Does the bubonic plague still exist?

Yes: Plague is still present in the southwestern United States, as well as many other parts of the world. It is easily treatable with antibiotics if diagnosed early.

Yes: Almost all of the approximately 3000 annually reported cases of plague in the world occur in African countries: Botswana, Kenya, Madagascar, Mozambique, Tanzania, and Zaire. A few cases are seen in other parts of the world. The U.S. has 10-15 cases per year, usually in CO, UT, NM, and AZ. Europe has not had plague since WWII. Australia also does not have plague.

There are rare cases: in the US. Yes. See: https://www.usatoday.com/story/news/nation-now/2018/06/14/idaho-child-contracts-rare-plague-states-first-case-two-decades/700824002/