Not only World War II started in 1939 in Europe. Another disturbing event that went on until 1980s was epidemic of rabies. The disease was carried by red foxes, and it spread onto domestic animals. Rabies is almost always fatal, also for humans (unless a vaccine is provided).
Heroin and synthetic opioids are among most dangerous drugs in the world. Heroin has caused almost 16,000 deaths in the United States in 2017, a huge increase from 2,000-3,000 annual deaths between 2002 and 2010. This tragic trend asks for solutions. Other countries may have found them, but some persons may not like this treatment idea.