A virus which affects the empathic abilities of older betazoids, causing them to project their own emotions onto others in close proximity during such an attack -- manifested as a passing headache. The emotion only took hold in subjects where a latent propensity in that direction was present; a simple wide-spectrum anti-viral agent is enough to cure it; the effect on others fades in a day or two. Lwaxana's case aboard Deep Space Nine during the Gratitude Festival sends Jake chasing Major Kira, her Bareil lusting for Science Officer Dax, who in turn wanted Commander Sisko; later, Doctor Bashir and Major Kira coupled up and even Quark went for Keiko. Ironically, Chief O'Brien proved immune to it, as did Constable Odo.