New UK figures show further rise in sexually transmitted infections

The incidence of sexually transmitted infections is continuing to rise in the United Kingdom, particularly in young people and women, show the latest figures, which also indicate a drift towards resistance of gonorrhoea to the only remaining effective antibiotics.

The Health Protection Agency’s figures show that the number of new diagnoses increased by 3% (from 470 701 to 482 696) between 2008 and 2009, continuing the upward trend of the past 10 years.

The rise was primarily due to an increase in genital chlamydia, the number of new diagnoses of which went up by 7% over the past year (from 203 773 to 217 570). This was partly because of greater availability of screening.

New cases of gonorrhoea rose by 6% (16 451 to 17 385) and genital herpes by 5% (28 807 to 30 126) in the same period, while new diagnoses of genital warts were relatively unchanged and those of syphilis fell slightly.

“In recent years we have seen a steady increase in new sexually transmitted infections,” said Justin McCracken, the agency’s chief executive. “This year is no exception. These are all preventable infections, and it is a cause of considerable concern that we are still seeing increases across the UK, especially in gonorrhoea, where we know drug resistance is emerging.”

Women are at particular risk, the figures indicate, with a 4% rise in new infections in women over the past year, whereas the rise in men was 1%.

New infection rates were highest in adults under the age of 25 years, and this age group accounted for around two thirds of new diagnoses in women and over half of those in men. The peak age for sexually transmitted infection was 19-20 years in women and 20-23 years in men.

Nearly two thirds (65%) of diagnoses of chlamydia, half (50%) of all cases of gonorrhoea, and a similar proportion of genital warts (55%) and genital herpes (43%) occurred in the under 25 age group, according to figures for people attending genitourinary medicine clinics in 2009.

Men who have sex with men also showed a high rate of new diagnoses. Figures for 2009 where sexual orientation was recorded showed that about 66% of new diagnoses of syphilis and 36% of those of gonorrhoea were in this group.

“These figures show that poor sexual health remains a serious problem among the UK’s young adults and among men who have sex with men,” said Gwenda Hughes, head of the agency’s sexually transmitted infection section. The increase in new diagnoses is partly due to more testing for these infections and the use of more sensitive diagnostic tests, she said. “But unsafe sexual behaviour is continuing—particularly in certain groups.”

The new figures show that rates of re-infection in young adults are high. More than one in 10 (11% of women and 12% of men) 16 to 19 year olds who were given a diagnosis and were treated for a sexually transmitted infection last year were given a diagnosis of a further infection within one year.

Among the latest findings from a surveillance programme for gonococcal resistance to antimicrobials was the emergence of potential resistance to cephalosporins, the only antibiotic class that is still effective. Although no cases of treatment failure have yet been reported, laboratory testing of isolates showed an increase of bacteria with decreased susceptibility to cefixime (the main antibiotic currently used to treat gonorrhoea in the UK), from 0.1% in 2005 to 10.6% in 2009.

Cathy Ison, from the agency’s centre for infections, said, “At the moment the antibiotics we use are still effective for treating gonorrhoea. But our lab tests show that the bacteria are becoming less sensitive to these drugs, and we don’t have another one down the line.”