Scientists found a very old plague. It lived in people 5,500 years ago near Lake Baikal in Siberia.

科學家發現了一種非常古老的瘟疫。它在 5,500 年前出現在西伯利亞貝加爾湖附近的人類身上。

Scientists looked at old teeth from 46 people. They found the plague bacteria in 18 people. Many people in one village were sick.

科學家研究了 46 人的古舊牙齒。他們在 18 人的牙齒中發現了瘟疫細菌。某個村莊的許多人都染病了。

Before this, scientists thought the plague only happened in big cities with farms. But these people were hunters. They moved a lot. This means the plague can kill people even in small groups.

在此之前，科學家認為瘟疫僅發生在擁有農場的大城市中。但這些人是獵人，他們經常遷徙。這意味著即使在小規模群體中，瘟疫也能造成死亡。

This old plague was different. It did not use fleas. It moved from person to person through the air. It was very dangerous for children.

這種古老瘟疫與後來的不同。它不透過跳蚤傳播，而是透過空氣在人與人之間傳染。這對兒童來說非常危險。

Scientists think the plague came from marmots. Marmots are large animals. Hunters touched the animals and got sick.

科學家認為瘟疫源自土撥鼠。土撥鼠是一種大型動物，獵人接觸這些動物後便染病了。

The plague was in Siberia 5,500 years ago. It was different from the plague in later years.

5,500 年前的西伯利亞曾出現過瘟疫，與後期的瘟疫有所不同。

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。

Researchers have identified the earliest known instances of plague within hunter-gatherer populations near Lake Baikal, dating to approximately 5,500 years ago.

研究人員在貝加爾湖附近的狩獵採集人群中，發現了已知最早的鼠疫病例，時間約在 5,500 年前。

The discovery originated from the analysis of dental pulp samples from 46 individuals across four cemeteries along the Angara River. Utilizing shotgun sequencing, an international team identified Yersinia pestis DNA in 18 subjects. The prevalence rate at the Ust’-Ida I site is noted to be comparable to that of known medieval plague mass graves, suggesting a high level of community-wide infection.

此發現源於對沿安加拉河四座墓地中 46 個個體的牙髓樣本分析。一個國際團隊利用散彈槍定序技術，在 18 個樣本中發現了鼠疫桿菌（Yersinia pestis）的 DNA。Ust’-Ida I 遺址的盛行率與已知中世紀鼠疫大屠殺墓地相當，顯示當時社區整體的感染率極高。

Historically, epidemiological consensus posited that lethal plague outbreaks were contingent upon the transition to sedentary agricultural societies and the subsequent increase in population density and proximity to domestic animals. However, these findings indicate that highly virulent strains existed among mobile hunter-gatherers centuries prior to the Neolithic farming era. This suggests that the pathogen's lethality was not dependent on urban settlement patterns.

在歷史上，流行病學的共識認為，致命的鼠疫爆發取決於向定居農業社會的轉型，以及隨後的人口密度增加和與家畜接觸的緊密程度。然而，這些發現表明，在 Neolithic 農耕時代之前的數世紀，高致病性的菌株已存在於流動的狩獵採集者之中。這顯示病原體的致命性並不依賴於城市定居模式。

Genomic sequencing revealed that this ancestral strain lacked the specific genetic markers required for the formation of buboes and the murine toxin necessary for efficient flea-borne transmission. Consequently, it is hypothesized that the disease manifested as a pneumonic infection, facilitating human-to-human transmission via respiratory droplets. The presence of a superantigenic toxin is cited as the primary mechanism for the observed disproportionate mortality among children and adolescents, as their developing immune systems are more susceptible to the resulting systemic inflammatory overreaction.

基因組定序顯示，這種祖先菌株缺乏形成淋巴結腫大（buboes）所需的特定基因標記，以及有效經跳蚤傳播所需的鼠類毒素。因此，研究人員假設該疾病表現為肺炎感染，透過飛沫在人與人之間傳播。研究指出，超抗原毒素是導致兒童與青少年死亡率異常之高的主要機制，因為其發育中的免疫系統更容易對由此引起的全身性炎症過激反應產生反應。

Regarding the zoonotic origin, the researchers suggest a spillover event from marmots, which remain plague reservoirs in the region. The transmission likely occurred through direct contact during the hunting or processing of these rodents. This evidence supports the theory that the pathogen emerged in Central or North-East Asia before its subsequent dispersal across Eurasia.

關於動物源頭，研究人員認為是從旱兔（marmots）傳播而來，該動物至今仍是該地區的鼠疫宿主。傳播很可能是在狩獵或處理這些齧齒類動物時，透過直接接觸而發生。此證據支持了病原體先在中亞或東北亞出現，隨後才傳播至歐亞大陸的理論。

The study establishes that lethal plague outbreaks occurred in prehistoric Siberia 5,500 years ago, predating the agricultural era and utilizing different transmission mechanisms than later bubonic strains.

研究證實 5,500 年前的史前西伯利亞曾出現致命鼠疫爆發，早於農業時代，且傳播機制與後來的腺鼠疫菌株不同。