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.

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.

Mucosal and systemic immune responses to plasmid protein pgp3 in patients with genital and ocular Chlamydia trachomatis infection.

The circulating and cervical B cell responses to Chlamydia trachomatis plasmid protein pgp3 were characterized in children and adults with ocular or genital chlamydial infection using the enzyme-linked immunospot assay (ELISPOT) and ELISA. No pgp3-specific ASCs were detected in healthy controls, but predominantly IgA ASCs were detected in UK adults with uncomplicated cervicitis or urethritis (P = 0.03, 0.019). In patients with extragenital complications or pelvic inflammatory disease a mixed response with more IgG and IgM ASCs was evident, suggesting a breach of mucosal immune compartmentalization with more extensive infection. In women with chlamydial cervicitis, ASCs secreting predominantly IgA, but also IgG, to pgp3 were present in cervix at presentation, with a frequency 30-50 times higher than blood. Cervical ASC numbers, especially IgG, fell markedly six weeks after antibiotic treatment. We detected principally IgA pgp3-specific antibody secreting cells (ASCs) in children resident in a Gambian endemic area, with a trend towards suppression of IgA responses during intense trachomatous inflammation (P = 0.06), as previously reported for other chlamydial antigens, and in keeping with the findings in genital disease. These data provide a rationale for further studies of immune responses to pgp3 in humans and animal models of chlamydia-induced disease, and its potential use in diagnostic assays and protective immunization strategies.

Is bacterial vaginosis associated with cervical intraepithelial neoplasia?

Previous research has produced conflicting results regarding the association of bacterial vaginosis (BV) and cervical intraepithelial neoplasia (CIN). These studies have been weakened in their conclusions mainly by failure to adequately control for the presence of sexually transmitted infections (STIs). One proposed mechanism suggesting that carcinogenic nitrosamines acting either independently or via human papilloma virus (HPV) has not been fully tested previously. We undertook a prospective, case-controlled, cross-sectional study where the presence of STIs, in particular human papillomavirus (HPV) which is known to be associated with the development of CIN, was controlled for. Women with BV were not found to have CIN more frequently than women with normal vaginal flora and the quantities of nitrosamines produced by women with BV did not differ significantly from women without BV. We thus found that BV is not associated with CIN.

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.

Effect of intravaginal clindamycin cream on pregnancy outcome and on abnormal vaginal microbial flora of pregnant women.

OBJECTIVES: To determine whether intravaginal clindamycin cream reduces the incidence of abnormal pregnancy outcome in women with abnormal vaginal microbial flora graded as intermediate or BV and to investigate the effect of the antibiotic on vaginal microbial flora. METHODS: A prospective cohort study of pregnant women in an antenatal clinic of a district general hospital. The subjects were 268 women who had abnormal vaginal microbial flora at first clinic visit by examination of a Gram-stained vaginal smear and 34 women with a normal vaginal flora. Two hundred and thirty-seven women were evaluable. Women with abnormal Gram-stained smears (graded as II or III) on clinic recall were randomised to receive treatment (intravaginal clindamycin cream) or placebo and followed to assess outcome of pregnancy, vaginal flora, and detection of Mycoplasma hominis and Ureaplasma urealyticum after treatment. RESULTS: Abnormal outcomes of pregnancy were not significantly different in treated and placebo groups by Chi square (P = 0.2). However, women with grade III flora responded better to clindamycin than women with grade II flora by numbers of abnormal outcomes (P = 0.03) and return to normal vaginal flora (P = 0.01) (logistic regression analysis model). This may be due to differences in vaginal bacterial species in these grades. Women whose abnormal vaginal flora had spontaneously returned to normal on follow-up and were therefore not treated (revertants) had as many abnormal outcomes as placebos suggesting that damage by abnormal bacterial species occurred early in pregnancy. CONCLUSIONS: Gram-stain screening distinguishing grade II from grade III flora may be helpful in prescribing treatment other than clindamycin for women with grade II flora. Earlier diagnosis and treatment may be more effective in preventing an abnormal outcome, possibly as soon as pregnancy is diagnosed or even offered as a pre-conception screen.

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.

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.

Characterization of B-cell responses to Chlamydia trachomatis antigens in humans with trachoma.

The circulating B-cell responses to Chlamydia trachomatis of 60 children and 34 adults in The Gambia were characterized in a cross-sectional study of different grades of trachoma, using the enzyme-linked immunospot (ELISPOT) assay. Antibody-secreting cells (ASCs) specific to chlamydial major outer membrane protein (MOMP), heat shock protein 60, and whole elementary bodies were detected in children with no evidence of ocular disease, and the immunoglobulin (IgA) response was significantly increased in those with follicular trachoma. In marked contrast, children with the most intense ocular inflammation paradoxically had an almost completely absent B-cell response of all isotypes and to all chlamydial antigens, but with normal serum IgG and IgA responses, which was even lower than in the group with no ocular inflammation. Adults with or without evidence of trachomatous scarring had equivalent numbers of circulating B cells, principally IgA, to all chlamydial antigens. Plasmablasts secreting antibodies to MOMP were present in the urine of children in the absence of urogenital infection detectable by PCR, and relative numbers were 8 to 25 times higher than in blood, suggesting site-specific homing within a common mucosal immune system. These results suggest that ELISPOT assay of ongoing B-cell responses detects suppression of chlamydia-specific IgA ASCs during the proinflammatory response to ocular chlamydial infection seen in intense trachoma, which may play a role in tissue damage leading to trachomatous scarring.

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.

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?