SIOUX FALLS, S.D. (KELO AM) - The State Health Department says influenza has been particularly hard on South Dakota's eldery with hospitalizations and deaths.     As the flu season begins winding down, health experts say it's still not too late for a flu shot.     Sioux Falls Public Health Manager Sandy Frentz advises contacting your doctor, the health department or pharmacy to find available vaccine.     Frentz says you can also contact the health information lines affiliated with both Sioux Falls hospital and they can help direct you to clinics with vaccine.     Frentz says you can help prevent the spread of colds and flu by practicing good hygiene:  wash your hands, don't touch your face and if you're sick, stay home.