An analysis of bodies discovered in a 200-year-old Hungarian crypt has shown how tuberculosis (TB) took hold in 18th century Europe, scientists say.
Researchers said that samples taken from naturally mummified bodies found in an 18th century crypt in the Dominican church of Vac in Hungary have yielded 14 tuberculosis genomes, suggesting that mixed infections were common when TB was at peak prevalence in Europe.
Lead author Professor Mark Pallen, from the University of Warwick, said the discovery was significant for current and future infection control and diagnosis.
"Microbiological analyses of samples from contemporary TB patients usually report a single strain of tuberculosis per patient," Pallen said.
"By contrast, five of the eight bodies in our study yielded more than one type of tuberculosis - remarkably from one individual we obtained evidence of three distinct strains," he said.
The team used a technique called "metagenomics" to identify TB DNA in the historical specimens - that is direct sequencing of DNA from samples without growing bacteria or deliberately fishing out TB DNA.
Researchers also found evidence of an intimate link between strains from a middle-aged mother and her grown-up daughter, suggesting both family members died from this devastating infection.
The team used the 18th century sequences to date the origin of the lineage of TB strains commonly found in Europe and America to the late Roman period, which fits in with the recent suggestion that the most recent common ancestor of all TB strains occurred as recently as 6,000 years ago.
"By showing that historical strains can be accurately mapped to contemporary lineages, we have ruled out, for early modern Europe, the kind of scenario recently proposed for the Americas - that is wholesale replacement of one major lineage by another - and have confirmed the genotypic continuity of an infection that has ravaged the heart of Europe since prehistoric times," Pallen said.
The study is published in the journal Nature Communications.