Geographical and demographic clustering of gonorrhoea in London

BACKGROUND: Gonorrhoea is an important cause of sexual ill health and is concentrated in geographical areas and demographic groups. This study explores the distribution of gonorrhoea across London. METHODS: Epidemiological data on all gonorrhoea cases were collected from 13 major genitourinary clinics in London between 1 June and 30 November 2004. Samples were stored centrally and typed using NG-MAST. The postcode of each case's main residence was used to calculate incidence of gonorrhoea by borough using data from the UK 2001 census and a population survey on residence of men who have sex with men (MSM). RESULTS: 2,891 cases were confirmed, 1,822 of which had postcode data, resided in London, and had their strain successfully typed. There was a very high incidence of gonorrhoea in MSM (1,834 per 100,000 population) and heterosexuals of black ethnicity (392 per 100,000). The incidence among heterosexuals was highest in City of London (390 per 100,000, 95% CI 213 to 566), Southwark (308 per 100,000, 95% CI 280 to 336), Hackney (284 per 100,000, 95% CI 254 to 313), and Lambeth (216 per 100,000, 95% CI 194 to 239) and was not associated with measures of social deprivation (correlation coefficient = 0.0008, p = 0.97) but was strongly associated with black ethnicity (correlation coefficient = 0.48, p = 0.01). 45% of cases had one of the 21 major strains; eight of these strains were significantly clustered geographically and persisted for a shorter duration than those that were not clustered. Patients travelled a mean of 7.7 km from their home to the clinic. CONCLUSIONS: High gonorrhoea incidence in London is observed in MSM and heterosexuals of black ethnicity. Endemic strains in both MSM and heterosexuals are diagnosed at multiple clinics. Interventions, including partner notification, must therefore operate between clinics.     

Mezlocillin in the treatment of gonorrhoea.

A single, intramuscular dose of 2 g of mezlocillin was used for the treatment of 158 patients with gonorrhoea. In only three out of 144 patients with urogential gonorrhoea who were re-examined did the treatment fail. Of 12 patients with pharyngeal gonorrhoea who were examined after treatment 10 were treated successfully with the same dose. The sensitivities of the gonococci to mezlocillin and penicillin G correlated well, although mezlocillin seemed to be active at lower concentrations on both highly sensitive and less sensitive isolates.     

Recent developments in the treatment of gonorrhoea

Rising failure rates with single injections of penicillin in gonorrhea are causing alarm. In the Far East, the failure rate is about 30% after single injections of 2.4 mega units of aqueous procaine penicillin. In London, although there is rising gonoccoccus resistance to penicillin, single injections of 1.2 mega units of aqueous procaine penicillin nets a cure rate of 85.8% to 91.5% in male patients. Other recent experiences in the treatment of gonorrhea in London men are outlined in this article. The failure rate was reduced to 5.8% when a single injection of 2.4 mega units of procaine penicillin was given. When 1 gm probenecid was given orally along with 1.2 mega units of procaine penicillin, the failure rate was 6.6%. Streptomycin is so ineffective now against gonorrhea that it is no longer acceptable even as a first treatment in patients who are allergic to penicillin. In London, the failure rate with streptomycin is 31.7%. Experts think the rate will jump to 85.8% in the next year. Many other antibiotics can be used against gonorrhea, but, as in the case of streptomycin, they may lose their effectiveness. Some recent experiences show that a combination of rolitetracycline by injection and tetracycline by mouth does not give as good results as a single injection of aqueous procaine penicillin but that comparable results can be obtained with single oral doses of rifampicin and superior results (95.7% success) were obtained with 2 oral doses of dementhylchlortetracycline.     

Amoxycillin in the treatment of gonorrhoea.

A series of 162 patients with uncomplicated genital gonorrhoea was assessed after single-dose treatment with 3 g. amoxycillin. This seems to be an acceptable method of treatment, resulting in clearance rates in both male and female patients of 99 and 95% respectively at the first follow-up. The default rates on follow-up over a 4-week period are also shown.     

Ceftizoxime in the treatment of uncomplicated gonorrhoea

A total of 74 men and 26 women with uncomplicated gonorrhoea were treated with ceftizoxime sodium 0.5 g intramuscularly. The cure rate was 99% and included successful treatment of four infections due to beta-lactamase producing organisms. The minimum inhibitory concentrations (MICs) of ceftizoxime in vitro were very much lower than those of penicillin and cefuroxime, and side effects were minimal. We conclude that ceftizoxime is effective against Neisseria gonorrhoeae in vivo and in vitro.     

Amoxycillin in the treatment of gonorrhoea.

A series of 162 patients with uncomplicated genital gonorrhoea was assessed after single-dose treatment with 3 g. amoxycillin. This seems to be an acceptable method of treatment, resulting in clearance rates in both male and female patients of 99 and 95% respectively at the first follow-up. The default rates on follow-up over a 4-week period are also shown.     

Acrosoxacin in the treatment of uncomplicated gonorrhoea

Acrosoxacin was given as a single 300 mg oral dose to 105 patients with acute gonorrhoea. Of the 100 patients followed completely there was a 93% cure rate and 33% of men developed postgonococcal urethritis (PGU). This compared with a 97% cure and 30% PGU with 2 megaunits penicillin. The in vitro activity of acrosoxacin in Nottingham against strains of Neisseria gonorrhoeae showed that it was a highly active agent with 90% of strains inhibited by a concentration of 0.03 mg/l.     

Mezlocillin in the treatment of gonorrhoea.

A single, intramuscular dose of 2 g of mezlocillin was used for the treatment of 158 patients with gonorrhoea. In only three out of 144 patients with urogential gonorrhoea who were re-examined did the treatment fail. Of 12 patients with pharyngeal gonorrhoea who were examined after treatment 10 were treated successfully with the same dose. The sensitivities of the gonococci to mezlocillin and penicillin G correlated well, although mezlocillin seemed to be active at lower concentrations on both highly sensitive and less sensitive isolates.