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.

Increased ciprofloxacin resistance in gonococci isolated in Scotland.

A review of the susceptibility of Neisseria gonorrhoeae isolated from 4415 episodes of infection in Scotland between 1991 and 1999 showed that the proportion of isolates with lowered susceptibility (ciprofloxacin minimum inhibitory concentration [MIC] > or = 0.05 mg/L) increased from 0.5% in 1991 to 5% in 1999 (p<0.001), whereas the proportion of isolates with clinical resistance (ciprofloxacin MIC > or = 1 mg/L) was significantly higher in 1999 than the average for the preceding 4 years (2.2% vs 0.9%; p=0.02). Ciprofloxacin is a recommended treatment for gonococcal infection in the UK but if resistance continues to increase at the present rate it might not be suitable as a first-line treatment of gonorrhoea for much longer.

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.

The sac-4 gene of Neisseria gonorrhoeae and co-existing chlamydial infection.

BACKGROUND/OBJECTIVES: Recently, the sac-4 gene in Neisseria gonorrhoeae was postulated to increase the risk of developing mixed gonococcal and chlamydial infection. The aims of this study were to determine the frequency of the sac-4 gene in a larger sample of isolates of different serovars and to assess the prevalence of sac-4 in gonococcal isolates from patients with and without coexisting chlamydial infection. METHODS: Isolates from 259 episodes of gonorrhoea were tested by a PCR assay for the sac-4 gene. The presence of co-existing chlamydial infection was determined from both laboratory and GUM clinical records. RESULTS: The overall prevalence of sac-4 was 57.5% (149/259). The prevalence was not the same in all serovars and ranged from 34.9% in serovar 1B2 to 100% in serovar 1B18. Exact logistic regression analysis indicated significant differences in sac-4 prevalence in isolates of different serovars. The prevalence of sac-4 was 69.5% (41/59) in gonococcal isolates from patients with co-existing chlamydial infection compared with 57.9% (62/107) for those without chlamydial infection. Exact logistic regression analysis showed that the slightly increased sac-4 prevalence among chlamydia positive patients (p = 0.2) virtually disappeared when serovar status was taken into account (p > 0.9). CONCLUSION: The sac-4 gene of the gonococcus does not increase the risk for mixed chlamydial infection.

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.

Epidemiology and treatment outcome of infection with antibiotic resistant strains of Neisseria gonorrhoeae in Scotland.

Antibiotic resistance in Neisseria gonorrhoeae occurs worldwide and may limit the efficacy of treatment. This study reports the epidemiology and treatment outcome for 125 episodes of infection with antibiotic resistant gonococci diagnosed in Scotland in 1996. Infections with penicillinase producing N. gonorrhoeae (PPNG) and/or high level plasmid mediated tetracycline resistant N. gonorrhoeae (TRNG) and isolates showing reduced susceptibility to ciprofloxacin were more likely to belong to an unusual serovar and have been acquired abroad by heterosexual intercourse than isolates showing chromosomal resistance to penicillin or tetracycline, which were more likely to belong to a common serovar and to have been acquired in the United Kingdom by homosexual intercourse. Among the 88 episodes of infection whose outcome was known initial treatment with an antibiotic to which the isolate was resistant failed in nine out of 16 infections and in three out of the 72 infections treated with an antibiotic to which the organism was sensitive. In the case of high level plasmid mediated resistance, treatment with an inappropriate antibiotic always resulted in failure. Continuous monitoring of treatment outcome is essential to guide clinicians in prescribing the most appropriate antibiotic for individual patients.

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.

PCR testing of genital and urine specimens compared with culture for the diagnosis of chlamydial infection in men and women.

Our aim was to determine the number of chlamydial infections detected by Cobas Amplicor CT/NG multiplex polymerase chain reaction (PCR) testing of genital and first-voided urine (FVU) specimens compared with routine culture. Two hundred and eighty-six female and 276 male patients attending the Genito-Urinary Medicine (GUM) Unit at Edinburgh Royal Infirmary were included in the study. Case notes were analysed retrospectively to determine how many infected patients would not have been treated had diagnosis relied on routine culture. Polymerase chain reaction on FVU from women had a sensitivity, specificity, positive and negative predictive value of 91%, 100%, 100% and 99.1%: corresponding values for genital PCR and culture were 96%, 100%, 100%, 99.6% and 65%, 100%, 100%, 96.7% respectively. PCR on FVU from men had a sensitivity, specificity, positive and negative predictive value of 96%, 99.1%, 92.6% and 99.5%: corresponding values for genital PCR and culture were 89%, 99.5%, 95.8%, 98.6% and 48%, 100%, 100%, 94.3% respectively. In both men and women genital PCR and urine PCR were significantly more sensitive than culture. PCR almost doubled the number of patients detected by culture (49 vs 27). Of the 22 cases detected only by PCR 8 would not have received treatment on the basis of clinic treatment policy.

Novel recombinant-antigen enzyme immunoassay for serological diagnosis of syphilis.

Enzyme immunoassay (EIA) is an ideal method for screening large numbers of patients for syphilis. We evaluated a novel immune-capture EIA (ICE Syphilis; Murex Diagnostics) that uses three recombinant Treponema pallidum antigens (TpN15, TpN17, and TpN47) and compared the results with those obtained by the native T. pallidum antigen EIA (Captia SelectSyph-G; Centocor) that we currently use for the serodiagnosis of syphilis. Specificity was evaluated by screening 1,184 unselected serum specimens in parallel by the ICE Syphilis and SelectSyph-G assays, while sensitivity was tested with a panel of 101 serum specimens containing antitreponemal antibodies (treated and untreated) from patients with various stages of infection. The specificity of the ICE Syphilis EIA (99.8%) on screening was significantly higher (P < 0.02) than that of the SelectSyph-G EIA (99.2%). The sensitivity of the ICE Syphilis EIA was significantly higher (P < 0.01) than that of the SelectSyph-G EIA on both initial (99 versus 91.4%) and repeat (100 versus 92.4%) testing. The ICE Syphilis EIA was also significantly more sensitive (P < 0.01) than the fluorescent treponemal antibody-abs (92.4%) but not the T. pallidum hemagglutination assay (97.1%). Sera containing antitreponemal antibodies gave a much higher antibody index (absorbance of test serum/kit cutoff) by the ICE Syphilis EIA than by the SelectSyph-G EIA. This combined with the overall high sensitivity makes the ICE Syphilis EIA an ideal test for excluding or detecting treponemal infection in human immunodeficiency virus (HIV)-infected patients. The ICE Syphilis EIA was positive with sera from all 15 HIV-infected patients in the study, whereas sera from 3 HIV-infected patients were negative by the SelectSyph-G EIA. We conclude that the high sensitivity and specificity of the ICE Syphilis EIA and its suitability for automation make it an ideal screening test.

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.

Failure of Neisseria gonorrhoeae to grow in the ATB NH susceptibility test system.

The ATB NH system designed for antibiotic susceptibility testing of Neisseria gonorrhoeae, Neisseria meningitidis and Haemophilus influenzae was evaluated using 94 clinical isolates of gonococci representing a wide variety of serovar/auxotype strains. Using the manufacturer's automated system 55% of the clinical isolates failed to grow, compared with a 33% failure rate for manual processing and visual reading. Growth failure was significantly higher with 1A isolates (73% automated and 69% manual) than with 1B isolates (49% automated and 25% manual). The higher failure rate of 1A isolates correlated with multiple auxotrophy. The inability of the ATB NH system to support the growth of common serovar/auxotypes makes the ATB NH system unsuitable for antibiotic susceptibility testing of N. gonorrhoeae.

Corneal transplantation in children with Peters anomaly and mesenchymal dysgenesis. Multicenter Pediatric Keratoplasty Study.

OBJECTIVE: The purpose of the study is to describe graft and visual outcomes of penetrating keratoplasty among young children with Peters anomaly and associated mesenchymal dysgeneses. DESIGN: The design was a multicenter retrospective analysis of the indications and outcome in pediatric keratoplasty. PARTICIPANTS: The records of all children aged 12 years and younger who underwent penetrating keratoplasty for mesenchymal dysgenesis between January 1975 and May 1993 at the participating centers were reviewed. MEASURES: The data were analyzed regarding graft survival and postoperative visual acuity. RESULTS: Forty-seven corneal transplants in 36 eyes of 29 patients with mesenchymal dysgenesis were studied. The majority of eyes operated on (30) had Peters anomaly (83%). Patients' mean age at the time of keratoplasty was 7 months. After a mean follow-up period of 38 months, 61% of eyes retained full graft clarity. One and 3-year survival rates were 79% (95% confidence interval [CI] = 65%-93%) and 62% (95% CI = 45%-79%), respectively. Postoperative corneal ulcers/nonhealing epithelial defects (P = 0.03), and additional noncorneal surgical procedures at the time of transplantation (P = 0.05) were associated with graft failure. Provision of postoperative optical aids (P = 0.01) was associated with better postoperative visual acuity levels. CONCLUSIONS: Penetrating keratoplasty for Peters anomaly and related mesenchymal dysgeneses in young children has a reasonable chance of success during the critical years of visual maturation and is associated with satisfactory visual results in one third to half the cases. The data suggest that complicated cases requiring additional surgical procedures have a worse prognosis.

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.

Non-cultural detection of rectal and pharyngeal gonorrhoea by the Gen-Probe PACE 2 assay.

OBJECTIVE: To assess the sensitivity and specificity of the Gen-Probe PACE 2 assay, which uses a chemiluminescent labelled single-stranded DNA probe to detect gonococcal ribosomal RNA (rRNA), for the non-cultural detection of rectal and pharyngeal gonorrhoea in homosexual men. SUBJECTS: 161 homosexual men attending the Department of Genitourinary Medicine, Edinburgh Royal Infirmary during the latter half of 1995 and the first quarter of 1996. METHODS: Duplicate rectal and pharyngeal swabs were collected for culture on modified New York City (MNYC) medium and detection of gonococcal nucleic acid by the Gen-Probe assay. Repeatedly reactive Gen-Probe specimens from culture negative patients were also tested by the Gen-Probe competition assay (PCA). RESULTS: Of the 161 patients, 23 (14.3%) gave a positive culture at one or both sites (rectum 10, throat 8, rectum and throat 5) compared with 28 (16.7%) who gave a positive Gen-Probe result at one or both sites (rectum 9, throat 11, rectum and throat 8). After resolution of discrepant results by PCA the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Gen-Probe was 94.1%, 100%, 100% and 99.3% for rectal specimens while the corresponding values for pharyngeal specimens were 86.4%, 100%, 100%, and 97.9%. The sensitivity and NPV of rectal culture were 88.2% and 98.6% while the corresponding values for pharyngeal culture were 59% and 93.9%. Gen-Probe was significantly more sensitive than throat culture (p < 0.05) but not rectal culture (p > 0.2). The average Relative Light Units (RLU) value for the cut-off was 386 (range 351-450) while the average for a positive result was 20306 (range 403-110104): this was, however, significantly higher (p = 0.019) in rectal specimens 31325 (range 1705-110104) than in throat specimens 10447 (range 403-15633). CONCLUSIONS: Gen-Probe PACE 2 assay is a sensitive and specific method for the detection of rectal and pharyngeal gonorrhoea. As the Gen-Probe assay may detect nucleic acid from non viable gonococci the clinical significance of a probe positive culture negative specimen from a patient without culture evidence of gonorrhoea at another site is uncertain and requires further consideration. Nevertheless a positive result does indicate exposure to infection and could be important in ensuring appropriate partner notification action. If non-cultural methods are used to screen for gonococcal infection cultures should be obtained from patients with positive results in order that the antibiotic susceptibility and molecular epidemiology of the gonococcal population can be monitored.

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.

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.

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.

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.

Serovar specific immunity to Neisseria gonorrhoeae: does it exist?

OBJECTIVE: To determine whether the host immune response to gonorrhoea provides limited serovar specific protection from reinfection. SUBJECTS: 508 episodes of gonorrhoea diagnosed at a city centre genitourinary medicine clinic including 22 patients with multiple infections over a 4 year period. METHODS: Patients with recurrent gonococcal infection were analysed with respect to the initial and subsequent serovars isolated. RESULTS: No significant difference was seen in the prevalence of serovars isolated following a repeat infection compared with those without repeat infections. The site of the initial infection did not appear to influence the subsequent serovar isolated. CONCLUSION: We found no evidence of serovar specific immunity in our population. It remains possible that populations with a higher prevalence of gonorrhoea and more frequent infections may have a quantitatively greater immune response.