Black Death survivors lived longer and healthier than those before the 1347 epidemic, according to a University of South Carolina study.

Black Death or bubonic plague, caused by the bacteria Yersinia pestis, erased nearly 30 percent of Europeans and 50 percent of Londoners from 1347 - 1351.

Researchers said that analysis of an epidemic helps scientists and medical practitioners understand its emergence and impact on person's health.

"Knowing how strongly diseases can actually shape human biology can give us tools to work with in the future to understand disease and how it might affect us," anthropologist Sharon DeWitte in the College of Arts and Sciences, said in a statement.

For the study, the researchers examined over 1,000 skeletons (collected from London cemeteries including St. Mary Spital, Guildhall Yard, St. Nicholas Shambles and St. Mary Graces) of individuals who lived before, during and after the 14th-century Black Death.  In the process, the researchers determined the biological sex and age at death and at the same time analysed specific markers like porous lesions and teeth to measure individual's general health.

The researchers found that post-Black death samples comprised of a higher percentage of older adults, 70 or 80 years compared to pre-Black Death populations. Before the Black Death, only about 10 percent of people lived beyond 70 years, whereas the same figure rose to 20 percent post the plague, Live Science reports.

The researchers also discovered that the plague was not an arbitrary execution as previously claimed, but attacked people in poor health of all ages.

DeWitte said that prolonged life observed post the plague might be the outcome of two probabilities - the epidemic wiping out the old and the weak or the survivors had more resources (fish and high quality bread) in larger quantities at their disposal as a result of the death of half of the population.

DeWitte claimed that this is a first of a kind study due to the uniqueness and rareness of the samples studied.

"..., most medieval historical records only tell about the experience of men. We have little information about the experiences of women and children and the poor in general during medieval plague epidemics, including the Black Death. My bioarchaeological data allows us to understand how the population in general fared during and after the epidemic," DeWitte said

The findings are published in the journal PLOS ONE.