Evaluation of the serodia Treponema pallidum particle agglutination, the Murex Syphilis ICE and the Enzywell TP tests for serodiagnosis of syphilis.

We evaluated the Treponema pallidum haemagglutination assay (TPHA), a treponemal test, with three other treponemal tests, the Serodia T. pallidum particle agglutination assay, the Murex Syphilis ICE IgG + IgM enzyme immunoassay (EIA) and the Enzywell TP IgG + M EIA (a new rapid EIA) for use in conjunction with the rapid plasma reagin test (RPR), a non-treponemal test, for serodiagnosis of syphilis. In all, 124 serum samples were found reactive with RPR and/or TPHA after testing by the routine laboratory protocol. Twenty-three (18.5%) of them were positive only by RPR test and were evaluated as biologically false-positive, 16 were positive only by the TPHA and 84 by both the RPR and TPHA tests; one sample was non-specific (heterophile reaction) in the TPHA. Agreements of the TPHA with the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP tests were 96.7%, 100% and 99.1%, respectively. We conclude that each one of the tests, the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP, is an appropriate substitute for screening for serodiagnosis of syphilis.

Antiviral therapy after penetrating keratoplasty for herpes simplex keratitis.

OBJECTIVE: To assess the efficacy of prophylactic topical antiviral therapy after penetrating keratoplasty for herpes simplex keratitis in the postoperative period and during the treatment of allograft rejection episodes with topical steroids. We used these data to make predictions of the sample size required to perform a prospective study of prophylactic oral acyclovir in the postoperative period. DESIGN: Retrospective review. SETTING: A university referral cornea service. PATIENTS: One hundred thirty-two consecutive penetrating keratoplasties for herpes simplex keratitis in 119 eyes of 118 patients. Only four grafts were performed in actively inflamed eyes. INTERVENTIONS: Sixty-six (52%) of the grafts performed in quiescent eyes received prophylactic postoperative topical antiviral treatment, three (2%) received oral acyclovir, and 59 (46%) received no antiviral therapy. The mean (+/- SD) duration of antiviral therapy was 12.8 +/- 22.5 months. MAIN OUTCOME MEASURES: Herpetic recurrence, allograft rejection episodes, and graft failure. RESULTS: Multivariate analysis showed that early antiviral use was associated with a decreased risk of herpes simplex keratitis recurrence (relative risk [RR] = 0.44; 95% confidence interval [CI], 0.21 to 0.94; P = .007) and allograft rejection (RR = 0.43; 95% CI, 0.25 to 0.75; P = .002). Graft failure was associated with herpetic recurrence within the first year (RR = 2.25; 95% CI, 1.09 to 4.64; P = .001) and allograft rejection episodes (RR = 2.56; 95% CI, 1.20 to 5.26; P = .003). Using these data, a prospective trial of postoperative oral acyclovir would require between 59 and 112 patients per group. CONCLUSIONS: Postoperative prophylactic antiviral treatment is associated with decreased rates of herpes simplex viral keratitis recurrence and allograft rejection. Early recurrence is associated with an increased risk of graft failure. A prospective study of postoperative oral acyclovir would require a multicentered approach.

Outcome of penetrating keratoplasty after ocular trauma in children.

OBJECTIVE: To characterize the outcome of penetrating keratoplasty in children for the visual rehabilitation of corneal injury. DESIGN: Multicenter retrospective study of the outcome of penetrating keratoplasty for ocular trauma in children. PATIENTS: All children aged 12 years and younger who underwent penetrating keratoplasty between January 1975 and May 1993 for penetrating corneal (n = 18) or corneoscleral (n = 3) trauma and nonpenetrating corneal trauma (n = 1). MAIN OUTCOME MEASURES: Graft survival and postoperative visual acuity improvement. RESULTS: Twenty-two children underwent 25 penetrating keratoplasties during the study period. Graft survival was 84% at 1 year and 70% at 2 years after surgery. Visual acuity improved in 15 (83%) of the 18 children with measurable preoperative and postoperative vision. Children with posterior segment injury before keratoplasty were less likely to maintain a clear graft (P = .04) and less likely to have improved vision postoperatively (P = .06). Children who received amblyopia treatment and appropriate optical correction postoperatively were more likely to have visual improvement than those who did not (P = .02). CONCLUSIONS: Penetrating keratoplasty for corneal trauma is generally a successful operation in the pediatric age group, with visual improvement seen in more than four fifths of cases. Graft survival and visual outcome are best in patients with trauma limited to the anterior segment. Aggressive postoperative refractive correction and amblyopia management also appear to contribute to a better visual outcome in pediatric keratoplasty.

Comparison of susceptibility of Neisseria meningitidis to sodium sulphadiazine and sodium fusidate in vitro.

Out of 100 strains of meningococci examined 62 were resistant to 1 mg/l or more of sodium sulphadiazine, including 82% of group W135 strains and 69% of group B strains. All strains were sensitive in vitro to 0.5 mg/l of sodium fusidate. Sodium fusidate should be considered as a chemoprophylactic agent for those who may be at risk of meningococcal disease.

Comparison of laboratory methods in the diagnosis of urinary tract infection.

Three methods of semiquantitative culture and two techniques of microscopy were compared with a surface viable count for the detection of significant bacteriuria in one thousand midstream specimens of urine. The results obtained with the blotting-paper-strip method on MacConkey agar and with Uricult dip-slides correlated well with the results of the surface viable count, and both methods were suitable for routine use. The blotting-paper-strip method was preferred for laboratory use because of expense but dip-slides are useful for general practice and outpatient clinics. Semi-quantitative culture by Microstix dip-strips gave less accurate results, and the nitrite test area detected only a small proportion of infected specimens. The microscopic examination of a Gram-stained film of the centrifuged deposit of urine specimens yielded more useful information and was more reproducible than examination of a wet film of the untreated urine.

Enzyme immunoassay for anti-treponemal IgG: screening or confirmatory test?

AIMS: To review the performance of the Venereal Diseases Research Laboratory (VDRL) test and the Treponema pallidum haemagglutination assay (TPHA) as a combined screen for syphilis to provide a baseline for assessing screening by anti-treponemal IGG EIA. METHODS: Between 1980 and 1987 all serum samples were screened by both VDRL and TPHA tests. The FTA-ABS test was also used in suspected early primary syphilis, or when one of the other tests was positive. A positive result in a screening test was confirmed by quantitative testing. From 1988 all specimens were screened with an enzyme immunoassay (Captia Syph G) as a single screening test. RESULTS: Of the 44 primary, 47 secondary, and 38 early latent cases of syphilis, the VDRL and TPHA detected 32 (73%) and 31 (71%) of the primary cases; the combination detected 37 (84%). All 85 cases of cases of secondary and early latent infection were reactive in the TPHA test, whereas the VDRL was reactive in only 68 (80%). EIA had a reported sensitivity of 82% for primary infection. CONCLUSIONS: EIA can be used as a single screening test for detecting early syphilis because its results are comparable with those of the combined VDRL and TPHA tests. The conventional VDRL test should not be used as a single screening test.

An analysis of lectin agglutination as a means of sub-dividing gonococcal serovars.

Sixteen lectins were examined for their ability to agglutinate 298 strains of Neisseria gonorrhoeae. Seven lectins failed to agglutinate any of the strains; the remaining nine lectins gave 22 different agglutination patterns. The 298 strains were divided into 14 serovars with a single panel of monoclonal antibody typing reagents; lectin agglutination subdivided these into 57 serovar/lectin patterns. A combination of two monoclonal antibody serotyping panels divided the strains into 32 serovar combinations; lectin agglutination further subdivided these into 79 serovar/lectin patterns. There was no correlation between lectin pattern and serovar. Lectin agglutination is a simple supplementary typing method and could be particularly useful in micro-epidemiological studies.

An evaluation of pre-poured selective media for the isolation of Neisseria gonorrhoeae.

Fourteen commercial media supplied as pre-poured plates were compared with an 'in-house' selective medium for their ability to support the growth of 105 gonococcal isolates (representing a wide variety of serovars encountered in natural infection), 25 meningococcal and 20 Neisseria lactamica isolates, and to inhibit the growth of 71 isolates of non-pathogenic neisseriae and miscellaneous organisms. Only two of the pre-poured plate media and the in-house selective medium yielded growth of duplicate cultures of all 105 gonococcal isolates after incubation for 24 h: one other medium provided growth of all the isolates after incubation for 48 h. The ability of the various media to suppress the growth of the 71 isolates of non-pathogenic neisseriae and miscellaneous organisms ranged from 97.2 to 71.8% of isolates inhibited. Of the four media that enabled growth of all the gonococcal strains, inhibition was 94.4% for the in-house medium, 85.9% and 80.3% for the two media on which all gonococci grew after 24 h and 71.8% for the medium on which all of the gonococci grew after 48 h. Failure of growth of gonococci was associated with: serogroup IA isolates (p<0.001), AHU auxotype (p<0.001) and the presence of vancomycin rather than lincomycin in the selective medium (p < 0.02). The use of 10% blood and a highly nutritious medium based on the original New York City (NYC) or modified New York City (MNYC) formulation were also important in supporting growth of gonococci. One of the main problems in lack of selectivity was a failure to inhibit the growth of yeasts. As effective inhibition of yeasts was obtained with other media containing the same concentration of amphotericin, failure may be due to batch variation of supplement, media preparation, or reduced shelf life of the media. None of the commercially available pre-poured media performed as well as the in-house medium despite the fact that some of the media were prepared to a very similar formula.

Corneal transplantation in young children with congenital hereditary endothelial dystrophy. Multicenter Pediatric Keratoplasty Study.

PURPOSE: To describe the surgical success rate and visual results of penetrating keratoplasty in a series of young children with congenital hereditary endothelial dystrophy and to summarize the current literature on outcomes of keratoplasty for congenital hereditary endothelial dystrophy, with particular attention to the timing of surgery. METHODS: The authors conducted a retrospective study of children aged 12 years and younger who underwent penetrating keratoplasty between 1975 and 1994 at four participating eye centers, and who were followed for at least 6 months postoperatively. For this report, 21 corneal transplants performed in 16 eyes of nine patients with congenital hereditary endothelial dystrophy were studied. Patients' median age at the time of first keratoplasty was 40 months (range, 3 months to 10 years). RESULTS: During a mean follow-up period of over 70 months (range, 6 to 240 months), 11 (69%) of 16 eyes retained full graft clarity. The 2-year survival rate of first grafts was 71% (95% confidence interval, 47% to 95%). Postoperative visual acuity improvement of 1 or more Snellen lines was seen in five of 10 eyes in which the patients were old enough for accurate assessment of visual acuity; however, just four of these 10 eyes attained a visual acuity of 20/200 or better. CONCLUSIONS: Penetrating keratoplasty for congenital hereditary endothelial dystrophy in children has a reasonable chance of surgical success when performed at a young age; however, the prognosis for improved visual acuity in children appears to be more guarded. Decisions on the timing of surgical intervention for congenital hereditary endothelial dystrophy should be made on a case-by-case basis. Although the threat of irreversible amblyopia in untreated eyes and good surgical success rates even among very young children argue for the consideration of relatively early surgical intervention in the most severely affected cases, there is evidence to support delaying surgery in some cases.

Tissue utilization at the Minnesota Lions' Eye Bank.

The purpose of this study was to examine the utilization of corneas procured by the Minnesota Lions' Eye Bank to determine why corneas were excluded from transplantation and to identify methods to safely increase the number of tissues made available for transplantation. We performed a retrospective review of the eye bank charts of 2,382 corneas evaluated by the Minnesota Lions' Eye Bank between December 1, 1992 and November 30, 1993. During that time 748 corneas (31%) were made available for transplantation; 1,597 (67%) were directed toward research or training. Thirty-seven corneas (1.5%) were disposed of for safety reasons. Six hundred and sixty of the corneas which were excluded from transplantation (40%) were excluded for a donor aged over 75 years. Three hundred and ninety-one corneas (24%) were rejected because of a contraindication in the donor's past ocular or medical history. Another 395 corneas (24%) were excluded for poor tissue quality. The most common reason for exclusion of tissue based on tissue quality was abnormalities seen on specular microscopic examination (200 corneas). Of interest, only 14 corneas were rejected for low endothelial cell counts. This review of our tissue evaluation process has led us to reevaluate and change our policy regarding exclusion of corneas for epithelial defects and arcus senilis. These data suggest that further evaluation of the abnormalities seen on specular microscopic examination and their validity as exclusion criteria should be undertaken. Other areas for further evaluation are how to improve the timeliness of tissue procurement and whether excluding all tissues over age 75 years and all postsurgical eyes is valid.

Povidone-iodine (betadine) in the treatment of experimental Pseudomonas aeruginosa keratitis.

Topical 5% povidone-iodine for the treatment of corneal ulcers was observed in Sierra Leone, West Africa by one of us (D.J.D.). To test the efficacy of topical 5% povidone-iodine for infectious keratitis, experimental Pseudomonas aeruginosa keratitis was induced in 12 rabbits by first abrading the central 3 mm of corneal epithelium. Thirty milliliters of broth of P. aeruginosa strain ATCC 27835 (1.8 x 10(7) viable bacteria) was dropped twice on the wounded cornea. After 22 h, all corneas were clinically infected. Eight rabbits were treated with 5% povidone-iodine solution and four with 0.9% NaCl solution. All were given hourly drops. Twenty-four hours after treatment began, the central 8-mm button of the infected cornea was excised, homogenized, and serial dilutions plated onto MacConkey agar. The total number of viable Pseudomonas organisms was calculated. The treatment group had 5.2 +/- 0.4 CFUs (colony-forming units) per cornea. The control group had 4.8 +/- 0.4 CFUs per cornea (p = 0.11). The clinical scores (Hobden grading system) were 6.9 +/- 1.5 for the treated group and 7.3 +/- 2.5 for the control group (p = 0.74). There was no statistical difference between the treated and control groups. Povidone-iodine (5%) is not effective in the acute treatment of P. aeruginosa keratitis in this rabbit model.

Azithromycin and erythromycin resistant Neisseria gonorrhoeae following treatment with azithromycin.

A pre-treatment and a 3-week post-treatment isolate of Neisseria gonorrhoeae from a 13-year-old boy treated with azithromycin in a single 1 g oral dose were characterized microbiologically. Both isolates were of the same serovar/auxotype (1B6/non-requiring) and had similar antibiograms apart from erythromycin and azithromycin: the pre- and post-treatment MICs (minimum inhibitory concentrations) were: 1 mg/L and 32 mg/L to erythromycin and 0.125 mg/L and 3 mg/L to azithromycin. The finding that both isolates were 1B6/NR, had similar antibiograms (other than azithromycin and erythromycin), and no other 1B6/NR isolates were resistant to erythromycin supports the view that macrolide resistance developed following treatment. A high overall level of azithromycin susceptibility was confirmed by testing 67 clinical isolates: MIC90 0.5 mg/L (range 0.023-0.75 mg/L). We conclude that the long half-life of azithromycin which is beneficial in treating chlamydial infection may result in increased selective pressure for resistance in gonococci. This report also highlights the importance of antibiotic susceptibility surveillance of gonococci and stresses the need for appropriate treatment of gonococcal infection, particularly when it is prescribed outwith departments of genitourinary medicine.

Rectal gonorrhoea in homosexual men: source of infection.

The objective of this retrospective study was to determine the possible source of infection in homosexual men with rectal gonorrhoea: the probable source of rectal gonorrhoea was identified in 46/155 cases. Although the urethra was the site of infection in 33 (72%) of these contacts, only pharyngeal gonorrhoea was identified in 9 (20%) men. In 25/26 cases, there was concordance in the auxo/serotypes of Neisseria gonorrhoeae between contacts with urethral gonorrhoea and the index men with rectal gonorrhoea. Eleven out of 12 pharyngeal isolates were of the same auxo/serotype as the index cases. This study supports the hypothesis that rectal gonorrhoea in homosexual men can be acquired from the oropharynx. Because infection at this site is an independent risk factor for acquisition of HIV, screening for rectal and pharyngeal gonorrhoea should be offered to men who have sex with men, even when there is no history of unprotected receptive anal intercourse.

Enzywell recombinant enzyme immunoassay for the serological diagnosis of syphilis.

The aim of this study was to evaluate Enzywell TP, a new rapid enzyme immunoassay (EIA) that uses 2 recombinant Treponema pallidum antigens for the serological diagnosis of syphilis. Specificity was evaluated by screening 1055 unselected bloods requesting serological tests for syphilis in parallel with Enzywell TP and the Syphilis ICE EIA which is our standard screening test for syphilis. Sensitivity was evaluated using a panel of 159 known treponemal sera representing various stages of syphilis and 5 treponemal sera detected on screening. The specificity of Enzywell TP on initial and repeat testing (99.6% and 99.7% respectively) was similar to that of the Syphilis ICE test (99.8% and 99.9% respectively). The sensitivity of Enzywell TP (100%) was similar to that of Syphilis ICE (99.4%): both tests were significantly more sensitive (P=0.01) than the fluorescent antibody absorbed test (94.5%) but not the T. pallidum particle agglutination (TPPA) assay (99.4%). Both Enzywell TP and Syphilis ICE were positive with sera from 16 known HIV-infected patients who had been treated for syphilis many years previously (mean 9.4 years) confirming the value of these tests in excluding previous syphilis in HIV-infected individuals. We conclude that the Enzywell recombinant EIA is simple, rapid, highly sensitive and specific, and is a welcome addition to the range of currently available diagnostic tests for syphilis.

Determinants of the gonococcal serovar pattern in Edinburgh, Scotland: a multivariate analysis.

The geographical and temporal variety of gonococcal serovar patterns are well described but it remains uncertain what characteristics possessed by the organism, or sexual behaviour pattern in the patients, determine the particular serovar pattern in a given area at a given time. This study was designed to assess the relative contribution of various demographic and clinical features of infection to the observed pattern of serovars in Edinburgh between 1990 and 1993. Five hundred and eight isolates were included in a multivariate analysis model to control for potential interactions between variables. Associations were noted between certain serovars and an asymptomatic clinical presentation, method of acquisition and site of infection. Certain physical characteristics of Neisseria gonorrhoeae in conjunction with the sexual behaviour patterns of patients are partially responsible for observed serovar patterns but more detailed analysis requires further sub-classification of serovars using molecular techniques.

Subtyping of high-level plasmid-mediated tetracycline resistant Neisseria gonorrhoeae isolated in Scotland between 1992 and 1998.

Tetracycline resistant Neisseria gonorrhoeae (TRNG) contain a 25.2 MDa TetM plasmid encoding a 68 KDa cytoplasmic protein which confers high-level tetracycline resistance. The aim of this study was to subtype all TRNG isolated in Scotland between 1992 and 1998. Subtyping was performed by a polymerase chain reaction (PCR) assay which characterizes the TetM plasmid as either the Dutch variant (443 base pair product) or the American variant (777 base pair product). Of the 78 TRNG isolates, 35 were the American variant and 43 were the Dutch variant. TRNG were distributed amongst 30 serovar/auxotype classes, the most common being 1A6/NR (11.5%), 1A6/P (14.1%) and 1B4/NR (14.1%). The country where infection was acquired was known for 36 of the 46 TRNG strains isolated between 1996 and 1998. All infections acquired in Asia and South America were the Dutch variant whereas all infections acquired in Africa were the American variant. A penicillinase plasmid was present in 66% (23/35) of the American variant TRNG compared with 51% (22/43) of the Dutch variant: the 3.2 MDa penicillinase plasmid was found in 87% of the American variant TRNG whereas the 4.4 MDa penicillinase plasmid was found in 68% of the Dutch variant TRNG. We conclude that subtyping of TRNG by PCR is a useful tool in studying the epidemiology of gonococcal infection due to plasmid-mediated resistant isolates.

Markers of past syphilis in HIV infection comparing Captia Syphilis G anti-treponemal IgG enzyme immunoassay with other treponemal antigen tests.

The sensitivity of the Captia Syphilis G anti-treponemal IgG enzyme immunoassay (EIA-IgG) was compared with the Treponema pallidum haemagglutination assay (TPHA) and the Fluorescent Treponemal Antibody Absorbed (FTA-Abs) test as a marker for past syphilis in 28 HIV-infected and 31 HIV-negative patients with a past history of syphilis. The specificity of EIA-IgG was compared in 89 patients without a history of syphilis who were known to be HIV antibody positive with a control group of 89 patients who had tested HIV negative. In patients with a past history of syphilis each treponemal test (EIA-IgG, TPHA and FTA-Abs) gave a lower sensitivity (82%, 86%, 79%) in the HIV-positive group than in the HIV-negative group (97%) but the difference was significant only in the case of the FTA-Abs test (P < 0.05). In the HIV-positive patients 11% (3/28) were negative in all 3 treponemal tests while 25% (7/28) were negative in at least one treponemal test. In patients without a past history of syphilis the EIA-IgG antibody index in the HIV-positive group (0.436) was significantly higher than in the HIV-negative group (0.378): the specificity, however, was similar in the HIV-positive (100%) and HIV-negative group (99%). We conclude that the Captia Syphilis G anti-treponemal IgG enzyme immunoassay is of similar specificity in HIV-positive and HIV-negative patients and is of similar sensitivity to the TPHA and FTA-Abs as a marker of past syphilis in HIV-infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)

A new recombinant antigen latex agglutination test (Syphilis Fast) for the rapid serological diagnosis of syphilis.

We report an assessment of Syphilis Fast, a new latex test that uses a pool of 3 recombinant Treponema pallidum antigens (TpN15, TpN17, and TpN47) for the serodiagnosis of syphilis. Specificity was evaluated by screening 1518 unselected blood specimens in parallel with Syphilis Fast, the Captia SelectSyph-G EIA and the Venereal Disease Research Laboratory (VDRL) cardiolipin antigen test while sensitivity was tested using a panel of 99 treponemal sera (treated and untreated) representing various stages of infection and 15 treponemal sera detected on screening. The specificity of Syphilis Fast on initial testing (99.8%) was significantly higher (P<0.02) than that of Captia SelectSyph-G (99.2%) and the VDRL (99.1%): the specificity of Syphilis Fast remained significantly higher (P<0.02) after repeat testing (respective values 99.9%, 99.5% and 99.4%). There was no difference in the sensitivity of Syphilis Fast and Captia SelectSyph-G on initial (93% vs 92.1%) or repeat (95.6% vs 94.7%) testing: both were significantly more sensitive (P<0.001) than the VDRL (46.5% on initial and 43.9% on repeat testing). The sensitivities of the Treponema pallidum haemagglutination test (TPHA) and FTA-abs were 98.2% and 95.6% respectively. Negative reactions in Syphilis Fast and SelectSyph-G were associated with treated infections and correlated with low TPHA titres (< or = 80). We conclude that Syphilis Fast is a highly specific, simple and fast screening test with a sensitivity comparable to native antigen treponemal tests and that it merits consideration as a front-line screening test.

Anogenital non-gonococcal neisseriae: prevalence and clinical significance.

Over a 13-year period non-gonococcal neisseriae (NGN) were isolated from 114 of 88,670 patients (0.13%) screened for anogenital gonorrhoea at a Genitourinary Medicine Unit. During the same period there were approximately 9000 anogenital gonococcal infections (10%). The prevalence of NGN was 0.09% (27/31,500) in women, 0.04% (20/52,800) in heterosexual men and 1.5% (67/4370) in homosexual men: the differences in prevalence between women and heterosexual men (P < 0.01) and between heterosexual patients and homosexual men (P < 0.001) are highly significant. Neisseria meningitidis was isolated most frequently and accounted for 85% (99/114) of the NGN. Whenever possible, N. meningitidis was serogrouped and its occurrence correlated with patient symptoms. Eleven of 18 heterosexual men who had meningococci isolated from their urethras had urethritis but co-existing chlamydial infection was excluded in only 5. None of 9 women with cervical colonization had clinical evidence of pelvic inflammation. Only one of 49 men with rectal colonization had proctitis. The management of anogenital NGN infection is discussed in relation to our findings and those of previously published studies. Within each patient group the prevalence and incidence of anogenital NGN were similar at the beginning and end of the study period indicating that levels have not been influenced by the advent of AIDS.

Temporal changes in the sensitivity of Neisseria gonorrhoeae to penicillin in Edinburgh, Scotland.

Increased resistance of Neisseria gonorrhoeae to penicillin has been reported from many centres around the world since the introduction of antibiotic therapy in the 1940s. This study reports the temporal changes in gonococcal penicillin sensitivity over a 3-year period. All patients with a diagnosis of gonorrhoea in the city of Edinburgh, Scotland between 1990 and 1992 were included in the study. Penicillin sensitivity of isolates was analysed in relation to the sex and sexual orientation of the patient and the antibiotic therapy given. Four hundred and twenty-seven new patient episodes of infection occurred of which penicillin sensitivities were available in 426. Eleven episodes of PPNG infection occurred. Chromosomally mediated penicillin resistance did not increase over the study period. No differences were evident in the sensitivity of isolates from homosexual and heterosexual patients. Unlike many other areas the relative resistance of N. gonorrhoeae is not increasing in Edinburgh at present. This may relate to local antibiotic policies combined with intrinsic characteristics of N. gonorrhoeae itself. Unlike previous reports there did not appear to be any increased resistance to penicillin in isolates from gay men.