Diagnostic accuracy of a prototype rapid chlamydia and gonorrhoea recombinase polymerase amplification assay: a multicentre cross-sectional preclinical evaluation.

OBJECTIVES: Rapid and accurate sexually transmitted infection diagnosis can reduce onward transmission and improve treatment efficacy. We evaluated the accuracy of a 15-minute run-time recombinase polymerase amplification-based prototype point-of-care test (TwistDx) for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). METHODS: Prospective, multicentre study of symptomatic and asymptomatic patients attending three English sexual health clinics. Research samples provided were additional self-collected vulvovaginal swab (SCVS) (female participants) and first-catch urine (FCU) aliquot (female and male participants). Samples were processed blind to the comparator (routine clinic CT/NG nucleic acid amplification test (NAAT)) results. Discrepancies were resolved using Cepheid CT/NG GeneXpert. RESULTS: Both recombinase polymerase amplification and routine clinic NAAT results were available for 392 male and 395 female participants. CT positivity was 8.9% (35/392) (male FCU), 7.3% (29/395) (female FCU) and 7.1% (28/395) (SCVS). Corresponding NG positivity was 3.1% (12/392), 0.8% (3/395) and 0.8% (3/395). Specificity and positive predictive values were 100% for all sample types and both organisms, except male CT FCU (99.7% specificity (95% confidence interval (CI) 98.4-100.0; 356/357), 97.1% positive predictive value (95% CI 84.7-99.9; 33/34)). For CT, sensitivity was ≥94.3% for FCU and SCVS. CT sensitivity for female FCU was higher (100%; 95% CI, 88.1-100; 29/29) than for SCVS (96.4%; 95% CI, 81.7-99.9; 27/28). NG sensitivity and negative predictive values were 100% in FCU (male and female). CONCLUSIONS: This prototype test has excellent performance characteristics, comparable to currently used NAATs, and fulfils several World Health Organization ASSURED criteria. Its rapidity without loss of performance suggests that once further developed and commercialized, this test could positively affect clinical practice and public health.

The Effect of Exercise and Social Activity Interventions on Nutritional Status in Older Adults with Dementia Living in Nursing Homes: A Randomised Controlled Trial.

OBJECTIVES: Examine the effects of a 24-week exercise intervention against a social intervention on body weight, body mass index (BMI) and nutritional status in PWD living in nursing homes. DESIGN: Randomized controlled trial. PARTICIPANTS: Ninety-one older people with dementia living in nursing homes. INTERVENTIONS: Exercise (n=44) or social-based activities (n=47), taking place twice per week, for 60 minutes/session, during 24 weeks. MEASUREMENTS: Nutritional status was measured with the mini-nutritional assessment (MNA), weight and BMI. RESULTS: After the 24-week intervention, none of MNA (B-coeff. 1.28; 95% CI -2.55 to 0.02), weight (-0.06; -1.58 to 1.45) and BMI (-0.05; -0.85 to 0.74) differed significantly between groups after adjustment for multiplicity. In the social group, MNA significantly improved while it remained stable in the exercise group. The percentage of at-risk and malnourished patients reduced in both groups by more than 6%. CONCLUSION: The results suggest that social activities have as good effects as exercise activities on nutritional status in PWD nursing home residents.

Chlamydia related bacteria (Chlamydiales) in early pregnancy: community-based cohort study.

OBJECTIVES: Serological case-control studies suggest that certain chlamydia-related bacteria (Chlamydiales) which cause cows to abort may do the same in humans. Chlamydiales include Waddlia chondrophila, Chlamydia abortus and Chlamydia trachomatis. Data on prevalence of Chlamydiales in pregnancy are sparse. Using stored urine samples from a carefully characterised cohort of 847 newly pregnant women recruited from 37 general practices in London, UK, we aimed to investigate the prevalence and types of Chlamydiales infections. We also explored possible associations with miscarriage or spontaneous preterm birth. METHODS: Samples were tested using W. chondrophila and pan-Chlamydiales specific real-time PCRs targeting the 16S rRNA gene. Samples positive on either PCR were subjected to DNA sequencing and C. trachomatis PCR. RESULTS: The overall prevalence of Chlamydiales was 4.3% (36/847, 95% CI 3.0% to 5.8%). The prevalence of W. chondrophila was 0.6% (n = 5), C. trachomatis 1.7% (n = 14), and other Chlamydiales species 2.0% (n = 17). Infection with C. trachomatis was more common in women aged <25, of black ethnicity or with bacterial vaginosis, but this did not apply to W. chondrophila or other Chlamydiales. Follow up was 99.9% at 16 weeks gestation and 90% at term. No infection was significantly associated with miscarriage at ≤12 weeks (prevalence 10%, 81/827) or preterm birth <37 weeks (prevalence 4%, 23/628). Of 25 samples sequenced, seven (28%) were positive for Chlamydiales bacterium sequences associated with respiratory tract infections in children. CONCLUSION: In the first study to use the pan-Chlamydiales assay on female urine samples, 4% of pregnant women tested positive for Chlamydiales, including species known to be pathogenic in mothers and neonates.

Simplification of procedures used to test urine samples for Chlamydia trachomatis.

Two methods of simplifying the procedure for examining urine samples for Chlamydia trachomatis were investigated. When 73 urine samples from 56 men with acute non-gonococcal urethritis were examined by direct immunofluorescence (MicroTrak), centrifuging 1 ml volumes of urine at 13,000 rpm for five minutes was at least as efficient for detecting C trachomatis as centrifuging larger volumes at 3000 rpm for 30 minutes. Furthermore, examination of urine produced during a visit to a sexually transmitted disease clinic was at least as efficient as examination of early morning urine for detecting C trachomatis by MicroTrak, or by an enzyme immunoassay (IDEIA). Both modifications have practical advantages and should encourage the use of urine samples for diagnosing chlamydial infections in men.

Detection of Chlamydia trachomatis by the polymerase chain reaction in swabs and urine from men with non-gonococcal urethritis.

A polymerase chain reaction (PCR) was developed for Chlamydia trachomatis in which a 380 base pair DNA fragment was amplified. Amplification occurred with the DNA from the 15 serovars but not with that from other Chlamydia spp or with DNA from a variety of other organisms. Chlamydial DNA (10(-16) g) could be detected and the PCR seemed to be able to detect single organisms. Urethral swabs were obtained from 37 men with acute non-gonococcal urethritis (NGU), 18 (49%) of whom were positive for C trachomatis by MicroTrak. As a result of clinical re-examinations 65 urethral swabs were available for analysis by the PCR. In comparison with MicroTrak, PCR had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 86% and a negative predictive value of 98%. The PCR was apparently less sensitive (82%) in tests on urine samples. Overall, however, values of sensitivity and specificity of the PCR compared favourably with those of MicroTrak. The PCR for C trachomatis is likely to be a valuable technique for research, but problems of DNA contamination suggest that it should not be recommended for routine diagnosis.

Use of the polymerase chain reaction to detect DNA sequences specific to pathogenic treponemes in cerebrospinal fluid.

The polymerase chain reaction was used to detect Treponema pallidum in specimens of cerebrospinal fluid (CSF), as a means of diagnosing syphilis. Segments of the TmpA and 4D genes were amplified to provide an estimated threshold sensitivity of approximately 65 organisms in 0.5 ml. A spectrum of pathogens known to cause meningitis, and several non-pathogenic treponemes were unreactive. Treponema pertenue, and only one of 30 control specimens of CSF were positive. In contrast, 10 of 19 CSFs from patients being evaluated for latent or tertiary syphilis were positive, as were 7 of 28 specimens from HIV-positive patients.

Recurrent bacterial vaginosis.

Bacterial vaginosis (BV) is a common condition causing an offensive fishy smelling vaginal discharge. Some women have frequent symptomatic recurrences. Our lack of understanding of the trigger factors for the onset and resolution of BV limits our ability to manage these women effectively. Current approaches involve repeated treatment with antibiotics, with or without antifungal agents. Current studies are investigating the value of replacing the vaginal flora with cultured Lactobacillus strains. Control of BV may reduce the incidence of complications including preterm birth and possibly the acquisition of HIV infection.

Defining bacterial vaginosis: to BV or not to BV, that is the question.

The history of bacterial vaginosis (BV), now extending over more than 40 years, has been remarkable not only in terms of repeatedly changing the name of the bacterium that we now know as Gardnerella vaginalis but also in relation to what is thought to constitute the condition, what it should be called and how the diagnosis can best be made. The composite clinical criteria are often confusing for the nonspecialist, provide room for inter-observer error, and misinterpretation of just one criterion can lead to considerable over or under diagnosis. There is no doubt that diagnosis should be through a Gram-stained vaginal smear, allowing detection not only of 'full blown' BV but also patterns of vaginal flora that while not in this category are nevertheless abnormal. Accurate diagnosis is important in view of the ever-growing list of other important conditions that may occur as a consequence of the abnormal flora. In addition to this, we raise the question of whether the name and abbreviation BV is the best either scientifically or from the point of view of the lay public. While recognizing that it now may be too ingrained for further change, is it possible to have a better term, at least for lay use?

Sex, thrush and bacterial vaginosis.

Bacterial vaginosis (BV) is the most common cause of vaginal discharge in women of childbearing age. In some women it shows a relapsing and remitting course with apparently spontaneous onset and resolution. There are intermediate patterns of vaginal flora in which lactobacilli and other species co-exist. We asked women with recurrent BV to prepare vaginal smears daily, and to record symptoms, time of menstruation, sexual activity and use of douches or medication. We Gram-stained the smears and assigned a Nugent score for BV, and noted the presence of candida, pus cells, sperm and blood. Eighteen women collected daily vaginal smears for up to 10 months. Forty months of slides were collected in total. Bacterial vaginosis arose spontaneously on 23 occasions. We saw candida arise 11 times. Bacterial vaginosis appeared after candida on 9 of these 11 episodes. We saw BV regress spontaneously 13 times. Nine of these resolutions occurred within 48 h of unprotected sexual intercourse: BV only arose on one occasion within 48 h of unprotected intercourse. The intermediate pattern was seen for up to 10 days, and occurred as BV began or resolved in some women, and sometimes resolved without developing into BV. Bacterial vaginosis arose most often in the first 7 days of a menstrual cycle, and resolved spontaneously most often in mid-cycle. In women with recurrent BV, BV arises most often around the time of menstruation and resolves spontaneously in mid-cycle. Recurrences often follow an episode of candidiasis, and BV often regresses after unprotected sexual intercourse.

Mycoplasma genitalium in chronic non-gonococcal urethritis.

Seventy-eight men with a history of chronic urethritis were referred for investigation. Of 52 men diagnosed as having persistent or recurrent non-gonococcal urethritis (NGU) at the time of referral, 11 (21%) were infected with Mycoplasma genitalium and three with Chlamydia trachomatis. Men who were M. genitalium-positive had not previously received less antibiotic, in terms of treatment duration, than those who were M. genitalium-negative, suggesting a possible resistance to the antibiotics given. In the current investigation, of 11 M. genitalium-positive men with persistent or recurrent NGU who were treated for four to six weeks with erythromycin, 500 mg four times daily, nine (82%) responded clinically and microbiologically, but later six relapsed without M. genitalium being detected. The results of observing and investigating a patient for about one year, the only one to have concurrent chlamydial and mycoplasmal infections, is presented, a feature being the intermittent persistence of the mycoplasma.

A comparison of the use of Papanicolaou-stained cervical cytological smears with Gram-stained vaginal smears for the diagnosis of bacterial vaginosis in early pregnancy.

Our objective is to compare the efficacy of using Papanicolaou (PAP)-stained cervical cytology smears with a standardized method of interpreting Gram-stained vaginal smears for the diagnosis of bacterial vaginosis (BV) in pregnancy. High vaginal smears were Gram-stained and examined by a single observer to characterize 3 grades of vaginal flora and diagnose BV. Cervical smears were PAP-stained and examined for characteristic patterns of vaginal flora including evidence of BV by either a number of cytotechnicians or a single cytopathologist. The results of the 2 methods were compared. Seven hundred and forty-seven women attending an antenatal clinic in a district general hospital who consented to have a smear of vaginal secretions and cervical cytology in early pregnancy. The main outcome measure is the diagnosis of BV by different methods in a pregnant population. Compared with the Gram-stain method for the diagnosis of BV, there was good agreement between PAP-stain interpretation by a single observer but the agreement was not as good with PAP-stain interpretation by multiple cytotechnicians. When the grades were consolidated to normal (grade I) and abnormal flora (grades II and III), compared to Gram-stained smears, PAP cytology undertaken by several cytotechnicians had a sensitivity of 80.7% and a specificity of 90.7%. The sensitivity and specificity increased to 87% and 97%, respectively, when the PAP-stained smears were read by a single cytopathologist. Using kappa scores, only those readings made by a single cytopathologist were reliable. The setting in a cytopathology laboratory comprises multiple cytotechnicians, so that PAP-stain analysis of vaginal smears for the diagnosis of BV is likely to provide results which are less reliable than those obtained by Gram staining. The latter should be the first choice and every effort should be made to set up this service.

The role of Chlamydia trachomatis in urethritis and urethral symptoms in women.

One hundred and fifty women who attended a genitourinary medicine clinic and who required a speculum examination were investigated to determine the association between Chlamydia trachomatis and urethral symptoms and signs. Those who had taken antibiotics with anti-chlamydial activity within 3 months or those who were menstruating, pregnant or using an intrauterine contraceptive device were excluded. C. trachomatis infection of the urethra, or infection of the urethra and cervix together, combined with each separately, were strongly associated with > = 5 polymorphonuclear (PMN) leucocytes per high-power field (x 1000) in a Gram-stained urethral smear (P < 0.00005 and P < 0.0005, respectively). This appeared not to arise from leucocyte contamination from the lower genital tract. However, C. trachomatis infection of the urethra was not associated with symptoms of dysuria or frequency. In conclusion, it seems likely that C. trachomatis infection of the urethra in women probably causes urethritis which is usually asymptomatic. Women who have objective evidence of urethritis might best be managed by appropriate antibiotic therapy and counselling, and advice that partners should attend for review.

A reappraisal of chlamydial and nonchlamydial acute non-gonococcal urethritis.

A cohort of 112 men presenting with acute non-gonococcal urethritis (NGU) was investigated for the presence of Chlamydia trachomatis. Men with 3 or more episodes of NGU in the preceding 12 months, or who had received treatment for NGU in the preceding 3 months were excluded. C. trachomatis was sought by examination of urethral smears by direct immunofluorescence, and by examination of the centrifuged deposit from a first pass urine (FPU) sample by direct immunofluorescence, IDEIA, and the polymerase chain reaction. Urethral samples from 48 men were positive for CT, and the FPU samples from an additional 7 men were positive by at least 2 assays. With such intensive investigation it is likely that those men identified as chlamydia-negative were genuinely free from the infection. The clinical history and response to treatment of those men who were chlamydia-positive were compared with those of the chlamydia-negative men. They differed in that a larger proportion of the chlamydia-positive men reported having had intercourse with more than one partner in the previous 3 months, and having had fewer previous episodes of NGU. Moreover, in contrast to some previous studies, after one week of treatment with doxycycline, a larger proportion (65%) of the chlamydia-negative men than the chlamydia-positive men (40%) was cured, although the difference was not sustained following later treatment.

Abnormal bacterial colonisation of the genital tract and subsequent preterm delivery and late miscarriage.

OBJECTIVE: To find out whether women with bacterial vaginosis detected early in pregnancy are at increased risk of preterm delivery. DESIGN: Prospective description cohort study. SETTING: Antenatal clinic in a district general hospital. SUBJECTS: 783 women examined during their first antenatal clinic visit and screened for recognised risk factors for preterm delivery and the presence of bacterial vaginosis or intermediate abnormal flora detected by examination of a vaginal smear stained by Gram's method. MAIN OUTCOME MEASURES: Gestational age at delivery classified as late miscarriage (16-24 weeks' gestation), preterm delivery (24-37 weeks' gestation), term delivery (> or = 37 weeks' gestation). RESULTS: Multiple logistic analysis showed that there was an increased incidence of preterm delivery in women with a previous preterm delivery (9/24; odds ratio 25; 95% confidence interval 9 to 70; P < 0.001) and bacterial vaginosis (9/115; 2.8; 1.1 to 7.4; P = 0.04). A further logistic analysis of data from women recruited before 16 weeks' gestation showed that preterm deliveries or late miscarriages occurred more often in women with bacterial vaginosis (12/77; 5.5; 2.3 to 13.3; P < 0.001). CONCLUSIONS: Late miscarriage and preterm delivery are associated with the presence of bacterial vaginosis in early pregnancy. This is independent of recognised risk factors such as previous preterm delivery.

Validation of a simplified grading of Gram stained vaginal smears for use in genitourinary medicine clinics.

OBJECTIVES: To validate a simplified grading scheme for Gram stained smears of vaginal fluid for the diagnosis of bacterial vaginosis (BV) against the accepted "gold" standard of Amsel's composite criteria. METHODS: Women attending genitourinary medicine (GUM) clinics, as part of a multicentre study, were diagnosed as having BV if three or more of the following criteria were present; homogeneous discharge, elevated vaginal pH, production of amines, and presence of "clue" cells. Women with less than three of the criteria were considered as normal. Simultaneously, smears were made of vaginal fluid and Gram stained and then assessed qualitatively as normal (grade I), intermediate (grade II), or consistent with BV (grade III). Two new grades were used, grade 0, epithelial cells only with no bacteria, and grade IV, Gram positive cocci only. RESULTS: BV was diagnosed in 83/162 patient visits using the composite criteria, the remainder being regarded as normal. The majority of patients with BV had a smear assessed as grade III (80/83, 96%) and the majority of normal women had a smear assessed as grade I (normal, 48/79, 61%), giving a high sensitivity (97.5%), specificity (96%), and predictive value for a positive (94.1%) and negative (96%) test, kappa index = 0.91. Smears assessed as grade II were found predominantly (12/13) among patients diagnosed as normal, with less than three of the composite criteria. Grades 0 and IV were both only found among normal women. CONCLUSION: This simplified assessment of Gram stained smears can be used as an alternative to Amsel's criteria and is more applicable for use in busy GUM clinics.

Occurrence of Mycoplasma genitalium in different populations and its clinical significance.

Mycoplasma genitalium is predominantly flask-shaped with cytadsorptive and glass-adhering properties. These biological features of pathogenicity are reflected in its ability to cause urethritis and salpingitis in subhuman primates when given experimentally, although its role in human disease is less clear. M. genitalium was initially recovered by culture of specimens from two of 13 men with acute nongonococcal urethritis (NGU), but culture remains a laborious and insensitive means of detection. This organism has, however, been detected in the urethra of > or = 20% of men with acute NGU by using a polymerase chain reaction (PCR) and in a similar proportion of men with chronic NGU. The possibility of sexual transmission of M. genitalium is supported by the fact that by using the PCR it has been detected in the lower genital tract of about 20% of women who were attending a clinic for sexually transmitted diseases. It has also been detected, together with Mycoplasma pneumoniae, in a joint of a hypogammaglobulinemic patient who was suffering from polyarthritis after pneumonia and has been isolated, again with Mycoplasma pneumoniae, from the throat in culture. Such detection raises the question of the preferred mucosal site of M. genitalium, which has yet to be determined.

Diagnosis of bacterial vaginosis in a gynaecology clinic.

OBJECTIVE: To estimate the prevalence of bacterial vaginosis in women referred to a gynaecology clinic, and to compare two methods of diagnosing bacterial vaginosis. SETTING: Gynaecology Clinic at Northwick Park Hospital SUBJECTS: 114 women aged 16 to 65 referred consecutively to the gynaecology clinic of one consultant. MAIN OUTCOME MEASURES: Detection of bacterial vaginosis by standard compound criteria and by examination of a Gram stained smear of fluid from the posterior vaginal fornix. RESULTS: Bacterial vaginosis was detected by both the Gram stain and the compound criteria in 13 women. There was no correlation between the symptom of vaginal discharge and the diagnosis of bacterial vaginosis in this population, but the presence of discharge noted by the clinician was associated with bacterial vaginosis. CONCLUSIONS: The prevalence of bacterial vaginosis was 11%. The Gram stain provides a simple and inexpensive method for laboratory confirmation of bacterial vaginosis where facilities for using the compound criteria are not available.