The research project started as a way to identify Finnish bones from World War II, lost for decades in the wilderness of the Soviet Union and finally brought home in the last 17 years. In total, 106 soldiers were recovered and DNA was extracted from their bones in hopes of identifying the unknown men.
Researchers from University of Helsinki and the University of Edinburgh were curious beyond basic identification and wanted to examine the DNA for viral infections as a method of studying the incidence of historic diseases. They selected Parvovirus B19 (which causes Fifth Disease) as it is a fairly prevalent virus and one that, once established, persists within the body. Many viruses are cleared from the body by the immune system following infection, but some viruses, like herpes viruses for example, form life-long latent infections that can be detected years after the initial infection.
Of the 106 subjects, 43 (45%) tested positive for one of two different strains of Parvovirus (there are three genotypic strains in total). In fact, upon further testing, while 41 men tested positive for one strain, the 2 men that tested positive for the second strain were found via mitochondrial and Y chromosome testing to be Russian in origin and not part of the Finnish army at all. Only the Finns tested positive for that specific strain, one that disappeared from Europe in the 1970s, but was known at the time to be a Northern European strain.
This research opens up some interesting ideas about geographic identification. We’ve previously discussed the use of strontium isotopes as a way of identifying where an unknown victim was born or recently lived. This technique would give researchers a way of following an individual through wherever he or she has lived and been infected by selective viruses. And as soft tissue in victims can quickly decompose, leaving behind the hardier bones for decades or centuries, a long lasting substrate for analysis could be a crucial part of identification.
Personally, I found this story interesting as the overwhelming majority of viral infections occur in the body’s soft tissues. Dengue virus, one of the viruses I study in my day job in the lab, has been identified for decades, but there is still much to learn about it, including which tissue and specific cells it infects. Many other viruses have similar questions. So far, this research has only been conducted on DNA-based viruses. RNA-based viruses, including dengue, are much more fragile, and likely would not be able to withstand the long-term conditions involved in this case. But under the right conditions, it is possible that RNA viruses might be extracted and identified. Something for discussion at lab meeting perhaps?
It’s been a hectic few months, so Ann and I are going to take a few weeks off to enjoy the holiday season, but we’ll be back on January 5th. Happy holidays to all!
Photo credit: AJC ajcann.wordpress.com