O N Gill

The University of Warwick, Warwick, ENG, United Kingdom

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Publications (66)513.17 Total impact

  • Source
    Article: Bayesian evidence synthesis for a transmission dynamic model for HIV among men who have sex with men.
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    ABSTRACT: Understanding infectious disease dynamics and the effect on prevalence and incidence is crucial for public health policies. Disease incidence and prevalence are typically not observed directly and increasingly are estimated through the synthesis of indirect information from multiple data sources. We demonstrate how an evidence synthesis approach to the estimation of human immunodeficiency virus (HIV) prevalence in England and Wales can be extended to infer the underlying HIV incidence. Diverse time series of data can be used to obtain yearly "snapshots" (with associated uncertainty) of the proportion of the population in 4 compartments: not at risk, susceptible, HIV positive but undiagnosed, and diagnosed HIV positive. A multistate model for the infection and diagnosis processes is then formulated by expressing the changes in these proportions by a system of differential equations. By parameterizing incidence in terms of prevalence and contact rates, HIV transmission is further modeled. Use of additional data or prior information on demographics, risk behavior change and contact parameters allows simultaneous estimation of the transition rates, compartment prevalences, contact rates, and transmission probabilities.
    Biostatistics 05/2011; 12(4):666-81. · 2.14 Impact Factor
  • Article: The risk of variant Creutzfeldt-Jakob disease among UK patients with bleeding disorders, known to have received potentially contaminated plasma products.
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    ABSTRACT: The risk of variant Creutzfeldt-Jakob disease (vCJD) from potentially infected plasma products remains unquantified. This risk has been assessed for 787 UK patients with an inherited bleeding disorder prospectively followed-up for 10-20 years through the UK Haemophilia Centre Doctors' Organisation (UKHCDO) Surveillance Study. These patients had been treated with any of 25 'implicated' clotting factor batches from 1987 to 1999, which included in their manufacture, plasma from eight donors who subsequently developed clinical vCJD. Variant CJD infectivity of these batches was estimated using plasma fraction infectivity estimates and batch-manufacturing data. Total potential vCJD infectivity received by each patient has been estimated by cumulating estimated infectivity from all doses received during their lifetime. Of 787 patients, 604 (77%) were followed-up for over 13 years following exposure to an implicated batch. For these 604 patients, the estimated vCJD risk is ≥ 1% for 595, ≥ 50% for 164 and 100% for 51. This is additional to background UK population risk due to dietary exposure. Of 604 patients, 94 (16%) received implicated batches linked to donors who developed clinical vCJD within 6 months of their donations. One hundred and fifty-one (25%) had received their first dose when under 10 years of age. By 1st January 2009, none of these patients had developed clinical vCJD. The absence of clinical vCJD cases in this cohort to date suggests that either plasma fraction infectivity estimates are overly precautionary, or the incubation period is longer for this cohort than for implicated cellular blood product recipients. Further follow-up of this cohort is needed.
    Haemophilia 02/2011; 17(6):931-7. · 2.60 Impact Factor
  • Article: Prevalence of markers for HIV, hepatitis B and hepatitis C infection in UK military recruits.
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    ABSTRACT: An unlinked anonymous survey was conducted to measure the prevalence of selected markers for HIV, hepatitis B and C infection in recruits to the UK Armed Forces to inform future screening and hepatitis B vaccination policies. During 2007, nearly 14 000 left-over samples taken from new recruits for blood typing were collected, unlinked from identifiers and anonymously tested for HIV, hepatitis C and current and past cleared hepatitis B infection. Overall, serological evidence of HIV and hepatitis C was found in 0·06% and 0·06% of recruits, respectively. Evidence of past cleared and current hepatitis B infection was found in 3·63% and 0·37% of recruits, respectively. Overall, prevalence rates were broadly consistent with UK population estimates of infection. However, HIV and hepatitis B prevalence was higher in recruits of African origin than in those from the UK (P<0·0001). Screening for these infections is an option that could be considered for those entering Services from high-prevalence countries.
    Epidemiology and Infection 01/2011; 139(8):1166-71. · 2.84 Impact Factor
  • Article: The cost-effectiveness of screening and treatment for hepatitis C in prisons in England and Wales: a cost-utility analysis.
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    ABSTRACT: Prisoners have a high prevalence of hepatitis C virus (HCV) infection compared with the general population in England and Wales and in many locations throughout the world. This is because of large numbers of injecting drug users that engage in behaviours likely to transmit HCV being present within prison populations. It is, therefore, suggested that prison may be an appropriate location for HCV screening and treatment to be administered. Using cost-utility analysis, this study considers the costs and benefits of administering a single round of screening on reception into prison to all individuals followed by possible later screening in the community and comparing this to individuals who may only be tested and treated in the community at a later date. The cost/QALY of one round of prison testing and treatment was found to be 54,852 pounds sterling, although probabilistic sensitivity analysis showed extensive uncertainty about this estimate. One-way sensitivity analysis revealed the importance of the parameters describing the progression of chronic HCV and the discount rates. While the results presented here at baseline would suggest that screening and treatment for HCV in prisons is not cost-effective, these results are subject to much uncertainty. The importance of the rates describing the progression of chronic HCV on the cost-effectiveness of this intervention has been demonstrated and this suggests that future work should be undertaken to gain further insight into the rates that individuals progress to the later stages of chronic HCV infection.
    Journal of Viral Hepatitis 11/2008; 15(11):797-808. · 4.09 Impact Factor
  • Article: Modelling alternative strategies for delivering hepatitis B vaccine in prisons: the impact on the vaccination coverage of the injecting drug user population.
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    ABSTRACT: Since 2001 hepatitis B vaccination has been offered to prisoners on reception into prisons in England and Wales. However, short campaigns of vaccinating the entire population of individual prisons have achieved high vaccination coverage for limited periods, suggesting that short campaigns may be a preferable way of vaccinating prisoners. A model is used that describes the flow of prisoners through prisons stratified by injecting status to compare a range of vaccination scenarios that describe vaccination on prison reception or via regular short campaigns. Model results suggest that vaccinating on prison reception can capture a greater proportion of the injecting drug user (IDU) population than the comparable campaign scenarios (63% vs. 55.6% respectively). Vaccination on prison reception is also more efficient at capturing IDUs for vaccination than vaccination via a campaign, although vaccination via campaigns may have a role with some infections for overall control.
    Epidemiology and Infection 04/2008; 136(12):1644-9. · 2.84 Impact Factor
  • Article: HIV in gay and bisexual men in the United Kingdom: 25 years of public health surveillance.
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    ABSTRACT: It is more than 25 years since the first case of AIDS was reported in the United Kingdom. In December 1981 a gay man was referred to a London hospital with opportunistic infections indicative of immunosuppression. National surveillance began the following year, in September 1982, with the notification of deaths and clinical reports of AIDS and Kaposi's sarcoma plus laboratory reports of opportunistic infections. Since then epidemiological surveillance systems have evolved, adapting to, and taking advantage of advances in treatments and laboratory techniques. The introduction of the HIV antibody test in 1984 led to the reporting of HIV-positive tests by laboratories and the establishment of an unlinked anonymous survey in 1990 measuring undiagnosed HIV infection among gay men attending sexual health clinics. The widespread use of highly active antiretroviral therapies (HAART) since 1996 has averted many deaths among HIV-positive gay men and has also resulted in a large reduction in AIDS cases. This led to a need for an enumeration of gay men with HIV accessing NHS treatment and care services (1995 onwards), more clinical information on HIV diagnoses for epidemiological surveillance (2000 onwards) and the routine monitoring of drug resistance (2001 onwards). Twenty-five years after the first case of AIDS was reported, gay and bisexual men remain the group at greatest risk of acquiring HIV in the United Kingdom. Latest estimates suggest that in 2004, 26 500 gay and bisexual men were living with HIV in the United Kingdom, a quarter of whom were undiagnosed. In this review, we examine how national surveillance systems have evolved over the past 25 years in response to the changing epidemiology of HIV/AIDS among gay and bisexual men in the United Kingdom as well as advances in laboratory techniques and medical treatments. We also reflect on how they will need to continue evolving to effectively inform health policy in the future.
    Epidemiology and Infection 03/2008; 136(2):145-56. · 2.84 Impact Factor
  • Article: Estimates of human immunodeficiency virus prevalence and proportion diagnosed based on Bayesian multiparameter synthesis of surveillance data
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    ABSTRACT: Estimates of the number of prevalent human immunodeficiency virus infections are used in England and Wales to monitor development of the human immunodeficiency virus-acquired immune deficiency syndrome epidemic and for planning purposes. The population is split into risk groups, and estimates of risk group size and of risk group prevalence and diagnosis rates are combined to derive estimates of the number of undiagnosed infections and of the overall number of infected individuals. In traditional approaches, each risk group size, prevalence or diagnosis rate parameter must be informed by just one summary statistic. Yet a rich array of surveillance and other data is available, providing information on parameters and on functions of parameters, and raising the possibility of inconsistency between sources of evidence in some parts of the parameter space. We develop a Bayesian framework for synthesis of surveillance and other information, implemented through Markov chain Monte Carlo methods. The sources of data are found to be inconsistent under their accepted interpretation, but the inconsistencies can be resolved by introducing additional 'bias adjustment' parameters. The best-fitting model incorporates a hierarchical structure to spread information more evenly over the parameter space. We suggest that multiparameter evidence synthesis opens new avenues in epidemiology based on the coherent summary of available data, assessment of consistency and bias modelling. Copyright (c) 2008 Royal Statistical Society.
    Journal of the Royal Statistical Society Series A. 01/2008; 171(3):541-580.
  • Article: Twenty years of selective hepatitis B vaccination: is hepatitis B declining among injecting drug users in England and Wales?
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    ABSTRACT: Injection drug use is a common route of infection for the hepatitis B virus (HBV) in the UK. The aim of this study was to establish the prevalence and force of infection for HBV among injecting drug users (IDUs) recruited from multiple community and drug agency settings in England and Wales between 1990 and 2004. Cross-sectional studies of IDUs in and out of contact with drug agencies were conducted throughout the 15-year period. Oral fluid samples were tested for antibodies to the hepatitis B core antigen (anti-HBc). Logistic regression was used to investigate associations between risk factors and anti-HBc positivity and force of infection models were explored. In total, 2527 injectors were recruited from community settings, and 29 386 from drug agencies. Anti-HBc prevalence was 31% (95% CI 30.7-31.8%). It declined in the early 1990s from around 50% in 1992 to 25% in 1999, after which it increased slightly. It was also higher in those who had injected for longer, older IDUs, those recruited in London and North West England, and those reporting having a previous voluntary confidential HIV test. The force of infection models suggested that the incidence of infection increased in 1999-2004 compared with 1993-1998, and was higher in new injectors compared with those injecting for > or =1 year. In conclusion, findings suggest ongoing HBV transmission in recent years despite an overall decline in prevalence in the early and mid-1990s, and highlight the importance of targeting vaccination programmes at new IDUs who have high incidence rates of infection.
    Journal of Viral Hepatitis 09/2007; 14(8):584-91. · 4.09 Impact Factor
  • Article: Estimating adult HIV prevalence in the UK in 2003: the direct method of estimation.
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    ABSTRACT: 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. 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. 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. 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.
    Sexually Transmitted Infections 07/2006; 82 Suppl 3:iii78-86. · 2.85 Impact Factor
  • Article: Modelling the hepatitis B vaccination programme in prisons.
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    ABSTRACT: A vaccination programme offering hepatitis B (HBV) vaccine at reception into prison has been introduced into selected prisons in England and Wales. Over the coming years it is anticipated this vaccination programme will be extended. A model has been developed to assess the potential impact of the programme on the vaccination coverage of prisoners, ex-prisoners, and injecting drug users (IDUs). Under a range of coverage scenarios, the model predicts the change over time in the vaccination status of new entrants to prison, current prisoners and IDUs in the community. The model predicts that at baseline in 2012 57% of the IDU population will be vaccinated with up to 72% being vaccinated depending on the vaccination scenario implemented. These results are sensitive to the size of the IDU population in England and Wales and the average time served by an IDU during each prison visit. IDUs that do not receive HBV vaccine in the community are at increased risk from HBV infection. The HBV vaccination programme in prisons is an effective way of vaccinating this hard-to-reach population although vaccination coverage on prison reception must be increased to achieve this.
    Epidemiology and Infection 05/2006; 134(2):231-42. · 2.84 Impact Factor
  • Article: Monitoring the effectiveness of HIV and STI prevention initiatives in England, Wales, and Northern Ireland: where are we now?
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    ABSTRACT: Primary and secondary prevention are essential components of the response to HIV and sexually transmitted infections (STIs). We present findings from nationally implemented HIV/STI prevention interventions. In 2003, of those attending STI clinics at least 64% of men who have sex with men (MSM) and 55% of heterosexuals accepted a confidential HIV test; 88% of all HIV infections in women giving birth in England were diagnosed before delivery; 85% of MSM eligible for hepatitis B vaccination received a first dose of vaccine at their first STI clinic attendance; 74% of STI clinic attendees for emergency appointments, and 20% of those for routine appointments were seen within 48 hours of initiating an appointment; the National Chlamydia Screening Programme in England found a positivity of 10% and 13% among young asymptomatic women and men, respectively. Prevention initiatives have seen recent successes in limiting further HIV/STI transmission. However, more work is required if current levels of transmission are to be reduced.
    Sexually Transmitted Infections 03/2006; 82(1):4-10. · 2.85 Impact Factor
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    Article: Modelling the force of infection for hepatitis B and hepatitis C in injecting drug users in England and Wales.
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    ABSTRACT: Injecting drug use is a key risk factor, for several infections of public health importance, especially hepatitis B (HBV) and hepatitis C (HCV). In England and Wales, where less than 1% of the population are likely to be injecting drug users (IDUs), approximately 38% of laboratory reports of HBV, and 95% of HCV reports are attributed to injecting drug use. Voluntary unlinked anonymous surveys have been performed on IDUs in contact with specialist agencies throughout England and Wales. Since 1990 more than 20,000 saliva samples from current IDUs have been tested for markers of infection for HBV, HCV testing has been included since 1998. The analysis here considers those IDUs tested for HBV and HCV (n = 5,682) from 1998-2003. This study derives maximum likelihood estimates of the force of infection (the rate at which susceptible IDUs acquire infection) for HBV and HCV in the IDU population and their trends over time and injecting career length. The presence of individual heterogeneity of risk behaviour and background HBV prevalence due to routes of transmission other than injecting are also considered. For both HBV and HCV, IDUs are at greatest risk from infection in their first year of injecting (Forces of infection in new initiates 1999-2003: HBV = 0.1076 95% C.I: 0.0840-0.1327 HCV = 0.1608 95% C.I: 0.1314-0.1942) compared to experienced IDUs (Force of infection in experienced IDUs 1999-2003: HBV = 0.0353 95% C.I: 0.0198-0.0596, HCV = 0.0526 95% C.I: 0.0310-0.0863) although independently of this there is evidence of heterogeneity of risk behaviour with a small number of IDUs at increased risk of infection. No trends in the FOI over time were detected. There was only limited evidence of background HBV infection due to factors other than injecting. The models highlight the need to increase interventions that target new initiates to injecting to reduce the transmission of blood-borne viruses. Although from the evidence here, identification of those individuals that engage in heightened at-risk behaviour may also help in planning effective interventions. The data and methods described here may provide a baseline for monitoring the success of public health interventions.
    BMC Infectious Diseases 02/2006; 6:93. · 3.12 Impact Factor
  • Article: HIV transmission in part of the US prison system: implications for Europe.
    Euro surveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 02/2006; 11(5):E060525.2. · 6.15 Impact Factor
  • Article: Epidemiology of HIV among black and minority ethnic men who have sex with men in England and Wales.
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    ABSTRACT: To examine the epidemiology of HIV among black and minority ethnic (BME) men who have sex with men (MSM) in England and Wales (E&W). Ethnicity data from two national HIV/AIDS surveillance systems were reviewed (1997-2002 inclusive), providing information on new HIV diagnoses and those accessing NHS HIV treatment and care services. In addition, undiagnosed HIV prevalence among MSM attending 14 genitourinary medicine (GUM) clinics participating in the Unlinked Anonymous Prevalence Monitoring Programme and having routine syphilis serology was examined by world region of birth. Between 1997 and 2002, 1040 BME MSM were newly diagnosed with HIV in E&W, representing 12% of all new diagnoses reported among MSM. Of the 1040 BME MSM, 27% were black Caribbean, 12% black African, 10% black other, 8% Indian/Pakistani/Bangladeshi, and 44% other/mixed. Where reported (n = 395), 58% of BME MSM were probably infected in the United Kingdom. An estimated 7.4% (approximate 95% CI: 4.4% to 12.5%) of BME MSM aged 16-44 in E&W were living with diagnosed HIV in 2002 compared with 3.2% (approximate 95% CI: 2.6% to 3.9%) of white MSM (p<0.001). Of Caribbean born MSM attending GUM clinics between 1997 and 2002, the proportion with undiagnosed HIV infection was 15.8% (95% CI: 11.7% to 20.8%), while among MSM born in other regions it remained below 6.0%. Between 1997-2002, BME MSM accounted for just over one in 10 new HIV diagnoses among MSM in E & W; more than half probably acquired their infection in the United Kingdom. In 2002, the proportion of BME MSM living with diagnosed HIV in E&W was significantly higher than white MSM. Undiagnosed HIV prevalence in Caribbean born MSM was high. These data confirm the need to remain alert to the sexual health needs and evolving epidemiology of HIV among BME MSM in E&W.
    Sexually Transmitted Infections 09/2005; 81(4):345-50. · 2.85 Impact Factor
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    Article: Increasing hepatitis B vaccine coverage in prisons in England and Wales.
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    ABSTRACT: The most frequently reported risk factor for hepatitis B infection in England and Wales is injecting drug use (38%). Since approximately 61% of injecting drug users (IDUs) had been imprisoned and less than 40% had received hepatitis B vaccine, a prison based hepatitis B vaccination programme was set up in 2001. At the 42 establishments participating in this study, all prisoners were offered vaccine at reception. Prisoners over 18 years were vaccinated using the 0, 7 and 21 days schedule and those under 18 years, using the 0, 1 and 2 months schedule. As far as possible a fourth dose was given to all after 12 months. In 2003, 14,163 prisoners received at least one dose of vaccine and altogether 26,265 doses were administered. A further 1111 prisoners reported they had already been vaccinated against hepatitis B. The median vaccine coverage rate was 17% (range 0-94%). Despite low coverage levels, the vaccination programme in prisons can be said to have vaccinated a sizable number of young, male prisoners, a group that have previously been shown to be at high risk of infection. The prisons which achieved vaccine coverage levels over 50% had designated nursing staff who ran the vaccination clinics.
    Communicable disease and public health / PHLS 01/2005; 7(4):306-11.
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    Article: Hepatitis A vaccination--a prison-based solution for a community-based outbreak?
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    ABSTRACT: In December 2001, an increase in cases of hepatitis A was observed in South Yorkshire. Cases were predominantly young males who reported injecting drug use. A community-based vaccination programme was introduced in November 2002, but new cases continued to occur. In March 2003, a vaccination campaign was implemented in the local prison for a four-week period. One thousand two hundred and thirty-six (91%) prisoners were vaccinated. Two thirds (895/1,363) of the prisoners came from the area affected by the outbreak and 52% (465/895) reported injecting drugs. The median age of injectors was 25 years. Notifications of cases of hepatitis A from South Yorkshire ceased in August 2003. Although on this occasion the prison vaccination campaign was probably implemented too late to have had a significant impact on the local outbreak, a large number of young male injectors from the local area were successfully vaccinated. This suggests that a prison-based intervention offers a potentially effective way of immunising the IDU population and interrupting a community-based outbreak.
    Communicable disease and public health / PHLS 01/2005; 7(4):289-93.
  • Article: Recent trends in HIV and other STIs in the United Kingdom: data to the end of 2002.
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    ABSTRACT: Sexual health in the United Kingdom has deteriorated in recent years with further increases in HIV and other sexually transmitted infections (STIs) reported in 2002. This paper describes results from the available surveillance data in the United Kingdom from the Health Protection Agency and its national collaborators. The data sources range from voluntary reports of HIV/AIDS from clinicians, CD4 cell count monitoring, a national census of individuals living with HIV, and the Unlinked Anonymous Programme, to statutory reports of STIs from genitourinary medicine (GUM) clinics and enhanced STI surveillance systems. In 2002, an estimated 49500 adults aged over 15 years were living with HIV in the United Kingdom, of whom 31% were unaware of their infection. Diagnoses of new HIV infections have doubled from 1997 to 2002, mainly driven by heterosexuals who acquired their infection abroad. HIV transmission also continues within the United Kingdom, particularly among homo/bisexual men who, in 2002, accounted for 80% of all newly diagnosed HIV infections acquired in the United Kingdom. New diagnoses of syphilis have increased eightfold, and diagnoses of chlamydia and gonorrhoea have doubled from 1997 to 2002 overall; STI rates disproportionately affect homo/bisexual men and young people. Effective surveillance is essential in the provision of timely information on the changing epidemiology of HIV and other STIs; this information is necessary for the targeting of prevention efforts and through providing baseline information against which progress towards targets can be monitored.
    Sexually Transmitted Infections 07/2004; 80(3):159-66. · 2.85 Impact Factor
  • Article: Is HIV incidence increasing in homo/bisexual men attending GUM clinics in England, Wales and Northern Ireland?
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    ABSTRACT: Laboratory recognition of recent infection allows HIV incidence to be monitored. We have determined HIV incidence in homo/bisexual men attending 15 genitourinary medicine clinics (GUM) across England, Wales and Northern Ireland (EW&NI). The estimated HIV incidence for 2002 was 3.5%, an increase from the 2.5% incidence seen in 2000 and 2001. Incidence was higher in London than outside, though outside London the overall incidence has recently increased over two-fold from 1% in 2001 to 2.5% in 2002. Throughout the UK HIV incidence may have risen in homo/bisexual men attending GUM clinics.
    Communicable disease and public health / PHLS 04/2004; 7(1):11-4.
  • Article: Epidemiology of HIV in young people in England, Wales and Northern Ireland.
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    ABSTRACT: We describe the epidemiology of HIV among young people (15-24 years) in England, Wales and Northern Ireland (E, W&NI) between 1997 and 2001 inclusive. Rising rates of sexually transmitted infections (STIs) and 'risk' behaviours suggest that they are at increased risk of acquiring HIV. Data from three national surveillance systems are reviewed. Over the period, 1,624 young people were diagnosed with HIV (10% of all new diagnoses). In 1997 there were 254 new diagnoses, rising to 493 in 2001, a 1.9-fold increase. Of the total, 890 (55%) were heterosexually infected (81% female), 631 through sex between men, and the remainder via other routes. Where probable country of infection was reported (1,139), 618 (54%) were infected in Africa and 362 (32%) in the UK. In 1997, 675 young people accessed HIV-related services, rising to 975 in 2001: an increase of 1.4 fold. In 2001, for 34 of those accessing services the likely route of infection was perinatal. Between 1997 and 2001 inclusive, HIV prevalence among young heterosexual genitourinary medicine (GUM) clinic attendees was 0.17% (193/116,443), and for young homo/bisexual males, 3.4% (174/5,086). Sixty-five percent (104/159) of previously undiagnosed HIV-infected heterosexuals and 47% (51/108) of previously undiagnosed HIV-infected homo/bisexual males left the clinic unaware of their infection. In 2000 and 2001, overall prevalence was 0.11% (77/70,455) among young women giving birth. HIV diagnoses in young people have increased in recent years, while HIV prevalence among young people attending GUM clinics and giving birth has remained low. However, with dramatic increases in chlamydia rates among young women over the past decade, and the highest rates of gonorrhoea and concurrent partnerships among young people, concern about the potential for HIV transmission remains.
    Communicable disease and public health / PHLS 04/2004; 7(1):15-23.
  • Article: Black Caribbean adults with HIV in England, Wales, and Northern Ireland: an emerging epidemic?
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    ABSTRACT: HIV is now well established in the Caribbean, with prevalence in several countries being surpassed only by those of sub-Saharan Africa. Continuing inward migration from the Caribbean and a high incidence of some bacterial STIs among Britain's black Caribbean communities, suggests a considerable potential for HIV spread. Data from three national HIV/AIDS surveillance systems were reviewed, providing information on new HIV diagnoses, numbers accessing treatment and care services, and HIV prevalence. Between 1997 and 2001, 528 black Caribbean adults were newly diagnosed with HIV; 62 new diagnoses in 1997, rising to 176 in 2001. Probable heterosexual acquisition accounted for 335 (63%) infections (161 (48%) males, 174 females), and sex between men 171 (32%). Infection was acquired both in the Caribbean and in the United Kingdom. Numbers of black Caribbeans accessing treatment and care services more than doubled between 1997 (294) and 2001 (691). In 2001, 528 (76%) black Caribbeans accessing services were London residents. Among the Caribbean born previously undiagnosed heterosexuals, HIV prevalence was 0.7%; among men who have sex with men (MSM) it was 10.4%. Of those born in the Caribbean, 73% of male heterosexuals, 50% of female heterosexuals, and 65% of MSM who were previously undiagnosed left the clinic unaware of their HIV infection. Numbers of black Caribbean adults newly diagnosed and accessing treatment and care services in England, Wales, and Northern Ireland increased between 1997 and 2001. Despite a high prevalence of diagnosed bacterial STIs, prevalence among Caribbean born heterosexuals remains low, but it is high among MSM. Surveillance data highlight the need for targeted HIV prevention among black Caribbeans.
    Sexually Transmitted Infections 03/2004; 80(1):18-23. · 2.85 Impact Factor

Institutions

  • 2008
    • The University of Warwick
      • Biological Sciences
      Warwick, ENG, United Kingdom
  • 2004–2008
    • Health Protection Agency
      • Health Protection Agency - North East
      London, ENG, United Kingdom
  • 2007
    • Medical Research Council (UK)
      • MRC Clinical Trials Unit
      London, ENG, United Kingdom
  • 1998–2005
    • International Society for Disease Surveillance
      Brighton, ENG, United Kingdom
    • Barts and The London School of Medicine and Dentistry
      London, ENG, United Kingdom
  • 1999–2000
    • The Bracton Centre, Oxleas NHS Trust
      Dartford, ENG, United Kingdom
  • 1997–1999
    • University of Oslo
      • Department of Biostatistics
      Oslo, Oslo, Norway
  • 1989
    • London School of Hygiene and Tropical Medicine
      London, ENG, United Kingdom
    • University College London Hospitals
      London, ENG, United Kingdom