When Brittany Strickland heard that the United States recorded its first polio case in almost a decade, she was terrified -- the 33-year-old wasn't vaccinated against the disabling disease. Strickland was inoculated in Pomona, in New York's Rockland County where the first US polio case since 2013 was identified in July. Since then, the disease has been detected in wastewater samples in the area, as well as in a neighboring county and in New York City sewage, suggesting the virus is spreading. "I had considered it a virus that was on its way to extinction," John Dennehy, a virologist at the City University of New York, tells AFP. Health officials are urging anyone not immunized to get vaccinated, with Rockland County offering free shots. IMAGES AND SOUNDBITES