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Background: Occupational exposures to bloodborne viruses are very common. Whilst occupational HIV transmissions are rare, the serious physical, psychological and cost implications of potential transmission make this an important public health topic. European and UK guidelines recommend HIV post-exposure prophylaxis (PEP) as a valuable tool of preventing occupational HIV infection. Yet one in five UK healthcare workers did not initiate PEP despite having been exposed to an HIV-positive source patient. The aim of the study is to examine factors associated with PEP uptake behaviour., Methods: The study is based on an analysis of the UK Health Protection Agency surveillance database of 'Significant Occupational Exposures to Bloodborne Viruses in Healthcare Workers'. Associations between possible predicting factors and PEP-uptake have been examined with univariate analysis and logistic regression modelling., Results: Univariate analysis and logistic regression found significant associations between PEP-uptake and visible blood on the device (p<0.0001) and a linear relationship with increasing injury depth (p<0.0001). Doctors were significantly more likely to start PEP than nurses (OR 1.88, 1.16; 3.02). Multiple imputation of missing values did not significantly alter these results., Conclusions: PEP-uptake was associated with known transmission risk factors, suggesting awareness of current guidelines. The significant differences in PEP-uptake across occupation categories may be due to differential risk perceptions or other underlying factors. This is the first national study to examine PEP-uptake following occupational exposures to HIV. Further research and exploration of these findings are warranted, to understand the role of PEP-uptake behaviour in preventing occupational HIV transmission.

Background: The clinical treatment of patients with HIV and adverse drug events may be enhanced by an understanding of the underlying mechanisms. About 4% of patients with HIV receiving the potent antiretroviral drug abacavir develop a hypersensitivity reaction. This idiosyncratic reaction appears to have an immunologic component that has yet to be defined. Given that the T-cell type 2 cytokine IL-4 may be overproduced by patients with allergy or other immunologic dysregulation, an index cytokine profile could help elucidate the character of a drug-specific hypersensitivity reaction., Objective: Quantitation of the production of the type 2 IL-4 and the counterregulatory type 1 cytokine IFN-gamma in patients with abacavir-related hypersensitivity., Methods: Intracellular cytokines were enumerated in blood T cells by flow cytometry. Subjects were grouped for evaluation as patients with a hypersensitive response after abacavir treatment, patients initiating abacavir who also were evaluated again after 1 month on abacavir, patients on abacavir for 6 months without hypersensitivity, and HIV-naive control individuals., Results: There was a significant association between increased IL-4 production by CD4 and CD8 T lymphocytes and hypersensitivity reactions to abacavir. Lymphocytes from hypersensitive subjects expressed CD28 and the anti-HIV chemokine macrophage inflammatory protein 1beta with a frequency comparable with HIV-naive control cells, suggesting the possibility that the activated T cells from patients with hypersensitivity are functional., Conclusion: The expansion of type 0 and type 2 T cells phenotyped by IL-4 production may correlate with abacavir-associated hypersensitivity. The data suggest a cytokine bias that may facilitate B-cell differentiation and downregulate T-cell cytotoxic responses.

Aim: To characterize HIV-1 Gag p24-specific CD4 cell responses in HIV-exposed-seronegative (ES) individuals., Methodology: Twelve ES individuals, of diverse ethnicity and wild type for the CCR5 Delta-32 mutation, were identified. Controls were HIV-negative blood donors. Gag p24-specific and total Vbeta+ CD4 cells that expressed MIP-1beta, IFN-gamma and IL-2 were enumerated by intracytoplasmic cytokine staining. beta-Chemokine expression was correlated with susceptibility to R5 HIV-1 infection, as measured by polymerase chain reaction for integrated HIV-1 and by p24 enzyme-linked immunosorbent assay., Results: Similar numbers of mitogen-stimulated and Vbeta+ MIP-1beta+, IFN-gamma+ and IL-2+ T cells were found in ES and HIV-negative control subjects. However, all ES subjects tested had an HIV Gag p24-specific MIP-1beta+, IFN-gamma+ and IL-2+ CD4 T-cell response that was rare in controls. p24-Specific cells of all ES but no control subjects could be expanded by in-vitro Ag/IL-2 stimulation, and when re-stimulated with an overlapping peptide series showed evidence of a broad CD4 cell memory response directed against multiple regions of Gag p24. Mitogen-stimulated ES CD4 cells were as susceptible to HIV infection as those from control subjects, but p24-specific IFN-gamma+ CD4 cells of six out of seven ES subjects tested were less susceptible to R5 HIV-1 infection than the counterpart fraction depleted of p24-specific IFN-gamma+ cells. The addition of blocking anti-beta-chemokine antibodies did not promote R5 HIV-1 infection of p24-specific IFN-gamma+ cells., Conclusion: Specific CD4 cell immunity, characterized by a broadly directed memory Gag-p24 CD4 cell response and reduced susceptibility of specific CD4 cells to R5 HIV-1 infection, is a likely correlate of non-transmission.

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. [ABSTRACT FROM AUTHOR]