Black Death unveiled
Completion of the Yersinia pestis sequencing will hopefully allow researchers to develop more drugs to combat the disease, which is still prevalent in some parts of the world. One vaccine produced at the Ministry of Defence's Porton Down establishment is already undergoing trials.
In recent times 'Black Death' is believed to have killed 200 million people, wiping out one-third of the European population in the 14th century. Even today up to 3,000 cases are reported annually to the World Health Organisation.
The 30-strong team of scientists working on the project were based at:
- The Wellcome Trust's Sanger Centre, where much of the human genome sequencing took place
- The Defence Science and Technology Laboratory at Porton Down
- The London School of Hygiene and Tropical Medicine
- St Bartholomew's Hospital
- Imperial College, London
A sample of the bacteria which was used during the three-year £330,000 study came from a vet in Colorado, USA, who died in 1992 after a plague-infested cat sneezed on him as he was trying to rescue it from underneath a house.
"Many people do not realise that plague is still with us, although it is not as common as it was. There are even some drug-resistant strains in Africa. It's down but not out, which is why this research is so important."
Dr Julian Parkhill, who led research at the Sanger Centre in Hinxton, Cambridgeshire
Recent research has revealed that Yersinia pestis - frequently carried by fleas which infest rats - may have evolved to its lethal state around 1,500 years ago. Until then it was a bug which caused gastroenteritis.
"During sequencing we discovered that the bacteria changed by gaining some bits of DNA and losing others. It has really adapted a different lifestyle in a remarkably short space of time, changing from being basically a stomach bug to a killer that has devastated the world. As we carried out the work it was as if we were looking through a window onto the evolution of pathogens, which we have never seen from any other bacteria. In the future this knowledge may be useful for surveillance and in predicting disease outbreaks."
Professor Brendan Wren, from the London School of Hygiene and Tropical Medicine
Details of the sequencing are posted on the internet so the information is freely available to researchers around the world.
"The benefits of making this kind of information publicly available greatly outweigh the risk of someone getting it and using it for nefarious purposes. It is much more valuable to someone who wants to develop vaccines or antibiotics. By putting this information out we can help accelerate research, especially in developing countries where they might not have sophisticated equipment. Indeed sequencing Yersinia pestis has helped development of a vaccine which is currently undergoing clinical trials."
Rick Titball, Technical Manager of Microbiology at Porton Down
The vet who died in America caught pneumonic plague, which is passed through coughing or sneezing and is fatal in nearly 100% of cases. Death can come within days. However most outbreaks today - in north America, Africa and south east Asia - are of the bubonic variety. This causes painful swellings under the arms and around the groin but is treatable. Fleas which carry the disease live on squirrels, rats and other wildlife. Having bitten their animal host they then pass it to humans. Apart from swellings symptoms can include, fever, chills and extreme exhaustion. A paper detailing the annotated sequence is published in this week's (4 October 2001) edition of Nature magazine.
- In the last major outbreak 855 people died from pneumonic plague in Surat, India in 1994
- One of the last known casualties of the disease in this country was a Mrs Bugg. She died in 1918 in Suffolk, followed a few days later by the last victim
- The plague bacillus was first isolated in 1894 by bacteriologist Andre Yersin who originally named it Pasteuralla pestis - after his teacher.