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Biomedical subjects

C Ison

Publications and source records attributed to C Ison.

At least 19 recordsLinked to original sources
PubMed2004

How is the high vaginal swab used to investigate vaginal discharge in primary care and how do GPs' expectations of the test match the tests performed by their microbiology services?

OBJECTIVES: To describe the management of vaginal discharge in general practice, with particular regard to the use of the high vaginal swab (HVS), and to compare GPs' expectations of this test with the processing and reporting undertaken by different laboratories. METHODS: A postal questionnaire survey of 2146 GPs in the North Thames area and postal questionnaire study of the 22 laboratories serving the same GPs were carried out. GPs were asked how they would manage a young woman with vaginal discharge and what information they would like on an HVS report. Laboratories were asked how they would process and report on the HVS sample from the same patient. RESULTS: Response rate was 26%. 72% of GPs would take an HVS and 62% would refer on to a genitourinary medicine (GUM) clinic. 45% would offer empirical therapy and 47% of these would treat for candida initially. 75% of GPs routinely request "M,C&S" on HVS samples but 55% only want to be informed about specific pathogens. Routine processing of HVS samples varies widely between laboratories and 86% only report specific pathogens. 78% of GPs would like to be offered a suggested diagnosis on HVS reports, and 74% would like a suggested treatment. 43% of laboratories ever provide a diagnosis, and 14% provide a suggested treatment. CONCLUSIONS: GPs frequently manage vaginal discharge and most of them utilise the HVS. GPs' expectations of the test are not well matched to laboratory processing or reporting of the samples.

Attitude of Health Personnel↗
PubMed2004

Gonorrhoea in young heterosexuals attending urban STD clinics in Britain: a cross-sectional survey.

Young people in the UK bear the brunt of sexually transmitted infections, in particular of gonorrhoea. We aimed to assess whether young people with gonorrhoea (under 21 years) attending sexual health clinics differed from older individuals with gonorrhoea in their behavioural and clinical characteristics and management outcomes. The results of this cross-sectional study suggest that young people were more likely to be female (66.2% vs 34.1%), have concurrent infection with Chlamydia trachomatis (55.4% vs 30.2%) and a history of recent gonococcal infection (81.3% vs 35.5%) if they ever had gonorrhoea. Young women were more likely to experience treatment delay and not to attend for follow-up than older women. Resistance to ciprofloxacin was high in both age groups but the prevalence of penicillinase-producing Neisseria gonorrhoeae was higher in older patients (11.5% vs 1.3%). Different management protocols for young and older patients with gonorrhoea may need to be considered.

Adult↗
PubMed2002

An international study of the interobserver variation between interpretations of vaginal smear criteria of bacterial vaginosis.

An international workshop on vaginal smear-based diagnosis of bacterial vaginosis was organized where 13 investigators scoring 258 slides with smears from vaginal fluid. Interobserver reproducibility of interpretations of Nugent scores, Hay/Ison scores and wet smear scores for the diagnosis of bacterial vaginosis was shown to be high. Detailed analysis of individual scoring results however indicated that basic standards of quality control to ensure robust individual readings of slides must be adhered to.

Bacteriological Techniques↗
PubMed2000

Neisseria gonorrhoeae in a London sexually transmitted infection clinic not fully sensitive to quinolones: are isolates imported and how effective is ciprofloxacin as a first-line therapy?

Our objectives were to determine the prevalence of Neisseria gonorrhoeae not fully sensitive to ciprofloxacin from a sexually transmitted infection (STI) clinic in London and where the isolates were acquired from. Data of antibiotic sensitivities of N. gonorrhoeae from 292 patients were reviewed over a 6-month period at St Mary's Genitourinary Medicine (GUM) Clinic, London. Isolates which exhibited reduced susceptibility (minimum inhibitory concentration [MIC] 0.03-0.12 mg/l) and high level resistance (MIC>0.12 mg/l) to ciprofloxacin represented 10% and 1.3% of the total respectively. All patients infected with a high level resistant isolate to ciprofloxacin had had a recent sexual partner from abroad but 18 of the 28 patients infected with a reduced susceptibility isolate denied recent travel. None of the 20 patients with a non-sensitive isolate who re-attended for post treatment cultures had persistant gonococcal infection. From this study we concluded that although N. gonorrhoeae resistant to ciprofloxacin was rare and probably always acquired abroad, isolates exhibiting reduced susceptibility were more common and were mainly as a result of infection from the UK. A stat dose of ciprofloxacin 500 mg and doxycycline 100 mg twice a day for one week was effective treatment.

Adolescent↗
PubMed1999

Molecular typing of Neisseria gonorrhoeae causing repeated infections: evolution of porin during passage within a community.

Thirty-three Neisseria gonorrhoeae isolates from 15 persons infected multiple times with the same serovar were compared using por gene sequencing, opa-typing, and arbitrarily primed-polymerase chain reaction. All three molecular techniques were more discriminatory than serotyping and identified differences between some isolates belonging to the same serovar. Although there were differences among Por sequences within some serovars, 10 of 15 subjects became reinfected with gonococci expressing identical Por proteins. Sequence analysis of por genes revealed evidence of horizontal genetic exchange and point mutations in potential surface-exposed regions during passage in the community.

Amino Acid Sequence↗
PubMed1999

Humoral immune responses to Neisseria meningitidis in children.

An understanding of the nature of immunity to serogroup B meningococci in childhood is necessary in order to establish the reasons for poor responses to candidate vaccines in infancy. We sought to examine the nature of humoral immune responses following infection in relation to age. Serum bactericidal activity was poor in children under 12 months of age despite recent infection with Neisseria meningitidis. The highest levels of bactericidal activity were seen in children over 10 years of age. However, infants produced levels of total immunoglobulin G (IgG) and IgG subclass antibodies similar to those in older children in a meningococcal enzyme-linked immunosorbent assay. Most antibody was of the IgG1 and IgG3 subclasses. This striking age dependency of bactericidal antibody response following infection is not apparently due to failure of class switching in infants but might be due to qualitative differences in antibody specificity or affinity.

Adult↗
PubMed1999

Cellular immune responses to Neisseria meningitidis in children.

There is an urgent need for effective vaccines against serogroup B Neisseria meningitidis. Current experimental vaccines based on the outer membrane proteins (OMPs) of this organism provide a measure of protection in older children but have been ineffective in infants. We postulated that the inability of OMP vaccines to protect infants might be due to age-dependent defects in cellular immunity. We measured proliferation and in vitro production of gamma interferon (IFN-gamma), tumor necrosis factor alpha, and interleukin-10 (IL-10) in response to meningococcal antigens by peripheral blood mononuclear cells (PBMCs) from children convalescing from meningococcal disease and from controls. After meningococcal infection, the balance of cytokine production by PBMCs from the youngest children was skewed towards a TH1 response (low IL-10/IFN-gamma ratio), while older children produced more TH2 cytokine (higher IL-10/IFN-gamma ratio). There was a trend to higher proliferative responses by PBMCs from older children. These responses were not influenced by the presence or subtype of class 1 (PorA) OMP or by the presence of class 2/3 (PorB) or class 4 OMP. Even young infants might be expected to develop adequate cellular immune responses to serogroup B N. meningitidis vaccines if a vaccine preparation can be formulated to mimic the immune stimulus of invasive disease, which may include stimulation of TH2 cytokine production.

Adult↗
PubMed1998

Sexual networks: the integration of social and genetic data.

New methods for studying sexual networks are presented, drawing upon routine procedures followed in genitourinary medicine clinics in the UK for tracing partners and identifying strains of infection. The routine social procedures were developed to incorporate a structured interview. The routine microbiological diagnosis of gonorrhoea was augmented by phenotyping and the development of new genetic techniques for the fine discrimination of gonococcal strains (opa-typing). Selected results from a study in Sheffield, UK show that each method has limitations, when conducted separately, but these are minimised when the methods are combined. Moreover, the use of simple and routine methods of data collection resolve issues of scale and sample that have beset other network studies, as they provide a means of covering a larger and defined population. Popular concepts about these methods are discussed in the conclusion. The integrated approach employed in our research raises questions both about social methods, 'of people who lie, particularly when they talk about sex', and about microbiological methods, 'of genes that tell the truth' and bypass what people say and think altogether. We argue that these stereotypes are misleading insofar as they suggest that genetic techniques can substitute for the social, and we suggest that even the finest discrimination of organisms at the genetic level will never obviate the need for their interpretation in the light of social data.

Adult↗
PubMed1998

Sexual histories, partnerships and networks associated with the transmission of gonorrhoea.

We aimed to describe and compare sexual links among people with gonorrhoea, by studying patients in 2 UK departments of genitourinary medicine. Interviews were completed for 510 and 235 cases in London and Sheffield respectively. There was a greater proportion of cases in men, homosexual men, non-white and non-British people and fewer female sex workers in London. Total networks of 1738 people in London and 570 people in Sheffield were described. Large linked heterosexual networks identified in Sheffield were associated with local contact, including men with higher numbers of sexual partners. Condom use for vaginal sex was reported for 11% of heterosexual partnerships in Sheffield, and 27% in London, with little difference between regular and casual partners. It was more difficult to define networks in London due to a high proportion of relatively anonymous contacts. These difficulties suggest that research and interventions may profitably focus upon venues for meeting partners as well as partner notification.

Adolescent↗
PubMed1996

Association of bacterial vaginosis with a history of second trimester miscarriage.

The aim of this study was to determine whether bacterial vaginosis (BV) is associated with a history of recurrent pregnancy loss. A total of 500 consecutive patients attending the Recurrent Miscarriage Clinic were screened for the presence of BV. In women who had had at least one late miscarriage BV was found twice as commonly (27/130; 21%) as in women who had had only early losses (31/370; 8%) (P < 0.001). The difference was even larger (26 versus 8%) if women who had had term pregnancies were excluded. Moreover, BV was found three times more commonly in Afro-Caribbean women [17 (29%) of 58] than in Caucasian women [36 (9%) of 379] and, in both groups of women, BV was diagnosed at least twice as frequently in those with a history of at least one late miscarriage than in those who had experienced first trimester pregnancy losses only (P < 0. 001). The condition occurred twice as often among smokers than non-smokers and, in both groups, it was at least twice as common in women with a history of at least one late miscarriage as in those who had had early pregnancy losses only (P < 0.001). However, the relationship between BV and smoking was independent of ethnic origin. Women who douched with chloroxylenol were mostly Afro-Caribbean and had BV more than twice as often as women who did not douche.

Abortion, Habitual↗
PubMed1995

Estimating the sexual mixing patterns in the general population from those in people acquiring gonorrhoea infection: theoretical foundation and empirical findings.

STUDY OBJECTIVES: To describe mathematically the relationship between patterns of sexual mixing in the general population and those of people with gonorrhoea infection, and hence to estimate the sexual mixing matrix for the general population. DESIGN: Integration of data describing sexual behaviour in the general population, with data describing sexual behaviour and mixing among individuals infected with gonorrhoea. Use of these data in a simple mathematical model of the transmission dynamics of gonorrhoea infection. SETTING: The general population of London and a genitourinary medicine (GUM) clinic in west London. PARTICIPANT: These comprised 1520 men and women living in London who were randomly selected for the national survey of sexual attitudes and lifestyles and 2414 heterosexual men and women who presented to the GUM clinic with gonorrhoea. MAIN RESULTS: The relationship between sexual mixing among people with gonorrhoea and sexual mixing in the general population is derived mathematically. An empirical estimate of the sexual mixing matrix for the general population is presented. The results provide tentative evidence that individuals with high rates of acquisition of sexual partners preferentially select other individuals with high rates as partners (assortative mixing). CONCLUSIONS: Reliable estimates of sexual mixing have been shown to be important for understanding the evolution of the epidemics of HIV infection and other sexually transmitted diseases. The possibility of estimating patterns of sexual mixing in the general population from information routinely collected in gonorrhoea contact tracing programmes is demonstrated. Furthermore, the approach we describe could, in principle, be used to estimate the same patterns of mixing, using contact tracing data for other sexually transmitted diseases, thus providing a way of validating our results.

Adolescent↗
PubMed1994

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.

Abortion, Spontaneous↗