Strains of gonorrhoea with high levels of resistance to the antibiotic azithromycin have emerged in the United Kingdom, the Health Protection Agency (HPA) is warning.
The warning was made on April 4th and comes after six cases of gonorrohea were detected that were highly resistant to azithromycin; five in Liverpool and one in Cardiff. All six cases involved heterosexual transmission.
A single 1g dose of azithromycin is one of the recommended treatments for the sexually transmitted infection chlamydia. There is also evidence showing that a single 2g dose of the drug is highly effective against strains of gonorrhoea that are sensitive to the drug, but is associated with stomach upset. It is important to note that azithromycin is not recommended as a standard treatment for gonorrhoea in the UK.
Since 2000, the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) has been gathering data on drug resistant strains of gonorrhoea. In 2005, 2.2% of gonorrhoea cases involved resistance to azithromycin, but in some regions of the UK 5% of cases of the infection are azithromycin-resistant.
Many patients infected with gonorrhoea also have chlamydia and the HPA cautions “use of azithromycin to manage chlamydia may be treat[ing] undetected gonococcal infections also.”
None of the six patients with high-level azithromycin-resistant gonorrhoea reported by the HPA had a history of azithromycin therapy. Further, all six patients had gonorrhoea which could be treated with other antibiotics including penicillin, ciprofloxacin, spectinomycin, ceftriaxone and cefixime.
The HPA is stressing to clinicians that azithromycin should not be used for the treatment of gonorrhoea. Furthermore, patients treated with either doxycycline or azithromycin for chlamydia should not be regarded as being adequately treated for gonorrhoea.
Current UK treatment guidelines recommend an intramuscular injection of ceftriaxone or cefixime for gonorrhoea, and this should be provided at the same time of chlamydia therapy in patients with both infections.
The HPA is using its alert to remind clinicians that all laboratories should test gonorrhoea samples for resistance to ceftriaxone and cefixime as well as azithromycin, doxycyline, ciprofloxacin and penicillin and that cases of resistance should be reported.