1,721,040 research outputs found
Examining the association between self-reported condom use and sexually transmitted infections
Get PDFTwo analyses were performed using data from an 18-month study of a condom promotion intervention among 1000 female sex workers (FSW) in two cities in Madagascar. The first analysis explored whether participating in such a study and being exposed to such an intervention over time would change the strength of the association between self-reported condom use and incident sexually transmitted infections (STI). The analysis found no evidence of a change in the association over time. In addition, there was no indication of a dose-response relationship between the number of reported unprotected sex acts and incidence of STI. The second analysis tested the risk of STI associated with self-reported condom use by partner type. Over the 18 months of the study, participants reported greatly increased rates of condom use with clients, but continued low condom use with personal partners. Participants who reported less than 100% condom use with personal partners, but 100% condom use with clients had no increased odds of STI as compared to those who reported 100% condom use with both partner types (odds ratio (OR) 0.9, 95% confidence interval (CI) 0.5, 1.6). Conversely, participants who reported inconsistent condom use with clients, but consistent condom use with their personal partners had an 8.3 times higher odds of STI (95% CI 0.5, 138.0) as compared to consistent condom users with both partner types. We conclude that asking study participants to report the actual number of sex acts and the number of those sex acts that were protected by condoms may result in falsely precise estimates of their exposure to risky sex acts. The results indicating that unprotected sex with personal partners does not contribute to risk of STI are contrary to indications from other recent studies in West Africa about the infection status of personal partners of FSW. The relationship should be further explored before programs change the message that FSW should use condoms with all partners
Understanding concurrent sexual partnerships among US men: examining relationship characteristics and racial differences
Get PDFRacial and ethnic minorities continue to be disproportionately affected by sexually transmitted infections (STIs), including Human Immunodeficiency Virus (HIV), in the United States. Concurrent sexual partnerships, those that overlap in time, have been associated with increased STI prevalence and increase the spread of infection through a network. Different patterns of concurrent partnerships may be associated with varying STI risk depending on the partnership type (primary vs. non-primary) and the likelihood of condom use with each concurrent partner. One pattern potentially associated with high STI risk involves concurrency in the context of a co-parenting relationship, one in which a man and woman are the joint biological parents of a child. We examined the relationship between co-parenting and concurrency using data from 4,928 male respondents age 15-44 in the National Survey of Family Growth Cycle 6. Among men engaging in concurrency in the past 12 months, 18% included a co-parent as at least one of the concurrent sex partners. One third of black men involved in co-parenting concurrency were <25 years, compared to 23% of Hispanics and 6% of whites. Young black men (age 15-24) were more likely to engage in co-parenting concurrency than white men, adjusting for socio-demographic characteristics, sexual and other high-risk behaviors, and relationship quality. The largest racial differences in co-parenting concurrency prevalence were observed among men age 15-24. In the second aim, concurrent partnerships were further classified based on pattern of overlap. Compared to men engaging in non-co-parenting concurrency, men engaging in co-parenting concurrency were more likely to report inconsistent condom use during the last month and less likely to have used a condom with either concurrent partner at last sexual intercourse in bivariable analyses. In multivariable analyses, concurrency duration was longer for men engaging in co-parenting concurrency than for men engaging in non-co-parenting concurrency, but there were no differences in STI preventive/protective behaviors. These findings show that co-parenting concurrency is more common among young black and Hispanic men and suggest that concurrency involving co-parents could be associated with a high risk of STI transmission. A comprehensive understanding of the types of concurrent sexual partnerships and the contexts in which they occur is necessary
Association of STI/HIV Infection with Reported Behavior Change and Concurrency among Rural Youth in South Africa and Malawi
Get PDFHIV prevalence in rural southern Africa is increasing towards urban levels, highlighting intervention needs of rural youth. Being faithful is a common HIV prevention message as concurrency, or having more than one sexual partnership at one time, has been associated with STI transmission. Two surveys concerning sexual behaviors and STI prevalence conducted with youth in South Africa (SA) and Malawi were used. Analyses were stratified by gender and country and restricted to rural, sexually experienced youth 15-24 years old. We studied the association between reporting behavior change since hearing of HIV and HIV infection. Many youth reported changed behavior, ranging from 48.2% among Malawian females to 70.6% among SA females. HIV prevalence was 19.0% (95%CI 14.9, 23.1), 4.5% (95%CI 2.6, 6.3), 4.7% (95%CI 3.0, 6.5) and 1.9% (95%CI 0.6, 3.1) for SA women, Malawian women, SA men, and Malawian men, respectively. We found little to no association between behavior change and HIV infection among youth. Analyses stratified by specific behavior changes uncovered that some behaviors were protective while others were riskier, leading to an attenuated effect when all behaviors were combined into a single measure. SA women who reported that they changed their behavior to abstinence were 2.90 (95%CI 1.01, 8.38) times more likely to be HIV+ than those who reported another behavior change. We hypothesized that rural Malawian youth who reported concurrency were more likely to have STIs. Concurrency was reported by women (5.0%) and men (16.0 %). The overall prevalences of STIs and HIV were 10.4% and 4.4% for women and 0.3% and 2.1% for men, respectively. Concurrency was not associated with STIs for either gender or with HIV infection among males. Using multiple imputation methods and controlling for confounders, women reporting concurrency were 6.08 (95% CI 1.23, 30.16) times more likely to be HIV+ than women not reporting concurrency. The cross sectional data may mask the temporal relationship between behavior change or concurrency and STI infection. Further research needs to focus on better measurement of type and duration of prevention behaviors. Innovative HIV prevention methods, highlighting the risk associated with concurrency, are needed to reach rural youth
Optimization of pediatric antiretroviral therapy in sub-Saharan Africa : timing of initiation in HIV/TB co-infected children and using gains in weight, height, or CD4 count to monitor the response
Get PDFBackgroung: Antiretroviral therapy (ART) has revolutionized the treatment of HIV, but substantial drug interactions between anti-TB and ART and the lack of health care infrastructures complicate the management of HIV/TB co-infected children in resource poor countries. More than 50% of TB infected children in some high burden countries in sub-Saharan Africa are also infected with HIV, but the optimal timing of ART in those children is unknown. In addition, though the drug-interactions and the high pill burden to treat HIV and TB require strict monitoring, regular measurements of viral load that is routine for ART monitoring in developed countries is not always possible in sub-Saharan Africa. This study had two aims. 1) Construct reference charts for gains in weight, height, absolute CD4 count, and CD4% in the first 6 months of ART, and to test the value of the 3rd, 10th, 25th, 33rd, and 50th percentiles as predictors of subsequent death, virological suppression, or treatment failure. 2) Determine the effect of delaying ART for at least 15, 30, or 60 days in HIV/TB co-infected children on virological suppression and survival. Methods: We used information from an observational clinical cohort of HIV-infected children who sought care at an outpatient clinic at Chris Hani Baragwanath Hospital in Soweto, South Africa. To construct the reference charts, we assumed a Box Cox power exponential distribution for the 6 month gains in weight, height, CD4 count and CD4% and used the generalized additive model for location, scale, and shape to estimate the parameters of each of the four distributions. Hazard ratios for the association of the selected centiles with the three outcomes were estimated using Cox proportional hazard model. For aim 2, though per guidelines all HIV-infected children with TB were eligible for ART, the decision whether to initiate or delay ART for a given child was made at each visit and sicker children were initiated earlier. Moreover, some children for whom ART was delayed could die before it was possible to classify them for exposure. To control for the time-dependent confounding by indication and the lead time on survival, mortality hazard ratios were estimated using the inverse-probability-of-treatment-weighting of marginal structural modelling. Adjusted hazard ratios for virological suppression were estimated using multivariate Cox proportional modelling. Results: Overall, information from 1394 and from 573 children was used for aim 1 and aim 2 respectively. Children whose weight, absolute CD4, or CD4% gain were below the 33rd percentile for age or gender had poorer ART outcomes with a three to four-fold higher hazard of death, about 0.75 -fold lower hazard of virological suppression and about two-fold higher hazard of treatment failure. Delaying ART tended to be associated with increased mortality: adjusted hazard ratios (aHR) for 15, 30, and 60 days delay were: 0.90 (95%CI: 0.30, 2.75), 1.05 (95%CI: 0.29, 3.75), 2.18 (95%CI: 0.64, 7.48) respectively. Delaying ART appear to be potentially detrimental for the hazard of viral suppression: aHR: 0.98 (95%CI: 0.76, 1.26), 0.95, (95%CI: 0.73, 1.23), 0.84 (95%CI: 0.61, 1.15) for 15, 30, and 60 days delay respectively. Conclusion: Six-month weight gain and CD4 cell gain (count and CD4%) below the 33rd percentile were equally strong predictors of poor ART outcomes suggesting that, pending construction of more generalizable charts, weight gain can be used in children on ART to discriminate those who are failing the treatment from those who are responding. Since delaying ART beyond 30 days appears to negatively affect both survival and viral response, the recommendation should be reevaluated and necessary delays should not exceed 30 days
The effects of highly active antiretroviral therapy on survival and CD4 cell percentage in HIV-infected children in Kinshasa, Democratic Republic of Congo
Get PDFIn HIV-infected children, the effects of highly active antiretroviral therapy (HAART) on survival and CD4 responses are understood incompletely. As most pediatric HIV infections occur in lower-income countries, our objective was to provide the first estimates of these effects among children in a resource-deprived setting. Observational data from HAART-naive children enrolled into an HIV care and treatment program in Kinshasa, Democratic Republic of Congo between December 2004 and May 2010 were analyzed. Marginal structural models were used to quantify the effects of HAART on survival and CD4 percentage while accounting for time-dependent confounders affected by prior exposure to HAART. At the start of follow-up, the median age of the 790 children was 5.9 years; 528 (67%) had advanced or severe immunodeficiency and 405 (51%) were in HIV clinical stage 3 or 4. The children were observed for a median of 31 months and contributed 2,090 person-years. Eighty children (10%) died, 619 (78%) initiated HAART, six (1%) transferred care to another facility, and 76 (10%) were lost to follow-up. The mortality rate was 3.2 per 100 person-years (95% CI: 2.4, 4.2) during HAART and 6.0 (95% CI: 4.1, 8.6) during receipt of primary HIV care only. The mortality hazard ratio comparing HAART to no HAART was 0.25 (95% CI: 0.06, 0.95). Compared to no HAART, the estimated absolute rise in CD4 percentage was 6.8% (95% CI: 4.7%, 8.9%) after six months of HAART, 8.6% (95% CI: 7.0%, 10.2%) after 12 months, and 20.5% (95% CI: 16.1%, 24.9%) after 60 months. HAART-mediated CD4 percentage gains were slowest but greatest among children who had a baseline CD4 percentage <15. The cumulative incidence of recovery to not significant WHO age-specific immunodeficiency was lower if HAART was initiated when immunodeficiency was severe rather than mild or advanced. HAART reduced the hazard of mortality and increased CD4 percentages among HIV-infected children in a resource-deprived setting to a similar degree as previously noted for children in the United States. The more gradual and protracted immunological recovery observed in children with lower baseline CD4 percentages supports earlier initiation of pediatric HAART
Barriers and Facilitators of Adherence to Pediatric Antiretroviral Therapy Regimens in Resource Limited Settings: A Systematic Review and Qualitative Research Plan
Get PDFIntroduction: Good adherence to ART is known to be extremely important for successful suppression of HIV viral load and to improve clinical outcomes in children. However, high rates of adherence, greater than 95%, are needed to achieve these goals. Therefore it is important that clinical and support staff who work with caregivers and their HIV children understand the importance of good adherence and convey this message to their patients. To do this, we need a foundation of knowledge with which to base an adherence theory on and an understanding of the barriers and facilitators to ART adherence. Though much work on understanding ART adherence has been done in developed settings, the majority on adults, there continues to be a paucity of research and lack of guiding theory regarding ART adherence in children in resource limited settings. This is a significant problem, as the number of children living with HIV in resource limited settings continues to grow, especially in places like sub-Saharan Africa which accounts for 90% of all children living with HIV. Recent scale-up efforts of ART to children in resource limited settings means that adherence has become a highly salient issue. Studies to date on pediatric ART adherence in resource limited settings incorporate a wide array of study populations, study designs, adherence measurement strategies, and definitions of adherence. Drawing conclusions from these studies and development of a culturally appropriate adherence theory has been difficult. Prior studies recommend that more qualitative, formative research will be helpful in the development of such an adherence theory and to help inform the design of more uniform future studies.Master of Public Healt
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Inflammation of Innate Immune Responses in the Female Genital Tract: Association with Use of Injectable Progestin-Only Contraception, Reproductive Tract Infections and Risk of HIV Acquisition
Get PDFThe successes and failures of many HIV prevention trials, including those of microbicides, antiretrovirals and vaccines, have led to a renewed interest in the biological mechanisms at the site of HIV infection. In women, the anatomical site of exposure and first infection is most often the vaginal and cervical mucosa.[1] Well accepted biological risk factors for HIV infection in women include mucosal disruption; immune factors, including the availability of CD4+/CCR5+ cells types; sexually transmitted infections (STI) and disturbances in the vaginal biome (e.g., bacterial vaginosis (BV)).[2] More recently, the profile of innate immune biomarkers - including cytokines, chemokines and antibacterial proteins - and associated levels of cellular activation have become a focus of interest as a potential mechanism of increased HIV risk. The results of prior studies in this area are varied, and additional research is needed. Potential reasons for the variability in results includes use of different specimen collection methods, methodological and analytical differences, statistical consequences (the increased probability of finding significant, yet spurious, associations in the case of measurement of multiple outcomes and multiple hypothesis testing) and differential selection of endpoints. Stored specimens from FEM-PrEP trial participants offered an opportunity to overcome some of the aforementioned challenges in studying the relationship between inflammatory cytokines, chemokines and antibacterial proteins with HIV and associated risk factors. FEM-PrEP was a Phase III, randomized, double-blind, placebo-controlled effectiveness and safety trial to assess the role of emtricitabine/tenofovir disoproxil fumarate (FTC/TDF, i.e., Truvada) in preventing HIV acquisition in women. FEM-PrEP was conducted in Bondo, Kenya; Pretoria and Bloemfontein, South Africa; and Arusha, Tanzania.[3] The trial enrolled HIV-negative women between the ages of 18-35 who met medical and behavioral eligibility criteria including being at high risk of HIV. Using stored specimens from the trial we estimated innate immune biomarker concentrations among Kenyan and South African women at high risk of HIV infection in the absence of known risk factors, and explored the association of those risk factors on biomarker concentrations, and analyzed elevated innate immune biomarker concentrations as a risk factor for HIV infection in a longitudinal analysis.Doctor of Philosoph
- …
