Pulitzer Prize winner Jeffrey Eugenides has the worst luck just before his public appearances. We reported last summer that the author of “The Marriage Plot” showed up to a Paris Review reading with a shiner after being attacked by drunken goons on a train. This time, he took the stage at the 92nd Street Y on Monday night suffering from food poisoning. “It gives a whole new meaning to the words going viral,” quipped the author, whose novel is No. 10 on the New York Times best-seller list. He explained he got a stomach bug traveling in Europe, and he was still suffering its effects. Eugenides appeared with fellow Pulitzer winner Jennifer Egan, author of “A Visit From the Goon Squad.”