  A number of anomalous results in short-baseline oscillation may hint at the
existence of one or more light sterile neutrino states in the eV mass range and
have triggered a wave of new experimental efforts to search for a definite
signature of oscillations between active and sterile neutrino states. The
present paper aims to provide a comprehensive review on the status of light
sterile neutrino searches in mid-2019: we discuss not only the basic
experimental approaches and sensitivities of reactor, source, atmospheric, and
accelerator neutrino oscillation experiments but also the complementary bounds
arising from direct neutrino mass experiments and cosmological observations.
Moreover, we review current results from global oscillation analyses that
include the constraints set by running reactor and atmospheric neutrino
experiments. They permit to set tighter bounds on the active-sterile
oscillation parameters but as yet are not able to provide a definite conclusion
on the existence of eV-scale sterile neutrinos.
