  We present two epidemiological models, which extend the classical SEIR model
by accounting for the effect of indiscriminate quarantining, isolation of
infected individuals based on testing and the presence of asymptomatic
individuals. Given a constraint that limits the maximal number of simultaneous
active cases, we demonstrate that the isolation rate, which enforces this
constraint, decreases with the increasing testing rate. The models predict that
massive testing allows to control the infection spread using a much lower
isolation rate than in the case of indiscriminate quarantining. We also show
that dynamics of infection are more sensitive to the parameters of the
asymptomatic groups than the corresponding parameters of the symptomatic
groups.
