Understanding the Risks Measles is not just any illness; it's a highly contagious viral infection that can cause serious health problems. Recently, the impact of this disease hit close to home with a confirmed case in Kootenai County. It's more crucial than ever to understand measles, its symptoms, and preventive measures, including vaccinations. What is Measles? Measles is a viral infection that spreads through the air when an infected person coughs or sneezes. The virus can