Geoffrey L. Ridgway

Evaluation of microbicidal activity of a new disinfectant: Sterilox 2500 against Clostridium difficile spores, Helicobacter pylori, vancomycin resistant Enterococcus species, Candida albicans and several Mycobacterium species

The microbicidal activity of a new disinfectant Sterilox, a super-oxidized water, containing a mixture of oxidizing substances, was tested against Clostridium difficile spores, Helicobacter pylori, vancomycin resistant Enterococcus species, Candida albicans and several Mycobacterium species using membrane filters. All tests were performed in duplicate with and without added horse serum at 1% and 5% v/v. Distilled water, 0.35% peracetic acid (Nu-Cidex) and 2% glutaraldehyde were included as controls. Sterilox: spore suspension (9:1 v/v) achieved log10 kill of > 5 with 5% horse serum in 2 min against H. pylori, vancomycin resistant Enterococcus species, C. albicans and four atypical Mycobacterium species: M. avium, M. chelonei, M. xenopi and M. smegmatis. Sporicidal activity of Sterilox against Clostridium difficile was markedly diminished in the presence of 5% horse serum. Sterilox may be an effective alternative in endoscopy units, as it is a potent microbicidal agent and the manufacturer claims it is not corrosive to metal and is nontoxic to biological tissues.

Clinical, laparoscopic and microbiological findings in acute salpingitis: report on a United Kingdom cohort

Objective To determine the clinical features and microbial aetiology of acute salpingitis in women attending an inner city teaching hospital.

Cross-infection between animals and man: Possible feline transmission of Staphylococcus aureus infection in humans?

An outbreak of epidemic methicillin-resistant Staphylococcus aureus occurred on a rehabilitation geriatric ward. Intensive screening of patients and staff revealed an unusually high carriage rate in the nursing staff (38%), thought to be related to a ward cat which was heavily colonized from the environment. Infection control measures and removal of the cat led to rapid resolution of the outbreak.

Chlamydia trachomatis and Neisseria gonorrhoeae infection and the sexual behaviour of men who have sex with men

Background: : Rates of bacterial sexually transmitted infections (STIs) continue to rise among men who have sex with men (MSM) in the UK. Objective: To evaluate factors associated with Chlamydia trachomatis and Neisseria gonorrhoeae among MSM attending a genitourinary medicine clinic in inner London. Study design: : 599 MSM undergoing testing for STIs were recruited. Specimens for ligase chain reaction (LCR), strand displacement amplification (SDA) assay and culture were collected from the pharynx, urethra and rectum for the detection of C trachomatis and N gonorrhoeae. Details regarding demographics, symptoms, signs and sexual behaviour were recorded. Associations of these factors with each infection were tested, adjusting for other risk factors. Results: The prevalence of C trachomatis and N gonorrhoeae was 11.0% and 16.0%, respectively. LCR and SDA performed well for the detection of C trachomatis and N gonorrhoeae from urethra and rectum. Using either method, compared with our current testing policy, over 18% of those with C trachomatis and N gonorrhoeae would not have had their infection diagnosed or treated. Age, sexual behaviour, urethral and rectal symptoms and signs were strongly associated with both infections. A total of 33.7% of men reported at least one episode of unprotected anal intercourse in the previous month. Men reporting multiple episodes were markedly more likely to be HIV positive. Conclusion: The prevalence of infection, rates of partner acquisition and unprotected anal intercourse reported among these MSM are alarming. Improved detection of C trachomatis and N gonorrhoeae using nucleic acid amplification tests has major public health implications for STI and possibly HIV transmission in this population.

Comparison of two methods of screening for genital chlamydial infection in women attending in general practice: cross sectional survey

Abstract Objectives: To estimate the prevalence of Chlamydia trachomatis in asymptomatic women attending general practice; to assess the potential of the ligase chain reaction as a screening tool; and to evaluate selective screening criteria. Design: Cross sectional survey. Setting: Four general practices in northeast London. Subjects: 890 women aged 18-35 years attending general practice for a cervical smear or a “young well woman” check between October 1994 and January 1996. The women were tested for C trachomatis with confirmed enzyme immunoassay (endocervical specimens) and ligase chain reaction assay on urine specimens. Main outcome measures: Prevalence of C trachomatis infection in women aged 18-35 on the basis of each test; sensitivity and specificity of both tests in this population. Results: Prevalence of confirmed infection was 2.6% (95% confidence interval 1.6% to 3.6%) in all women. Prevalence on the basis of enzyme immunoassay was 1.6% (0.8% to 2.7%), with a sensitivity of 60% and a specificity of 100%. Prevalence on the basis of ligase chain reaction was 2.5% (1.5% to 3.9%), with 90% sensitivity and 99.8% specificity. Screening all women aged ≤25 and all women who had had two or more partners in the past year would have detected 87% (20/23) of infections. Conclusion: Ligase chain reaction on urine samples performs at least as well as enzyme immunoassay on cervical specimens in this low prevalence population. It offers potential as a non-invasive screening tool. A simple selective screening strategy might be appropriate and would be able to detect most cases of infection. However, a rigorous economic evaluation of possible screening strategies is needed first. Key messages Chlamydia trachomatis causes a common sexually transmitted infection, which is often asymptomatic but may lead to pelvic inflammatory disease, ectopic pregnancy, and tubal infertility in 10%-25% of infected women Over 1 in 20 women aged 18-25 years attending general practice may have undiagnosed infection New screening tests that do not require a cervical sample should improve the prospects for community based screening for chlamydia Rigorous evaluation of the cost effectiveness of such screening is now a priority

Home screening for chlamydial genital infection: is it acceptable to young men and women?

Objectives: To determine the acceptability, to young men and women, of home screening for chlamydial infection. Methods: We wrote to a random sample of 208 women aged 18–25 years and 225 men aged 18–35 years from three general practices, inviting them to undergo home screening for chlamydial infection. They were asked to return, by normal post, a urine specimen (for men and half of the women) or a vulval swab (other half of the women) for ligase chain reaction (LCR) testing for chlamydial infection. They were also asked to return a short questionnaire about risk status and the acceptability of this approach. Results: The participation rate among the available sample was 39% for women and 46% for men (p=0.3). However, among women, the rate was slightly higher (p=0.05) for urine samples (47%) than for vulval swabs (32%). Six per cent of women and 9% of men declined to take part, while 42% of women and 33% of men failed to respond. Two men objected to receiving the package at home. We received few other comments, positive and negative in about equal measure. Conclusion: Home screening for chlamydial infection is a potentially efficient method of reaching young people who may have little contact with health services. Men were at least as likely as women to respond to this screening approach. Home screening might form a useful component of a future chlamydial screening programme in the United Kingdom.

Chlamydial urethritis in heterosexual men attending a genitourinary medicine clinic: prevalence, symptoms, condom usage and partner change.

A prospective study of 356 consecutive heterosexual male patients attending the Department of Genitourinary Medicine at University College Hospital was carried out to determine the prevalence of Chlamydia trachomatis. Patients were asked about their symptoms, use of condoms and change of sexual partner. The prevalence of non-gonococcal urethritis (NGU—chlamydia positive and negative urethritis) was 37% (131 of 356). C. trachomatis was shown to be the causative organism in 24% (31 of 131) of patients with NGU. The prevalence of other STDs in men with C. trachomatis and with non-chlamydial urethritis was 15% and 10% respectively. Men with C. trachomatis were significantly more likely than men with non-chlamydial urethritis to be asymptomatic (56% vs 35%). The prevalence of C. trachomatis was highest in men who had changed partner in the previous 3 months (20 of 32 men). A third of men never used condoms in the first 3 months of a new relationship and over half failed to use them after 3 months. There was no evidence that the reported use of condoms reduced the rate of infection with C. trachomatis.

The Activity of Ciprofloxacin and Other 4-Quinolones Against Chlamydia trachomatis and Mycoplasmas In Vitro

Ciprofloxacin was found to be the most active of a group of 4-quinolone antibiotics tested against the SA2 f strain of Chlamydia trachomatis (MBC and MIC 1.0 mg/l). Against genital isolates of Chlamydia trachomatis, ciprofloxacin was twice as active as rosoxacin. Ciprofloxacin showed similar activity to that of oxytetracycline against clinical isolates of Mycoplasma hominis and Ureaplasma urealyticum, and was 8-fold more active than rosoxacin against the latter.

The activity of ciprofloxacin and other 4-quinolones againstChlamydia trachomatis andMycoplasmas in vitro

Ciprofloxacin was found to be the most active of a group of 4-quinolone antibiotics tested against the SA2 f strain ofChlamydia trachomatis (MBC and MIC 1.0 mg/l). Against genital isolates ofChlamydia trachomatis, Ciprofloxacin was twice as active as rosoxacin. Ciprofloxacin showed similar activity to that of oxytetracycline against clinical isolates ofMycoplasma hominis andUreaplasma urealyticum, and was 8-fold more active than rosoxacin against the latter.

Evaluation of self-taken samples for the presence of genital Chlamydia trachomatis infection in women using the ligase chain reaction assay

The aim of this study was to evaluate the sensitivity and acceptability of self-taken vulval-introital (VI) samples, first-catch urine (FCU) samples and clinician-obtained cervical samples for the presence of genital Chlamydia trachomatis infections in women using the ligase chain reaction (LCR) assay. One hundred and four patients were enrolled, of whom 54 patients had chlamydial DNA in at least one of the samples tested. The sensitivity of the cervical sample was 96.3%, vulval-introital sample in LCR buffer 92.6%, vulval-introital swab collected dry 88.9%, FCU stored at +2–8°C 81.5%, FCU stored at room temperature 77.8% and FCU stored with 2% w/v boric acid at room temperature 87.0%. Self-taken vulval-introital LCR samples were shown to be an acceptable alternative to a clinician-obtained LCR sample. The addition of boric acid may overcome the need for a continuous cold chain for FCU samples.