The sexually transmitted disease once caused widespread epidemics and is still a major cause of illness and death around the world.

It was almost eradicated from Britain 20 years ago, but now public health specialists are calling for new publicity campaigns to help prevent the spread of the infection.

Syphilis can be treated with injections of penicillin or other antibiotics.

Complacency

However, the early symptoms can be mild, absent or mimic those of other diseases, which means that many people do not seek treatment when they first become infected.

Health experts fear an increase in syphilis among homosexual men could be a sign of "complacency" about the dangers of HIV and other sexually transmitted diseases.

Due in part to safer sex practices promoted during the Aids scares of the early 80s, the disease virtually disappeared.

However, researchers writing in the British Medical Journal have said they are noticing dramatic increases in cases of syphilis.

In England the number of cases doubled in two years.

Many people who acquire syphilis have very very few symptoms to start with and may not know that they are infected

Dr Andy Winter

London, Manchester and Brighton are the worst affected. The spread of infection in these areas is largely being blamed on gay sex.

In Glasgow, specialists said only one or two cases were reported annually until the year 2000.

However, the city has seen about 20 cases in the last year.

Dr Andy Winter of Glasgow's Sandyford Institute - the city's leading clinic for sexually transmitted infections - told BBC Scotland that there had been a change in sexual behaviour over the last decade.

"For some reason syphilis has got into a number of people and once the sexual networks are set up then syphilis can spread very very easily by any unprotected sex, including unprotected oral sex."

He said the disease was more infectious than HIV - and could be difficult to spot in the early stages.

Testing plea

"Many people who acquire syphilis have very very few symptoms to start with and may not know that they are infected," he said.

"If they are not found in time to be treated then these late manifestations of syphilis, such as your nose being eaten away, could still be seen on these streets in 30 years time."

Dr Winter said the treatment was a straightforward course of penicillin.

"We are encouraging people who think they have been at risk of syphilis to come forward for testing and accept the treatment if they can," he added.