New-generation gels that deliver potent antiretroviral drugs against human immunodeficiency virus type 1 have renewed hopes for topical prophylaxis as a prevention strategy. Previous preclinical research with monkey models suggested that high concentrations and drug combinations are needed for high efficacy. We evaluated two long-acting reverse transcriptase inhibitors, tenofovir (TFV) and emtricitabine (FTC), by using a twiceweekly repeat challenge macaque model and showed that a preexposure vaginal application of gel with 1% TFV alone or in combination with 5% FTC fully protected macaques from a total of 20 exposures to simian-human immunodeficiency virus SF162p3. FTC and TFV were detected in plasma 30 min after vaginal application, suggesting rapid absorption. FTC was detected more frequently than TFV and showed higher levels, reflecting the fivefold-higher concentration of this drug than of TFV. Two of 12 repeatedly exposed but protected macaques showed limited T-cell priming, which did not induce resistance to infection when macaques were rechallenged. Thus, single drugs with durable antiviral activity can provide highly effective topical prophylaxis and overcome the need for noncoital use or for drug combinations which are more complex and costly to formulate and approve.

BackgroundXMRV, a xenotropic murine leukemia virus (MuLV)-related virus, was recently identified by PCR testing in 67% of persons with chronic fatigue syndrome (CFS) and in 3.7% of healthy persons from the United States. To investigate the association of XMRV with CFS we tested blood specimens from 51 persons with CFS and 56 healthy persons from the US for evidence of XMRV infection by using serologic and molecular assays. Blinded PCR and serologic testing were performed at the US Centers for Disease Control and Prevention (CDC) and at two additional laboratories.ResultsArchived blood specimens were tested from persons with CFS defined by the 1994 international research case definition and matched healthy controls from Wichita, Kansas and metropolitan, urban, and rural Georgia populations. Serologic testing at CDC utilized a Western blot (WB) assay that showed excellent sensitivity to MuLV and XMRV polyclonal or monoclonal antibodies, and no reactivity on sera from 121 US blood donors or 26 HTLV-and HIV-infected sera. Plasma from 51 CFS cases and plasma from 53 controls were all WB negative. Additional blinded screening of the 51 cases and 53 controls at the Robert Koch Institute using an ELISA employing recombinant Gag and Env XMRV proteins identified weak seroreactivity in one CFS case and a healthy control, which was not confirmed by immunofluorescence. PCR testing at CDC employed a gag and a pol nested PCR assay with a detection threshold of 10 copies in 1 ug of human DNA. DNA specimens from 50 CFS patients and 56 controls and 41 US blood donors were all PCR-negative. Blinded testing by a second nested gag PCR assay at the Blood Systems Research Institute was also negative for DNA specimens from the 50 CFS cases and 56 controls.ConclusionsWe did not find any evidence of infection with XMRV in our U.S. study population of CFS patients or healthy controls by using multiple molecular and serologic assays. These data do not support an association of XMRV with CFS.

Objectives. To describe and control an outbreak of HIV infection among people who inject drugs (PWID). Methods. The investigation included people diagnosed with HIV infection during 2015 to 2018 linked to 2 cities in northeastern Massachusetts epidemiologically or through molecular analysis. Field activities included qualitative interviews regarding service availability and HIV risk behaviors. Results. We identified 129 people meeting the case definition; 116 (90%) reported injection drug use. Molecular surveillance added 36 cases to the outbreak not otherwise linked. The 2 largest molecular groups contained 56 and 23 cases. Most interviewed PWID were homeless. Control measures, including enhanced field epidemiology, syringe services programming, and community outreach, resulted in a significant decline in new HIV diagnoses. Conclusions. We illustrate difficulties with identification and characterization of an outbreak of HIV infection among a population of PWID and the value of an intensive response. Public Health Implications. Responding to and preventing outbreaks requires ongoing surveillance, with timely detection of increases in HIV diagnoses, community partnerships, and coordinated services, all critical to achieving the goal of the national Ending the HIV Epidemic initiative.