Wednesday, October 6, 1999 Published at 17:17 GMT 18:17 UK
Diphtheria genetic code cracked
Sneezing can spread diphtheria
By BBC News Online Science Editor Dr David Whitehouse
Scientists at the UK's Sanger genome sequencing centre are about to post the genetic sequence for the bacterium that causes Diphtheria on the Internet.
Diphtheria is an infection of the respiratory tract and a major killer in developing countries. It is passed from person to person through close physical contact or through coughs and sneezes. Transmission is increased in conditions of poor hygiene and overcrowding.
The bacterium comes in many strains and the Sanger scientists have chosen to sequence strain NCTC13129. This has only recently been isolated despite being the cause of a current epidemic in Eastern Europe.
Decoding the entire genetic sequence of the bacterium will, hopefully, provide the information needed to develop better vaccines against the disease.
By knowing how many genes the bacterium has and how they function scientists hope to be able to design a drug that will interfere with a key gene that the bacterium needs to live.
During the Second World War it has been estimated that there were over a million cases of Diphtheria, with more than 50,000 fatalities in 1943 alone. Before the widespread use of vaccines in the 1950's Diphtheria was a major killer in almost all countries.
In temperate climates, the main victims of this disease are pre- and school-age children. Use of vaccines has reduced the death toll considerably but it still surges back from time to time in developing countries.
Recent outbreaks have occurred in Algeria, China, Jordan, Lesotho and the Sudan.