The image you sent does not show some key symptoms of aster yellows, however, we cannot make a definitive diagnosis from a photo alone.

Typically with aster yellows, the whole plant is affected. In additional to malformed flower heads, you would also see stunted, yellowing leaves. 

Also, aster yellows typically cause greening of the flowerhead with small tufts of green leaves sprouting from the flower head itself. Often, the growth is spoon-shaped. 

This information from Piedmont Master Gardens has a succinct list of the symptoms to look for: 
https://piedmontmastergardeners.org/article/aster-yellows-what-is-it-and-what-do-i-do-about-it/

In the article linked above, they also talk about Eriophyid Mite damage, which causes similar deformity of the flower head. This information from Ohio State University has some great side by side comparisons of aster yellows vs. mite damage: 
https://bygl.osu.edu/node/881

The mites are not visible to the naked eye, you will need a microscope to see them, if they are in fact the culprit. 

There is no treatment for aster yellows, however the mites can be treated. The Missouri Botanical Garden has comprehensive information on how to the treat the mites:
Missouri Botanical Gardens.

To keep aster yellows from spreading throughout your garden, you would need to remove the entire plant, including the roots and plant material that has fallen on the soil. Don't compost it, dispose of it in a sealed trash bag. 

If you descriptions of the symptoms in the articles linked above don't help you come to a decision about what is affecting your plant, you can take a cutting to a plant lab in order to
receive a definitive diagnosis. In the Denver area, you can mail or bring in a cutting to the CSU Spur diagnostic clinic. Here is information about how to submit a sample: 
https://agsci.colostate.edu/agbio/plantclinic/