The story I read indicated the Russians were veeeeeerrrrrry interested whenever there appeared an outbreak anywhere in the world and were practically the first ones on hand to "help." Their experts took samples back home to study (and exploit), paying particular attention to a strain that struck a village in India. It's virulity rate was more along the lines of 80% mortality, versus the traditional 10-30% mortality rate. They chose that strain to weaponize because of its potency. They even experimented with a mixture of ebola and smallpox, a particularly lethal combination. Does it surprise you to know that so many brilliant and highly educated people devote their entire lives to finding increasingly horrible ways to get rid of Americans? It did me.
In India, all diseases seem to have high mortality rates, due to their over-all poor health and nutrition (likely stemming from their abysmal spiritual condition)