What motivates or demotivates injecting drug users to participate in hypothetical HIV vaccine efficacy trials? A qualitative study from urban Tanzania

Background: HIV vaccine efficacy trials require the active participation of volunteers who are committed and adherent to the study protocol. However, information about the influence of Injecting Drug Users (IDUs) to participate in HIV vaccine efficacy trials in low-income countries is inadequate. The present study explored the factors that motivate or hinder IDUs from participating in HIV vaccine efficacy trials in Dar es Salaam, Tanzania.Methods: A qualitative descriptive study design was employed among IDUs at Muhimbili National Hospital (MNH). A purposeful sampling technique was used to recruit the participants. Three (3) focus group discussions (FGDs) and 10 In-Depth Interviews (IDIs) were used to collect the data. The data from participants were audio-recorded, transcribed, and analysed using the content analysis approach.Findings: The participants reported that altruism and the desire to reduce risks of HIV infection were the motivators to participate in hypothetical HIV vaccine trials. In addition, participants reported to consult close relatives towards motivation to participate in the vaccine trial. In contrast, the perceived fear of vaccine side effects, lack of information about HIV vaccine studies, and HIV-related stigma towards participants were described as barriers to participate in the HIV vaccine trials.Conclusion: Participation in a hypothetical HIV vaccine trial among IDUs is influenced by positive and negative factors. Actual recruitment plans could be made through a better explanation of HIV vaccine trials, the expected individual and collective benefits associated with the trials. Community involvement and sensitisation is likely to enhance participation in future HIV vaccine trials in Tanzania

Low prevalence of detectable serum cardiac troponin I among healthy Tanzanian adults: observational study

Background: Cardiac troponin test is used in detecting various heart disorders. The objective of this study was to establish normal reference levels for serum cardiac Troponin I which could be utilized for selection of vaccines and determine any electrocardiogram (EKG) changes among healthy volunteers.Methods: A total of 263 healthy blood donors from Dar es Salaam, Tanzania were included in this sub-study. A thorough medical history and physical examination to rule out any major chronic disease like heart failure, chronic kidney diseases, diabetes mellitus and HIV was undertaken.  Ten mL of blood sample for the purpose of establishing normal reference values for Troponin I assessment and parallel EKG was performed to all participants. Results: Of the 263 subjects, males were156 (59.3%) and females were 107 (40.7%). Median (range) age was 34 years old. The manufacture’s reference level for serum Cardiac Troponin I was 0.00-0.39 µg/L. Serum Cardiac Troponin I was detected in two blood donors (0.76%). However, their Troponin I levels were within the manufacturer’s normal range (0.01-0.36 µg/L).  Clinically both subjects were healthy and their EKG tracing were unremarkable.Conclusions: Our study has shown that among healthy subjects, detectable serum cardiac Troponin I is a rare finding. The manufacturer’s range is applicable in our setting and can be used in the ongoing vaccine trial. The significance of minimally elevated serum cardiac Troponin I may represent a subclinical cardiac injury and have important clinical implications, a hypothesis that should be tested in future longitudinal outcome studies

Factors that Influence the Willingness of Young Adults in Dar es Salaam, Tanzania, to Participate in Phase I/II HIV Vaccine Trials.

HIV/AIDS continues to destroy the lives of young people especially in low-income countries. The inclusion of youths in HIV vaccine trials is of utmost importance in obtaining an effective vaccine that is acceptable to them.\ud To characterize the willingness of young adults in Tanzania to participate in an HIV vaccine trial and the factors that influence this willingness. Four hundred and fifty young adults who visited a youth-friendly Infectious Diseases Clinic (IDC) from February 2012 to September 2012 completed a self-administered questionnaire concerning sociodemographic information, their knowledge about and perception of HIV vaccine studies, and the availability of social support. Of our participants, 50.6% expressed willingness to participate in HIV vaccine trials, and this willingness was positively correlated with having some knowledge about HIV vaccine studies (AOR, 2.2; 95% CI: 1.4-3.4), a positive perception toward such studies (AOR, 2.3; 95% CI: 1.5-3.6), having a relationship with someone who could help them make a decision (AOR, 2.5; 95% CI: 1.3-4.9), and age at the time of sexual debut (AOR, 2.6; 95% CI 1.0-6.7) for 15- to 19-year-olds and (AOR, 2.7; 95% CI 1.0-7.1) for older participants. The participants exhibited a moderate willingness to participate in HIV vaccine trials, which was associated with a positive perception of and some knowledge about such trials, having a relationship with someone who might influence their decision as well as age at time of sexual debut. More efforts should be made to inform the youths about specific HIV vaccine trials and related matters, as well as to engage significant others in the decision-making process

Declining HIV-1 Prevalence and Incidence among Police Officers - A potential Cohort for HIV Vaccine Trials, in Dar es Salaam, Tanzania.

A safe effective and affordable HIV vaccine is the most cost effective way to prevent HIV infection worldwide. Current studies of HIV prevalence and incidence are needed to determine potentially suitable cohorts for vaccine studies. The prevalence and incidence of HIV-1 infection among the police in Dar es Salaam in 1996 were 13.8% and 19.6/1000 PYAR respectively. This study aimed at determining the current prevalence and incidence of HIV in a police cohort 10 years after a similar study was conducted. Police officers in Dar es Salaam, Tanzania were prospectively enrolled into the study from 2005 and followed-up in an incidence study three years later. HIV infection was determined by two sequential enzyme linked immunosorbent assays (ELISAs) in the prevalence study and discordant results between two ELISAs were resolved by a Western blot assay. Rapid HIV assays (SD Bioline and Determine) were used for the incidence study. A total of 1,240 police participated in the HIV prevalence study from August 2005 to November 2008. Of these, 1101 joined the study from August 2005-September 2007 and an additional 139 were recruited between October 2007 to November 2008 while conducting the incidence study. A total of 726 (70%) out of the 1043 eligible police participated in the incidence study.The overall HIV-1 prevalence was 65/1240 (5.2%). Females had a non-statistically significant higher prevalence of HIV infection compared to males 19/253, (7.5%) vs. 46/987 (4.7%) respectively (p = 0.07). The overall incidence of HIV-1 was 8.4 per 1000 PYAR (95% CI 4.68-14.03), and by gender was 8.8 and 6.9 per 1000 PYAR, among males and females respectively, (p = 0.82). The HIV prevalence and incidence among the studied police has declined over the past 10 years, and therefore this cohort is better suited for phase I/II HIV vaccine studies than for efficacy trials

Radio Interferometric Planet Search II: Constraints on sub-Jupiter-Mass Companions to GJ 896A

We present results from the Radio Interferometric Planet (RIPL) search for compan- ions to the nearby star GJ 896A. We present 11 observations over 4.9 years. Fitting astrometric parameters to the data reveals a residual with peak-to-peak amplitude of ~ 3 mas in right ascension. This residual is well-fit by an acceleration term of 0.458 \pm 0.032 mas/y^2. The parallax is fit to an accuracy of 0.2 mas and the proper motion terms are fit to accuracies of 0.01 mas/y. After fitting astrometric and acceleration terms residuals are 0.26 mas in each coordinate, demonstrating that stellar jitter does not limit the ability to carry out radio astrometric planet detection and characterization. The acceleration term originates in part from the companion GJ 896B but the amplitude of the acceleration in declination is not accurately predicted by the orbital model. The acceleration sets a mass upper limit of 0.15 MJ at a semi-major axis of 2 AU for a planetary companion to GJ 896A. For semi-major axes between 0.3 and 2 AU upper limits are determined by the maximum angular separation; the upper limits scale from the minimum value in proportion to the inverse of the radius. Upper limits at larger radii are set by the acceleration and scale as the radius squared. An improved solution for the stellar binary system could improve the exoplanet mass sensitivity by an order of magnitude.Comment: Accepted for publication in Ap

The Origins of [CII] Emission in Local Star-forming Galaxies

The [CII] 158um fine-structure line is the brightest emission line observed in local star-forming galaxies. As a major coolant of the gas-phase interstellar medium, [CII] balances the heating, including that due to far-ultraviolet photons, which heat the gas via the photoelectric effect. However, the origin of [CII] emission remains unclear, because C+ can be found in multiple phases of the interstellar medium. Here we measure the fractions of [CII] emission originating in the ionized and neutral gas phases of a sample of nearby galaxies. We use the [NII] 205um fine-structure line to trace the ionized medium, thereby eliminating the strong density dependence that exists in the ratio of [CII]/[NII] 122um. Using the FIR [CII] and [NII] emission detected by the KINGFISH and Beyond the Peak Herschel programs, we show that 60-80% of [CII] emission originates from neutral gas. We find that the fraction of [CII] originating in the neutral medium has a weak dependence on dust temperature and the surface density of star formation, and a stronger dependence on the gas-phase metallicity. In metal-rich environments, the relatively cooler ionized gas makes substantially larger contributions to total [CII] emission than at low abundance, contrary to prior expectations. Approximate calibrations of this metallicity trend are provided.Comment: 8 pages, accepted for publication in Ap

Estimating the star formation rate at 1 kpc scales in nearby galaxies.

Using combinations of H alpha, ultraviolet (UV), and infrared (IR) emission, we estimate the star formation rate (SFR) surface density, Sigma(SFR), at 1 kpc resolution for 30 disk galaxies that are targets of the IRAM HERACLES CO survey. We present a new physically motivated IR spectral-energy-distribution-based approach to account for possible contributions to 24 mu m emission not associated with recent star formation. Considering a variety of "reference" SFRs from the literature, we revisit the calibration of the 24 mu m term in hybrid (UV+IR or H alpha+IR) tracers. We show that the overall calibration of this term remains uncertain at the factor of two level because of the lack of wide-field, robust reference SFR estimates. Within this uncertainty, published calibrations represent a reasonable starting point for 1 kpc-wide areas of star-forming disk galaxies, but we re-derive and refine the calibration of the IR term in these tracers to match our resolution and approach to 24 mu m emission. We compare a large suite of Sigma(SFR) estimates and find that above Sigma(SFR) similar to 10(-3)M(circle dot) yr(-1) kpc(-2) the systematic differences among tracers are less than a factor of two across two orders of magnitude dynamic range. We caution that methodology and data both become serious issues below this level. We note from simple model considerations that when focusing on a part of a galaxy dominated by a single stellar population, the intrinsic uncertainty in H alpha- and FUV-based SFRs is similar to 0.3 and similar to 0.5 dex.Peer reviewe

Risk Factors for Mortality among HIV-Positive Patients with and Without Active Tuberculosis in Dar es Salaam, Tanzania.

The aim of this study was to describe risk factors for mortality and clinical characteristics of HIV-infected patients with and without tuberculosis (TB) coinfection. A cohort of HIV-infected patients with CD4(+) T-cell counts of ≤200 cells/μl was recruited, consisting of 255 HIV-infected patients without active TB and 231 patients with active TB. All received a well-supervised treatment with an efavirenz-based HAART, and those coinfected with TB received appropriate anti-TB treatment. They were followed up for 48 weeks after HAART initiation. Common presenting symptoms in HIV-only patients were fever (36.5%), headache (34.5%), skin rash (34.5%) and weight loss (32%), while in HIV-TB patients the symptoms were weight loss (58%), cough (57.6%), night sweats (44.6%) and fever (34.2%). HIV-TB patients had significantly lower body mass index, Karnofsky scores and haemoglobin levels compared to those infected with HIV only, despite similar baseline CD4(+) T-cell counts. Overall, 12 (4.7%) HIV patients developed TB and 7 (3%) HIV-TB patients had worsening of their TB symptoms during the study period. Mortality was similar in the two groups, being 10.9% (16 deaths per 100 person years) and 11.3% (17 deaths per 100 person years) in HIV-only and HIV-TB patients, respectively. Overall, more males (13.1%) died compared to females (9.6%). Predictors of mortality were presence of oral candidiasis, Kaposi's sarcoma, low Karnofsky score, and low baseline white blood cell and CD4(+) T-cell counts. The outcomes following well-supervised treatment of HIV-TB patients are similar to those in patients with HIV alone. Predictors of mortality were those of advanced disease