Interesting. Plague Outbreak 5,500 Years Ago

Ars Technica reports that "Hunter-gatherers in Siberia died of a plague outbreak 5,500 years ago." The article relates that "[p]lague swept through groups of hunter-gatherers in southeastern Siberia 5,500 years ago, leaving dozens dead in its wake—with DNA from Yersinia pestis bacteria still trapped inside their teeth." A few points:

• The reason this is significant is because the previously belief was that the plague only became deadly to humans after humans had settled in communities living in close association with rats or other animals that were hosts to the fleas carrying the Y. pestis bacterium. But this outbreak was among hunter gatherers. Thus, not only was close and long term contact not needed to produce a plague deadly to humans, but something that was as deadly as later plagues had already arisen much earlier than believed possible.
• The article indicates that the plague DNA was extracted from "plague victims at four ancient cemeteries in the area around Russia’s Lake Baikal." This is significant because it seems to be part of the large marmot based plague reservoir. Lake Baikal is in Russia, just north of central Mongolia. The 14th Century plague was traced back to the Lake Issyk Kul, which is in modern day eastern Kyrgyzstan. Not exceptionally close, but both part of the natural range of marmots in Central Asia (see the map below).
• Finally, the article indicates that "Bubonic plague spreads through flea bites, but pneumonic plague is a respiratory disease, which spreads in a similar way to the flu or COVID-19, and that seems to be how this early version would have passed from person to person." This is also what made the 14th Century Black Death so deadly and allowed it spread so quickly. It didn't need or use fleas once it became pneumonic. 

Perhaps this particular outbreak was largely contained simply because there were not the extensive trade routes and number of people as in the 14th Century, but it would be interesting to know how far the plague spread from this 5,500 B.C. event. My suspicions are that if we were to ever see another plague outbreak comparable to the Black Death, it will also originate in this Central Asian marmot reservoir.

Lake Baikal is the largest lake just above Mongolia in this map, while Lake Issyk Kul is the only lake you can see in Kyrgyzstan in this map. (Source)