Gonorrhea could become extremely difficult to treat if its increasing resistance to antibiotics is not addressed soon, says a British specialist on the sexually transmitted infection.

Some strains of the gonococcal bacteria that cause the disease are showing less sensitivity to the antibiotics used to treat them, Professor Catherine Ison of the Health Protection Agency in London told a meeting of the Society for General Microbiology in Edinburgh on Tuesday.

'There are few new drugs available, and so, it is probable that the current use of a single dose [of antibiotics] may soon need to be revised.'— Catherine Ison

The infection can be transmitted through oral, genital or anal sex with an infected person. If left untreated, the disease can cause other problems, including infertility in women, pelvic inflammatory disease, a greater susceptibility to HIV and serious blood, joint and immune complications.

Two antibiotics, ceftriaxone and cefixime, are used to treat the infection.

"The current drugs of choice, ceftriaxone and cefixime, are still very effective, but there are signs that resistance, particularly to cefixime, is emerging, and soon, these drugs may not be a good choice," Ison said in a news release.

Bacteria isolated from people diagnosed with gonorrhea are tested for their susceptibility to various antibiotics to monitor patterns of resistance both locally and nationally.

"There are few new drugs available, and so, it is probable that the current use of a single dose may soon need to be revised, and treatment over several days or with more than one antibiotic will need to be considered," Ison said.

"If this problem isn't addressed, then there is a real possibility that gonorrhea will become a very difficult infection to treat."

Cases of a gonorrhea superbug, that is, strains of the bacteria that are resistant to multiple drugs, have started to appear in Japan and Hong Kong. Japanese health authorities have decided to use the same antibiotic at a higher dose, Ison told Reuters.

Microbiologists say the most important protection against any sexually transmitted infection is to practice safe sex, including using condoms.

In February 2009, researchers in Ontario reported that in 2006, 28 per cent of gonorrhea cases treated with another type of antibiotics, known as quinolones, were found to be resistant to it, compared with only two per cent in 2001.

Since 2006, guidelines have cautioned doctors against using quinolone antibiotics such as ciprofloxacin and oflloxacin to treat gonorrhea. The Ontario team said the findings underscored the importance of following the recommendation.

A commentary accompanying that study stressed the importance of ongoing testing for antibiotic resistance to ensure multi-drug resistance is quickly identified and contained given the reports of resistance to cefixime and ceftriaxone in Japan and Hong Kong.