Understanding the Plague

With the world facing biowarfare after the recent Anthrax cases in Florida, scientists say they have mapped all the genes in the plague bacterium which could speed up research into vaccines and treatments. Along with smallpox and anthrax, the bubonic plague is one of the most feared potential biological weapons.

A 30 member team of scientists at Britain?s Wellcome Trust Sanger Center in Cambridge has discovered how the bacterium turned itself from a irritating stomach bug into the Black Death that killed 200 million people, or a third of Europe, in the 14th century. They have sequenced the 4,012 genes of the plague bacterium, or Yersinia pestis, and believe it evolved into such a lethal agent by gaining and losing bits of DNA around 1,500 years ago.

?This bacterium has made a radical change in lifestyle. Being able to see exactly what it is in the genome that has enabled it to do it is interesting. Hopefully it will shed light on the way it causes disease,? says Julian Parkhill, the head of the research team. ?You don?t need this sort of data to use it as a weapon. But you do need this data if you want to defend yourself against it. It is a potential biowarfare agent but it is also endemic. It is a naturally occurring disease that kills people.?

Although the disease is associated with the Middle Ages, up to 3,000 cases of bubonic plague are reported each year to the World Health Organization. The disease, which is transmitted by infected fleas to rodents and then humans, is still found in parts of south-east Asia, Africa and North America. It causes painful swelling under the arms and around the groin, chills, exhaustion and fever.

The researchers used a strain of plague that killed a veterinarian in the United States in 1992 who died after a cat infected with plague sneezed on him. Without effective drug treatments with antibiotics, the disease is nearly always fatal.

The mapping of the genome has allowed scientists to see, step by step, how it became so lethal. ?Having this data will without a doubt accelerate and facilitate subsequent research of the organism in terms of new drugs or vaccines,? says Parkhill. Antibiotics are an effective treatment and vaccines are available, but scientists fear that if the bacterium was used as a biological weapon there would not be enough stockpiles to treat and vaccinate large numbers of people.

?The benefits of making this kind of information publicly available greatly outweigh the risk of someone getting it and using it for nefarious purposes,? says Rick Titball of Britain?s Porton Down biological defense laboratory. ?It is much more valuable to someone who wants to develop vaccines and antibiotics.?

NOTE: This news story, previously published on our old site, will have any links removed.