Sikhulile Moyo

Increased Risk of Preterm Delivery Among HIV-Infected Women Randomized to Protease Versus Nucleoside Reverse Transcriptase Inhibitor-Based HAART During Pregnancy

BACKGROUND Protease inhibitor (PI)-based highly active antiretroviral therapy (HAART) use in pregnancy has been associated with preterm deliveries in some observational studies. METHODS HIV-infected, HAART-naive pregnant women with CD4+ counts ≥200 cells/mm(3) were randomized between 26 and 34 weeks gestation to lopinavir/ritonavir/zidovudine/lamivudine (PI group) or abacavir/zidovudine/lamivudine (NRTI group) in a clinical trial to prevent mother-to-child HIV transmission. Risk factors for preterm delivery (<37 weeks) and differences by randomization arm were evaluated for live infants by logistic regression. RESULTS Preterm delivery rates were higher among 267 women in the PI group than 263 women in the NRTI group (21.4% vs 11.8%, P = .003). PI-based HAART was the most significant risk factor for preterm delivery [odds ratio = 2.03, 95% confidence interval 1.26-3.27, P = .004]. Mean change in maternal body mass index (BMI) 1 month after HAART initiation was lower in the PI group (P < .001); however, this was not significantly associated with preterm delivery. Neither infant hospitalizations nor mortality through 6 months of life differed by maternal regimen. CONCLUSIONS PI-based HAART was associated with increased preterm delivery but not increased infant hospitalizations or mortality in a clinical trial setting. The association between PI use and lower increase in BMI in late pregnancy warrants further study.

Optimising growth conditions for the pectinolytic activity of Kluyveromyces wickerhamii by using response surface methodology

This present study was undertaken to find optimum conditions of pH, temperature and, period of incubation for the pectinolytic activity of Kluyveromyces wickerhamii isolated from rotting fruits and to assess the effect of these factors by use of response surface methodology (RSM). A central composite rotatable design was used as an experimental design for the analysis of the allocation of treatment combinations. A second order polynomial regression model was fitted and was found adequate, with an R(2) of 0.94469 (P<0.001). The effects of temperature and pH were the most significant factors in influencing enzyme production. Estimated optimum conditions were as follows: pH 5.0, temperature, 32 degrees C and an incubation period of 91 h. Pectinesterase (PE), pectin lyase (PL), and cellulase activities were not detected. Pectinase production was partially constitutive. Pectin was degraded by the isolated strain of K. wickerhamii in the current study, and the pectinolytic activity is referred to as polygalacturonase (PG) activity. Crude enzyme extract was thermostable at various temperatures and, stimulated by the presence of Ca(2+) ions but inhibited by other ions like Mg(2+), Zn(2+), Co(2+), Mn(2+) and Na(+).

Higher-than-expected rates of lactic acidosis among highly active antiretroviral therapy-treated women in Botswana: preliminary results from a large randomized clinical trial.

Background: The ability of nucleoside reverse transcriptase inhibitors (NRTIs) to inhibit human mitochondrial polymerase-γ results in impaired synthesis of mitochondrial enzymes that generate adenosine triphosphate (ATP) by oxidative phosphorylation. This has been associated with several long-term mitochondrial toxicities, which include lactic acidosis and pancreatitis, peripheral neuropathy, and lipoatrophy. Methods: Enrolled highly active antiretroviral therapy (HAART)-treated adults have completed nearly 2 years of follow-up as part of the ongoing randomized clinical trial Adult Antiretroviral Treatment and Drug Resistance (Tshepo) study. All patients were intensively screened for the presence of ARV-related toxicities. Results: Six hundred fifty adults (69% female) were initiated on NRTI-based HAART. Overall, 2.0% of patients developed moderate to severe symptomatic hyperlactatemia, with 7 (1.0%), all female, diagnosed with lactic acidosis. Female gender (P = 0.008) and being overweight, namely having a body mass index (BMI) of greater than 25 (P = 0.001), were predictive for the development of moderate to severe symptomatic hyperlactatemia or lactic acidosis. Older age (age >40 years) showed a statistical trend (P = 0.053) as a predictor for the development of toxicity, whereas exposure to d4T and/or ddI for 6 or more months was not predictive (P = 0.102). Those diagnosed with lactic acidosis had a mean BMI of 32.38 (interquartile range [IQR] = 29.4 to 35) at the time of toxicity and had been receiving HAART for a mean of 12.1 months (IQR = 7 to 20.8). Four of the 7 (57%) died of lactic acidosis and/or hemorrhagic pancreatitis; these 4 patients also had a comorbid diagnosis of severe clinical pancreatitis with grade 3/4 lipase elevations and abdominal symptoms at the time of their demise. Conclusions: Rates of lactic acidosis appear to be higher in southern Africa when compared with rates previously described elsewhere. Risk factors for the development of moderate to severe symptomatic hyperlactatemia or lactic acidosis appear to be multifactorial but include female gender and having a BMI of greater than 25. Additional studies are ongoing to evaluate for other possible risk factors, such as host genetic differences.

Botswana's progress toward achieving the 2020 UNAIDS 90-90-90 antiretroviral therapy and virological suppression goals: a population-based survey

BACKGROUND HIV programmes face challenges achieving high rates of HIV testing and treatment needed to optimise health and to reduce transmission. We used data from the Botswana Combination Prevention Project study survey to assess Botswanas progress toward achieving UNAIDS targets for 2020: 90% of all people living with HIV knowing their status, 90% of these receiving sustained antiretroviral therapy (ART), and 90% of those having virological suppression (90-90-90). METHODS A population-based sample of individuals was recruited and interviewed in 30 rural and periurban communities from Oct 30, 2013, to Nov 24, 2015, as part of a large, ongoing community-randomised trial designed to assess the effect of a combination prevention package on HIV incidence. A random sample of about 20% of households in each community was selected. Consenting household residents aged 16-64 years who were Botswana citizens or spouses of citizens responded to a questionnaire and had blood drawn for HIV testing in the absence of documentation of positive HIV status. Viral load testing was done in all HIV-infected participants, irrespective of treatment status. We used modified Poisson generalised estimating equations to obtain prevalence ratios, corresponding Huber robust SEs, and 95% Wald CIs to examine associations between individual sociodemographic factors and a binary outcome indicating achievement of the three individual and combined overall 90-90-90 targets. The study is registered at ClinicalTrials.gov, number NCT01965470. FINDINGS 81% of enumerated eligible household members took part in the survey (10% refused and 9% were absent). Among 12 610 participants surveyed, 3596 (29%) were infected with HIV, and 2995 (83·3%, 95% CI 81·4-85·2) of these individuals already knew their HIV status. Among those who knew their HIV status, 2617 (87·4%, 95% CI 85·8-89·0) were receiving ART (95% of those eligible by national guidelines, and 73% of all infected people). Of the 2609 individuals receiving ART with a viral load measurement, 2517 (96·5%, 95% CI 96·0-97·0) had viral load of 400 copies per mL or less. Overall, 70·2% (95% CI 67·5-73·0) of HIV-infected people had virological suppression, close to the UNAIDS target of 73%. INTERPRETATION UNAIDS 90-90-90 targets are achievable even in resource-constrained settings with high HIV burden. FUNDING US Presidents Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

Response to zidovudine/didanosine-containing combination antiretroviral therapy among HIV-1 subtype C-infected adults in Botswana: two-year outcomes from a randomized clinical trial.

Background:Numerous national antiretroviral (ARV) treatment initiatives offering protease inhibitor-sparing combination antiretroviral therapy (cART) have recently commenced in southern Africa, the first of which began in Botswana in January 2002. Evaluation of the efficacy and tolerability of various protease inhibitor-sparing cART regimens requires intensive study in the region, as does investigation of the development of drug resistance and the optimal means of sustaining adherence. The “Tshepo” Study is the first large-scale, randomized, clinical trial that addresses these important issues among HIV-1 subtype C-infected ARV treatment-naive adults in southern Africa. Methods:The Tshepo Study is a completed, open-labeled, randomized study that enrolled 650 ARV-naive adults between December 2002 and 2004. The study is a 3 × 2 × 2 factorial design comparing the efficacy and tolerability among factors: (1) 3 combinations of nucleoside reverse transcriptase inhibitors (NRTIs): zidovudine (ZDV) + lamivudine (3TC), ZDV + didanosine (ddI), and stavudine (d4T) + 3TC; (2) 2 different nonnucleoside reverse transcriptase inhibitors (NNRTIs): nevirapine and efavirenz; and (3) 2 different adherence strategies: the current national “standard of care” versus an “intensified adherence strategy” incorporating a “community-based directly observed therapy.” Study patients were stratified into 2 balanced CD4+ T-cell count groups: less than 201 versus 201-350 cells per cubic millimeter with viral load greater than 55,000 copies per milliliter. Following Data Safety Monitoring Board recommendations in April 2006, ZDV/ddI-containing arms were discontinued due to inferiority in primary end point, namely, virologic failure with resistance. We report both overall data and pooled data from patients receiving ZDV/ddI- versus ZDV/3TC- and d4T/3TC-containing cART through April 1, 2006. Results:Four hundred fifty-one females (69.4%) and 199 males with a median age of 33.3 years were enrolled into the study. The median follow-up as of April 1, 2006, was 104 weeks, and loss to follow-up rate at 2 years was 4.1%. The median baseline CD4+ T-cell count was 199 cells per cubic millimeter [interquartile ratio (IQR) 136-252], and the median plasma HIV-1 RNA level was 193,500 copies per milliliter (IQR 69-250, 472-500). The proportion of participants with virologic failure and genotypic resistance mutations was 11% in those receiving ZDV/ddI-based cART versus 2% in those receiving either ZDV/3TC- or d4T/3TC-based cART (P = 0.002). The median CD4+ T-cell count increase at 1 year was 137 cells per cubic millimeter (IQR 74-223) and 199 cells per cubic millimeter (IQR 112-322) at 2 years with significantly lower gain in the ZDV/ddI arm. At 1 and 2 years, respectively, 92.0% and 88.8% of patients had an undetectable plasma HIV-1 RNA level (≤400 copies/mL). Kaplan-Meier survival estimates at 1 and 2 years were 96.6% and 95.4%. One hundred twenty patients (18.2%) had treatment-modifying toxicities, of which the most common were lipodystrophy, anemia, neutropenia, and Stevens-Johnson syndrome. There was a trend toward difference in time to treatment-modifying toxicity by pooled dual-NRTI combination and no difference in death rates. Conclusions:The preliminary study results show overall excellent efficacy and tolerability of NNRTI-based cART among HIV-1 subtype C-infected adults. ZDV/ddI-containing cART, however, is inferior to the dual NRTIs d4T/3TC or ZDV/3TC when used with an NNRTI for first-line cART.

HIV-1 Subtype C-Infected Individuals Maintaining High Viral Load as Potential Targets for the “Test-and-Treat” Approach to Reduce HIV Transmission

The first aim of the study is to assess the distribution of HIV-1 RNA levels in subtype C infection. Among 4,348 drug-naïve HIV-positive individuals participating in clinical studies in Botswana, the median baseline plasma HIV-1 RNA levels differed between the general population cohorts (4.1–4.2 log10) and cART-initiating cohorts (5.1–5.3 log10) by about one log10. The proportion of individuals with high (≥50,000 (4.7 log10) copies/ml) HIV-1 RNA levels ranged from 24%–28% in the general HIV-positive population cohorts to 65%–83% in cART-initiating cohorts. The second aim is to estimate the proportion of individuals who maintain high HIV-1 RNA levels for an extended time and the duration of this period. For this analysis, we estimate the proportion of individuals who could be identified by repeated 6- vs. 12-month-interval HIV testing, as well as the potential reduction of HIV transmission time that can be achieved by testing and ARV treating. Longitudinal analysis of 42 seroconverters revealed that 33% (95% CI: 20%–50%) of individuals maintain high HIV-1 RNA levels for at least 180 days post seroconversion (p/s) and the median duration of high viral load period was 350 (269; 428) days p/s. We found that it would be possible to identify all HIV-infected individuals with viral load ≥50,000 (4.7 log10) copies/ml using repeated six-month-interval HIV testing. Assuming individuals with high viral load initiate cART after being identified, the period of high transmissibility due to high viral load can potentially be reduced by 77% (95% CI: 71%–82%). Therefore, if HIV-infected individuals maintaining high levels of plasma HIV-1 RNA for extended period of time contribute disproportionally to HIV transmission, a modified “test-and-treat” strategy targeting such individuals by repeated HIV testing (followed by initiation of cART) might be a useful public health strategy for mitigating the HIV epidemic in some communities.

Transmission of single and multiple viral variants in primary HIV-1 subtype C infection.

To address whether sequences of viral gag and env quasispecies collected during the early post-acute period can be utilized to determine multiplicity of transmitted HIVs, recently developed approaches for analysis of viral evolution in acute HIV-1 infection [1], [2] were applied. Specifically, phylogenetic reconstruction, inter- and intra-patient distribution of maximum and mean genetic distances, analysis of Poisson fitness, shape of highlighter plots, recombination analysis, and estimation of time to the most recent common ancestor (tMRCA) were utilized for resolving multiplicity of HIV-1 transmission in a set of viral quasispecies collected within 50 days post-seroconversion (p/s) in 25 HIV-infected individuals with estimated time of seroconversion. The decision on multiplicity of HIV infection was made based on the models fit with, or failure to explain, the observed extent of viral sequence heterogeneity. The initial analysis was based on phylogeny, inter-patient distribution of maximum and mean distances, and Poisson fitness, and was able to resolve multiplicity of HIV transmission in 20 of 25 (80%) cases. Additional analysis involved distribution of individual viral distances, highlighter plots, recombination analysis, and estimation of tMRCA, and resolved 4 of the 5 remaining cases. Overall, transmission of a single viral variant was identified in 16 of 25 (64%) cases, and transmission of multiple variants was evident in 8 of 25 (32%) cases. In one case multiplicity of HIV-1 transmission could not be determined. In primary HIV-1 subtype C infection, samples collected within 50 days p/s and analyzed by a single-genome amplification/sequencing technique can provide reliable identification of transmission multiplicity in 24 of 25 (96%) cases. Observed transmission frequency of a single viral variant and multiple viral variants were within the ranges of 64% to 68%, and 32% to 36%, respectively.

Viral load and CD4+ T-cell dynamics in primary HIV-1 subtype C infection.

Background:Most knowledge of primary HIV-1 infection is based on subtype B studies, whereas the evolution of viral parameters in the early phase of HIV-1 subtype C infection is not well characterized. Methods:The kinetics of viral RNA, proviral DNA, CD4+ T-cell count, and subsets of CD4+ T cells expressing CCR5 or CXCR4 were characterized in 8 acute and 62 recent subtype C infections over the first year postseroconversion. Results:The viral RNA peak was 6.25 ± 0.92 log10 copies per milliliter. After seroconversion, heterogeneity among acute cases was evident by patterns of change in viral load and CD4+ T-cell count over time. The patterns were supported by the rate of viral RNA decline from peak (P = 0.022), viral RNA means (P = 0.005), CD4 levels (P < 0.001), and CD4 decline to 350 (P = 0.011) or 200 (P = 0.046). Proviral DNA had no apparent peak and its mean was 2.59 ± 0.69 log10 per 106 peripheral blood mononuclear cell. In recent infections, viral RNA set point was 4.00 ± 0.97 log10 and viral RNA correlated inversely with CD4+ T cells (P < 0.001) and directly with proviral DNA (P < 0.001). Conclusions:Distinct patterns of viral RNA evolution may exist shortly after seroconversion in HIV-1 subtype C infection. The study provides better understanding of the early phase of subtype C infection.

Length of secondary schooling and risk of HIV infection in Botswana: evidence from a natural experiment

Background An estimated 2·3 Million individuals are newly infected with HIV each year. Existing cross-sectional and longitudinal studies have found conflicting evidence on the association between education and HIV risk, and no randomized experiment to date has identified a causal effect of education on HIV incidence. Methods A 1996 policy reform changed the grade structure of secondary school in Botswana and increased educational attainment. We use this reform as a ‘natural experiment’ to identify the causal effect of schooling on HIV infection. Data on HIV biomarkers and demographics were obtained from the 2004 and 2008 Botswana AIDS Impact Surveys, nationally-representative household surveys (N = 7018). The association between years of schooling and HIV status was described using multivariate OLS regression models. Using exposure to the policy reform as an instrumental variable, we estimated the causal effect of years of schooling on the cumulative probability that an individual contracted HIV up to his or her age at the time of the survey. The cost-effectiveness of secondary schooling as an HIV prevention intervention was assessed in comparison to other established interventions. Findings Each additional year of secondary schooling induced by the policy change led to an absolute reduction in the cumulative risk of HIV infection of 8·1% points (p = 0·008), relative to a baseline prevalence of 25·6%. Effects were particularly large among women (11·6% points, p = 0·046). Results were robust to a wide array of sensitivity analyses. Secondary school was cost-effective as an HIV prevention intervention by standard metrics. Interpretation Additional years of secondary schooling had a large protective effect against HIV risk, particularly for women, in Botswana. Increasing progression through secondary school may be a cost-effective HIV prevention measure in HIV-endemic settings, in addition to yielding other societal benefits. Funding Takemi Program in International Health at the Harvard School of Public Health, Belgian American Educational Foundation, and Fernand Lazard Foundation.

Increased risk of severe infant anemia after exposure to maternal HAART, Botswana.

Background:Maternal highly-active antiretroviral therapy (HAART) reduces mother-to-child HIV transmission but may increase the risk for infant anemia. Methods:The incidence of first severe anemia (grade 3 or 4, Division of AIDS 2004 Toxicity Table) was assessed among HIV-uninfected infants in the Mashi and Mma Bana mother-to-child HIV transmission prevention trials in Botswana. Severe anemia rates were compared between 3 groups: infants exposed to maternal HAART in utero and during breastfeeding (BF) and 1 month of postnatal zidovudine (ZDV) (HAART-BF); infants exposed to maternal ZDV in utero, 6 months of postnatal ZDV, and BF (ZDV-BF); and infants exposed to maternal ZDV in utero, 1 month of postnatal ZDV, and formula-feeding (ZDV-FF). Results:A total of 1719 infants were analyzed-691 HAART-BF, 503 ZDV-BF, and 525 ZDV-FF. Severe anemia was detected in 118 infants (7.4%). By 6 months, 12.5% of HAART-BF infants experienced severe anemia, compared with 5.3% of ZDV-BF (P < 0.001) and 2.5% of ZDV-FF infants (P < 0.001). In adjusted analysis, HAART-BF infants were at greater risk of severe anemia than ZDV-BF or ZDV-FF infants (adjusted odds ratios 2.6 and 5.8, respectively; P < 0.001). Most anemias were asymptomatic and improved with iron/multivitamin supplementation and cessation of ZDV exposure. However, 11 infants (0.6% of all infants) required transfusion for symptomatic anemia. Microcytosis and hypochromia were common among infants with severe anemia. Conclusions:Exposure to maternal HAART starting in utero was associated with severe infant anemia. Confirmation of this finding and possible strategies to mitigate hematologic toxicity warrant further study.