This year the start of the Christmas party season has coincided with a Ministry of Health report on the considerable recent rise in the number of syphilis cases.

The thought of syphilis has terrified careless partygoers for hundreds of years. Indeed, past cynics even suggested that the disease was as important as a belief in Hell in keeping young people on the path of righteousness.

The incidence of syphilis has leapt up in the few years since I stopped practising NHS genito-urinary medicine. New cases were then a rarity, with only 137 registered in the UK in 1996. In 2005 nearly 3,000 were recorded. Fortunately, if syphilis is diagnosed early, massive doses of penicillin will cure it.

There are now more cases of other sexually transmitted diseases, too, especially chlamydia, which is too readily underestimated. Most doctors consider chlamydia to be the principal cause of pelvic inflammatory disease — infection of the Fallopian tubes and the peri-ovarian tissue — that is a frequent factor in infertility and ectopic pregnancies. An attack of pelvic inflammatory disease induces infertility in one woman in ten, and increases the risk of an ectopic pregnancy six or sevenfold. Chlamydia may also reduce male fertility and in both sexes there are rarer complications such as Reiter’s syndrome — an unpleasant combination of arthritis, discharge, eye problems and skin troubles.

A recent study indicated that two thirds of young people who have unprotected sex never have a sexual health check-up. Unfortunately they extend this ignorance-is-bliss philosophy to their sexual partners. Half of all those in the study would not inform their regular partner if they were found to have an STD, despite knowing that they could have infected them. Less surprisingly, more than 60 per cent said that they would not tell their partners if they had sex with another man or woman without taking any precautions.

Research suggests that even though people would be well advised to have periodic check-ups at a genito-urinary clinic, many are unwilling, too busy or too embarrassed to attend one. All those who have unprotected sex and don’t attend such clinics regularly should find out about the new reliable, discreet self-help kits of the SELFCheck range. These are available to test for chlamydia from Tesco, Rowlands pharmacies, the Co-op and Day Lewis.