Enfoques interdisciplinarios de divulgación, discusión y reflexión de temas medievales
sábado, 1 de febrero de 2014
Return of the Black Death: Ancient bug plagues us once again
Scientists this week warned a strain of plague that killed more than 100million people could rise from the dead and strike again.
Their chilling vision sounds like something from a fanciful Hollywood script but for the people of Madagascar, it is a grim reality.
About 40 people on the island, just off the coast of south-east Africa, have died of the plague. Characterised by painful swellings, or buboes, in the lymph nodes, bubonic plague – or the Black Death – killed an estimated 25million people in Europe during the Middle Ages.
It is most commonly transmitted by flea bites and can be treated with antibiotics, if the strain is not drug-resistant. In its pneumonic form, plague is even more lethal. It can kill within 24 hours and is transmitted from person to person through infected droplets spread by coughing.
The recent outbreak was one of the worst globally in the past few years, with the Red Cross warning Madagascar was at risk of an epidemic.
The country has problems with overcrowding and unhygienic conditions and there has been a programme in prisons to exterminate rats, fleas and cockroaches.
But should we be taken aback by the news?
‘Not really,’ said Sandy Cairncross, a professor of environmental health at the London School of Hygiene and Tropical Medicine.
‘Many of the things that were life-threatening to people in Britain in the Middle Ages or even up until the 18th or 19th centuries are still fairly common in developing countries.
‘I guess some people are surprised when they find that developing countries are as backward as they turn out to be in terms of public health.’
His colleague, Brendan Wren, professor of microbial pathogenesis, said: ‘Plague is a “down but not out” disease. So you do get 2,000 to 3,000 cases a year worldwide.
‘What might be surprising is it’s endemic in parts of the US as well, particularly the forest areas in some of the national parks, thanks to ground squirrels and small furry animals that are indigenous to western parts of the country. Trappers occasionally get plague and they do die of it. Cats can carry it as well.’ Prof Wren added ‘you’ll probably never ever get rid of it in the US’.
He said: ‘To eliminate it completely, you’d need to get rid of it in all humans and wildlife, and that’s virtually impossible. The best we can say is we have the organism under control.’
The disease spreading today is caused by the Yersinia pestis bacterium and is identical to the one during the Middle Ages.
Prof Cairncross said the disease can lie dormant for long periods because it has ‘animal reservoirs’, allowing the bug to survive in various creatures before passing back to humans again.
He had a brush with plague himself while helping to build a district water supply in Lesotho, southern Africa – spotting a flea on one of the workers before discovering a dead mouse while excavating near the pipeline.
Prof Cairncross knows the value of antibiotics after his uncle died in the 1940s of leptospirosis, or Weil’s disease, after fishing in a Yorkshire river and scratching his leg in the water.
The drugs that could have saved his life were only just coming into use.
But Prof Wren says plague is highly unlikely ever to return to Britain.
‘Unless there’s a release for nefarious purposes,’ he said. ‘It is on the bio-terrorist threat agents list and that’s the only way it could come back to the UK.
But other ‘ancient’ diseases are cropping up here again.
More than 8,750 tuberculosis cases were reported last year – 3,426 of them in London, the TB capital of western Europe.
There has not been a case of cholera in England since 1893.
However, Haiti, the scene of a catastrophic earthquake four years ago, suffered an epidemic thought to have been started accidentally by UN soldiers sent to help.
Leprosy also still stalks the planet.
Mia Hadrill became determined to correct people’s mistaken beliefs after a trip to southern India, where she volunteered at a specialist hospital, followed by time spent as an intern at The Leprosy Mission Scotland.
The Londoner has now written Bela, a picture book for children to educate them about the condition.
‘I’ve heard every leprosy joke going. But in India, I learnt first-hand how misconceptions have a devastating effect on people living with it in the 21st century,’ she said.
‘Whether it is believed to be caused by divine punishment, witchcraft, or being licked by a two-headed snake, false belief can cause self-loathing, ostracism, abandonment and isolation for the many people who live with this disease around the world.’