ECIS. Cells were seeded onto collagen-coated gold electrode arrays and allowed to reach confluence (108 hours post-seeding). Monolayers were then infected with either mock, killed Romero, killed Candid#1, Romero, or Candid#1 at MOI = 4, and impedance measurements were made continuously for 100 hours. Live JUNV infection decreased HUVEC and HMVEC-L monolayer electrical resistance. (A) HUVECs or (B) HMVEC-Ls infected with JUNV Romero or Candid#1 show decreased electrical resistance beginning at approximately 60 hours post-infection. Mock and killed virus data show no decrease in electrical resistance. Data shown are the mean ± SD of three independent experiments. Insets show phase-contrast images of cell monolayers, indicating no visible cytopathology during experimental JUNV infections in either (A) HUVECs or (B) HMVEC-Ls.