Saturday, January 28, 2023
News on Pathogens and Preparedness
Global Biodefense
  • Featured
  • COVID-19
  • Funding
  • Directory
  • Jobs
  • Events
  • Subscribe
No Result
View All Result
  • Featured
  • COVID-19
  • Funding
  • Directory
  • Jobs
  • Events
  • Subscribe
No Result
View All Result
Global Biodefense
No Result
View All Result
Home Featured News

Smallpox Research Blurs Line Between Ancient Diseases, Emerging Infections

by Global Biodefense Staff
December 20, 2016
Smallpox

SmallpoxNew research suggests that smallpox, a pathogen that caused millions of deaths worldwide, may not be an ancient disease but a much more modern killer.

An international team of researchers from McMaster University, University of Helsinki, Vilnius University and the University of Sydney raise new questions about the role smallpox may have played in human history and fuels a longstanding debate over when the virus that causes smallpox, variola, first emerged and later evolved in response to inoculation and vaccination.

“Scientists don’t yet fully comprehend where smallpox came from and when it jumped into humans,“ says evolutionary geneticist Hendrik Poinar, senior author of the study, director of the McMaster Ancient DNA Centre and a researcher with Michael G. DeGroote Institute of Infectious Disease Research. “This research raises some interesting possibilities about our perception and the age of the disease.”

Smallpox, one of the most devastating viral diseases ever to strike humankind, had long been thought to have appeared in human populations thousands of years ago in ancient Egypt, India and China, with some historical accounts suggesting that the pharaoh Ramses V – who died in 1145 BC — suffered from smallpox.

In an attempt to better understand its evolutionary history, and after obtaining clearance from the World Health Organization in Geneva, scientists extracted heavily fragmented DNA from the partial mummified remains of a Lithuanian child believed to have died between 1643 and 1665 – a period in which several smallpox outbreaks were documented throughout Europe with increasing levels of mortality.

The smallpox DNA was captured, sequenced and the ancient genome, one of the oldest viral genomes to date, was completely reconstructed. There was no indication of live virus in the sample and so the mummies are not infectious.

Researchers compared and contrasted the 17th Century strain to those from a modern databank of samples dating from 1940 up to its eradication in 1977. Strikingly, the work shows that the evolution of smallpox virus occurred far more recently than previously thought, with all the available strains of the virus having an ancestor no older than 1580.

“This study sets the clock of smallpox evolution to a much more recent time-scale,” said evolutionary biologist Eddie Holmes, a professor at the University of Sydney, Australia.

“Although it is still unclear what animal is the true reservoir of smallpox virus and when the virus first jumped into humans.”

The pox viral strains that represent the true reservoir for human smallpox remains currently unsampled. Both the closest gerbil (Tetarapox) and camel pox are very distantly related and consequently are not the likely ancestors to smallpox, suggesting that the real reservoir remains at large or has gone extinct.

Researchers also discovered that smallpox virus evolved into two circulating strains, variola major and minor, after English physician Edward Jenner famously developed a vaccine in 1796.

One form of VARV (Variola virus), known as V. major was highly virulent and deadly, the other V, minor much more benign. However, scientists say, the two forms experienced a ‘major population bottleneck’ with the rise of global immunization efforts. The date of the ancestor of the minor strain corresponds well with the Atlantic Slave trade which was likely responsible for partial worldwide dissemination.

“This raises important questions about how a pathogen diversifies in the face of vaccination. While smallpox was eradicated in human populations, we can’t become lazy or apathetic about its evolution – and possible reemergence—until we fully understand its origins,” says Ana Duggan, a post doctoral fellow in the McMaster Ancient DNA Centre.

Whether the date of the ancestor, approximately 1580, precludes the massive destruction of aboriginal populations in central America by smallpox, introduced by the Spanish, remains questionable. To that end, researchers must carefully examine the remains of individuals buried in epidemic burials in central and southern America, say scientists.

“This work blurs the line between ancient diseases and emerging infections. Much of smallpox evolution apparently happened in historic time,” says Margaret Humphreys, historian of medicine at Duke University.

The World Health Organization declared smallpox eradicated in 1980.

Tags: PoxvirusesSmallpox

Related Posts

Influenza Proteins Tilt and Wave in ‘Breath-like’ Motions
Pathogens

Influenza Proteins Tilt and Wave in ‘Breath-like’ Motions

January 25, 2023
NIH Grant Awarded to Study Evolution of Lyme Disease Bacteria in Deer Ticks
Pathogens

NIH Grant Awarded to Study Evolution of Lyme Disease Bacteria in Deer Ticks

December 7, 2022
Bat Virus Receptor Studies Vital to Predict Spillover Risk
Pathogens

Bat Virus Receptor Studies Vital to Predict Spillover Risk

December 7, 2022
2022 Oral Rabies Vaccine Efforts Underway in Eastern United States
Pathogens

2022 Oral Rabies Vaccine Efforts Underway in Eastern United States

August 8, 2022
Load More

Latest News

Partner Therapeutics’ Novel Approach to Stratify Sepsis Patients Gains Backing From BARDA

Biopreparedness Research Virtual Environment (BRaVE) Initiative Backed by $105M DOE Funding

January 25, 2023
Influenza Proteins Tilt and Wave in ‘Breath-like’ Motions

Influenza Proteins Tilt and Wave in ‘Breath-like’ Motions

January 25, 2023
Biodefense Headlines – 24 January 2023

Biodefense Headlines – 24 January 2023

January 24, 2023
Biodefense Headlines – 17 January 2023

Biodefense Headlines – 17 January 2023

January 17, 2023

Subscribe

  • About
  • Contact
  • Privacy
  • Subscribe

© 2022 Stemar Media Group LLC

No Result
View All Result
  • Featured
  • COVID-19
  • Funding
  • Directory
  • Jobs
  • Events
  • Subscribe

© 2022 Stemar Media Group LLC