If you are like me, then you may not know much about the disease sleeping sickness. I thought that sleeping sickness was a disease only found in very hot, humid climates in places like Africa or lands close to the equator. I also thought that the tsetse fly was the only carrier of the illness.
Actually that is only partially true. Sleeping sickness (Its medical name is African trypanosomiosis.) is only found in Africa and is passed by the bite of the tsetse fly. A special form of the illness in animals is called animal African trypanosomiosis. Also several conditions that cause lethargy in man are referred to as sleeping sickness or medical fatigue.
But back in the 1910's and 1920's another form of sleeping sickness swept the entire world. It is an unusual form of encephalitis (a disease that attacks the brain) called encephalitis lethargica. This form of encephalitis spread quickly all over the world and lasted more than 10 years. It disappeared as quickly as it appeared and has not been seen in the world since. This sleeping sickness was also spread by mosquitoes just as in this week's story. There doesn't seem to be any fear of this form of sleeping sickness coming back. The disease may have had genes that quickly mutated helping it to survive and spread as it did. But the mutation process apparently eventually killed off encephalitis lethargica.
The writers of Ranger Bill worked hard to write stories that were in the news at that time or were historically correct. I think this is one of those historically based shows that we don't have much knowledge of today.