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Ambitious World Health Organization targets for disease elimination require monitoring of epidemics using routine health data in settings of decreasing and low incidence. We evaluated 2 methods commonly applied to routine testing results to estimate incidence rates that assume a uniform probability of infection between consecutive negative and positive tests based on 1) the midpoint of this interval and 2) a randomly selected point in this interval. We compared these with an approximation of the Poisson binomial distribution, which assigns partial incidence to time periods based on the uniform probability of occurrence in these intervals. We assessed bias, variance, and convergence of estimates using simulations of Weibull-distributed failure times with systematically varied baseline incidence and varying trend. We considered results for quarterly, half-yearly, and yearly incidence estimation frequencies. We applied the methods to assess human immunodeficiency virus (HIV) incidence in HIV-negative patients from the Treatment With Antiretrovirals and Their Impact on Positive and Negative Men (TAIPAN) Study, an Australian study of HIV incidence in men who have sex with men, between 2012 and 2018. The Poisson binomial method had reduced bias and variance at low levels of incidence and for increased estimation frequency, with increased consistency of estimation. Application of methods to real-world assessment of HIV incidence found decreased variance in Poisson binomial model estimates, with observed incidence declining to levels where simulation results had indicated bias in midpoint and random-point methods. [ABSTRACT FROM AUTHOR]

Introduction: Broad availability of direct-acting antiviral therapy for hepatitis C virus (HCV) raises the possibility that HCV prevalence and incidence can be reduced through scaling-up treatment, leading to the elimination of HCV. High rates of linkage to HIV care among HIV-infected gay and bisexual men may facilitate high uptake of HCV treatment, possibly making HCV elimination more achievable in this group. Areas covered: This review covers HCV elimination in HIV-infected gay and bisexual men, including epidemiology, spontaneous clearance and long term sequelae in the absence of direct-acting antiviral therapy; direct-acting antiviral therapy uptake and effectiveness in this group; HCV reinfection following successful treatment; and areas for further research. Expert commentary: Early data from the direct-acting antiviral era suggest that treatment uptake is increasing among HIV infected GBM, and SVR rates are very promising. However, in order to sustain current treatment rates, additional interventions at the behavioral, physician, and structural levels may be required to increase HCV diagnosis, including prompt detection of HCV reinfection. Timely consideration of these issues is required to maximize the population-level impact of HCV direct-acting antiviral therapy. Potential HCV transmissions from HIV-uninfected GBM, across international borders, and from those who are not GBM also warrant consideration. [ABSTRACT FROM AUTHOR]

This systematic review and meta-analysis of 58 studies found that antiretroviral therapy is not associated with increased sexual or injecting risk-taking behavior among HIV-infected individuals undergoing treatment.Background. Increased global access and use of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) has been postulated to undermine HIV prevention efforts by changing individual risk-taking behavior. This review aims to determine whether ART use is associated with changes in sexual or injecting risk-taking behavior or diagnosis of sexually transmitted infections (STIs).Methods. A systematic review and meta-analysis was conducted of HIV-seropositive participants receiving ART compared with no ART use in experimental or observational studies. Primary outcomes included (1) any unprotected sexual intercourse, (2) STI diagnoses, and (3) any unsafe injecting behavior.Results. Fifty-eight studies met the selection criteria. Fifty-six studies containing 32 857 participants reported unprotected sex; 11 studies containing 16 138 participants reported STI diagnoses; and 4 studies containing 1600 participants reported unsafe injecting behavior. All included studies were observational. Unprotected sex was lower in participants receiving ART than in those not receiving ART (odds ratio [OR], 0.73; 95% confidence interval [CI], .64–.83; P < .001; heterogeneity I2 = 79%) in both high-income (n = 38) and low-/middle-income country (n = 18) settings, without any evidence of publication bias. STI diagnoses were also lower among individuals on ART (OR, 0.58; 95% CI, .33–1.01; P = .053; I2 = 92%); however, there was no difference in injecting risk-taking behavior with antiretroviral use (OR, 0.90; 95% CI, .60–1.35; P = .6; I2 = 0%).Conclusions. Despite concerns that use of ART might increase sexual or injecting risk-taking, available research suggests that unprotected sex is reduced among HIV-infected individuals on treatment. The reasons for this are not yet clear, although self-selection and mutually reinforcing effects of HIV treatment and prevention messages among people on ART are likely. [ABSTRACT FROM PUBLISHER]

Undiagnosed HIV infections contribute disproportionately to the HIV epidemic. We recruited 639 gay men attending social venues, who completed a cross-sectional survey with oral fluid collection for HIV testing in 2008. We calculated HIV and undiagnosed HIV prevalence and used χ2 tests and logistic regression to examine associations between participant characteristics and HIV status. Among 639 men, 61 (9.5%, 95% confidence interval: 7.4% to 12.1%) tested HIV positive, of which 19 (31.1%, 95%confidence interval: 19.9% to 44.3%) were classified as undiagnosed HIV positive. Almost a third of HIV-positive men were unaware of their HIV status, and of these men, a large proportion engaged in high-risk behaviors. [ABSTRACT FROM AUTHOR]

Abstract: This paper outlines a commentary response to an article published by Young and colleagues in Preventive Medicine that evaluated the feasibility of using Twitter as a surveillance and monitoring took for HIV. We draw upon the broader literature on disease surveillance and public health prevention using social media and broader considerations of epidemiological and surveillance methods to provide readers with necessary considerations for using social media in epidemiology and surveillance. [Copyright &y& Elsevier]