Rickettsiae and Ehrlichiae are obligately intracellular bacteria.
Rickettsial diseases have been one of the major scourges of mankind and
they still threaten public health. Human ehrlichiosis is the new
emerging disease. Dr Yu's research interest is to study the pathogenesis of
rickettsial diseases and human ehrlichiosis using molecular biological
methods. He is investigating the mechanisms of host immune evasion by
E. chaffeensis, which include modulation of cytokine production and
inhibition of phagosome and lysosome fusion.