particles (droplets)	Rare	Strong
Transmission by fomites or contact	No	Weak
Isolation of viable pathogen in room air	No	Yes
Identification of pathogen by PCR in room air	Yes	Yes
Isolation (culture) of pathogen from cough aerosols	Yes	No
Isolation of pathogen from exhaled breath	Yes	Yes
Risk to household contacts	High	High
Risk to health-care providers	High	High
Risk with proximity to index case	High	High
Risk of transmission from asymptomatic case	Probable	High
Risk of transmission outdoors	Low	Low
Risk of transmission indoors	High	High
Reduction of risk by patient mask use	Yes	Yes
Susceptibility of pathogen to ultraviolet light	High	Probably high
Superspreading epidemiology	Yes	Yes