Nzovu Ulenga
Harvard University
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Featured researches published by Nzovu Ulenga.
AIDS Research and Human Retroviruses | 2008
Nzovu Ulenga; Abdoulaye Dieng Sarr; Donald J. Hamel; Jean-Louis Sankalé; Souleymane Mboup; Phyllis J. Kanki
The APOBEC family of mammalian cytidine deaminases, such as APOBEC3G (hA3G), has been demonstrated to function as a host viral restriction factor against HIV-1. hA3G has been shown to cause extensive G-to-A mutations in the HIV-1 genome, which may play a role in viral restriction. To investigate the role of G-to-A mutations in HIV-1 pathogenesis, we isolated, amplified, and sequenced HIV-1 sequences (vif, gag, and env) from 29 therapy-naive HIV-1-infected individuals. The levels of G-to-A mutations correlated with the expression levels of hA3G in the vif (rho = 0.438, p = 0.041) and the env regions (rho = 0.392, p = 0.038), but not in the gag region (rho = 0.131, p = 0.582). There is no correlation between viral load and the level of G-to-A mutations in the vif (rho = 0.144, p = 0.522), env (rho = 0.168, p = 0.391), or gag regions (rho = -0.254, p = 0.279). Taken together, these findings suggest that the hA3G-induced G-to-A mutations may not be the mechanism by which hA3G restricts or controls viral replication. Thus, hA3G might be restricting viral growth in infected individuals through a mechanism that is independent of the cytidine deaminase activities of hA3G.
The Journal of Infectious Diseases | 2008
Nzovu Ulenga; Abdoulaye Dieng Sarr; Seema Thakore-Meloni; Jean-Louis Sankalé; Geoff Eisen; Phyllis J. Kanki
BACKGROUND Human immunodeficiency virus type 1 (HIV-1)-infected individuals with a high viral set point progress to acquired immunodeficiency syndrome (AIDS) more rapidly than those with a low viral set point. It is not entirely clear which host and viral factors are responsible for the viral set point. Host factors that affect virus replication are likely to influence the viral set point. Human APOBEC proteins have been shown to restrict HIV-1 replication. METHODS This prospective study was conducted to determine the relationship between human APOBEC3G (hA3G) and APOBEC3F (hA3F) levels and the viral set point. Fourteen subjects were classified as having a high viral set point, and 16 were classified as having a low viral set point. We quantified the levels of hA3G and hA3F mRNA in HIV-1-infected, antiretroviral drug-naive individuals before and after infection. RESULTS We found a significant correlation between the hA3G mRNA level and the viral set point. The expression of hA3G and hA3F increased after infection, and the levels of hA3G and hA3F mRNA were significantly higher after infection in the low viral set point group, compared with the high viral set point group. CONCLUSIONS The results suggest that the level of hA3G expression affects the establishment of the viral set point and may therefore function as a host determinant in the pathogenesis of HIV-1 infection.
Journal of Antimicrobial Chemotherapy | 2016
Claudia Hawkins; Nzovu Ulenga; Enju Liu; Said Aboud; Ferdinand Mugusi; Guerino Chalamilla; David Sando; Eric Aris; Deborah Carpenter; Wafaie W. Fawzi
OBJECTIVES There are few data on ART failure rates and drug resistance from Tanzania, where there is a wide diversity of non-B HIV subtypes. We assessed rates and predictors of virological failure in HIV-infected Tanzanians and describe drug resistance patterns in a subgroup of these patients. METHODS ART-naive, HIV-1-infected adults enrolled in a randomized controlled trial between November 2006 and 2008 and on ≥24 weeks of first-line NNRTI-containing ART were included. Population-based genotyping of HIV-1 protease and reverse transcriptase was performed on stored plasma from patients with virological failure (viral load >1000 copies/mL at ≥24 weeks of ART) and at baseline, where available. RESULTS A total of 2403 patients [median (IQR) age 37 (32-43) years; 70% female] were studied. The median (IQR) baseline CD4+ T cell count was 128 (62-190) cells/μL. Predominant HIV subtypes were A, C and D (92.2%). The overall rate of virological failure was 14.9% (95% CI 13.2%-16.1%). In adjusted analyses, significant predictors of virological failure were lower CD4+ T cell count (P = 0.01) and non-adherence to ART (P < 0.01). Drug resistance mutations were present in 87/115 samples (75.7%); the most common were M184V/I (52.2%) and K103N (35%). Thymidine analogue mutations were uncommon (5.2%). The prevalence of mutations in 45 samples pre-ART was 22%. CONCLUSIONS High levels of early ART failure and drug resistance were observed among Tanzanian HIV-1-infected adults enrolled in a well-monitored study. Initiating treatment early and ensuring optimal adherence are vital for the success and durability of first-line ART in these settings.
Contemporary clinical trials communications | 2016
Dale Barnhart; Ellen Hertzmark; Enju Liu; Ester Mungure; Aisa Muya; David Sando; Guerino Chalamilla; Nzovu Ulenga; Till Bärnighausen; Wafaie W. Fawzi; Donna Spiegelman
Introduction Researchers planning cluster-randomized controlled trials (cRCTs) require estimates of the intra-cluster correlation coefficient (ICC) from previous studies for sample size calculations. This paper fills a persistent gap in the literature by providing estimates of ICCs for many key HIV-related clinical outcomes. Methods Data from HIV-positive patients from 47 HIV care and treatment clinics in Dar es Salaam, Tanzania were used to calculate ICCs by site of enrollment or site of ART initiation for various clinical outcomes using cross-sectional and longitudinal data. ICCs were estimated using linear mixed models where either clinic of enrollment or clinic of ART initiation served as the random effect. Results ICCs ranged from 0 to 0.0706 (95% CI: 0.0447, 0.1098). For most outcomes, the ICCs were large enough to meaningfully affect sample size calculations. For binary outcomes, the ICCs for event prevalence at baseline tended to be larger than the ICCs for later cumulative incidences. For continuous outcomes, the ICCs for baseline values tended to be larger than the ICCs for the change in values from baseline. Conclusion The ICCs for HIV-related outcomes cannot be ignored when calculating sample sizes for future cluster-randomized trials. The differences between ICCs calculated from baseline data alone and ICCs calculated using longitudinal data demonstrate the importance of selecting an ICC that reflects a studys intended design and duration for sample size calculations. While not generalizable to all contexts, these estimates provide guidance for future researchers seeking to design adequately powered cRCTs in Sub-Saharan African HIV treatment and care clinics.
Journal of the International AIDS Society | 2018
Sumona Chaudhury; Ellen Hertzmark; Aisa Muya; David Sando; Nzovu Ulenga; Lameck Machumi; Donna Spiegelman; Wafaie W. Fawzi
Global scale up of anti‐retroviral therapy (ART) has led to expansion of HIV treatment and prevention across sub‐Saharan Africa. However, age and gender‐specific disparities persist leading to failures in fulfillment of Sustainability Development Goals, including SDG3 (achieving healthy lives and wellbeing for all, at all ages) and SDG5 (gender equality). We assessed ART initiation and adherence, loss to follow‐up, all‐cause death and early death, according to SDG3 and SDG5 indicators among a cohort of HIV‐infected children and adolescents enrolled in care in Dar‐es‐Salaam, Tanzania
Journal of Acquired Immune Deficiency Syndromes | 2017
Claudia Hawkins; Beatrice Christian; Emanuel Fabian; Irene Macha; Cecilia Gawile; Shida Mpangala; Nzovu Ulenga; Chloe L. Thio; Lauren Rose Ammerman; Ferdinand Mugusi; Wafaie W. Fawzi; Richard M. Green; Robert L. Murphy
Background: In sub-Saharan Africa, the burden of liver disease associated with chronic hepatitis B virus (HBV) and HIV is unknown. We characterized liver disease using aspartate aminotransferase-to-platelet ratio index (APRI) and FIB-4 in patients with HIV, HBV, and HIV/HBV coinfection in Tanzania. Methods: Using a cross-sectional design, we compared the prevalence of liver fibrosis in treatment-naive HIV monoinfected, HBV monoinfected, and HIV/HBV-coinfected adults enrolled at Management and Development for Health (MDH)-supported HIV treatment clinics in Dar es Salaam, Tanzania. Risk factors associated with significant fibrosis (APRI >0.5 and FIB-4 >1.45) were examined. Results: Two hundred sixty-seven HIV-infected, 165 HBV-infected, and 63 HIV/HBV-coinfected patients were analyzed [44% men, median age 37 (interquartile range 14), body mass index 23 (7)]. APRI and FIB-4 were strongly correlated (r = 0.78, P < 0.001, R2 = 0.61). Overall median APRI scores were low {HIV/HBV [0.36 (interquartile range 0.4)], HIV [0.23 (0.17)], HBV [0.29 (0.15)] (P < 0.01)}. In multivariate analyses, HIV/HBV coinfection was associated with APRI >0.5 [HIV/HBV vs. HIV: odds ratio (OR) 3.78 (95% confidence interval: 1.91 to 7.50)], [HIV/HBV vs. HBV: OR 2.61 (1.26 to 5.44)]. HIV RNA per 1 log10 copies/mL increase [OR 1.53 (95% confidence interval: 1.04 to 2.26)] and HBV DNA per 1 log10 copies/mL increase [OR 1.36 (1.15, 1.62)] were independently associated with APRI >0.5 in HIV-infected and HBV-infected patients, respectively. Conclusions: HIV/HBV coinfection is an important risk factor for significant fibrosis. Higher levels of circulating HIV and HBV virus may play a direct role in liver fibrogenesis. Prompt diagnosis and aggressive monitoring of liver disease in HIV/HBV coinfection is warranted.
PLOS Medicine | 2018
Pascal Geldsetzer; Joel M. Francis; David Sando; Gerda Asmus; Irene A. Lema; Eric Mboggo; Happiness Koda; Sharon Lwezaula; Ramya Ambikapathi; Wafaie W. Fawzi; Nzovu Ulenga; Till Bärnighausen
Background With the increase in people living with HIV in sub-Saharan Africa and expanding eligibility criteria for antiretroviral therapy (ART), there is intense interest in the use of novel delivery models that allow understaffed health systems to successfully deal with an increasing demand for antiretroviral drugs (ARVs). This pragmatic randomized controlled trial in Dar es Salaam, Tanzania, evaluated a novel model of ARV community delivery: lay health workers (home-based carers [HBCs]) deliver ARVs to the homes of patients who are clinically stable on ART, while nurses and physicians deliver standard facility-based care for patients who are clinically unstable. Specifically, the trial aimed to assess whether the ARV community delivery model performed at least equally well in averting virological failure as the standard of care (facility-based care for all ART patients). Methods and findings The study took place from March 1, 2016, to October 27, 2017. All (48) healthcare facilities in Dar es Salaam that provided ART and had an affiliated team of public-sector HBCs were randomized 1:1 to either (i) ARV community delivery (intervention) or (ii) the standard of care (control). Our prespecified primary endpoint was the proportion of adult non-pregnant ART patients with virological failure at the end of the study period. The prespecified margin of non-inferiority was a risk ratio (RR) of 1.45. The mean follow-up period was 326 days. We obtained intent-to-treat (ITT) RRs using a log-binomial model adjusting standard errors for clustering at the level of the healthcare facility. A total of 2,172 patients were enrolled at intervention (1,163 patients) and control (1,009 patients) facilities. Of the 1,163 patients in the intervention arm, 516 (44.4%) were both clinically stable on ART and opted to receive ARVs in their homes or at another meeting point of their choosing in the community. At the end of the study period, 10.9% (95/872) of patients in the control arm and 9.7% (91/943) in the intervention arm were failing virologically. The ITT RR for virological failure demonstrated non-inferiority of the ARV community delivery model (RR 0.89 [1-sided 95% CI 0.00–1.18]). We observed no significant difference between study arms in self-reported patient healthcare expenditures over the last 6 months before study exit. Of those who received ARVs in the community, 97.2% (95% CI 94.7%–98.7%) reported being either “satisfied” or “very satisfied” with the program. Other than loss to follow-up (18.9% in the intervention and 13.6% in the control arm), the main limitation of this trial was that substantial decongestion of healthcare facilities was not achieved, thus making the logic for our preregistered ITT approach (which includes those ineligible to receive ARVs at home in the intervention sample) less compelling. Conclusions In this study, an ARV community delivery model performed at least as well as the standard of care regarding the critical health indicator of virological failure. The intervention did not significantly reduce patient healthcare expenditures, but satisfaction with the program was high and it is likely to save patients time. Policy-makers should consider piloting, evaluating, and scaling more ambitious ARV community delivery programs that can reach higher proportions of ART patients. Trial registration ClinicalTrials.gov NCT02711293.
American Journal of Tropical Medicine and Hygiene | 2018
Kosuke Kawai; Claudia Hawkins; Ellen Hertzmark; Joel M. Francis; David Sando; Aisa Muya; Nzovu Ulenga; Wafaie W. Fawzi
We examined the incidence of herpes zoster (HZ) before and after the initiation of antiretroviral therapy (ART), and risk factors for HZ among human immunodeficiency virus (HIV)-infected individuals in Tanzania. A cohort study was conducted among HIV-positive individuals enrolled in HIV care and treatment clinics in Dar es Salaam, Tanzania. A Cox proportional hazard model was used to examine the effect of ART on the risk of HZ after adjusting for sociodemographics and time-varying clinical and nutritional factors. Among 72,670 HIV-positive individuals, 2,312 incident cases of HZ (3.2%) occurred during the median follow-up of 15 months (interquartile range: 3-35). The incidence rate of HZ significantly declined from 48.9 (95% confidence interval [CI] = 46.7-51.0) per 1,000 person-years before ART to 3.7 (95% CI = 3.3-4.1) per 1,000 person-years after the initiation of ART (P < 0.001). The risk of HZ declined with longer duration on ART. Low CD4 cell count, older age, female sex, district of Dar es Salaam, and year of enrollment were independently associated with the risk of HZ in the multivariate analysis. Low body mass index and anemia were not associated with the risk of HZ. The risk of HZ substantially declined after ART initiation in this large cohort of HIV-infected individuals. Earlier initiation of ART could reduce the risk of HZ and other opportunistic infections among HIV-infected individuals in sub-Saharan Africa.
PLOS ONE | 2017
Ramadhani A. Noor; Ajibola I. Abioye; Nzovu Ulenga; Salum Msham; George Kaishozi; Nilupa S. Gunaratna; Ramadhani S. Mwiru; Erin N. Smith; Christina Nyhus Dhillon; Donna Spiegelman; Wafaie W. Fawzi
There is widespread vitamin and mineral deficiency problem in Tanzania with known deficiencies of at least vitamin A, iron, folate and zinc, resulting in lasting negative consequences especially on maternal health, cognitive development and thus the nation’s economic potential. Folate deficiency is associated with significant adverse health effects among women of reproductive age, including a higher risk of neural tube defects. Several countries, including Tanzania, have implemented mandatory fortification of wheat and maize flour but evidence on the effectiveness of these programs in developing countries remains limited. We evaluated the effectiveness of Tanzania’s food fortification program by examining folate levels for women of reproductive age, 18–49 years. A prospective cohort study with 600 non-pregnant women enrolled concurrent with the initiation of food fortification and followed up for 1 year thereafter. Blood samples, dietary intake and fortified foods consumption data were collected at baseline, and at 6 and 12 months. Plasma folate levels were determined using a competitive assay with folate binding protein. Using univariate and multivariate linear regression, we compared the change in plasma folate levels at six and twelve months of the program from baseline. We also assessed the relative risk of folate deficiency during follow-up using log-binomial regression. The mean (±SE) pre–fortification plasma folate level for the women was 5.44-ng/ml (±2.30) at baseline. These levels improved significantly at six months [difference: 4.57ng/ml (±2.89)] and 12 months [difference: 4.27ng/ml (±4.18)]. Based on plasma folate cut-off level of 4 ng/ml, the prevalence of folate deficiency was 26.9% at baseline, and 5% at twelve months. One ng/ml increase in plasma folate from baseline was associated with a 25% decreased risk of folate deficiency at 12 months [(RR = 0.75; 95% CI = 0.67–0.85, P<0.001]. In a setting where folate deficiency is high, food fortification program with folic acid resulted in significant improvements in folate status among women of reproductive age.
Journal of Antimicrobial Chemotherapy | 2017
Claudia Hawkins; Ellen Hertzmark; Donna Spiegelman; Aisa Muya; Nzovu Ulenga; Sehee Kim; Polyna Khudyakov; Beatrice Christian; David Sando; Eric Aris; Wafaie W. Fawzi
Objectives In a large cohort of HIV-infected Tanzanians, we assessed: (i) rates of first-line treatment failure and switches to second-line ART; (ii) the effect of switching to second-line ART on death and loss to follow-up; and (iii) treatment outcomes on second-line ART by regimen. Methods HIV-1-infected adults (≥15 years) initiated on first-line ART between November 2004 and September 2012, and who remained on initial therapy for at least 24 weeks before switching, were studied. Survival analyses were conducted to examine the effect of second-line ART on mortality and loss to follow-up in: (i) the whole cohort; (ii) all patients eligible for second-line ART by immunological failure (IF) and/or virological failure (VF) criteria; and (iii) patients eligible by VF criteria. Results In total, 47 296 HIV-infected patients [mean age 37.5 (SD 9.5) years, CD4 175 (SD 158) cells/mm 3 , 71% female] were included in the analyses. Of these, 1760 (3.7%) patients switched to second-line ART (incidence rate = 1.7/100 person-years). Higher rates of mortality were observed in switchers versus non-switchers in all patients and patients with ART failure using IF/VF criteria. Switching only protected against mortality in patients with ART failure defined virologically and with the highest level of adherence [switching versus non-switching; >95% adherence; adjusted HR = 0.50 (95% CI = 0.26-0.93); P = 0.03]. Conclusions Switching patients to second-line ART may only be beneficial in a select group of patients who are virologically monitored and demonstrate good adherence. Our data emphasize the need for routine viral load monitoring and aggressive adherence interventions in HIV programmes in sub-Saharan Africa.