A disease that wiped out a third of the population of Europe in the Middle Ages has returned to the African island of Madagascar and killed 20 people, medical experts have confirmed.
All the deaths occurred in a village near the northwestern town of Mandritsara. The Pasteur Institute of Madagascar ran tests and confirmed all victims had died from the bubonic plague.
The International Red Cross (ICRC) launched a campaign in October to prevent the disease spreading after warnings that the island nation was at serious risk of an epidemic.
In 2012, Madagascar recorded 256 cases of the plague with 60 deaths, according to the World Health Organisation. The source of the disease has been traced to prisons where conditions are filthy.
The bubonic plague, also known as the Black Death, killed an estimates 25 million people across Europe during the Middle Ages.
"The chronic overcrowding and the unhygienic conditions in prisons can bring on new cases of the disease," said Christoph Vogt, head of the ICRC delegation in Madagascar. "That's dangerous not only for the inmates but also for the population in general."
The disease is spread to humans via fleas on rats. The ICRC was trying to eradicate all rats from Madagascar's prisons to help control the spread of the plague.
Vogt added: "Rat control is essential for preventing the plague because rodents spread the bacillus to fleas that can then infect humans. So the relatives of a detainee can pick up the disease on a visit to the prison. And a released detainee returning to his community without having been treated can also spread the disease."
According to the ICRC, there has been on average 500 of the plague recorded in Madagascar every year since 2009. Outbreaks have also been in countries such as India, Indonesia, Algeria, and the Democratic Republic of Congo.