Transmission of STIs/HIV at the partnership level: Beyond individual-level analyses

Mathematical modeling of transmission dynamics of sexually transmitted infections (STIs) and HIV has considerably advanced HIV research by highlighting the importance of certain types of partnerships in epidemic spread. Notably, concurrent partnerships, defined as a sexual partnership in which one or more of the partnership members have other sexual partners while continuing sexual activity with the original partner, have been shown to play a fundamental role in potentiating the spread of STIs and HIV. Risk behaviors such as concurrency and sex without condoms as well as STI/HIV prevalence vary with physical, social, and emotional factors within partnerships. The efficiency of STI/HIV transmission appears to vary across types of concurrent partnerships according to the differing dynamics within them. Previous research on partnership dynamics has improved our understanding of the multidimensional aspects of sexual partnering, but little is understood of how these aspects of sexual partnering interact and increase risks for HIV, nor how types of partnerships, partnership dynamics, and concurrency work together to affect both the behavior of condom use and the biological transmission of disease. In this article, we discuss the need to extend our understanding of concurrency to include partnerships among men who have sex with men (MSM) and to differentiate between types of partnerships and to develop interventions to modify risk within partnerships. We also introduce a conceptual framework that reflects how individual and partner characteristics influence partnership dynamics that in turn influence risk behaviors, such as concurrency and not using condoms, and associated risks for STIs and HIV.     

Evoked potentials to light during aging

Neuroscience and Behavioral Physiology -     

Anaerobes survive in clinical specimens despite delayed processing.

Quantitative cultures were performed on 11 purulent specimens of at least 2 ml from mixed aerobic-anaerobic infections to determine the effect of prolonged exposure to air on the recovery of anaerobes. The specimens were processed immediately and after air exposure for periods of 10 min and 1, 4, and 24 h. There were at total of 37 anaerobic and 36 aerobic strains recovered from these specimens. Of the anaerobes, 26 were isolated with the initial processing and 22 were still present after air exposure for 24 h. The numerical concentrations of anaerobes showed little change with the sequential samplings. Eleven anaerobic strains were not detected in the initial culture but appeared sporadically in subsequent cultures. Using the types of specimens and method of processing employed in this study, most pathogenic anaerobes survived in purulent exudate despite extended periods of air exposure. The major cause of discrepent results with periodic cultures was attributed to vagaries in sampling.     

The effect of corticosteroids on subcutaneous abscess formation in the mouse.

We have used a recently developed model for s.c. abscess formation to study the effect of corticosteroids on abscess formation in mice. Mice were given daily i.p. injections of either hydrocortisone, 20 mg/kg/day or dexamethasone, 0.8 mg/kg/day, starting 3 days before inoculation with Staph, aureus and continuing for the duration of the experiment. Another group of mice was given a single injection of dexamethasone, 8 mg/kg, 1 h after inoculation with Staph. aureus. Encapsulated abscesses developed in all animals by Day 4, and there was no mortality. Abscess volume +/- s.l. mean at 4 days was reduced (p less than 0.0005) from 39.9 +/- 3.0 mm3 in controls to 16.7 +/- 3.6 mm3 in the daily dexamethasone group. Abscess volume at 4 days after a single dose of dexamethasone was 39.9 +/- 8.0 mm3. Bacterial concentrations per ml of pus were equivalent in all groups (10(10,6)-10(10.9). The effect of steroids on formation of sterile abscesses was also studied. Abscess volumes were smaller in animals given daily hydrocortisone or dexamethasone when compared to controls, but the difference was significant only for mice receiving daily hydrocortisone. These results suggest that prolonged high-dose steroid administration decreased the magnitude of the acute inflammatory reaction responsible for abscess formation in the soft tissue but did not interfere significantly with the process of containment and encapsulation of s.c. abscesses. A single massive dose of steroid did not influence abscess formation.     

Sexual Network Patterns and Their Association With Genital and Anal Human Papillomavirus Infection in Adolescent and Young Men

PurposeThis study aimed to determine individual- and partner-level factors associated with human papillomavirus (HPV) infection in vaccinated and unvaccinated men.MethodsA total of 747 men, aged 13–26 years, completed a survey of sexual behaviors and were tested for genital and perianal/anal HPV (36 types). Sexual network variables included recent and lifetime concurrency (being in more than one sexual relationship at the same time) and recent sex partner discordance (by race, ethnicity, age, and number of sexual partners). We determined individual-level and sexual network variables associated with ≥1 HPV type and HPV16/18, stratified by vaccination status, using separate multivariable logistic regression models.ResultsParticipants' mean age was 21.2 years; 64% were positive for ≥1 HPV type and 21% for HPV16/18. Factors associated with ≥1 HPV type in unvaccinated men included recruitment site and lifetime concurrency. Factors associated with ≥1 HPV type among vaccinated men included recruitment site, Chlamydia history, main male partner, number of lifetime female partners, and no condom use with female partner. Factors associated with HPV16/18 in unvaccinated men included race and partner concurrency. Factors associated with HPV16/18 in vaccinated men included ethnicity, main male partner, and recent concurrency.ConclusionsSexual network variables associated with HPV infection were different based on vaccination status and HPV type, suggesting risk factors for HPV infection may change as the proportion of vaccinated men increases. In addition, participant report of concurrency and not knowing whether one had practiced concurrency were consistent risk factors; clinicians should consider including concurrency in the sexual history to determine the risk of HPV.     

Piperacillin/tazobactam in the treatment of polymicrobial infections

Polymicrobial infections are characterized by the presence of micro-organisms from more than one group of bacteria. Empirical treatment of polymicrobial infections requires an agent active against both anaerobic and aerobic/facultative bacteria. An aminoglycoside used in combination with an anti-anaerobe agent is commonly used to treat polymicrobial infections. However, aminoglycoside nephrotoxicity and treatment failures raise questions about the use of such regimens. Among non-aminoglycoside treatment regimens such as penicillin and cephalosporins, effectiveness has been compromised by bacteria producing extended spectrum -lactamases. Cefoxitin shows satisfactory results for treatment of intra-abdominal infections. Other studies have shown good results with imipenem, cefotetan and piperacillin used as single agents. Piperacillin/tazobactam, a new combination broad-spectrum antibiotic and potent -lactamase inhibitor, can be used for the treatment of infections caused by piperacillin-sensitive microorganisms as well as -lactamase-producing, piperacillin-resistant organisms. This broad-spectrum activity is appropriate for infections traditionally treated empirically by double or triple antibiotic therapy.     

Use of the Location-Based Social Networking Application GRINDR as a Recruitment Tool in Rectal Microbicide Development Research

Mobile phone social networking applications such as GRINDR are potential tools for recruitment of men who have sex with men (MSM) for HIV prevention research. Demographics and sexual risk behaviors of men recruited through GRINDR and through traditional media were compared. GRINDR participants were younger (mean age 31 vs. 42, p?<?0.0001), more White identified (44 vs. 30?%, p?<?0.01), and had more sex partners in the previous 14 days (1.88 vs. 1.10, p?<?0.05) than other recruits. Email responses were less successful for enrollment than phone calls (5 vs. 50?%). This approach resulted in successful recruitment of younger and more educated, White identified MSM.     

The Cumulative Effects of Medication Use,Drug Use,and Smoking on Erectile Dysfunction Among Men Who Have Sex with Men

IntroductionErectile dysfunction (ED) is highly prevalent among human immunodeficiency virus‐seropositive (HIV+) men who have sex with men (MSM). There is a need for additional research to determine the correlates of HIV+ and HIV‐seronegative (HIV?) MSM, especially regarding nonantiretroviral medication use.AimsThis study examined the prevalence of ED and the sociodemographic, medical conditions, medication use, and substance use correlates of ED among HIV+ and HIV? MSM.MethodsA modified version of the International Index of Erectile Function (IIEF) for MSM was self‐administered by participants enrolled in the Multicenter AIDS Cohort Study, an ongoing prospective study of the natural and treated histories of HIV infection among MSM in the United States. The study sample included 1,340 participants, including 612 HIV+ and 728 HIV? men. Poisson regression with robust error variance was used to estimate prevalence ratios of ED in multivariable models in combined (HIV+/?) and separate analyses.Main Outcome MeasureED was determined by the summed scores of a modified version of the IIEF validated among MSM.ResultsTwenty‐one percent of HIV+ MSM and 16% of HIV? MSM reported ED. Being >55 years of age, black race, cumulative pack years of smoking, cumulative antihypertensive use, and cumulative antidepressant use had significant positive associations with the prevalence of ED in the total sample. Among HIV+ men, duration of antihypertensive use and antidepressant use were significantly associated with increasing prevalence of ED. Among HIV? men, being >55 years of age, black race, and cigarette smoking duration were associated with increased prevalence of ED.ConclusionPredictors of ED may differ by HIV status. Although smoking cessation and effective medication management may be important as possible treatment strategies for ED among all MSM, there may be a burden on sexual functioning produced by non‐HIV medications for HIV+ men. Hart TA, Moskowitz D, Cox C, Li X, Ostrow DG, Stall RD, Gorbach PM, and Plankey M. The cumulative effects of medication use, drug use, and smoking on erectile dysfunction among men who have sex with men. J Sex Med 12;9:1106–1113.     

Acceptability of Potential Rectal Microbicide Delivery Systems for HIV Prevention: A Randomized Crossover Trial

We assessed the acceptability of three of over-the-counter products representative of potential rectal microbicide (RM) delivery systems. From 2009 to 2010, 117 HIV-uninfected males (79 %) and females (21 %) who engage in receptive anal intercourse participated in a 6-week randomized crossover acceptability trial. Participants received each of three products (enema, lubricant-filled applicator, suppository) every 2 weeks in a randomized sequence. CASI and T-ACASI scales assessed product acceptability via Likert responses. Factor analysis was used to identify underlying factors measured by each scale. Random effects models were fit to examine age and gender effects on product acceptability. Three underlying factors were identified: Satisfaction with Product Use, Sexual Pleasure, and Ease of Product Use. For acceptability, the applicator ranked highest; however, differences between product acceptability scores were greatest among females and younger participants. These findings indicate that RM delivery systems impact their acceptability and should be considered early in RM development to enhance potential use.