Public health implications of transmissions during asymptomatic
period
According to different kinds of literature and scientific pieces of
evidence, the existence of persons with asymptomatic SARS-CoV-2
infection who are capable of transmitting the virus to others has so
many implications. Because many SARS-CoV-2 cases are recovering without
showing signs and symptoms (29), the attack rate and case-fatality rates
of COVID-19 might be lower or inaccurate related to currently estimated
ratios, if asymptomatic SARS-CoV-2 infections are included (30, 31).
This is the first implication that should be introduced during the
surveillance and reporting of SARS-CoV-2 in each country. The second and
the very important implication to slow the transmission of COVID-19 is
transmission while asymptomatic reinforces the value of community
interventions. Clearly understanding of the asymptomatic transmission is
possible and even risk. Center for Diseases Prevention and Control (CDC)
and WHO recommended that the very important intervention method is
physical distancing(32, 33), use of face-covering materials like cloth
in public places (34), and universal masking in healthcare
facilities(35) to prevent SARS-CoV-2 transmission by asymptomatic and
symptomatic persons. Third but might not be the final implication of
asymptomatic transmission is that it could enhance the need to increase
the capacity for widespread testing and thorough contact tracing to
detect asymptomatic infections, interrupt undetected transmission
chains, and further curve down the epidemic curve. Contact tracing
(36-38), and implementation of multipronged surveillance and containment
measures(39) are the key approaches for limiting the transmission rate.