A Pueblo resident was exposed to a measles outbreak in Mexico during travel and tested positive for the disease. Here's everything you need to know.

An unvaccinated adult who lives in Pueblo developed measles after visiting a part of Mexico that has an ongoing outbreak.

Dr. Rachel Herlihy, state epidemiologist for the Colorado Department of Public Health and Environment, states, “Measles is actually the most transmissible infectious disease that we know of. It's much more infectious than other infectious diseases that we see more commonly and have come to know over the last couple of years.