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1.  Rapid Disease Progression in HIV-1 Subtype C–Infected South African Women 
This study shows that one-third of HIV subtype C–infected women require antiretroviral therapy within 12 months of infection, increasing to 69% if the initiation CD4 count is 500 cells/µL. This has significant implications for program implementation, resource allocation, and HIV prevention.
Background. Whereas human immunodeficiency virus (HIV) subtype B–infected individuals generally progress to AIDS within 8–10 years, limited data exist for other clades, especially from Africa. We investigated rates of HIV disease progression of clade C–infected South African women.
Methods. Prospective seroincidence cohorts in KwaZulu-Natal were assessed for acute HIV infection monthly (n = 245) or every 3 months (n = 594) for up to 4 years. Rapid disease progression was defined as CD4 decline to <350 cells/µL by 2 years postinfection. Serial clinical and laboratory assessments were compared using survival analysis and logistic regression models.
Results. Sixty-two women were identified at a median of 42 days postinfection (interquartile range, 34–59), contributing 282 person-years of follow-up. Mean CD4 count dropped by 39.6% at 3 months and 46.7% at 6 months postinfection in women with preinfection measurements. CD4 decline to <350 cells/µL occurred in 31%, 44%, and 55% of women at 1, 2, and 3 years postinfection, respectively, and to <500 cells/µL in 69%, 79%, and 81% at equivalent timepoints. Predictors of rapid progression were CD4 count at 3 months postinfection (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.31–3.28; P = .002), setpoint viral load (HR, 3.82; 95% CI, 1.51–9.67; P = .005), and hepatitis B coinfection (HR, 4.54; 95% CI, 1.31–15.69; P = .017). Conversely, presence of any of HLAB*1302, B*27, B*57, B*5801, or B*8101 alleles predicted non–rapid progression (HR, 0.19; 95% CI, .05–.74; P = .016).
Conclusions. Nearly half of subtype C–infected women progressed to a CD4 count <350 cells/µL within 2 years of infection. Implementing 2013 World Health Organization treatment guidelines (CD4 count <500 cells/µL) would require most individuals to start antiretroviral therapy within 1 year of HIV infection.
PMCID: PMC4271037  PMID: 25038116
HIV disease progression; acute HIV infection; subtype C; viral load; women
3.  Evolution of Extensively Drug-Resistant Tuberculosis over Four Decades: Whole Genome Sequencing and Dating Analysis of Mycobacterium tuberculosis Isolates from KwaZulu-Natal 
PLoS Medicine  2015;12(9):e1001880.
The continued advance of antibiotic resistance threatens the treatment and control of many infectious diseases. This is exemplified by the largest global outbreak of extensively drug-resistant (XDR) tuberculosis (TB) identified in Tugela Ferry, KwaZulu-Natal, South Africa, in 2005 that continues today. It is unclear whether the emergence of XDR-TB in KwaZulu-Natal was due to recent inadequacies in TB control in conjunction with HIV or other factors. Understanding the origins of drug resistance in this fatal outbreak of XDR will inform the control and prevention of drug-resistant TB in other settings. In this study, we used whole genome sequencing and dating analysis to determine if XDR-TB had emerged recently or had ancient antecedents.
Methods and Findings
We performed whole genome sequencing and drug susceptibility testing on 337 clinical isolates of Mycobacterium tuberculosis collected in KwaZulu-Natal from 2008 to 2013, in addition to three historical isolates, collected from patients in the same province and including an isolate from the 2005 Tugela Ferry XDR outbreak, a multidrug-resistant (MDR) isolate from 1994, and a pansusceptible isolate from 1995. We utilized an array of whole genome comparative techniques to assess the relatedness among strains, to establish the order of acquisition of drug resistance mutations, including the timing of acquisitions leading to XDR-TB in the LAM4 spoligotype, and to calculate the number of independent evolutionary emergences of MDR and XDR. Our sequencing and analysis revealed a 50-member clone of XDR M. tuberculosis that was highly related to the Tugela Ferry XDR outbreak strain. We estimated that mutations conferring isoniazid and streptomycin resistance in this clone were acquired 50 y prior to the Tugela Ferry outbreak (katG S315T [isoniazid]; gidB 130 bp deletion [streptomycin]; 1957 [95% highest posterior density (HPD): 1937–1971]), with the subsequent emergence of MDR and XDR occurring 20 y (rpoB L452P [rifampicin]; pncA 1 bp insertion [pyrazinamide]; 1984 [95% HPD: 1974–1992]) and 10 y (rpoB D435G [rifampicin]; rrs 1400 [kanamycin]; gyrA A90V [ofloxacin]; 1995 [95% HPD: 1988–1999]) prior to the outbreak, respectively. We observed frequent de novo evolution of MDR and XDR, with 56 and nine independent evolutionary events, respectively. Isoniazid resistance evolved before rifampicin resistance 46 times, whereas rifampicin resistance evolved prior to isoniazid only twice. We identified additional putative compensatory mutations to rifampicin in this dataset. One major limitation of this study is that the conclusions with respect to ordering and timing of acquisition of mutations may not represent universal patterns of drug resistance emergence in other areas of the globe.
In the first whole genome-based analysis of the emergence of drug resistance among clinical isolates of M. tuberculosis, we show that the ancestral precursor of the LAM4 XDR outbreak strain in Tugela Ferry gained mutations to first-line drugs at the beginning of the antibiotic era. Subsequent accumulation of stepwise resistance mutations, occurring over decades and prior to the explosion of HIV in this region, yielded MDR and XDR, permitting the emergence of compensatory mutations. Our results suggest that drug-resistant strains circulating today reflect not only vulnerabilities of current TB control efforts but also those that date back 50 y. In drug-resistant TB, isoniazid resistance was overwhelmingly the initial resistance mutation to be acquired, which would not be detected by current rapid molecular diagnostics employed in South Africa that assess only rifampicin resistance.
Editors' Summary
Tuberculosis (TB)—a contagious bacterial disease that usually infects the lungs—is a global public health problem. Every year, about 9 million people develop active TB disease, and 1.5 million people die from the disease. Mycobacterium tuberculosis, the organism that causes TB, is spread in airborne droplets when people with TB cough. The symptoms of TB include cough, weight loss, and fever. Diagnostic tests for the disease include sputum smear microscopy (microscopic analysis of mucus coughed up from the lungs) and chest X-rays. TB can be cured by taking a regimen of multiple antibiotics daily for 6 mo. However, the emergence of multidrug-resistant tuberculosis (MDR-TB, TB with resistance to both isoniazid and rifampicin) and extensively drug-resistant tuberculosis (XDR-TB, MDR-TB with additional resistance to both quinolones and second-line injectable agents), together with the spread of HIV (which increases susceptibility to TB), is now threatening TB control efforts. MDR-TB is caused by M. tuberculosis strains that have acquired mutations (genetic changes) that make them resistant to isoniazid, rifampicin, and sometimes other anti-TB drugs; XDR-TB is caused by bacteria that are resistant to isoniazid, rifampicin, one or more fluoroquinolones (for example, ofloxacin), and at least one injectable second-line drug (for example, kanamycin).
Why Was This Study Done?
A better understanding of the origins of drug-resistant TB is essential for effective control of TB. Public health experts need to know whether the emergence of drug-resistant TB is caused by inadequacies in TB control or related to other factors such as the spread of HIV and whether new resistant strains of M. tuberculosis repeatedly emerge during XDR-TB outbreaks or whether the transmission of a single drug-resistant strain drives these outbreaks. Here, the researchers use whole genome sequencing and dating analysis to investigate the origin and evolution of an XDR-TB outbreak identified in 2005 in Tugela Ferry, KwaZulu-Natal, South Africa. The predominant strain of XDR M. tuberculosis isolated during this large XDR-TB outbreak belongs to a subfamily called LAM4. Since the outbreak began, XDR-TB has also been reported in hospitals across KwaZulu-Natal, and some of these outbreaks have been caused by bacterial strains not falling within the LAM4 spoligotype (“spoligotyping” characterizes M. tuberculosis strains based on the presence of unique DNA sequences in a specific region of the bacterial genome).
What Did the Researchers Do and Find?
The researchers tested the antibiotic susceptibility of 337 clinical isolates of M. tuberculosis collected in KwaZulu-Natal between 2008 and 2013 and of three historical isolates—two collected in the province in the mid-1990s and a third from the Tugela Ferry XDR outbreak. They sequenced the whole genome of these isolates and used comparative techniques to assess the isolates’ relatedness and to investigate the acquisition of drug resistance. This analysis revealed a 50-member clone of XDR bacteria among the isolates collected across KwaZulu-Natal that was highly related to the LAM4 strain (a clone is defined here as a set of strains in which each member differs by no more than ten single nucleotide polymorphisms [SNPs] from at least one other member; an SNP is a type of genetic variant). Mutations that conferred isoniazid resistance in this clone were acquired in about 1957; MDR and XDR strains emerged in about 1984 and 1995, respectively. The analysis also indicates that MDR and XDR evolved de novo 56 times and nine times, respectively, and that isoniazid resistance nearly always evolved before rifampicin resistance.
What Do These Findings Mean?
These findings provide new information about the ordering and timing of the acquisition of drug-resistance mutations by M. tuberculosis in KwaZulu-Natal but do not necessarily represent the evolution of XDR-TB in other settings. Most notably, these findings indicate that the ancestral precursor of the Tugela Ferry XDR outbreak strain gained resistance to first-line antibiotics shortly after these antibiotics became available for clinical use. Subsequent stepwise accumulation of additional resistance mutations that occurred over decades led to the emergence of MDR and XDR strains. Importantly, the emergence of these strains occurred before the explosion of HIV in KwaZulu-Natal. Thus, these findings highlight the dire repercussions of the failure of historic attempts to control resistance to first-line anti-TB drugs and draw attention to the need for new anti-TB drugs to be used prudently to prevent early fixation of resistance and to protect the useful lifespan of these agents. Finally, the finding that isoniazid resistance is a key initiation event for progression to MDR and XDR suggests that TB control programs should test routinely for both isoniazid and rifampicin resistance to ensure early detection of drug-resistant TB.
Additional Information
This list of resources contains links that can be accessed when viewing the PDF on a device or via the online version of the article at
The World Health Organization (WHO) provides information (in several languages) on TB and on MDR-TB; the Global Tuberculosis Report 2014 provides information about TB around the world; a supplement to the report entitled “Drug-Resistant TB—Surveillance and Response” is available
The Stop TB Partnership is working towards TB elimination and provides personal stories about TB (in English and Spanish)
The United States Centers for Disease Control and Prevention provides information about TB and about drug-resistant TB (in English and Spanish)
The US National Institute of Allergy and Infectious Diseases also has detailed information on TB, including a drug-resistant TB visual tour
TB & Me, a collaborative blogging project run by patients being treated for MDR-TB and Mèdecins sans Frontiéres, provides more patient stories
The not-for-profit organization Global Health Education provides information about TB in South Africa
MedlinePlus has links to further information about TB (in English and Spanish)
PMCID: PMC4587932  PMID: 26418737
4.  Continued Follow-Up of Phambili Phase 2b Randomized HIV-1 Vaccine Trial Participants Supports Increased HIV-1 Acquisition among Vaccinated Men 
PLoS ONE  2015;10(9):e0137666.
The Phase 2b double-blinded, randomized Phambili/HVTN 503 trial evaluated safety and efficacy of the MRK Ad5 gag/pol/nef subtype B HIV-1 preventive vaccine vs placebo in sexually active HIV-1 seronegative participants in South Africa. Enrollment and vaccinations stopped and participants were unblinded but continued follow-up when the Step study evaluating the same vaccine in the Americas, Caribbean, and Australia was unblinded for non-efficacy. Final Phambili analyses found more HIV-1 infections amongst vaccine than placebo recipients, impelling the HVTN 503-S recall study.
HVTN 503-S sought to enroll all 695 HIV-1 uninfected Phambili participants, provide HIV testing, risk reduction counseling, physical examination, risk behavior assessment and treatment assignment recall. After adding HVTN 503-S data, HIV-1 infection hazard ratios (HR vaccine vs. placebo) were estimated by Cox models.
Of the 695 eligible, 465 (67%) enrolled with 230 from the vaccine group and 235 from the placebo group. 38% of the 184 Phambili dropouts were enrolled. Enrollment did not differ by treatment group, gender, or baseline HSV-2. With the additional 1286 person years of 503-S follow-up, the estimated HR over Phambili and HVTN 503-S follow-up was 1.52 (95% CI 1.08–2.15, p = 0.02, 82 vaccine/54 placebo infections). The HR was significant for men (HR = 2.75, 95% CI 1.49, 5.06, p = 0.001) but not for women (HR = 1.12, 95% CI 0.73, 1.72, p = 0.62).
The additional follow-up from HVTN 503-S supported the Phambili finding of increased HIV-1 acquisition among vaccinated men and strengthened the evidence of lack of vaccine effect among women.
Trial Registration NCT00413725
SA National Health Research Database DOH-27-0207-1539
PMCID: PMC4569275  PMID: 26368824
5.  High Prevalence of inhA Promoter Mutations among Patients with Drug-Resistant Tuberculosis in KwaZulu-Natal, South Africa 
PLoS ONE  2015;10(9):e0135003.
Drug-resistant tuberculosis (TB) remains extremely difficult to treat because there are often few remaining active medications and limited diagnostic options to detect resistance. Resistance to isoniazid is typically caused by mutations in either katG or the inhA promoter. inhA mutations confer low-level resistance to isoniazid and cross-resistance to ethionamide while katG mutations confer high-level isoniazid resistance and no cross-resistance. Line Probe Assays (LPAs) that detect mutations in katG and inhA are currently performed on all positive TB cultures in KwaZulu-Natal province, South Africa, but the frequency of inhA mutations in drug-resistant TB patients has not been examined.
We sought to determine the proportion of patients who could potentially benefit from high-dose isoniazid and who may be resistant to ethionamide. We reviewed 994 LPA (Hain MTBDRplus) results at the TB reference laboratory in KwaZulu-Natal to determine the frequency of mutations in either katG or the inhA promoter. We stratified these results by drug-resistance category (i.e., MDR-TB, pre-XDR-TB, and XDR-TB) as determined by phenotypic drug-susceptibility testing.
Among MDR- and XDR-TB isolates, the prevalence of inhA mutations without a concurrent katG mutation was 14.8% and 10.3% respectively. The prevalence of inhA mutations with OR without a katG mutation was 30.3% and 82.8%, respectively.
More than 10% of patients with MDR- and XDR-TB may benefit from high-dose isoniazid. Although ethionamide is empirically included in all MDR- and XDR-TB regimens, nearly a third of MDR-TB patients and a majority of XDR-TB patients likely have resistance to ethionamide. Laboratories performing line probe assays should report specific band patterns so that clinicians may adjust treatment regimens accordingly.
PMCID: PMC4557915  PMID: 26332235
6.  Impact of Antiretroviral Therapy on Health-Related Quality of Life among South African Women in the CAPRISA 002 Acute Infection Study 
AIDS and behavior  2014;18(9):1801-1807.
Concerns are often raised regarding potentially adverse effects of antiretroviral therapy (ART) on health-related quality of life (HRQoL), but there is limited longitudinal data to prove this. Building on our prior investigation, we examined the impact of ART on HRQoL among HIV-infected South African women with extensive follow-up in the CAPRISA 002 Acute Infection Cohort Study. Overall HRQoL and five sub-domains [physical well-being (PWB), emotional well-being (EWB), functional and global well-being (FGWB), social well-being (SWB) and cognitive functioning (CF)] were assessed using the Functional Assessment of HIV Infection (FAHI) instrument. Our analyses comparing FAHI scores between pre-ART (established infection) and ART phases using paired Wilcoxon signed-rank tests and adjusted mixed-effects regression models revealed improvements on ART in overall HRQoL, and in PWB, EWB, and SWB, but not in FGWB and CF. No long-term adverse impact of ART on HRQoL was detected, providing additional non-biomedical support to early treatment strategies.
PMCID: PMC4127113  PMID: 24849623
Health-related quality of life; South Africa; Acute HIV infection; Functional assessment of HIV infection; ART
7.  Incidence and Geographic Distribution of Extensively Drug-Resistant Tuberculosis in KwaZulu-Natal Province, South Africa 
PLoS ONE  2015;10(7):e0132076.
South Africa is experiencing a widespread drug-resistant tuberculosis epidemic, although data are limited regarding the current situation. This study finds that the extensively drug-resistant tuberculosis (XDR-TB) incidence in KwaZulu-Natal increased to 3.5 cases/100,000 (776 cases) in 2011-2012. XDR-TB cases are widely distributed geographically, with the majority of districts experiencing a rise in incidence.
PMCID: PMC4493033  PMID: 26147963
8.  Health-Related Quality of Life Dynamics of HIV-positive South African Women up to ART Initiation: Evidence from the CAPRISA 002 Acute Infection Cohort Study 
AIDS and behavior  2014;18(6):1114-1123.
Few studies have investigated the long-term dynamics in health-related quality of life (HRQoL) among HIV-positive persons from acute infection. From 2004, 160 women were enrolled into the CAPRISA 002 Acute Infection study at two sites in the province of KwaZulu-Natal and underwent 3–6 monthly HRQoL assessments using the functional assessment of HIV infection (FAHI) instrument. Overall and 5 sub-scale FAHI scores [physical well-being (PWB), emotional well-being (EWB), functional and global well-being (FGWB), social well-being (SWB) and cognitive functioning (CF)] were calculated up to antiretroviral therapy (ART) initiation and scores at enrollment were compared to the acute, early and established infection phases. Mixed-effects regression models adjusting for behavioral and clinical factors were applied to assess HRQoL trends and the proportion of women meeting minimally important differences was calculated. Our analyses revealed that overall/sub-scale scores improved over time, except from PWB and CF. A higher educational status, contraceptive use and a higher BMI were the strongest predictors of higher overall/sub-scale FAHI scores. CD4 count and HIV viral load were strongly associated with PWB and CF, but not overall FAHI and other sub-scales. Women newly diagnosed with acute HIV infection face profound HRQoL challenges. While early ART delivery may be important for PWB and CF, factors such as education, contraception provision and good nutritional status should be promoted to maximize HRQoL in HIV positive individuals.
PMCID: PMC4020968  PMID: 24368630
Health-related quality of life; South Africa; Acute HIV infection; Functional assessment of HIV infection
9.  The phase 2b HVTN 503/Phambili study test-of-concept HIV vaccine study, investigating a recombinant adenovirus type 5 HIV gag/pol/nef vaccine in South Africa: unblinded, long-term follow-up 
The Lancet. Infectious diseases  2014;14(5):388-396.
The Phambili study, conducted in South Africa amongst a predominantly heterosexual population, evaluated the efficacy of the MRK Ad5 gag/pol/nef subtype B HIV-1 preventive vaccine. Enrollment and vaccinations were stopped, participants unblinded, and follow-up extended when the Step study evaluating the same vaccine in the Americas, Caribbean and Australia was unblinded for non-efficacy with more HIV infections amongst vaccinee than placebo recipients [ZM1]. Extensive analyses over the complete follow-up period, most of which was unblinded, are reported.
Phambili participants were HIV-1 uninfected, sexually active men and women aged 18–35 years, followed for 3.5 years. HIV testing and risk reduction counseling occurred at weeks 0, 12, 30 and were switched to a 3 monthly schedule after unblinding. Cox proportional hazards models were used to estimate HIV-1 infection hazard ratios (HR) comparing vaccine to placebo recipients, overall and within subgroups. Long-term vaccine efficacy was evaluated in participants who were unblinded early in follow-up.
Of the 801 participants enrolled (400 vaccine, 401 placebo), 112 (28%) received 1 vaccination, 259 (65%) 2 vaccinations and 29(7%) 3 vaccinations. More infections occurred in vaccinees (n=63) as compared to placebo (n=37) (adjusted HR (vaccine:placebo) 1.70, 95% CI 1.13–2.55, p = 0.01). We found no increase in infections with the number of vaccinations received and that the HRs did not differ by gender, circumcision, or Ad5 serostatus. Differences in risk behavior at baseline or during the study, or differential drop-out (p=0.40) are unlikely explanations for the increased rate of HIV-1 infections seen in vaccinees.
The increased HR of HIV-1 acquisition, irrespective of number of doses received, warrants further investigation to understand the biological mechanism. Further use of the Ad5 vector for HIV vaccines is not warranted
PMCID: PMC4174314  PMID: 24560541
HIV; rAd5 HIV vaccines; HIV-1 vaccine efficacy studies; South Africa
10.  Posttraumatic Brain Abscess Caused by Aeromonas hydrophila 
Journal of Clinical Microbiology  2014;52(5):1796-1797.
Posttraumatic brain abscesses are usually caused by Gram-negative bacilli, notably Enterobacteriaceae and Staphylococcus aureus. Although Aeromonas hydrophila is a recognized cause of trauma-related sepsis, it has not been previously isolated from posttraumatic brain abscesses. We describe the first case of Aeromonas hydrophila brain abscess.
PMCID: PMC3993702  PMID: 24622098
11.  TRIM5α and TRIM22 Are Differentially Regulated According to HIV-1 Infection Phase and Compartment 
Journal of Virology  2014;88(8):4291-4303.
The antiviral role of TRIM E3 ligases in vivo is not fully understood. To test the hypothesis that TRIM5α and TRIM22 have differential transcriptional regulation and distinct anti-HIV roles according to infection phase and compartment, we measured TRIM5α, TRIM22, and type I interferon (IFN-I)-inducible myxovirus resistance protein A (MxA) levels in peripheral blood mononuclear cells (PBMCs) during primary and chronic HIV-1 infection, with chronic infection samples being matched PBMCs and central nervous system (CNS)-derived cells. Associations with biomarkers of disease progression were explored. The impact of IFN-I, select proinflammatory cytokines, and HIV on TRIM E3 ligase-specific expression was investigated. PBMCs from individuals with primary and chronic HIV-1 infection had significantly higher levels of MxA and TRIM22 than did PBMCs from HIV-1-negative individuals (P < 0.05 for all comparisons). PBMCs from chronic infection had lower levels of TRIM5α than did PBMCs from primary infection or HIV-1-uninfected PBMCs (P = 0.0001 for both). In matched CNS-derived samples and PBMCs, higher levels of MxA (P = 0.001) and TRIM5α (P = 0.0001) in the CNS were noted. There was a negative correlation between TRIM22 levels in PBMCs and plasma viral load (r = −0.40; P = 0.04). In vitro, IFN-I and, rarely, proinflammatory cytokines induced TRIM5α and TRIM22 in a cell type-dependent manner, and the knockdown of either protein in CD4+ lymphocytes resulted in increased HIV-1 infection. These data suggest that there are infection-phase-specific and anatomically compartmentalized differences in TRIM5α and TRIM22 regulation involving primarily IFN-I and specific cell types and indicate subtle differences in the antiviral roles and transcriptional regulation of TRIM E3 ligases in vivo.
IMPORTANCE Type I interferon-inducible TRIM E3 ligases are a family of intracellular proteins with potent antiviral activities mediated through diverse mechanisms. However, little is known about the contribution of these proteins to antiviral immunity in vivo and how their expression is regulated. We show here that TRIM5α and TRIM22, two prominent members of the family, have different expression patterns in vivo and that the expression pattern depends on HIV-1 infection status and phase. Furthermore, expression differs in peripheral blood versus central nervous system anatomical sites of infection. Only TRIM22 expression correlated negatively with HIV-1 viral load, but gene silencing of both proteins enhances HIV-1 infection of target cells. We report subtle differences in TRIM5α and TRIM22 gene induction by IFN-I and proinflammatory cytokines in CD4+ lymphocytes, monocytes, and neuronal cells. This study enhances our understanding of antiviral immunity by intrinsic antiviral factors and how their expression is determined.
PMCID: PMC3993776  PMID: 24478420
12.  Effects of introducing Xpert MTB/RIF test on multi-drug resistant tuberculosis diagnosis in KwaZulu-Natal South Africa 
BMC Infectious Diseases  2014;14:442.
An algorithm instituted following Xpert MTB/RIF (Xpert) introduction in South Africa advocates for treating all Xpert rifampicin resistant patients as MDR-TB cases while awaiting confirmation by phenotypic or genotypic drug susceptibility testing. This study evaluates how the Xpert has influenced the diagnosis and management of drug resistant TB in the highest burdened district of KwaZulu-Natal Province.
Data was retrospectively collected from all patients with rifampicin resistance on Xpert performed between March 2011 and April 2012. Xpert results were compared with those of phenotypic and/genotypic drug susceptibility testing. Patients’ records were used to determine the time to treatment initiation.
Out of 637 patients tested by Xpert, 50% had confirmatory results, of which a third were sent on the same day as Xpert test. The rate of rifampicin discordance and monoresistance was 8.8% and 13.4% respectively and there was no difference between phenotypic and genotypic confirmation. Among those who had been initiated on treatment, 28%, 40%, 21% and 8% of patients commenced within 2 weeks, 1 month, 2 months and 3 months of Xpert testing respectively, while the remaining 3% were observed without treatment.
This study emphasizes the importance of complying with the algorithm in confirming all Xpert rif resistant cases so as to ensure proper management of these patients. Despite the rapidity of the Xpert results, only about 70% of patients had been initiated treatment at one month. Therefore there is a definite need to improve the health systems in order to improve on these delays.
PMCID: PMC4141089  PMID: 25129689
Xpert; Rifampicin; Resistant; MTB; South Africa
13.  Predictors of HVTN 503 MRK-AD5 HIV-1 gag/pol/nef Vaccine Induced Immune Responses 
PLoS ONE  2014;9(8):e103446.
Phambili, the Merck (MRK)-Adenovirus Type 5 (Ad5) HIV-1 gag/pol/nef subtype B vaccine study, conducted in South Africa, suspended enrollment and vaccination when companion study, Step, was found non-efficacious. Although the vaccine did not prevent HIV-1 infection or lower viral-load setpoint, immune responses recognized clades B and C HIV-1 subtypes. We investigated predictors of the vaccine-induced antigen-specific immune responses.
Vaccine-induced immunogenicity was ascertained by interferon-γ ELISpot assays on the first 186 enrolled participants receiving two vaccinations. Analyses, stratified by study arm/sex, were performed on baseline demographics [sex, age, Body Mass Index (BMI), site, Adenovirus Type-5 (Ad5) titer, Herpes Simplex Virus Type-2 (HSV2) status, heavy drinking]. Multivariate logistic regression determined predictors.
Of the 186 participants, 53.7% (n = 100) were female, median BMI was 22.5 [IQR: 20.4–27.0], 85.5% (n = 159) were Ad5 seropositive, and 18.8% (n = 35) drank heavily. All vaccine recipients responded to both clade B (n = 87; 47%) and/or C (n = 74; 40%), p = 0.17. In multivariate analysis, female sex [Adjusted Odds Ratio (AOR): 6.478; p = 0.0159], overweight/obese BMI (AOR: 0.186; p = 0.0452), and heavy drinking (AOR: 0.270; p = 0.048) significantly predicted immune response to clade C for any antigens. A marginally significant predictor of clade C-pol antigen was female sex (AOR: 3.182; p = 0.0500).
Sex, BMI, and heavy drinking affected vaccine-induced HIV-1 specific immune responses to clade C antigens. The role of female sex and overweight/obese BMI boosting and suppressing vaccine-induced HIV-1 specific immune responses, respectively, requires elucidation, including any effect on HIV vaccine efficacy, especially in the era of colliding epidemics (HIV and obesity).
PMCID: PMC4121165  PMID: 25090110
14.  Differential Impact of Magnitude, Polyfunctional Capacity, and Specificity of HIV-Specific CD8+ T Cell Responses on HIV Set Point 
Journal of Virology  2014;88(3):1819-1824.
Defining the characteristics of HIV-specific CD8+ T cell responses that lead to viral control is crucial for vaccine development. We evaluated the differential impact of magnitude, polyfunctional capacity, and specificity of the CD8+ response at approximately 6 months postinfection on the viral set point at 12 months in a cohort of HIV-infected individuals. High frequencies of Gag and Nef responses endowed with four functions were the best predictors of a low viral set point.
PMCID: PMC3911608  PMID: 24227857
15.  The HVTN503/Phambili HIV vaccine trial: a comparison of younger and older participants 
By comparing younger to older participants enrolled in a HIV vaccine efficacy trial, we aimed to gain insights into the inclusion of adolescents in future trials. This was a sub-analysis of a multisite HIV vaccine randomized clinical trial in South Africa, conducted January-September, 2007. Motivations for trial enrollment, social harms, adverse events, and loss to follow-up were compared between younger (18-20 years old) and older participants (21-35 years old). Both younger (n=238) and older participants (n=563) were equally likely to report enrolling for altruistic reasons. Younger females were less likely than older participants to join for trial reimbursement (p=0.005), while younger males were more likely to enroll because the vaccine may provide protection from HIV-acquisition (p<0.001). There were no significant differences in the number of social harms reported. Compared to males over 20 years-old, 18-20-year-old females were less likely to experience adverse events (OR=0.1, CI 0.01-0.80) and no more likely to be lost to follow up (OR=0.7, CI 0.39-1.25), while 18-20-year-old males were no more likely to experience adverse events (OR=1.3, CI 0.58-2.83) or loss to follow-up (OR=0.8, CI 0.51-1.41). Our data support the inclusion of younger participants who are at risk for HIV in future HIV vaccine efficacy trials.
PMCID: PMC3968181  PMID: 24104693
HIV; vaccine trials; clinical trials; youth; South Africa
16.  Rapid, complex adaption of transmitted HIV-1 full-length genomes in subtype C-infected individuals with differing disease progression 
AIDS (London, England)  2013;27(4):507-518.
There is limited information on full-length genome sequences and the early evolution of transmitted HIV-1 subtype C viruses, which constitute the majority of viruses spread in Africa. The purpose of this study was to characterize the earliest changes across the genome of subtype C viruses following transmission, to better understand early control of viremia.
We derived the near full-length genome sequence responsible for clinical infection from five HIV subtype C-infected individuals with different disease progression profiles and tracked adaption to immune responses in the first six months of infection.
Near full-length genomes were generated by single genome amplification and direct sequencing. Sequences were analyzed for amino acid mutations associated with cytotoxic T-lymphocyte (CTL) or antibody (Ab)-mediated immune pressure, and for reversion.
Fifty-five sequence changes associated with adaptation to the new host were identified with 38% attributed to CTL pressure; 35% to antibody pressure; 16% to reversions and the remainder were unclassified. Mutations in CTL epitopes were most frequent in the first 5 weeks of infection, with the frequency declining over time with the decline in viral load. CTL escape predominantly occurred in nef, followed by pol and env. Shuffling/toggling of mutations was identified in 81% of CTL epitopes with only 7% reaching fixation within the six month period.
There was rapid virus adaptation following transmission, predominantly driven by CTL pressure, with most changes occurring during high viremia. Rapid escape and complex escape pathways provide further challenges for vaccine protection.
PMCID: PMC3720865  PMID: 23370465
HIV-1; Africa; genome; acute infection; cytotoxic T-lymphocytes; progression
17.  Rifampicin Mono-Resistance in Mycobacterium tuberculosis in KwaZulu-Natal, South Africa: A Significant Phenomenon in a High Prevalence TB-HIV Region 
PLoS ONE  2013;8(11):e77712.
The dual epidemics of HIV-TB including MDR-TB are major contributors to high morbidity and mortality rates in South Africa. Rifampicin (RIF) resistance is regarded as a proxy for MDR-TB. Currently available molecular assays have the advantage of rapidly detecting resistant strains of MTB, but the GeneXpert does not detect isoniazid (INH) resistance and the GenoTypeMTBDRplus(LPA) assay may underestimate resistance to INH. Increasing proportions of rifampicin mono-resistance resistance (RMR) have recently been reported from South Africa and other countries.
This laboratory based study was conducted at NHLS TB Laboratory, Durban, which is the reference laboratory for culture and susceptibility testing in KwaZulu-Natal. We retrospectively determined, for the period 2007 to 2009, the proportion of RMR amongst Mycobacterium tuberculosis (MTB) isolates, that were tested for both RIF and INH, using the gold standard of culture based phenotypic drug susceptibility testing (DST). Gender and age were also analysed to identify possible risk factors for RMR.
MTB culture positive sputum samples from 16,748 patients were analysed for susceptibility to RIF and INH during the period 2007 to 2009. RMR was defined as MTB resistant to RIF and susceptible to INH. For the purposes of this study, only the first specimen from each patient was included in the analysis.
RMR was observed throughout the study period. The proportion of RMR varied from a low of 7.3% to a high of 10.0% [overall 8.8%]. Overall, males had a 42% increased odds of being RMR as compared to females. In comparison to the 50 plus age group, RMR was 37% more likely to occur in the 25–29 year age category.
We report higher proportions of RMR ranging from 7.3% to 10% [overall 8.8%] than previously reported in the literature. To avoid misclassification of RMR, detected by the GeneXpert, as MDR-TB, culture based phenotypic DST must be performed on a second specimen, as recommended by the SA NDOH TB guidelines as well as WHO. We suggest that two sputum samples should be obtained at the first visit. The second sputum sample should be stored at 4°C. The latter sample is then readily available for performing additional DST (phenotypic or genotypic) for 2nd lines drugs, resulting in a decreased waiting period for DST results to become available.
PMCID: PMC3819362  PMID: 24223122
18.  Symptomatic Vaginal Discharge Is a Poor Predictor of Sexually Transmitted Infections and Genital Tract Inflammation in High-Risk Women in South Africa 
Background. Diagnosis and treatment of sexually transmitted infections (STIs) is a public health priority, particularly in regions where the incidence of human immunodeficiency virus (HIV) infection is high. In most developing countries, STIs are managed syndromically. We assessed the adequacy of syndromic diagnosis of STIs, compared with laboratory diagnosis of STIs, and evaluated the association between STI diagnosis and the risk of HIV acquisition in a cohort of high-risk women.
Methods. HIV-uninfected high-risk women (n = 242) were followed for 24 months. Symptoms of STIs were recorded, and laboratory diagnosis of common STI pathogens was conducted every 6 months. Forty-two cytokines were measured by Luminex in cervicovaginal lavage specimens at enrollment. Human immunodeficiency virus type 1 (HIV-1) infection was evaluated monthly.
Results. Only 12.3% of women (25 of 204) who had a laboratory-diagnosed, discharge-causing STI had clinically evident discharge. Vaginal discharge was thus a poor predictor of laboratory-diagnosed STIs (sensitivity, 12.3%; specificity, 93.8%). Cervicovaginal cytokine concentrations did not differ between women with asymptomatic STIs and those with symptomatic STIs and were elevated in women with asymptomatic STIs, compared with women with no STIs or bacterial vaginosis. Although laboratory-diagnosed STIs were associated with increased risk of HIV infection (hazard ratio, 3.3 [95% confidence interval, 1.5–7.2)], clinical symptoms were not.
Conclusions. Syndromic STI diagnosis dependent on vaginal discharge was poorly predictive of laboratory-diagnosed STI. Laboratory-diagnosed STIs were associated with increased susceptibility to HIV acquisition, while vaginal discharge was not.
PMCID: PMC3490689  PMID: 22517910
19.  Intersubtype Differences in the Effect of a Rare p24 Gag Mutation on HIV-1 Replicative Fitness 
Journal of Virology  2012;86(24):13423-13433.
Certain immune-driven mutations in HIV-1, such as those arising in p24Gag, decrease viral replicative capacity. However, the intersubtype differences in the replicative consequences of such mutations have not been explored. In HIV-1 subtype B, the p24Gag M250I mutation is a rare variant (0.6%) that is enriched among elite controllers (7.2%) (P = 0.0005) and appears to be a rare escape variant selected by HLA-B58 supertype alleles (P < 0.01). In contrast, in subtype C, it is a relatively common minor polymorphic variant (10 to 15%) whose appearance is not associated with a particular HLA allele. Using site-directed mutant viruses, we demonstrate that M250I reduces in vitro viral replicative capacity in both subtype B and subtype C sequences. However, whereas in subtype C downstream compensatory mutations at p24Gag codons 252 and 260 reduce the adverse effects of M250I, fitness costs in subtype B appear difficult to restore. Indeed, patient-derived subtype B sequences harboring M250I exhibited in vitro replicative defects, while those from subtype C did not. The structural implications of M250I were predicted by protein modeling to be greater in subtype B versus C, providing a potential explanation for its lower frequency and enhanced replicative defects in subtype B. In addition to accounting for genetic differences between HIV-1 subtypes, the design of cytotoxic-T-lymphocyte-based vaccines may need to account for differential effects of host-driven viral evolution on viral fitness.
PMCID: PMC3503133  PMID: 23015721
20.  Increased memory differentiation is associated with decreased polyfunctionality for HIV but not for CMV-specific CD8+ T cells 
The generation of polyfunctional CD8+ T cells, in response to vaccination or natural infection, has been associated with improved protective immunity. However, it is unclear whether the maintenance of polyfunctionality is related to particular cellular phenotypic characteristics. To determine whether the cytokine expression profile is linked to the memory differentiation stage, we analyzed the degree of polyfunctionality of HIV-specific CD8+ T cells within different memory subpopulations in 20 ART-naïve HIV-1 infected individuals at approximately 34 weeks post infection. These profiles were compared with CMV-specific CD8+ T cell responses in HIV-uninfected controls and in individuals chronically infected with HIV. Our results showed that the polyfunctional abilities of HIV-specific CD8+ T cells differed according to their memory phenotype. Early-differentiated cells (CD45RO+CD27+) exhibited a higher proportion of cells positive for three or four functions (p<0.001), and a lower proportion of mono-functional cells (p<0.001) compared to terminally-differentiated (CD45RO−CD27−) HIV-specific CD8+ T cells. The majority of terminally-differentiated HIV-specific CD8+ T cells were mono-functional (median 69% [IQR: 57–83]), producing predominantly CD107a or MIP1β. Moreover, proportions of HIV-specific mono-functional CD8+ T cells positively associated with proportions of terminally-differentiated HIV-specific CD8+ T cells (p=0.019, r=0.54). In contrast, CMV-specific CD8+ T cell polyfunctional capacities were similar across all memory subpopulations, with terminally- and early-differentiated cells endowed with comparable polyfunctionality. Overall, these data show that the polyfunctional abilities of HIV-specific CD8+ T cells are influenced by the stage of memory differentiation, which is not the case for CMV-specific responses.
PMCID: PMC3466366  PMID: 22966086
21.  Co-enrollment in multiple HIV prevention trials – Experiences from the CAPRISA 004 Tenofovir gel trial 
Contemporary clinical trials  2011;32(3):333-338.
In settings where multiple HIV prevention trials are conducted in close proximity, trial participants may attempt to enroll in more than one trial simultaneously. Co-enrollment impacts on participant’s safety and validity of trial results. We describe our experience, remedial action taken, inter-organizational collaboration and lessons learnt following the identification of co-enrolled participants.
Between February and April 2008, we identified 185 of the 398 enrolled participants as ineligible. In violation of the study protocol exclusion criteria, there was simultaneous enrollment in another HIV prevention trial (ineligible co-enrolled, n=135), and enrollment of women who had participated in a microbicide trial within the past 12 months (ineligible not co-enrolled, n=50). Following a complete audit of all enrolled participants, ineligible participants were discontinued via study exit visits from trial follow-up. Custom-designed education program on co-enrollment impacting on participants’ safety and validity of the trial results were implemented. Shared electronic database between research units were established to enable verification of each volunteer’s trial participation and to prevent future co-enrollments.
Lessons Learnt
Interviews with ineligible enrolled women revealed that high-quality care; financial incentives; altruistic motives; preference for sex with gel; wanting to increase their likelihood of receiving active gel; perceived low risk of discovery and peer pressure as the reasons for their enrolment in the CAPRISA 004 trial.
Instituting education programs based on the reasons reported by women for seeking enrolment in more than one trial and using a shared central database system to identify co-enrollments have effectively prevented further co-enrollments.
PMCID: PMC3616246  PMID: 21278001
HIV prevention trials; co-enrollment; young women
22.  Genital Tract Inflammation During Early HIV-1 Infection Predicts Higher Plasma Viral Load Set Point in Women 
The Journal of Infectious Diseases  2012;205(2):194-203.
Background. The biggest challenge in human immunodeficiency virus type 1 (HIV-1) prevention in Africa is the high HIV-1 burden in young women. In macaques, proinflammatory cytokine production in the genital tract is necessary for target cell recruitment and establishment of simian immunodeficiency virus (SIV) infection following vaginal inoculation. The purpose of this study was to assess if genital inflammation during early HIV-1 infection predisposes women to rapid disease progression.
Methods. Inflammatory cytokine concentrations were measured in cervicovaginal lavage (CVL) from 49 women 6, 17, 30, and 55 weeks after HIV-1 infection and from 22 of these women before infection. Associations between genital inflammation and viral load set point and blood CD4 cell counts 12 months after infection were investigated.
Results. Elevated genital cytokine concentrations 6 and 17 weeks after HIV-1 infection were associated with higher viral load set points and, to a lesser extent, with CD4 depletion. CVL cytokine concentrations during early infection did not differ relative to preinfection but were elevated in women who had vaginal discharge, detectable HIV-1 RNA in their genital tracts, and lower blood CD4 counts.
Conclusion. Genital inflammation during early HIV-1 infection was associated with higher viral load set point and CD4 depletion, which are markers of rapid disease progression. Strategies aimed at reducing genital inflammation during early HIV-1 infection may slow disease progression.
PMCID: PMC3244362  PMID: 22190580
23.  Short Communication Decreased Incidence of Dual Infections in South African Subtype C-Infected Women Compared to a Cohort Ten Years Earlier 
AIDS Research and Human Retroviruses  2011;27(11):1167-1172.
Previously, we determined the incidence of dual infections in a South African cohort and its association with higher viral setpoint. Ten years later, we compare the incidence and impact of dual infections at transmission on viral setpoint in a geographically similar cohort (n =  46) making use of both the heteroduplex mobility assay (HMA) and the more recent single genome amplification (SGA) approach. HIV incidence was lower in this cohort (7% compared to 18%), and we find a similar reduction in the number of dual infections (9% compared to 19%). Unlike the previous study, there was no association between either dual infection (n =  4) or multivariant transmission (n =  7) and disease progression. This study emphasized the importance of monitoring changes in the HIV epidemic as it may have important ramifications on our understanding of the natural history of disease.
PMCID: PMC3206740  PMID: 21198409
24.  APOBEC3G Expression is Dysregulated in Primary HIV-1 Infection and a Polymorphic Variant Influences CD4+ T Cell Counts and Plasma Viral Load 
AIDS (London, England)  2010;24(2):195-204.
In the absence of HIV-1 Vif, cellular cytosine deaminases such as APOBEC3G, inhibit the virus by inducing hypermutations on viral DNA, among other mechanisms of action. We investigated the association of APOBEC3G mRNA levels and APOBEC3G genetic variants on HIV-1 susceptibility, and early disease pathogenesis using viral load and CD4+ T cell counts as outcomes.
Study subjects were 250 South African females at high risk for HIV-1C infection. We used quantitative real-time PCR to measure the expression of APOBEC3G in HIV−ve and HIV+ve primary infection samples. APOBEC3G variants were identified by DNA re-sequencing and TaqMan genotyping.
We found no correlation between APOBEC3G expression levels and plasma viral loads (r=0.053, p=0.596) or CD4+ T cell counts (r=0.030, p=0.762) in 32 seroconverters. However, APOBEC3G expression levels were significantly higher in HIV−ve individuals compared to HIV+ve individuals (p<0.0001), including matched pre- and post infection samples from the same individuals (n=13, p<0.0001). 25 single nucleotide polymorphisms (SNPs), nine of which were novel, were identified within APOBEC3G by re-sequencing followed by genotyping of 168 individuals. The H186R mutation, a codon changing variant in exon 4, was associated with high viral loads (p=0.0097) and decreased CD4+ T cell levels (p=0.0081).
These data suggest that APOBEC3G transcription is rapidly downregulated upon HIV-1 infection. During primary infection, APOBEC3G expression levels in PBMCs do not correlate with viral loads or CD4+ T cell counts. However, structural variation of APOBEC3G may significantly affect early HIV-1 pathogenesis, although the mechanism remains unclear and warrants further investigation.
PMCID: PMC3470914  PMID: 19996938
APOBEC3G; HIV-1 C; Primary Infection; mRNA Expression; Polymorphisms; Host proteins
25.  Association of Polymorphisms in the LEDGF/p75 Gene (PSIP1) with Susceptibility to HIV-1 Infection and Disease Progression 
AIDS (London, England)  2011;25(14):1711-1719.
LEDGF/p75, encoded by the PSIP1 gene, interacts with HIV-1 integrase and targets HIV-1 integration into active genes. We investigated the influence of polymorphisms in PSIP1 on HIV-1 acquisition and disease progression in black South Africans.
Integrase binding domain (IBD) of LEDGF/p75 was sequenced in 126 participants. Four haplotype tagging SNPs, SNP1-SNP4 and one exonic SNP, SNP5 were genotyped in 195 HIV-1 seronegative, 52 primary and 403 chronically infected individuals using TaqMan assays. LEDGF/p75 expression was quantified by real-time RT-PCR. The impact of Q472L mutation on the interaction with HIV-1 IN was measured by AlphaScreen.
rs2277191A was more frequent among seropositives (p=0.06, Fisher's exact test), and among individuals followed longitudinally trended towards association with higher likelihood of HIV-1 acquisition (RH=2.21, p=0.08; Cox model) and it was also associated with rapid disease progression (RH=5.98, p=0.04; Cox model). rs12339417C was associated with slower decline of CD4+ T cell (p=0.02) and lower levels of LEDGF/p75 (p<0.01). Seroconverters had higher preinfection levels of LEDGF/p75 (p<0.01) but levels decreased after HIV infection (p=0.02).
Genetic variants of PSIP1 may affect HIV-1 outcomes. Further studies are needed to confirm the effect of genetic variation of PSIP1 on HIV-1 pathogenesis in different cohorts.
PMCID: PMC3233670  PMID: 21681054

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