Researchers have found the earliest known evidence of the plague in hunter-gatherer groups near Lake Baikal, dating back about 5,500 years.

研究人員在貝加爾湖附近的狩獵採集群體中，發現了已知最早的瘟疫證據，可追溯至約 5,500 年前。

The discovery was made after analyzing dental samples from 46 people in four different cemeteries along the Angara River. Using advanced DNA sequencing, an international team found Yersinia pestis (the plague bacteria) in 18 of these individuals. The infection rate at one specific site was similar to that of famous medieval plague graves, which suggests that the disease affected a large part of the community.

這次發現是在分析沿著安加拉河四個不同墓地中 46 人的牙齒樣本後得出的。一個國際團隊利用先進的 DNA 定序技術，在其中 18 人體內發現了鼠疫桿菌（Yersinia pestis，即瘟疫細菌）。其中一個特定地點的感染率與中世紀著名的瘟疫墓地相似，這表明該疾病影響了社區中的很大一部分人。

Previously, experts believed that deadly plague outbreaks only happened after humans started farming and living in crowded cities close to domestic animals. However, these findings show that dangerous strains of the plague existed among mobile hunter-gatherers long before the farming era. Consequently, this proves that the disease did not need urban settlements to become lethal.

此前，專家認為致命的瘟疫爆發僅在人類開始農耕並居住在靠近家畜的擁擠城市後才會發生。然而，這些發現顯示，在農耕時代之前，危險的瘟疫菌株就已經存在於移動的狩獵採集者之間。因此，這證明了該疾病不需要都市定居點即可變得致命。

Genetic analysis revealed that this ancient strain was different from later versions. It lacked the genes needed to create buboes or to be spread efficiently by fleas. Therefore, researchers believe the disease spread from person to person through the air as a respiratory infection. Furthermore, a specific toxin caused a severe immune reaction, which explains why the disease was especially deadly for children and teenagers.

基因分析顯示，這種古代菌株與後來的版本不同。它缺乏產生淋巴結腫大（buboes）或透過跳蚤高效傳播所需的基因。因此，研究人員認為該疾病是透過空氣，以呼吸道感染的方式在人與人之間傳播。此外，一種特定的毒素引起了嚴重的免疫反應，解釋了為什麼該疾病對兒童和青少年特別致命。

This study proves that lethal plague outbreaks occurred in prehistoric Siberia 5,500 years ago, showing that the disease could spread and kill effectively before the rise of agriculture.

這項研究證明了 5,500 年前的史前西伯利亞曾發生致命的瘟疫爆發，顯示出在農業興起之前，該疾病就能有效地傳播並致死。