Paleopathology, paleovirology and molecular biology are helping to uncover the complex history of ancient pathogens and diseases.These efforts are supported by sophisticated technologies such as next generation sequencingwhich enables scientists to analyze ancient DNA (aDNA) samples that are often thousands of years old.
A deeper understanding of the history of human interactions with pathogens, how different societies respond to disease, and the origins of pathogens supports our understanding of human health and evolution. It may even help enhance our preparedness for emerging diseases.
Let’s explore what we’re still learning about ancient pathogens and diseases.
A complex picture of life and death during the 1918 pandemic
The 1918 influenza, also known as the “Spanish Flu”, killed an estimated 50 million people worldwide. Because so many people develop the disease so quickly, the disease appears to have a high mortality rate among young people.
Research supports the idea that the 1918 influenza pandemic did not discriminate against young people, Health, disease, or infirmity relies heavily on historical documents. Life insurance records, census data and vital statistics have been analyzed, but they fail to capture data on pre-existing medical conditions or other factors such as a patient’s environment or diet.A recently published study Proceedings of the National Academy of Sciences This idea changed forever; the 1918 influenza pandemic did not kill large numbers of healthy and young people.1
The research was conducted by Dr. Amanda WislerAn assistant professor in the Department of Anthropology at McMaster University, his team analyzed the remains of 369 people who died between 1910 and 1938.
The remains are divided into two categories: those who died during the epidemic and those who died forward Pandemic as control group. The researchers looked for lesions (areas of damaged or altered bone) that may have been caused by infection in the remains’ tibiae. By understanding whether lesions were active or healed at the time of death, Wisler and colleagues can decipher whether a person had underlying health problems—i.e., they can gain insight into how frail they were.
“The results indicate that frail or unhealthy individuals are more likely to die during the pandemic than those who are not frail. During influenza, the estimated risk for individuals with active periosteal lesions at the time of death was more than double that of controls,” the research team explain.
“The results of our work are contrary to the narratives and anecdotes of the time,” Add to Wiesler. “This paints a very complex picture of life and death during the 1918 pandemic.”
New understanding of origins of disease in the Americas
During the colonial period, millions of people from the west coast of Africa were enslaved and forced to work as laborers in the Americas.professor Maria del Carmen Avila Arcos Leads the International Laboratory for Human Genome Research in Queretaro, Mexico. Here, her research team analyzes DNA and samples from modern populations, exploring the genetic history of understudied populations such as Native Americans and Afro-Mexicans.
The colonists’ invasion of the Americas resulted in mass deaths of the native populations through massacre and disease. Understanding the disease conditions to which these populations were exposed is an important application of Avila Arcos ancient DNA (aDNA) analysis. recenther team successfully extracted and sequenced viral DNA from skeletal remains found in mass graves dating back to the 16th century.th century.2
These tombs are located in what we know today as Mexico City. “One of the remarkable findings from aDNA is that some African-born people – who may have been forcibly brought to New Spain as part of the transatlantic slave trade – carried a number of viruses: hepatitis B and human parvovirus B19, which The virus may also have originated in Africa,” Avila Arcos explain.
The data suggests that some of the pathogens circulating during this period originated in Africa, challenging previous notions. It also highlights another negative impact of colonization on indigenous and African populations.
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Ancient viruses lurk in permafrost
Looking back can provide a deeper understanding of the challenges our ancestors faced. It can also awaken potential challenges that those of us now, or those after us, may encounter in the future.
At the Aix-Marseille University School of Medicine in Marseille, Professor Emeritus John Michel Clavery You spent many years analyzing samples of Siberian permafrost. As Earth’s temperatures continue to rise, melting permafrost will release organic matter, such as gases, that have been “trapped” for up to a million years.While these gases further contribute to global warming, which is a major cause for concern, Claverie’s focus is Others Lurking in the frozen land.
When permafrost thaws, cellular microorganisms and viruses are also released. Clavery’s research has previously shown that these pathogens, often referred to as “zombie” viruses, are still contagious.
Earlier this year, Claverie published a study reporting the characteristics of 13 new viruses isolated from seven ancient Siberian permafrost samples.3 One strain is estimated to be 48,500 years old, based on radiocarbon dating. The viruses belong to five different clades that have never been resurrected from permafrost before, including Pandoravirus, Sedaravirus, Megavirus, Parkmanvirus and a new strain of Pisovirus. All viruses are capable of infecting amoeba cells.
“It is therefore likely that ancient permafrost (ultimately older than 50,000 years old, our limits entirely depend on the range of validity of radiocarbon dating) could release these unknown viruses as they thaw,” the researchers said. ” Write.
Exactly how long the virus remains infectious once exposed to environmental conditions such as oxygen, heat and ultraviolet light is unclear. Nor is it known how likely the virus is to encounter and infect a host organism. But, as Clavera and colleagues describe, “risks are bound to increase in the context of global warming, permafrost melting will continue to accelerate, and as industrial enterprises rise, more people will live in Arctic.”
As we continue to explore ancient diseases and pathogens, it’s clear that the past holds valuable lessons. However, many mysteries remain for scientists to unravel.
refer to:
1. Wiesler A, DeWitt SN. Frailty and survival during the 1918 influenza pandemic. Proceedings of the National Academy of Sciences. 2023;120(42):e2304545120. doi:10.1073/pnas.2304545120
2. Guzmán-Solís AA, Villa-Islas V, Bravo-López MJ, et al. Ancient viral genomes reveal introduction of human-pathogenic viruses into Mexico during the transatlantic slave trade. Perry GH, Guerra Amorim CE, Houldcroft CJ, editors. electronic life. 2021.doi: 10.7554/eLife.68612
3. Alempic JM, Lartigue A, Goncharov AE, Grosse G, Strauss J, Tikhonov AN, Fedorov AN, Poirot O, Legendre M, Santini S, et al. Recent advances in resurrecting eukaryotic viruses from ancient permafrost. Virus. 2023.doi:10.3390/v15020564