Salivary Testosterone and Sexual Function and Behavior in Men and Women: Findings from the Third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

Using data from the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) we examined associations between salivary testosterone (Sal-T) and sexual function and behavior. Single morning saliva samples were self-collected from a subsample of participants aged 18-74 years and analyzed using mass spectrometry. 1,599 men and 2,123 women were included in the analysis (40.6% of those invited to provide a sample). We adjusted for confounders in a stepwise manner: in model 1 we adjusted for age only; model 2 for age, season and relationship status, and model 3 we added BMI and self-reported health. In the fully adjusted models, among men, Sal-T was positively associated with both partnered sex (vaginal sex and concurrent partners) and masturbation. Among women, Sal-T was positively associated with masturbation, the only association with partnered sex was with ever experience of same-sex sex. We found no clear association between Sal-T and sexual function. Our study contributes toward addressing the sparsity of data outside the laboratory on the differences between men and women in the relationship between T and sexual function and behavior. To our knowledge, this is the first population study, among men and women, using a mass spectrometry Sal-T assay to do so.

Predictors of CD4 cell recovery following initiation of antiretroviral therapy among HIV-1 positive patients with well-estimated dates of seroconversion.

OBJECTIVES: To investigate factors that predict speed of recovery and long-term CD4 cell count in HIV-1 seroconverters initiating combination antiretroviral therapy (cART), and to quantify the influence of very early treatment initiation. We make use of all pre-treatment CD4 counts, because analyses using only a single observation at initiation may be subject to biases. METHODS: We used data from the CASCADE (Concerted Action on SeroConversion to AIDS and Death in Europe) multinational cohort collaboration of HIV-1 seroconverters. We analysed pre- and post-treatment data of patients with seroconversion dates estimated January 2003-March 2014 (n = 7600 for primary analysis) using a statistical model in which the characteristics of recovery in CD4 counts are determined by multiple predictive factors. Secondary analyses were performed incorporating uncertainty in the exact timing of seroconversion to allow more precise estimation of the benefit of very early treatment initiation. RESULTS: 'True' CD4 count at cART initiation was the strongest predictor of CD4 count beyond 3 years on cART. Allowing for lack of complete certainty in the date of seroconversion, CD4 recovery was more rapid for patients in whom treatment was initiated within 4 months. For a given CD4 count, higher viral load (VL) at initiation was strongly associated with higher post-treatment CD4 recovery. For other patient and drug characteristics, associations with recovery were statistically significant but small in magnitude. CONCLUSIONS: CD4 count at cART initiation is the most important factor in predicting post-treatment recovery, but VL provides substantial additional information. If cART is initiated in the first 4 months following seroconversion, recovery of CD4 counts appears to be more rapid.

Salivary Testosterone Levels and Health Status in Men and Women in the British General Population: Findings from the Third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

CONTEXT: Salivary T (Sal-T) measurement by liquid chromatography-tandem mass spectroscopy resents the opportunity to examine health correlates of Sal-T in a large-scale population survey. OBJECTIVE: This study sought to examine associations between Sal-T and health-related factors in men and women age 18-74 years. DESIGN AND SETTING: Morning saliva samples were obtained from participants in a cross-sectional probability-sample survey of the general British population (Natsal-3). Self-reported health and lifestyle questions were administered as part of a wider sexual health interview. PARTICIPANTS: Study participants included 1599 men and 2123 women. METHODS: Sal-T was measured using liquid chromatography-tandem mass spectroscopy. Linear regression was used to examine associations between health factors and mean Sal-T. RESULTS: In men, mean Sal-T was associated with a range of health factors after age adjustment, and showed a strong independent negative association with body mass index (BMI) in multivariable analysis. Men reporting cardiovascular disease or currently taking medication for depression had lower age-adjusted Sal-T, although there was no association with cardiovascular disease after adjustment for BMI. The decline in Sal-T with increasing age remained after adjustment for health-related factors. In women, Sal-T declined with increasing age; however, there were no age-independent associations with health-related factors or specific heath conditions with the exception of higher Sal-T in smokers. CONCLUSIONS: Sal-T levels were associated, independently of age, with a range of self-reported health markers, particularly BMI, in men but not women. The findings support the view that there is an age-related decline in Sal-T in men and women, which cannot be explained by an increase in ill health. Our results demonstrate the potential of Sal-T as a convenient measure of tissue androgen exposure for population research.

Patterns of sexual mixing with respect to social, health and sexual characteristics among heterosexual couples in England: analyses of probability sample survey data.

Patterns of sexual mixing are major determinants of sexually transmitted infection (STI) transmission, in particular the extent to which high-risk populations mix with low-risk populations. However, patterns of mixing in the general population are poorly understood. We analysed data from a national probability sample survey of households, the Health Survey for England 2010. A total of 943 heterosexual couples living together, where at least one partner was aged between 16-44 years, were included. We used correlation coefficients to measure the strength of similarities between partners with respect to demographic characteristics, general health, health behaviours and sexual history. Males were on average 2 years older than their female partners, although this age difference ranged from a median of 0 years in men aged 16-24 years to a median of 2 years in men aged 35-44 years. A positive correlation between partners was found for all demographic characteristics. With respect to general health and health behaviours, a strongly positive correlation was found between men and women in reporting alcohol consumption at ⩾3 days a week and smoking. Men typically reported greater numbers of sexual partners than their female partner, although men and women with more partners were more likely to mix with each other. We have been able to elucidate the patterns of sexual mixing between men and women living together in England. Mixing based on demographic characteristics was more assortative than sexual characteristics. These data can better inform mathematical models of STI transmission.

Acute kidney injury among HIV-infected patients admitted to the intensive care unit.

We describe the incidence, associations and outcomes of acute kidney injury (AKI) among HIV-infected patients admitted to the intensive care unit (ICU). We retrospectively analysed 223 admissions to an inner-London, University-affiliated ICU between 1999 and 2012, and identified those with AKI and performed multivariate analysis to determine associations with AKI. Of all admissions, 66% were affected by AKI of any severity and 35% developed stage 3 AKI. In multivariate analysis, AKI was associated with chronic kidney disease (odds ratio [OR] = 3.19; p = 0.014), a previous AIDS-defining illness (OR = 1.93; p = 0.039) and the Acute Physiology and Chronic Health Evaluation (APACHE) II score, (OR = 3.49; p = 0.018, if > 30). No associations were demonstrated with use of anti-retroviral medication (including tenofovir), or an individual's HIV viral load or CD4 count. AKI was associated with higher inpatient mortality and longer duration of ICU admission. Among patients with stage 3 AKI, only 41% were alive 90 days after ICU admission. Among survivors, 74% regained good renal function, the remainder were dependent on renal replacement therapy or were left with significant ongoing renal dysfunction. Of note, many patients had baseline serum creatinine concentrations well below published reference ranges. AKI among HIV-infected patients admitted to ICU carries a poor prognosis.

A prognostic scoring tool for identification of patients at high and low risk of death from HIV-associated Pneumocystis jirovecii pneumonia.

A prognostic scoring tool (PST) was created to aid prediction of outcome from HIV-associated Pneumocystis jirovecii pneumonia (PCP) using data obtained from 577 episodes of PCP among 540 patients presenting to a specialist HIV treatment centre in London, UK. It used risk factors identifiable at/soon after hospitalization, previously identified as being associated with mortality: repeat episode of PCP, patient's age, haemoglobin (Hb) and oxygen partial pressure (PaO(2)) on admission, presence of medical co-morbidity (Comorb) and of pulmonary Kaposi sarcoma (PKS). The derived PST was 25.5+(age in years/10) + 2 (if a repeat episode of PCP) + 3 (if Comorb present) + 4 (if PKS detected) - PaO(2) (kPa) - Hb (g/dL), and produced scores that ranged between 0 and 19. Patients were divided into five groups according to their prognostic score: 0-3.9 = group 1 (0% mortality), 4-7.9 = group 2 (3% mortality), 8-10.9 = group 3 (9% mortality), 11-14.9 = group 4 (29% mortality) and ≥ 15 = group 5 (52% mortality). This PST facilitates rapid identification of patients early in their hospitalization who have mild or severe HIV-associated PCP and who are at high and low risk of in-hospital death from PCP. The PST may aid assessment of severity of illness and in directing treatment strategies, but requires validation in patient cohorts from other health-care institutions.

Survival of HIV-infected patients admitted to the intensive care unit in the era of highly active antiretroviral therapy.

We retrospectively studied outcomes for HIV-infected patients admitted to the intensive care unit (ICU) between January 1999 and June 2009. Patient demographics, receipt of highly active antiretroviral therapy (HAART), reason for ICU admission and survival to ICU and hospital discharge were recorded. Comparison was made against outcomes for general medical patients contemporaneously admitted to the same ICU. One hundred and ninety-two HIV-infected patients had 222 ICU admissions; 116 patients required mechanical ventilation (MV) and 43 required renal replacement therapy. ICU admission was due to an HIV-associated diagnosis in 113 patients; 37 had Pneumocystis pneumonia. Survival to ICU discharge and hospital discharge for HIV-infected patients was 78% and 70%, respectively, and was 75% and 68% among 2065 general medical patients with 2274 ICU admissions; P = 0.452 and P = 0.458, respectively. HIV infection was newly diagnosed in 42 patients; their ICU and hospital survival was 69% and 57%, respectively. From multivariable analysis, factors associated with ICU survival were patient's age (odds ratio [OR] = 0.74 [95% confidence interval (CI) = 0.53-1.02] per 10-year increase), albumin (OR = 1.05 [1.00-1.09] per 1 g/dL increase), Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR = 0.55 [0.35-0.87] per 10 unit increase), receipt of HAART (OR = 2.44 [1.01-4.94]) and need for MV (OR = 0.14 [0.06-0.36]). In the era of HAART, HIV-infected patients should be offered ICU admission if it is likely to be of benefit.

A critical review of methods for the assessment of patient-level interactions in individual participant data meta-analysis of randomized trials, and guidance for practitioners.

OBJECTIVE: Treatments may be more effective in some patients than others, and individual participant data (IPD) meta-analysis of randomized trials provides perhaps the best method of investigating treatment-covariate interactions. Various methods are used; we provide a comprehensive critique and develop guidance on method selection. STUDY DESIGN AND SETTING: We searched MEDLINE to identify all frequentist methods and appraised them for simplicity, risk of bias, and power. IPD data sets were reanalyzed. RESULTS: Four methodological categories were identified: PWT: pooling of within-trial covariate interactions; OSM: "one-stage" model with a treatment-covariate interaction term; TDCS: testing for difference between covariate subgroups in their pooled treatment effects; and CWA: combining PWT with meta-regression. Distinguishing across- and within-trial information is important, as the former may be subject to ecological bias. A strategy is proposed for method selection in different circumstances; PWT or CWA are natural first steps. The OSM method allows for more complex analyses; TDCS should be avoided. Our reanalysis shows that different methods can lead to substantively different findings. CONCLUSION: The choice of method for investigating interactions in IPD meta-analysis is driven mainly by whether across-trial information is considered for inclusion, a decision, which depends on balancing possible improvement in power with an increased risk of bias.

Seasonal variation in mortality of Pneumocystis jirovecii pneumonia in HIV-infected patients.

A seasonal variation in the presentation of Pneumocystis jirovecii pneumonia (PCP) has been reported and a previous study from this centre noted a seasonal variation in mortality rates. This study examined seasonal influences (including climatic factors) within-host factors (clinical and laboratory-derived variables), the infectious burden of P. jirovecii in bronchoalveolar lavage (BAL) fluid, the presence of dihydropteroate synthase (DHPS) mutations in P. jirovecii, variations in knowledge and skills of junior medical staff, and mortality in 547 episodes of PCP occurring in 494 HIV-infected patients. The overall mortality rate was 13.5%. There was a seasonal variation in mortality: highest in autumn (21.2%) and lowest in spring (9.7%), P = 0.047. After adjustment was made for prognostic factors previously identified as being associated with mortality (increasing patient age, second/third episode of PCP, low haemoglobin, low PaO(2), presence of medical co-morbidity and pulmonary Kaposi sarcoma), there was no seasonal association with mortality, P = 0.249. The quantity of P. jirovecii DNA in BAL fluid showed no evidence of seasonal variation, P = 0.67; DHPS mutations were identified with equal frequency in each season and the mortality rate for February and August (when junior medical staff arrive in new posts) was 16.7%, only slightly greater than for other months (13.0%).

Prognostic value of C-reactive protein in HIV-infected patients with Pneumocystis jirovecii pneumonia.

C-reactive protein (CRP) is a sensitive marker of inflammation and tissue damage. We aimed to describe CRP responses in HIV-infected patients presenting with Pneumocystis pneumonia (PCP), bacterial pneumonia (BP) and pulmonary tuberculosis (TB) and, in patients with PCP, to identify if elevated CRP has prognostic significance. Data obtained by case-note review of consecutive HIV-infected adults with acute respiratory episodes included admission CRP (elevated >5 mg/L), haemoglobin, white blood count, CD4 count and partial pressure of oxygen in the blood (PaO(2)), presence of pulmonary co-pathology/intercurrent infection and outcome (survival). Median (range) CRP in patients with BP = 120 mg/L (<5-620 mg/L), TB = 44 mg/L (<5-256.3 mg/L) and PCP = 35 mg/L (<5-254 mg/L). CRP was elevated in 93/103 (90.3%) patients with PCP; six patients died; and all had an elevated CRP. PaO(2) and CRP values were associated as follows: average CRP levels declined by 10% (95% confidence interval [CI] 0.20%) per kPa increase in PaO(2) = 0.002. Factors associated with death were higher CRP, odds ratio (OR) (95% CI) = 5.30 (1.61 to 17.51) per 100 mg/L increase, P = 0.006 and haemoglobin, OR (95% CI) = 0.52 (0.29 to 0.93) per g/dL, P = 0.033. CRP is elevated in the majority of HIV-infected patients with PCP, BP and TB. Admission CRP measurement lacks specificity, but in PCP elevations of CRP are associated with disease severity (PaO(2)) and poor outcome and might be used prognostically, together with other mortality risk factors; further prospective evaluation is needed.

Modelling the association between patient characteristics and the change over time in a disease measure using observational cohort data.

In observational cohort studies we may wish to examine the associations between fixed patient characteristics and the longitudinal changes from baseline in a repeated outcome measure. Many biological and other outcome measures are known to be subject to measurement error and biological variation. In an initial analysis we may fit a regression model to all outcome measurements, accounting for all the identified sources of variability, and see how the characteristics are linked to the change for typical patients. However, the characteristics may also be linked to different distributions of the underlying outcome value at baseline, which itself may be correlated with the change over time. Therefore, if we wish to examine the change over time for patients of different characteristics but with the same underlying baseline value then the initial approach is confounded by the baseline values. Furthermore, if we attempt to remove this confounding by including the observed baseline measure as a covariate in a model for later measurements, then this may provide an approximate solution but is likely to introduce some bias. We propose a method based on first following the initial approach but then, applying a correction to the parameter estimates. This allows the predicted trajectories to be plotted and valid significance tests of association with characteristics. Our approach is compared with other methods and illustrated through a simulation study and an analysis of the association between HIV-1 subtype and immunological response after starting antiretroviral therapy.

Evaluation of a home-delivery service for HIV-infected patients attending an inner London HIV treatment centre.

Home delivery (HD) of medication is a goal of the Department of Health's Pharmacy in the Future; Implementing the NHS Plan. We evaluated the safety and effectiveness of an HD service for antiretroviral therapy (ART). Patients on ART with stable viral load (VL) <50 were identified. Comparison was made between patients using HD and those using the clinic-based pharmacy (CP). The primary endpoint was HIV virological failure (VF) (HIV VL >400 copies/mL on two consecutive occasions). Secondary endpoints included frequency of outpatient attendances (OPA) and an incidence of adverse events. Cumulative incidences (CulmIn) for each outcome event were calculated. Incidence-rate ratios (IRR) were obtained using Poisson regression. Of 1663 patients identified; 450 received HD and 1213 used CP. CuImIn of VF was =4% in those using HD and =7% in those using CP (IRR [95% confidence intervals, CI] =0.53, 0.32-0.90). HD patients had fewer OPA, less frequent blood test monitoring and less frequent abnormal liver function results (IRR [95% CI]= 0.63 [0.59-0.67] and 0.59 [0.53-0.67], 0.68 [0.65-0.71] and 0.64 [0.53-0.78], respectively). Patients deemed stable enough on social, psychological and medical grounds to receive HD of ART had a lower risk of VF, fewer OPA and no increase in adverse events when compared with patients using CP.

Changes in the provision of post-exposure prophylaxis for HIV after sexual exposure following introduction of guidelines and publicity campaigns.

In July 2004, British Association of Sexual Health and HIV (BASHH) published guidelines for post-exposure prophylaxis following sexual exposure (PEPSE) and the Terence Higgins Trust (THT) launched a campaign promoting PEPSE among men who have sex with men (MSM). We evaluated subsequent changes in PEPSE attendances. Individuals requesting PEPSE in 2004 were identified from clinic databases. Comparisons of clinical data, exposure characteristics and follow-up were made pre and post campaign. Data were available for 197/216 (91%) PEP attendances. The proportion requesting PEP following sexual exposure increased significantly following the campaign. The majority commencing PEPSE were MSM, with the proportion of MSM increasing significantly from 36/46 (78%) pre to 76/80 (95%) following the campaign. Most prescriptions were in high-risk groups and within guidelines. Times to initiation and completion rates were unchanged. Access to PEPSE following the THT campaign and introduction of BASHH guidelines increased. Promotion of earlier initiation of PEPSE and improvement of completion and follow-up is required.

Sex partner acquisition while overseas: results from a British national probability survey.

BACKGROUND: Over the past 20 years, there has been a huge increase in the number of overseas trips made by UK residents. Although a number of studies have examined the frequency of overseas partner acquisition, they have used convenience samples and thus are not generalisable to the British general population. METHODS: A national probability sample survey was carried out in 1999-2001 of 12,110 men and women aged 16-44 years resident in Britain. Sociodemographic, health-related, travel, sexual behaviour and attitudinal data were collected by computer-assisted interviewing. The main outcomes were the proportion of British residents who reported new sexual partners overseas in the past 5 years, the country of origin of these new sex partners, and the association between reporting a new partner while overseas with a range of demographic, behavioural and attitudinal variables. RESULTS: 13.9% of men and 7.1% of women reported having new sexual partner(s) while overseas in the past 5 years. Among respondents who were aged 16-24 and never married, the proportions were significantly higher (23.0% of men and 17.0% of women). Half of those with new sex partners overseas reported their partner's origin as the UK, and over a third as another European country. In addition to age and marital status, reporting new partners overseas was associated with a higher number of partners, paying for sex (among men), reporting a diagnosis of sexually transmitted infection, and HIV testing. Adjustment for sociodemographic factors attenuated the magnitude of, but did not remove, these associations. CONCLUSIONS: A substantial minority of young, unmarried people form new sexual partnerships abroad, but these are typically with residents from the UK or other European countries. Those who have new partners abroad are likely to have higher-risk sexual lifestyles more generally, and to be at higher risk of sexually transmitted infections. Greater attention should be paid to sexual health promotion for travellers abroad, especially young travellers, emphasising the risks of new sexual relationships with compatriots as well as those from other countries in terms of STI/HIV acquisition and onwards transmission.

Survival of HIV-infected patients in the intensive care unit in the era of highly active antiretroviral therapy.

BACKGROUND: Several studies have described improved outcomes for HIV-infected patients admitted to the intensive care unit (ICU) since the introduction of highly active antiretroviral therapy (HAART). A study was undertaken to examine the outcome from the ICU for HIV-infected patients and to identify prognostic factors. METHODS: A retrospective study of HIV-infected adults admitted to a university affiliated hospital ICU between January 1999 and December 2005 was performed. Information was collected on patient demographics, receipt of HAART (no patient began HAART on the ICU), reason for ICU admission and hospital course. Outcomes were survival to ICU discharge and to hospital discharge. RESULTS: 102 patients had 113 admissions to the ICU; HIV infection was newly diagnosed in 31 patients. Survival (first episode ICU discharge and hospital discharge) was 77% and 68%, respectively, compared with 74% and 65% for general medical patients. ICU and hospital survival was 78% and 67% in those receiving HAART, and 75% and 66% in those who were not. In univariate analysis, factors associated with survival were: haemoglobin (OR = 1.25, 95% CI 1.03 to 1.51, for an increase of 1 g/dl), CD4 count (OR = 1.59, 95% CI 0.98 to 2.58, for a 10-fold increase in cells/microl), APACHE II score (OR = 0.51, 95% CI 0.29 to 0.90, for a 10 unit increase) and mechanical ventilation (OR = 0.29, 95% CI 0.10 to 0.83). CONCLUSIONS: The outcome for HIV-infected patients admitted to the ICU was good and was comparable to that in general medical patients. More than a quarter of patients had newly diagnosed HIV infection. Patients receiving HAART did not have a better outcome.

Climate and genotypes of Pneumocystis jirovecii.

This study explored whether seasonal and/or climatic factors influenced detection of specific genotypes of Pneumocystis jirovecii. Between 1989 and 2001, 155 isolates of P. jirovecii were obtained from patients undergoing bronchoscopic alveolar lavage. For each isolate, the month and climatic conditions were noted. Genotypes of P. jirovecii were distinguished by polymorphisms in the mitochondrial large-subunit rRNA gene. There were monthly and seasonal variations in the frequency of detection of mixed genotypes (p 0.018 and p 0.031, respectively) and genotype 2 (p 0.029 and p 0.086, respectively). There was no association between month/season and genotypes 1, 3 and 4, or between monthly temperature or rainfall and any genotype.

Who uses condoms with whom? Evidence from national probability sample surveys.

OBJECTIVES: To explore the changing pattern of condom use from 1990 to 2000; to identify sociodemographic and behavioural factors associated with condom use; and reasons for condom use in 2000. METHODS: Large probability sample surveys administered among those resident in Britain aged 16-44 (n = 13 765 in 1990, n = 11 161 in 2000). Face to face interviews with self completion components collected sociodemographic, behavioural, and attitudinal data. RESULTS: Condom use in the past year among sexually active 16-24 year old men increased from 61.0% in 1990 to 82.1% in 2000 (p<0.0001), and from 42.0% to 63.2% (p<0.0001) among women of the same age, with smaller increases among older age groups. Among individuals reporting at least two partners in the previous 4 week period, approximately two thirds reported inconsistent or no condom use (63.1% (95% CI 55.9% to 69.8%) of the men and 68.5% (95% CI 57.6% to 77.7%) of the women). CONCLUSIONS: Rates of condom use increased substantially between 1990 and 2000, particularly among young people. However, inconsistent condom use by individuals with high rates of partner acquisition may contribute significantly to the recent resurgence in STIs. This group is an important target for intensive and specific sexual health interventions.

A comparison of the population diagnosed with chlamydia in primary care with that diagnosed in sexual health clinics: implications for a national screening programme.

OBJECTIVES: To compare demographic, behavioural and HIV testing characteristics of individuals diagnosed with chlamydia infection in primary care with those in genitourinary medicine clinics, in the absence of a screening programme. The aim was to explore the current and potential contribution of primary care to the control of chlamydia. STUDY DESIGN AND METHODS: We analysed data on individuals who reported one or more chlamydia diagnoses in the past 5 years in a large probability sample survey of the resident, UK general population aged 16-44 years. Estimates were weighted and odds ratios calculated. RESULTS: Women diagnosed in primary care reported fewer sexual partners, and were less likely to have had an HIV test in the past 5 years than their counterparts diagnosed in genitourinary medicine clinics. Age, ethnicity, social class, educational attainment and urbanization of area of residence did not differ between the two groups. Too few men were diagnosed in primary care to allow for such a comparison. CONCLUSIONS: Primary care already diagnoses a large number of women with chlamydia infection, who may perceive themselves as low risk through age or sexual behaviour, yet are likely to comprise a substantial proportion of all infections. Few men are diagnosed in primary care. These groups need to be strategically targeted in the context of a future chlamydia screening programme, which will focus on the screening of younger women at high risk, and in which the role of primary care is still in development.

Behavioural predictors of subsequent hepatitis C diagnosis in a UK clinic sample of HIV positive men who have sex with men.

OBJECTIVE: To explore the associations between self reported high risk sexual behaviours and subsequent diagnosis with hepatitis C virus (HCV) infection. METHODS: The Sex, Health and Anti-Retrovirals Project (SHARP) was a cross sectional study of sexual behaviour in HIV positive, men who have sex with men (MSM) attending a London outpatient clinic. From July 1999 to August 2000 participants completed a computer assisted self interview questionnaire (CASI) on recent sexual behaviour, recreational drug use, and detailed reporting of the last two sexual episodes involving different partners. Results were combined with routine clinic data and subsequent testing for HCV up to 21 April 2005. A new HCV diagnosis was defined as anti-HCV antibody seroconversion or positive HCV RNA following a previous negative. Incident rate ratios (IRR) were calculated using Poisson regression in Stata (version 9). Men contributed time at risk from interview until either their diagnosis or their last negative test result. RESULTS: Of the 422 men who completed questionnaires, 308 (73%) had sufficient clinical and HCV testing data available for analysis. Incident HCV infection was identified in 11 men. Unprotected anal intercourse, more than 30 sex partners in the past year, higher numbers of new anal sex partners, rimming (oro-anal sex), fisting, use of sex toys, and intranasal recreational drug use were associated with HCV. In multivariate analysis only fisting remained associated with HCV (adjusted IRR 6.27, p = 0.005). CONCLUSIONS: In this study of HIV positive MSM, fisting is strongly associated with HCV infection. Where individuals report high risk sexual behaviours, clinicians should offer appropriate testing for HCV infection.

Estimating adult HIV prevalence in the UK in 2003: the direct method of estimation.

BACKGROUND: Estimates of the total number of prevalent HIV infections attributable to the major routes of infection make an important contribution to public health policy, as they are used for planning services. METHODS: In the UK, estimates were derived through the "direct method" which estimated the total number of diagnosed and undiagnosed HIV infections in the population. The direct method has been improved over a number of years since first used in 1994, as further data became available such as the inclusion of newly available behavioural survey data both from the National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) and community surveys of men who have sex with men (MSM). These data were used to re-estimate numbers of people unaware of their infection and provided ethnic breakdowns within behavioural categories. The total population was divided into 10 mutually exclusive behavioural categories relevant to HIV risk in the UK-for example, MSM and injecting drug users. Estimates of the population size within each group were derived from Natsal 2000 and National Statistics mid-year population estimates. The total number of undiagnosed HIV infections was calculated by multiplying the undiagnosed HIV prevalence for each group, derived from the Unlinked Anonymous HIV Prevalence Monitoring Programme surveys (UAPMP), by the population size. These estimates were then added to the prevalent diagnosed HIV infections within each group derived from the national census of diagnosed HIV infections, the Survey of Prevalent HIV Infections Diagnosed (SOPHID). The estimates were then adjusted to include all adults in the UK. Because undiagnosed HIV prevalence estimates were not available for each of the behavioural categories, the UAPMP prevalence estimates were adjusted using available data to provide the best estimates for each group. RESULTS: It is estimated that 53,000 individuals are infected with HIV in the UK in 2003, of whom 27% were unaware of their infection. Of the total of 53,000, an estimated 26,000 were among heterosexually infected and 24,500 among MSM. CONCLUSION: The direct method uses an explicit framework and data from different components of the HIV surveillance system to estimate HIV prevalence in the UK, allowing for a comprehensive picture of the epidemic.