55 research outputs found

    The control of tuberculosis in the HIV era : improved tuberculosis diagnosis and development of vaccines for HIV prevention.

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    The HIV pandemic has reversed the gains in TB control and has thus contributed to an increase in TB morbidity and mortality, especially in low and middle-income countries. Improved TB diagnosis, active case finding as well as interventions towards the control of HIV will therefore conceivably result in better control of TB. Availability of a safe, affordable and efficacious vaccine is the best control measure for HIV. Participation of developing countries in these efforts is crucial. The overall aim of this thesis is to improve tuberculosis control in the era of HIV. In study I, a cross-sectional study was performed in two urban HIV VCT centers so as to determine the magnitude of TB among clients attending these centers. TB was diagnosed by symptoms screen, sputum and lymph nodes smears and culture of TB. We recruited 1,318 participants, of these 347 (26%) were HIV infected and TB was diagnosed in 63 (4.7%). Pulmonary TB, the most infectious form of TB was the most prevalent form detected in 52 participants. In study II, we compared manual Isolator lysis centrifugation to automated MB BacT broth systems for the detection of disseminated TB, and also compared 20mLs to 40mLs of blood for detecting disseminated TB. We recruited 258 hospitalized HIV-infected patients suspected to have TB. TB was culture confirmed in 83 (32%) patients. There was no difference between 20mLs or 40mLs of blood for the detection TB [20(15%) vs 21(16%)] p=0.83]. The MB BacT system had a significantly greater yield in detecting disseminated TB compared to the Isolator system [31(76%) vs 20(49%) p=0.001]. 21(51%) of the patients died prior to blood culture detection, the median survival was 6 days range 0-58 days. In study III, the test performance of a simple rapid urine lipoarabinomannan (LAM) antigen ELISA was compared to sputum and blood culture for the detection of HIV associated TB. Urine LAM sensitivity and specificity was 65% and 86% respectively in culture confirmed TB while the sensitivity and specificity of sputum smear, the conventional TB diagnostic method was 36% and 98% respectively. Urine LAM sensitivity improved with a decrease in CD+4 T-cell counts. In study IV, we prospectively enrolled and followed up a cohort of police officers so as to determine their suitability for HIV vaccine studies through determination of the current HIV prevalence and incidence. The HIV prevalence and incidence was 5.2% and 8.4 per 1000 PYAR among the 1,240 recruited police. In study V, a randomized multisite phase IIa clinical trial compared the safety and immunogenicity of priming with HIV-DNA at a dose 1000 µg in five injections “standard regimen” to a dose of 600 µg in two injections as separate or combined plasmid pools “simplified regimen” followed by boosting with HIV-MVA. The proportion of IFN-γ ELISpot responders did not differ between 2 injections of 600 µg combined (87%), 2 injections of 600 µg separate (97%) and the 5 injections of 1000 µg separate (97%). Conclusion: TB screening in VCT centers is feasible and should be offered for early detection and treatment to prevent transmission. Automated liquid blood culture is optimal for diagnosing disseminated TB, however deaths occur prior to detection. Therefore urine LAM ELISA could be used as an adjuvant to sputum smear for rapid identification of TB in advanced HIV infection. The HIV incidence in the police cohort has declined and hence this cohort is now only suitable for phase I/II HIV vaccine trials. Therefore there is a need to prepare other cohorts for efficacy studies. The last study demonstrated a simpler way to administer HIV-DNA vaccines, suitable for efficacy trials

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

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    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

    Trends in Hospitalisation for Human Immunodeficiency Virus in a Tertiary Hospital in Dar es Salaam, Tanzania: A Case study

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    Background: Reports on a systematic evaluation of the impact of antiretroviral therapy(ART) on patients’ hospitalisation in Sub Saharan Africa (SSA) and Tanzania, in particular, are scarce. We aimed at documenting the trends of hospital admissions at Muhimbili National Hospital (MNH) following scale-up of free access to ART in Tanzania. Methods: Records for all admissions at MNH from June 2005 to June 2015 were reviewed. We extracted data from the Hospital Information Management System as well as from patients’ charts. Data extracted included diagnosis at discharge, the reason for admission and thereafter assessed admission trends over the decade. We summarised the data as frequency and percentages. We compared proportions using the Chi-squared test, P Results: Overall there were 209,101 admissions during the study period (June 2005 to June 2015) and 7864/209,101 (3.8%) were due to HIV infection. Whereas 598/4,519 (13.2%) of all admissions in 2005 were due to HIV, only 345/13,119 (2.6%) of admissions in 2015 were HIV-related; showing a significant drop over time (P-value for trend \u3c .001). Generally, females 3887/6679 (58.2%) were more likely to be admitted than males (41.8%). Median CD4 count for admitted HIV patients was 143 cells/μl. Majority of admissions occurred in the medical wards 3643/5310 (68.6%). Discharge diagnoses were Tuberculosis 1396/6482 (21.5%), anaemias 1016/6482 (15.6 %), malignancies 789/6482(12.2%), CNS infections 541/6482 (8.3%) and chronic kidney disease 308/6482 (4.8%). Three leading AIDS defining malignancies among hospitalised patients included Kaposi’s sarcoma 380/789 (48.2%), carcinoma of the cervix 77/789 (9.8%), and Non-Hodgkin’s lymphoma 44/789 (5.6%). Conclusion: Despite a drastic drop of HIV related admissions at Muhimbili National Hospital over the years, the infection remains a problem of the adults, largely females suffering from medical conditions and presenting with severe immunosuppression. Tuberculosis remained the most common opportunistic infection among hospitalized HIV infected patients. Anaemia and cancers became more important causes of admission than was diarrhoea which had been the most common among HIV infected patients in pre- ART

    Perceptions About Repeat HIV Testing in an Incidence Study: A Qualitative Study among a Potential Cohort for HIV Vaccine Trials in Dar es Salaam, Tanzania

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    Information regarding repeat HIV testing is useful in the conduct of HIV vaccine trials as potential trial participants are required to undergo repeat HIV testing. In an incidence study conducted in 2008 among 1042 Police Officers 30% of them did not participate in a repeat HIV test. This study was therefore conducted to explore perceptions on repeat HIV testing among members of the incidence study cohort that also served as a source of volunteers for subsequent HIV vaccine trials. This qualitative cross-sectional study was conducted in Dar es Salaam. The study included male and female Police Officers who were eligible to participate in the HIV incidence study. Participants were selected purposefully from eight Police stations out of the 32 stations. Data was collected using in-depth interviews and analysed qualitatively using the content analysis approach. A majority of participants were willing to undergo a repeat HIV test and stated that it was important to repeat an HIV test to confirm their health status, and hence continue protecting themselves. Participants who participated in a repeat HIV test as a part of incidence study reported that the repeat HIV testing process was acceptable because counselling was provided, testing was voluntary, there was trust in the health care providers and a freedom to choose where to test. Participants who did not repeat the HIV test held that repeat a HIV test was not necessary since they believed that the initial test was adequate. Others said that communication breakdown was the main cause as they weren't aware of the importance of a repeat HIV test. Fear of the test results was also mentioned as one of the reasons. The participants were eager to gain more knowledge about the importance of a repeat HIV test. In order to facilitate repeat HIV testing in potential cohorts for HIV vaccine trials, more information and education regarding the repeat HIV test is needed. It is also important to make sure that researchers are well informed on what study participants are supposed to know.\u

    Test Characteristics of Urinary Lipoarabinomannan and Predictors of Mortality among Hospitalized HIV-Infected Tuberculosis Suspects in Tanzania.

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    Tuberculosis is the most common cause of death among patients with HIV infection living in tuberculosis endemic countries, but many cases are not diagnosed pre-mortem. We assessed the test characteristics of urinary lipoarabinomannan (LAM) and predictors of mortality among HIV-associated tuberculosis suspects in Tanzania. We prospectively enrolled hospitalized HIV-infected patients in Dar es Salaam, with ≥2 weeks of cough or fever, or weight loss. Subjects gave 2 mLs of urine to test for LAM using a commercially available ELISA, ≥2 sputum specimens for concentrated AFB smear and solid media culture, and 40 mLs of blood for culture. Among 212 evaluable subjects, 143 (68%) were female; mean age was 36 years; and the median CD4 count 86 cells/mm(3). 69 subjects (33%) had culture confirmation of tuberculosis and 65 (31%) were LAM positive. For 69 cases of sputum or blood culture-confirmed tuberculosis, LAM sensitivity was 65% and specificity 86% compared to 36% and 98% for sputum smear. LAM test characteristics were not different in patients with bacteremia but showed higher sensitivity and lower specificity with decreasing CD4 cell count. Two month mortality was 64 (53%) of 121 with outcomes available. In multivariate analysis there was significant association of mortality with absence of anti-retroviral therapy (p = 0.004) and a trend toward association with a positive urine LAM (p = 0.16). Among culture-negative patients mortality was 9 (75%) of 12 in LAM positive patients and 27 (38%) of 71 in LAM negative patients (p = 0.02). Urine LAM is more sensitive than sputum smear and has utility for the rapid diagnosis of culture-confirmed tuberculosis in this high-risk population. Mortality data raise the possibility that urine LAM may also be a marker for culture-negative tuberculosis

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

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    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

    "I did not plan to have a baby. This is the outcome of our work": a qualitative study exploring unintended pregnancy among female sex workers.

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    BACKGROUND: High number of unintended pregnancies-often leading to induced abortions-are reported among female sex workers (FSWs), highlighting a major unmet need for contraception. To better understand barriers to contraceptive use, we explored FSW's pregnancy perceptions and experiences of unintended pregnancy. We hypothesized that sex work exacerbates barriers to contraceptive use and that FSW's pregnancy perceptions and experiences of unintended pregnancy influence future commitment to contraceptive use. METHODS: We conducted in-depth interviews with 11 FSWs (January-June 2019) in Dar es Salaam, Tanzania. We purposively sampled FSWs with a positive pregnancy test from those participating in a HIV vaccine preparedness cohort. We used open ended questions to explore how FSWs make decisions when facing barriers to contraceptive use, dealing with unintended pregnancy and adhering to contraceptive use after experiencing unintended pregnancy. All interviews were conducted in Kiswahili, audio-recorded, transcribed and translated into English. Grounded theory approach was used to analyse transcripts. Open and selective coding was performed using Nvivo software. RESULTS: FSWs reported that sex work impedes good contraceptive behaviour because sex workers felt unable to negotiate consistent condom use, avoided health services due to stigma, missed monthly contraceptive supplies because of inconvenient clinic operating hours or skipped contraceptive pills when intoxicated after taking alcohol. FSWs who perceived pregnancy to be a burden terminated the pregnancy because of fear of loss of income during pregnancy or child rearing expenses in case child support was not assured by their partners. FSWs who perceived pregnancy to be a blessing decided to keep the pregnancy because they desired motherhood and hoped that children would bring prosperity. Family planning counselling and availability of contraceptives during postpartum care influenced the initiation of contraception among FSWs. Financial hardships related to childrearing or painful abortion experiences influenced FSWs' commitment to good contraceptive practices. CONCLUSION: Our results demonstrate that FSWs face barriers to initiating and adhering to contraceptive use because of sex work stigma, inability to negotiate condoms and failure to access medical services at their convenience. Our findings underscore the need to integrate contraceptive services with HIV programs serving FSWs in their areas of work

    Experiences on Recruitment and Retention of Volunteers in the First HIV Vaccine Trial in Dar es Salam, Tanzania - The phase I/II HIVIS 03 trial.

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    Eventual control of HIV/AIDS is believed to be ultimately dependent on a safe, effective and affordable vaccine. Participation of sub-Saharan Africa in the conduct of HIV trials is crucial as this region still experiences high HIV incidences. We describe the experience of recruiting and retaining volunteers in the first HIV vaccine trial (HIVIS03) in Tanzania. In this trial enrolled volunteers from amongst Police Officers (POs) in Dar es Salaam were primed with HIV-1 DNA vaccine at months 0, 1 and 3; and boosted with HIV-1 MVA vaccine at months 9 and 21. A stepwise education provision/sensitization approach was employed to eventual recruitment. Having identified a "core" group of POs keen on HIV prevention activities, those interested to participate in the vaccine trial were invited for a first screening session that comprised of provision of detailed study information and medical evaluation. In the second screening session results of the initial assessment were provided and those eligible were assessed for willingness to participate (WTP). Those willing were consented and eventually randomized into the trial having met the eligibility criteria. Voluntary participation was emphasized throughout. Out of 408 POs who formed the core group, 364 (89.0%) attended the educational sessions. 263 out of 364 (72.2%) indicated willingness to participate in the HIV vaccine trial. 98% of those indicating WTP attended the pre-screening workshops. 220 (85.0%) indicated willingness to undergo first screening and 177 POs attended for initial screenings, of whom 162 (91.5%) underwent both clinical and laboratory screenings. 119 volunteers (73.5%) were eligible for the study. 79 were randomized into the trial, while 19 did not turn up, the major reason being partner/family advice. 60 volunteers including 15 females were recruited during a one-year period. All participated in the planned progress updates workshops. Retention into the schedule was: 98% for the 3 DNA/placebo vaccinations, while it was 83% and 73% for the first and second MVA/placebo vaccinations respectively. In this first HIV vaccine trial in Tanzania, we successfully recruited the volunteers and there was no significant loss to follow up. Close contact and updates on study progress facilitated the observed retention rates.\u

    Boosting with Subtype C CN54rgp140 Protein Adjuvanted with Glucopyranosyl Lipid Adjuvant after Priming with HIV-DNA and HIV-MVA Is Safe and Enhances Immune Responses: A Phase I Trial

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    Background A vaccine against HIV is widely considered the most effective and sustainable way of reducing new infections. We evaluated the safety and impact of boosting with subtype C CN54rgp140 envelope protein adjuvanted in glucopyranosyl lipid adjuvant (GLA-AF) in Tanzanian volunteers previously given three immunizations with HIV-DNA followed by two immunizations with recombinant modified vaccinia virus Ankara (HIV-MVA). Methods Forty volunteers (35 vaccinees and five placebo recipients) were given two CN54rgp140/GLA-AF immunizations 30-71 weeks after the last HIV-MVA vaccination. These immunizations were delivered intramuscularly four weeks apart. Results The vaccine was safe and well tolerated except for one episode of asymptomatic hypoglycaemia that was classified as severe adverse event. Two weeks after the second HIV-MVA vaccination 34 (97%) of the 35 previously vaccinated developed Env-specific binding antibodies, and 79% and 84% displayed IFN-gamma ELISpot responses to Gag and Env, respectively. Binding antibodies to subtype C Env (included in HIV-DNA and protein boost), subtype B Env (included only in HIV-DNA) and CRF01_AE Env (included only in HIV-MVA) were significantly boosted by the CN54rgp140/GLA-AF immunizations. Functional antibodies detected using an infectious molecular clone virus/peripheral blood mononuclear cell neutralization assay, a pseudovirus/TZM-bl neutralization assay or by assays for antibody-dependent cellular cytotoxicity (ADCC) were not significantly boosted. In contrast, T-cell proliferative responses to subtype B MN antigen and IFN-gamma ELISpot responses to Env peptides were significantly enhanced. Four volunteers not primed with HIV-DNA and HIV-MVA before the CN54rgp140/ GLA-AF immunizations mounted an antibody response, while cell-mediated responses were rare. After the two Env subtype C protein immunizations, a trend towards higher median subtype C Env binding antibody titers was found in vaccinees who had received HIV-DNA and HIV-MVA prior to the two Env protein immunizations as compared to unprimed vaccinees (p = 0.07). Conclusion We report excellent tolerability, enhanced binding antibody responses and Env-specific cell-mediated immune responses but no ADCC antibody increase after two immunizations with a subtype C rgp140 protein adjuvanted in GLA-AF in healthy volunteers previously immunized with HIV-DNA and HIV-MVA

    The Perceptions on Male Circumcision as a Preventive Measure Against HIV Infection and Considerations in Scaling up of the Services: A Qualitative Study Among Police Officers in Dar es Salaam, Tanzania.

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    \ud In recent randomized controlled trials, male circumcision has been proven to complement the available biomedical interventions in decreasing HIV transmission from infected women to uninfected men. Consequently, Tanzania is striving to scale-up safe medical male circumcision to reduce HIV transmission. However, there is a need to investigate the perceptions of male circumcision in Tanzania using specific populations. The purpose of the present study was to assess the perceptions of male circumcision in a cohort of police officers that also served as a source of volunteers for a phase I/II HIV vaccine (HIVIS-03) trial in Dar es Salaam, Tanzania. In-depth interviews with 24 men and 10 women were conducted. Content analysis informed by the socio-ecological model was used to analyze the data. Informants perceived male circumcision as a health-promoting practice that may prevent HIV transmission and other sexually transmitted infections. They reported male circumcision promotes sexual pleasure, confidence and hygiene or sexual cleanliness. They added that it is a religious ritual and a cultural practice that enhances the recognition of manhood in the community. However, informants were concerned about the cost involved in male circumcision and cleanliness of instruments used in medical and traditional male circumcision. They also expressed confusion about the shame of undergoing circumcision at an advanced age and pain that could emanate after circumcision. The participants advocated for health policies that promote medical male circumcision at childhood, specifically along with the vaccination program. The perceived benefit of male circumcision as a preventive strategy to HIV and other sexually transmitted infections is important. However, there is a need to ensure that male circumcision is conducted under hygienic conditions. Integrating male circumcision service in the routine childhood vaccination program may increase its coverage at early childhood. The findings from this investigation provide contextual understanding that may assist in scaling-up male circumcision in Tanzania.\u
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