All this anxiety about the flu got us thinking about the health of downtown Sacramento’s nightlife. For decades, downtown has struggled with chronic nighttime illness, evidenced by the well-known symptoms of empty streets and desperate acquaintances. An evening sidewalk stroll often was a furtive experience. Recently, however, downtown’s condition has improved. The prescription has included new housing and cultural venues, and a diet augmented by Pyramid Alehouse, Esquire Grill, Lucca, Sky Bar Cafe, Mikuni, P.F. Chang’s China Bistro, Morgan’s Central Valley Bistro, Zen Toro, Brew It Up Personal Brewery & Grill, The Melting Pot, Nishiki Sushi, Hukilau Island Grill, Public Market Bar, K Bar and The Naked Lounge. Treatment will be expanded in the coming year. More dog walkers and baby carriages on the sidewalks signal that the patient is feeling new vigor. It might not prevent the flu, but it might do you some good to toss your keys to the valet and check out the healthier downtown.