The Impact of Pre-Exposure Prophylaxis (PrEP) Use on Sexual Anxiety, Satisfaction, and Esteem Among Gay and Bisexual Men.

Gay and bisexual men (GBM) with heightened fears of human immunodeficiency virus (HIV) acquisition have reported high levels of sexual anxiety and low sexual self-esteem. Similarly, sexual satisfaction has been reported to be lower among some GBM who rely solely on condom use as HIV prevention. We sought to explore whether pre-exposure prophylaxis (PrEP) had an impact on the sexual satisfaction, anxiety, and esteem of GBM. As part of a longitudinal cohort study of 1,071 GBM, participants reported at three time points on PrEP use and completed the Multidimensional Sexual Self-Concept Questionnaire (MSSCQ). A total of 137 GBM began taking PrEP in the 24 months following baseline. Comparing their responses during times before initiating PrEP and after, within adjusted multilevel models, there was a significant decrease in sexual anxiety (B = -0.27, p = 0.03) but no significant changes in sexual esteem or satisfaction. Our findings indicate important psychological improvements resulting from PrEP initiation. Further research should explore the potential for other psychological benefits of PrEP use among GBM.

Ciprofloxacin residues in municipal biosolid compost do not selectively enrich populations of resistant bacteria.

Biosolids and livestock manure are valuable high-carbon soil amendments, but they commonly contain antibiotic residues that might persist after land application. While composting reduces the concentration of extractable antibiotics in these materials, if the starting concentration is sufficiently high then remaining residues could impact microbial communities in the compost and soil to which these materials are applied. To examine this issue, ciprofloxacin was added to biosolid compost feedstock to achieve a total concentration of 19 ppm, approximately 5-fold higher than that normally detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (1 to 3.5 ppm). This feedstock was placed into mesh bags that were buried in aerated compost bays. Once a week, a set of bags was removed and analyzed (treated and untreated, three replicates of each; 4 weeks). Addition of ciprofloxacin had no effect on the recovery of resistant bacteria at any time point (P = 0.86), and a separate bioassay showed that aqueous extractions from materials with an estimated 59 ppm ciprofloxacin had no effect on the growth of a susceptible strain of Escherichia coli (P = 0.28). Regression analysis showed that growth of the susceptible strain of E. coli can be reduced given a sufficiently high concentration of ciprofloxacin (P < 0.007), a result that is consistent with adsorption being the primary mechanism of sequestration. While analytical methods detected biologically significant concentrations of ciprofloxacin in the materials tested here, the culture-based methods were consistent with the materials having sufficient adsorptive capacity to prevent typical concentrations of ciprofloxacin residues from selectively enriching populations of resistant bacteria.