To estimate the frequency and duration of detectable Zika virus (ZIKV) RNA in human body fluids, we prospectively assessed a cohort of recently infected participants in Puerto Rico. We evaluated samples obtained from 295 participants (including 94 men who provided semen specimens) in whom ZIKV RNA was detected on reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay in urine or blood at an enhanced arboviral clinical surveillance site. We collected serum, urine, saliva, semen, and vaginal secretions weekly for the first month and at 2, 4, and 6 months. All specimens were tested by means of RT-PCR, and serum was tested with the use of anti–ZIKV IgM enzyme-linked immunosorbent assay. Among the participants with ZIKV RNA in any specimen at week 4, collection continued every 2 weeks thereafter until all specimens tested negative. We used parametric Weibull regression models to estimate the time until the loss of ZIKV RNA detection in each body fluid and reported the findings in medians and 95th percentiles. The medians and 95th percentiles for the time until the loss of ZIKV RNA detection were 15 days (95% confidence interval [CI], 14 to 17) and 41 days (95% CI, 37 to 44), respectively, in serum; 11 days (95% CI, 9 to 12) and 34 days (95% CI, 30 to 38) in urine; and 42 days (95% CI, 35 to 50) and 120 days (95% CI, 100 to 139) in semen. Less than 5% of participants had detectable ZIKV RNA in saliva or vaginal secretions. The prolonged time until ZIKV RNA clearance in serum in this study may have implications for the diagnosis and prevention of ZIKV infection. In 95% of the men in this study, ZIKV RNA was cleared from semen after approximately 4 months. (Funded by the Centers for Disease Control and Prevention.)

Objective: Evaluate changes in condomless anal sex at last sex among men who have sex with men (MSM) and assess if these changes are associated with the adoption of serosorting and biomedical prevention. Design: The National HIV Behavioral Surveillance is a crosssectional survey done in up to 21 cities in 2005, 2008, 2011 and 2014. Methods: MSM were recruited through venue-based sampling. Among men reporting at least one male partner, we evaluated changes in condomless anal sex at last sex with a partner with (1) HIV-concordant (proxy for serosorting) or (2) HIV-discordant (discordant/unknown) status. We hypothesized that if concordant condomless sex was increasing while discordant was stable/declining, the increases could be driven by more men attempting to serosort. We used generalized estimating equations assuming a Poisson distribution and robust variance estimator to explore whether temporal changes in the outcomes varied by selected characteristics. We also assessed changes in condomless anal sex by antiretroviral therapy (ART) use among HIV-positive MSM. Results: Among 5371 HIV-positive MSM, there were increases in concordant (19% in 2005 to 25% in 2014, P < 0.001) and discordant condomless sex (15 to 19%, P < 0.001). The increases were not different by ART use. Among 30 547 HIV-negative MSM, concordant (21 to 27%, P < 0.001) and discordant condomless sex (8 to 13%, P < 0.001) increased. Conclusion: Our data suggest that condom use decreased among MSM and that the trends are not explained by serosorting or ART. Promotion of condoms and increased access to preexposure prophylaxis are vital to ensure that the benefits of ART in reducing transmission of HIV are not undermined.

ACIP recommendations for use of dengue vaccine in the U.S.