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BMC Infect Dis ; 19(1): 721, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416439


BACKGROUND: Pre-exposure prophylaxis (PrEP) is a promising and effective tool to prevent human immunodeficiency virus (HIV) transmission; however, context-specific data to guide optimal implementation are currently lacking in China. This study aims to systematically collect comprehensive, empirical data to determine effective ways to implement PrEP among at-risk men who have sex with men (MSM) in China. METHODS: The CROPrEP project, a real-world study of PrEP use, will recruit 1000 high-risk HIV-negative MSM participants from four cities in China, who will be able to choose between daily or event-driven dosing regimens, according to their preference. Participants will be followed up at months 1, 3, 6, 9, and 12 for PrEP provision, clinical evaluation, laboratory testing (e.g., emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) concentrations, and HIV/sexually transmitted infections), alongside detailed, self-administered online questionnaires regarding sexual behaviors, adherence, and attitudes. Online weekly notes will be used to record pill use and sexual practice. Various measurements will be triangulated to assess adherence, including: self-reported adherence, pill count, and drug concentration. A propensity score matching model will be fitted to examine the effectiveness of PrEP use in HIV seroconversion compared with non-PrEP users selected from a local expanding cohort study of HIV-1-negative MSM at participating research centers. Analyses using a generalized estimating equation model will focus on elucidation of the cascade of PrEP implementation, effectiveness, safety, and possible effects of PrEP use on sexual behaviors. This study will provide a comprehensive assessment of real-world PrEP use among Chinese MSM, to develop guidelines and strategies for PrEP implementation in China. DISCUSSION: The CROPrEP project is the first study of the TDF/FTC combination as PrEP in China, which will provide primary data on PrEP implementation, including: the cascade of PrEP use, "real-world" effectiveness, adherence, and safety. The findings from this study have potential to be vital for promoting the integration of PrEP within the portfolio of HIV prevention interventions and developing guidance on PrEP implementation in China. TRIAL REGISTRATION: ChiCTR-IIN-17013762 (Chinese Clinical Trial Registry). Date of registration: 8 December 2017.

AIDS Behav ; 23(5): 1240-1249, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30632008


Social media interventions may enhance HIV services among key populations, including men who have sex with men (MSM). This longitudinal analysis examined the effect of recalling, sharing, and participating in different components of a social media intervention on HIV testing among MSM. The social media intervention included six images/texts and information about an online local community contest to promote testing. Of the 1033 men, they recalled a mean of 2.7 out of six images and shared an average of one image online. 34.5% of men recalled information on the online local community contest and engaged in a mean of 1.3 contest. Recalling images/texts (aOR = 1.13, 95% CI 1.02-1.25) and recalling a local contest (aOR = 1.59, 95% CI 1.13-1.24) were associated with facility-based HIV testing. This study has implications for the development and evaluation of social media interventions to promote HIV testing.

Participação da Comunidade/estatística & dados numéricos , Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Promoção da Saúde , Homossexualidade Masculina/estatística & dados numéricos , Programas de Rastreamento/organização & administração , Mídias Sociais , Adulto , China/epidemiologia , Humanos , Estudos Longitudinais , Masculino
J Med Internet Res ; 20(12): e11303, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578225


BACKGROUND: Men who have sex with men (MSM) frequently seek partners through mobile apps (geosocial networking [GSN] apps). However, it is unclear whether GSN apps' use is associated with the increase in HIV incidence among MSM. OBJECTIVE: The aim of this study was to clarify the characteristics of GSN apps' users and to determine the association and putative mechanisms between GSN apps' use behavior and HIV incidence. METHODS: We conducted an 18-month prospective cohort study of MSM in Shenyang, China, and the participants were surveyed every 3 months from March 2015 to December 2016. An in-person interview collected information on sociodemographics, GSN apps' use, recreational drug use, and sexual behaviors. In addition, blood was drawn to test for HIV and syphilis. We used a multivariable Cox regression model to determine possible predictors for increased HIV incidence. RESULTS: Of the enrolled 686 HIV-negative MSM, 431 (431/686, 62.8%) were GSN apps' users. Compared with GSN apps' nonusers, GSN apps' users were younger; had an earlier age of sexual debut; and in the past 3 months, were more likely to have used recreational drugs, more likely to have had 5 or more casual partners (CPs), more likely to have had group sex with males, and more likely to have had condomless anal intercourse (CAI) with male steady partners (SPs). In addition, 59.4% (256/431) of the GSN apps' users were willing to accept HIV and AIDS prevention information push services through GSN apps. In total, 19 MSM seroconverted to HIV during the follow-up period; the HIV incidence density rate was 8.5 (95% CI 5.0-13.5) per 100 person-years (PY) among GSN apps' users and 2.0 (95% CI 0.4-5.8) per 100 PY among nonusers. New HIV infections were independently associated with ever using GSN apps to seek male sexual partners (P=.04) and in the past 3 months, using recreational drugs (P=.048), having group sex with males (P=.01), and having CAI with male CPs (P=.02). CONCLUSIONS: GSN apps' use is associated with higher HIV incidence and may be mediated through recreational drug use and having multiple CPs. Researchers must develop an intervention propagated through GSN apps to reach this high-risk population to mitigate the HIV epidemic in the MSM community.

Stat Methods Med Res ; : 962280218805780, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30428780


Stochastic transmission dynamic models are needed to quantify the uncertainty in estimates and predictions during outbreaks of infectious diseases. We previously developed a calibration method for stochastic epidemic compartmental models, called Multiple Shooting for Stochastic Systems (MSS), and demonstrated its competitive performance against a number of existing state-of-the-art calibration methods. The existing MSS method, however, lacks a mechanism against filter degeneracy, a phenomenon that results in parameter posterior distributions that are weighted heavily around a single value. As such, when filter degeneracy occurs, the posterior distributions of parameter estimates will not yield reliable credible or prediction intervals for parameter estimates and predictions. In this work, we extend the MSS method by evaluating and incorporating two resampling techniques to detect and resolve filter degeneracy. Using simulation experiments, we demonstrate that an extended MSS method produces credible and prediction intervals with desired coverage in estimating key epidemic parameters (e.g. mean duration of infectiousness and R0) and short- and long-term predictions (e.g. one and three-week forecasts, timing and number of cases at the epidemic peak, and final epidemic size). Applying the extended MSS approach to a humidity-based stochastic compartmental influenza model, we were able to accurately predict influenza-like illness activity reported by U.S. Centers for Disease Control and Prevention from 10 regions as well as city-level influenza activity using real-time, city-specific Google search query data from 119 U.S. cities between 2003 and 2014.

J R Soc Interface ; 15(147)2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30305417


Seasonal influenza causes millions of illnesses and tens of thousands of deaths per year in the USA alone. While the morbidity and mortality associated with influenza is substantial each year, the timing and magnitude of epidemics are highly variable which complicates efforts to anticipate demands on the healthcare system. Better methods to forecast influenza activity would help policymakers anticipate such stressors. The US Centers for Disease Control and Prevention (CDC) has recognized the importance of improving influenza forecasting and hosts an annual challenge for predicting influenza-like illness (ILI) activity in the USA. The CDC data serve as the reference for ILI in the USA, but this information is aggregated by epidemiological week and reported after a one-week delay (and may be subject to correction even after this reporting lag). Therefore, there has been substantial interest in whether real-time Internet search data, such as Google, Twitter or Wikipedia could be used to improve influenza forecasting. In this study, we combine a previously developed calibration and prediction framework with an established humidity-based transmission dynamic model to forecast influenza. We then compare predictions based on only CDC ILI data with predictions that leverage the earlier availability and finer temporal resolution of Wikipedia search data. We find that both the earlier availability and the finer temporal resolution are important for increasing forecasting performance. Using daily Wikipedia search data leads to a marked improvement in prediction performance compared to weekly data especially for a three- to four-week forecasting horizon.