Moussa Sarr

The relationship of unsafe sexual behavior and the characteristics of sexual partners of HIV infected and HIV uninfected adolescent females

PURPOSE To compare characteristics of sexual relationships in HIV infected and HIV uninfected female adolescents and their association with condom use. METHODS HIV infected and uninfected subjects, aged 13-19 years, were enrolled in a prospective HIV study from 15 sites in 13 U.S. cities. Baseline data on demographic information, substance use, sexual behavior, partner information, and condom use were collected through direct and computer-assisted interviews from currently sexually active females. Univariate, multiple logistic regression, and repeated measures analyses were employed. RESULTS Data from 153 HIV infected and 90 HIV uninfected female subjects showed, on average, that current partners were 4-6 years older. In multivariate analysis, HIV infected subjects were older (OR = 1.37; 95% CI: 1.04-1.81), had more lifetime partners (OR = 2.23; 95% CI: 1.03-4.82), initiated consensual vaginal sex earlier (OR = .74; 95% CI:.58-.95), perceived partner to also be HIV infected (OR = 7.46; 95% CI: 3.2-17.4), and had less unprotected sex (OR = .27; 95% CI:.16-.45). Length of relationship was associated with more unprotected sex for both HIV infected and uninfected subjects (OR = 2.59, 95% CI: 1.27-5.27, OR = 4.13; 95% CI: 1.31-13.05, respectively). Mean partner age difference was greater among HIV infected than for HIV uninfected (OR = 1.06; 95%CI: 1.01-1.12); this greater age difference for HIV infected females was associated with less protection (OR = 1.09; 95% CI: 1.03-1.15). HIV disclosure influenced condom use: without disclosure, less condom use was reported (OR = 6.8; 95% CI: 2.29-20.24) controlling for perception that partner was also HIV infected (OR = 1.1; 95% CI: 1.02-1.21). CONCLUSIONS Because age differential influenced reported condom use, more research, particularly qualitative, is needed into the dynamics of these relationships. Prevention efforts must address partners, particularly older ones.

Mass drug administration of ivermectin in south-eastern Senegal reduces the survivorship of wild-caught, blood fed malaria vectors

BackgroundIn south-eastern Senegal, malaria and onchocerciasis are co-endemic. Onchocerciasis in this region has been controlled by once or twice yearly mass drug administration (MDA) with ivermectin (IVM) for over fifteen years. Since laboratory-raised Anopheles gambiae s.s. are susceptible to ivermectin at concentrations found in human blood post-ingestion of IVM, it is plausible that a similar effect could be quantified in the field, and that IVM might have benefits as a malaria control tool.MethodsIn 2008 and 2009, wild-caught blood fed An. gambiae s.l. mosquitoes were collected from huts of three pairs of Senegalese villages before and after IVM MDAs. Mosquitoes were held in an insectary to assess their survival rate, subsequently identified to species, and their blood meals were identified. Differences in mosquito survival were statistically analysed using a Glimmix model. Lastly, changes in the daily probability of mosquito survivorship surrounding IVM MDAs were calculated, and these data were inserted into a previously developed, mosquito age-structured model of malaria transmission.ResultsAnopheles gambiae s.s. (P < 0.0001) and Anopheles arabiensis (P = 0.0191) from the treated villages had significantly reduced survival compared to those from control villages. Furthermore, An gambiae s.s. caught 1-6 days after MDA in treated villages had significantly reduced survival compared to control village collections (P = 0.0003), as well as those caught pre-MDA (P < 0.0001) and >7 days post-MDA (P < 0.0001). The daily probability of mosquito survival dropped >10% for the six days following MDA. The mosquito age-structured model of malaria transmission demonstrated that a single IVM MDA would reduce malaria transmission (Ro) below baseline for at least eleven days, and that repeated IVM MDAs would result in a sustained reduction in malaria Ro.ConclusionsIvermectin MDA significantly reduced the survivorship of An. gambiae s.s. for six days past the date of the MDA, which is sufficient to temporarily reduce malaria transmission. Repeated IVM MDAs could be a novel and integrative malaria control tool in areas with seasonal transmission, and which would have simultaneous impacts on neglected tropical diseases in the same villages.

Ivermectin Mass Drug Administration to Humans Disrupts Malaria Parasite Transmission in Senegalese Villages

Ivermectin mass drug administration (MDA) to humans is used to control onchocerciasis and lymphatic filariasis. Recent field studies have shown an added killing effect of ivermectin MDA against malaria vectors. We report that ivermectin MDA reduced the proportion of Plasmodium falciparum infectious Anopheles gambiae sensu stricto (s.s.) in treated villages in southeastern Senegal. Ivermectin MDA is a different delivery method and has a different mode of action from current malaria control agents. It could be a powerful and synergistic new tool to reduce malaria transmission in regions with epidemic or seasonal malaria transmission, and the prevalence and intensity of neglected tropical diseases.

Human immunodeficiency virus prevalence, incidence, and residual risk of transmission by transfusions at Retrovirus Epidemiology Donor Study-II blood centers in Brazil

BACKGROUND: In Brazil nationally representative donor data are limited on human immunodeficiency virus (HIV) prevalence, incidence, and residual transfusion risk. The objective of this study was to analyze HIV data obtained over 24 months by the Retrovirus Epidemiology Donor Study‐II program in Brazil.

Motivational Enhancement System for Adherence (MESA): Pilot Randomized Trial of a Brief Computer-Delivered Prevention Intervention for Youth Initiating Antiretroviral Treatment

OBJECTIVE To pilot test a two-session computer-delivered motivational intervention to facilitate adherence among youth with HIV newly prescribed antiretroviral treatment (ART). METHODS Youth (N = 76) newly prescribed ART were recruited from 8 sites, and were randomized to the intervention or an active nutrition and physical activity control. Primary outcomes were HIV-1 viral load at baseline, 3 months, and 6 months, and self-reported adherence at 3 and 6 months. RESULTS Satisfaction ratings were high. Effect sizes suggested that the intervention group showed a greater drop than controls in viral load from baseline to 6 months (Cohens d = 0.39 at 3 months; d = 0.19 at 6 months), and had greater percent undetectable by 6 months (d = 0.28). Effects sizes were medium to large for 7-day and weekend adherence. CONCLUSIONS A brief computer-delivered motivational intervention showed promise for youth starting ART and is ready to be tested in a full-scale clinical trial.

Douching practices among HIV infected and uninfected adolescents in the United States

PURPOSE To characterize sexual behaviors and sociodemographic factors that are associated with douching among geographically diverse adolescent women with and without HIV infection. METHODS HIV infected subjects recruited preferentially and behaviorally comparable high-risk HIV uninfected subjects were enrolled in a prospective HIV study from 15 sites in 13 U.S. cities. Baseline interview data from 1996 to 1999 for females aged 12 to 19 years were analyzed using one-way analysis of variance and multiple logistic regression. RESULTS Among the 342 females/young women, 74.9% were black (non-Hispanic), 11.1% Hispanic/Latina, and 14.0% white or other race/ethnicity; 63.5% were HIV infected. Young women who had dropped out of high school comprised 23.4% of subjects. In the 3 months before the interview, 179 (52.3%) adolescents had douched at least once. In a multivariable logistic regression model, recent douching was more common among sexually active females (OR = 2.2; 95% CI: 1.2-4.2), Blacks (OR = 2.2; 95% CI: 1.2-4.1 vs. Hispanics/Whites/others), females who dropped out of high school (OR = 2.1; 95% CI: 1.2-3.7), and HIV infected females (OR = 1.7; 95% CI: 1.04-2.7). CONCLUSIONS In this nationwide study, adolescents who are sexually active, African-American, dropped out of high school, and HIV infected were most likely to douche. Interventions to discourage douching should pay special attention to these populations.

Incident pregnancy rates in HIV infected and HIV uninfected at-risk adolescents.

PURPOSE To compare pregnancy incidence between HIV infected and HIV uninfected adolescents over a 3-year period and to characterize factors that differentiate pregnant from nonpregnant HIV infected females. METHODS Female adolescents enrolled in Reaching for Excellence in Adolescent Care and Health (REACH), a national cohort study, and nonpregnant at baseline comprised the sample (n = 345). Subject information on pregnancy, risk behavior, and psychosocial characteristics was obtained through interview, chart review, physical examination and laboratory data collected every 3 months. Incident pregnancy rate was analyzed using Cox proportional hazards modeling; the predictors of incident pregnancy were evaluated using repeated measures analysis. RESULTS Ninety-four pregnancies were identified over 3 years. No significant difference in pregnancy incidence was detected between HIV infected and uninfected females (20.6 and 28.4 per 100 person-years, respectively, p = .16). However, for adolescents with living children at entry, HIV infected females were significantly less likely to become pregnant than HIV uninfected (HR = .45; p = .03). Among HIV infected adolescents, significant predictors of incident pregnancy were older age (p = .01) and not using hormonal contraception (p = .00), whereas increased spiritual hope and passive problem-solving capacity were protective against pregnancy (p = .02, and.05, respectively). Multivariate analysis revealed pregnancy prior to study entry to be predictive for (OR = 3.0; 95% CI: 1.2-7.7), and increased spiritual hope to be protective (OR = .4; 95% CI: .2-.9) against incident pregnancy in HIV infected females without the hormonal contraceptive variable in the model. CONCLUSIONS The pregnancy rate is high in this study population. Further research is needed into its determinants and attenuating factors, particularly the role of spiritual elements, to design better contraceptive services and reproduction-related education targeting high-risk youth.

Acceptability and Feasibility of a Cell Phone Support Intervention for Youth Living with HIV with Nonadherence to Antiretroviral Therapy

A pilot randomized clinical trial of youth ages 15-24 nonadherent to antiretroviral therapy (ART) utilizing daily cell phone support was found to have significant improvement in self-reported adherence and HIV RNA. Understanding acceptability and feasibility is critical for future implementation in clinic settings. Exit interviews were obtained from participants and adherence facilitators (AF). Acceptability was assessed from content analysis of exit interviews. Feasibility was assessed via intervention retention and study retention rates. Thirty-seven eligible youth were enrolled with 19 assigned to the intervention. Seven (37%) discontinued the intervention either due to missing over 20% of calls for two consecutive months (N=5) or missing 10 consecutive calls (N=2). Sixteen participants completed exit interviews, 15 reported the call length was just right, 13 reported they would have liked to continue calls after the 24-week intervention, and all participants reported they would recommend the intervention to friends. Scheduling and making calls required less than 1 h per week per participant. Providing cell phone support to youth nonadherent to ART was acceptable and feasible. While the cost is low compared to the price of ART, healthcare systems will need to explore how to cover the cost of providing cell phones (incentive).

Increased Proliferation within T Lymphocyte Subsets of HIV-Infected Adolescents

Proliferation within T lymphocyte subsets of HIV-infected adolescents was quantified by detection of Ki-67, a nuclear antigen found in cells in late G(1), S, or G(2) phases of the cell cycle. Median percentages and absolute counts of Ki-67(+) cells for all subsets tested (CD4 naive and memory, CD8 naive and memory) were significantly higher for HIV-infected adolescents compared to uninfected controls. CD8 naive cells of HIV-infected adolescents had the greatest increase in rate of proliferation and number of proliferating cells compared to uninfected controls. In HIV-infected adolescents, the percentage and absolute number of proliferating CD4 naive cells were considerably lower than corresponding values for the other subsets. CD4 percent correlated inversely with Ki-67 expression in CD4 memory, CD8 naive, and CD8 memory cells, while Ki-67 expression in CD4 and CD8 memory cells correlated directly with average CD38 molecules/CD8 cell and absolute number of CD8/CD38/HLA-DR cells, consistent with T cell activation. These results indicate that in adolescents, HIV infection is associated with increased proliferation within CD4 and CD8 naive and memory subsets. Proliferation within the CD8 naive subset was higher than that observed previously for HIV-infected adults, suggesting that adolescents have a greater ability to regenerate and/or expand CD8 naive cells. CD4 naive cells of HIV-infected adolescents had a low rate of proliferation, and the total number of CD4 naive cells was low, suggesting that regeneration and/or peripheral expansion are limited and may contribute to the reduced size of this subset. The Ki-67 assay provided new and useful information on in vivo lymphocyte proliferation in HIV-infected adolescents.

Evaluation of an Intervention Among Adolescents to Reduce Preventive Misconception in HIV Vaccine Clinical Trials

PURPOSE Placebo and randomization are important concepts that must be understood before youth can safely participate in HIV vaccine studies or other biomedical trials for HIV prevention. These concepts are central to the phenomenon of preventive misconception that may be associated with an increase in risk behavior among study participants related to mistaken beliefs. Persuasive messaging, traditionally used in the field of marketing, could enhance educational efforts associated with randomized clinical trials. METHODS Two educational brochures were designed to increase knowledge about HIV vaccine clinical trials via one- and two-sided persuasive messaging. Through the Adolescent Medicine Trials Network, 120 youth were enrolled, administered a mock HIV vaccine trial consent, and then randomized to receive either no supplemental information or one of the two brochures. RESULTS The two-sided brochure group in which common clinical trial misconceptions were acknowledged and then refuted had significantly higher scores on knowledge of randomization and interpretation of side effects than the consent-only control group, and the willingness to participate in an HIV vaccine trial was not decreased with the use of this brochure. CONCLUSION Two-sided persuasive messaging improves understanding of the concepts of randomization and placebo among youth who would consider participating in an HIV vaccine trial. Further evaluation of this approach should be considered for at-risk youth participating in an actual trial of a biomedical intervention for HIV prevention.