HIV testing rates, prevalence, and knowledge among outpatients in Durban, South Africa: Time trends over four years.

The HIV public health messages in South Africa have increased. Our objective was to evaluate changes over time in HIV testing behaviour, prevalence and knowledge. We prospectively enrolled adults (≥18 years) prior to HIV testing at one urban and one peri-urban outpatient department in Durban, South Africa. A baseline questionnaire administered before testing included the number of prior HIV tests and four knowledge items. We used test results to estimate previously undiagnosed HIV prevalence among those tested. We assessed linear trends over enrollment. From November 2006 to August 2010, 5229 subjects enrolled and 4877 (93%) were HIV tested and had results available. Subjects reporting prior testing over time increased, from 13% in study year 1 to 42% in year 4 (linear trend p < 0.001). The HIV prevalence among those tested declined steadily and significantly over time, from 64% of enrollees in study year 1 to 39% in the final year (linear trend p < 0.001). The percentage of subjects who recognised that medicine can help people with HIV live longer increased from 80% in study year 1 to 96% in study year 4. Rates of HIV testing have increased and prevalence among those tested has decreased in outpatients in Durban, South Africa.

Factors associated with self-reported repeat HIV testing after a negative result in Durban, South Africa.

BACKGROUND: Routine screening for HIV infection leads to early detection and treatment. We examined patient characteristics associated with repeated screening in a high prevalence country. METHODS: We analyzed data from a cohort of 5,229 adults presenting for rapid HIV testing in the outpatient departments of 2 South African hospitals from November 2006 to August 2010. Patients were eligible if they were ≥18 years, reported no previous diagnosis with HIV infection, and not pregnant. Before testing, participants completed a questionnaire including gender, age, HIV testing history, health status, and knowledge about HIV and acquaintances with HIV. Enrollment HIV test results and CD4 counts were abstracted from the medical record. We present prevalence of HIV infection and median CD4 counts by HIV testing history (first-time vs. repeat). We estimated adjusted relative risks (ARR's) for repeat testing by demographics, health status, and knowledge of HIV and others with HIV in a generalized linear model. RESULTS: Of 4,877 participants with HIV test results available, 26% (N = 1258) were repeat testers. Repeat testers were less likely than first-time testers to be HIV-infected (34% vs. 54%, p<0.001). Median CD4 count was higher among repeat than first-time testers (201/uL vs. 147/uL, p<0.001). Among those HIV negative at enrollment (N = 2,499), repeat testing was more common among those with family or friends living with HIV (ARR 1.50, 95% CI: 1.33-1.68), women (ARR: 1.24, 95% CI: 1.11-1.40), and those self-reporting very good health (ARR: 1.28, 95% CI: 1.12-1.45). CONCLUSIONS: In this high prevalence setting, repeat testing was common among those undergoing HIV screening, and was associated with female sex, lower prevalence of HIV infection, and higher CD4 counts at diagnosis.

Barriers to care among people living with HIV in South Africa: contrasts between patient and healthcare provider perspectives.

We collected qualitative data (semi-structured interviews with 11 healthcare providers and 10 patients; 8 focus groups with 41 patients) to identify barriers to linkage to care among people living with HIV in South Africa who were not yet taking antiretroviral treatment. Patients and providers identified HIV stigma as a sizable barrier. Patients felt that stigma-related issues were largely beyond their control, fearing discrimination if they disclosed to employers or were seen visiting clinics in their community. Providers believed that patients should take responsibility for overcoming internal stigma and disclosing serostatus. Patients had considerable concerns about inconvenient clinic hours, long queues, difficulty in appointment scheduling, and disrespect from staff. Providers seemed to minimize the effects of such barriers and not recognize the extent of patient dissatisfaction. Better communication and understanding between patients and providers are needed to facilitate greater patient satisfaction and retention in HIV care.

Drug-resistant tuberculosis among HIV-infected patients starting antiretroviral therapy in Durban, South Africa.

OBJECTIVE: To estimate the prevalence of drug-resistant tuberculosis (TB) and describe the resistance patterns in patients commencing antiretroviral therapy (ART) in an HIV clinic in Durban, South Africa. DESIGN: Cross-sectional cohort study. METHODS: Consecutive HIV-infected adults (≥ 18y/o) initiating HIV care were enrolled from May 2007-May 2008, regardless of signs or symptoms of active TB. Prior TB history and current TB treatment status were self-reported. Subjects expectorated sputum for culture (MGIT liquid and 7H11 solid medium). Positive cultures were tested for susceptibility to first- and second-line anti-tuberculous drugs. The prevalence of drug-resistant TB, stratified by prior TB history and current TB treatment status, was assessed. RESULTS: 1,035 subjects had complete culture results. Median CD4 count was 92/µl (IQR 42-150/µl). 267 subjects (26%) reported a prior history of TB and 210 (20%) were receiving TB treatment at enrollment; 191 (18%) subjects had positive sputum cultures, among whom the estimated prevalence of resistance to any antituberculous drug was 7.4% (95% CI 4.0-12.4). Among those with prior TB, the prevalence of resistance was 15.4% (95% CI 5.9-30.5) compared to 5.2% (95% CI 2.1-8.9) among those with no prior TB. 5.1% (95% CI 2.4-9.5) had rifampin or rifampin plus INH resistance. CONCLUSIONS: The prevalence of TB resistance to at least one drug was 7.4% among adults with positive TB cultures initiating ART in Durban, South Africa, with 5.1% having rifampin or rifampin plus INH resistance. Improved tools for diagnosing TB and drug resistance are urgently needed in areas of high HIV/TB prevalence.

Depressive symptoms and their impact on health-seeking behaviors in newly-diagnosed HIV-infected patients in Durban, South Africa.

We evaluated the prevalence and correlates of depressive symptoms prior to HIV diagnosis and determined the effect of these symptoms on seeking HIV care at an urban and rural clinic in Durban, South Africa. Adults were administered a questionnaire which included the 5-item Mental Health Index (MHI-5) before HIV testing. We determined the depressive symptoms among HIV-infected subjects. Of 1,545 newly-diagnosed HIV-infected subjects, 55% had depressive symptoms by MHI-5 score. Enrolling at the urban clinic and decreasing functional activity score were associated with depressive symptoms. Subjects with depressive symptoms who were referred for HIV testing by a healthcare provider were less likely to obtain a CD4 count than those without depressive symptoms who self-referred for testing. Depressive symptoms were common among newly-diagnosed HIV-infected participants and impacted CD4 uptake. Depression screening at the time of HIV diagnosis is critical for improving linkage to mental health and HIV services in South Africa.

Loss to follow-up and mortality among HIV-infected people co-infected with TB at ART initiation in Durban, South Africa.

OBJECTIVE: To quantify the impact of tuberculosis (TB) co-infection on death and loss to follow-up (LTFU) 12 months after entry into an ART program. DESIGN: Prospective intervention study. METHODS: From May 2007 to 2008, patients undergoing pre-ART training in Durban, South Africa, were screened for pulmonary TB using mycobacterial culture. Subjects missing appointments for >3 months were phoned. Patients who could not be reached were considered LTFU. Deaths were ascertained by report from family members. We used the Kaplan-Meier method to estimate time to LTFU or death for 3 groups at enrollment as follows: (1) newly diagnosed with TB by sputum culture; (2) on TB treatment (ie, previously diagnosed); and (3) TB free. We evaluated the role of TB on mortality and LTFU using Cox proportional hazards models. RESULTS: Nine hundred fifty-one HIV-infected subjects were enrolled; 59% were female, and median baseline CD4 count was 90 cells per microliter (IQR: 41-148 cells/µL). One hundred forty-four (15%) were newly diagnosed with TB by sputum culture; an additional 199 (21%) were already on TB treatment. By 12 months, 26% newly diagnosed with TB at enrollment died or were LTFU, compared with 19% already on TB treatment, and 14% who were TB free (P = 0.001). Controlling for age, sex, smoking, CD4, and opportunistic infection history, subjects newly diagnosed with pulmonary TB were 76% more likely to die or be LTFU (hazard ratio: 1.76, 95% confidence interval: 1.20 to 2.60) than those without TB. CONCLUSIONS: HIV/TB co-infected individuals are more likely to die or be LTFU within 12 months of ART clinic entry in South Africa. These patients require intensive follow-up during ART initiation.

Intensive tuberculosis screening for HIV-infected patients starting antiretroviral therapy in Durban, South Africa.

BACKGROUND: The World Health Organization (WHO) recommends cough as the trigger for tuberculosis screening in human immunodeficiency virus (HIV)-infected patients, with acid-fast bacillus (AFB) smear as the initial diagnostic test. Our objective was to assess the yield and cost of a more intensive tuberculosis screening in HIV-infected patients starting antiretroviral therapy (ART) in Durban, South Africa. METHODS: We prospectively enrolled adults, regardless of tuberculosis signs/symptoms, who were undergoing ART training from May 2007 to May 2008. After the symptom screen, patients expectorated sputum for AFB smear, tuberculosis polymerase chain reaction (PCR), and mycobacterial culture. Sensitivity and specificity of different symptoms and tests, alone and in combination, were compared with the reference standard of 6-week tuberculosis culture results. Program costs included personnel, materials, and cultures. RESULTS: Of 1035 subjects, 487 (59%) were female; median CD4 cell count was 100 cells/microL. A total of 210 subjects (20%) were receiving tuberculosis treatment and were excluded. Of the remaining 825 subjects, 158 (19%) had positive sputum cultures, of whom 14 (9%) had a positive AFB smear and 82 (52%) reported cough. The combination of cough, other symptoms, AFB smear, and chest radiograph had 93% sensitivity (95% confidence interval, 88%-97%) and 15% specificity (95% confidence interval, 13%-18%). The incremental cost of intensive screening including culture was $360 per additional tuberculosis case identified. CONCLUSIONS: Nearly 20% of patients starting ART in Durban, South Africa, had undiagnosed, culture-positive pulmonary tuberculosis. Despite WHO recommendations, neither cough nor AFB smear were adequately sensitive for screening. Tuberculosis sputum cultures should be performed before ART initiation, regardless of symptoms, in areas with a high prevalence of HIV and tuberculosis.

The "ART" of linkage: pre-treatment loss to care after HIV diagnosis at two PEPFAR sites in Durban, South Africa.

BACKGROUND: Although loss to follow-up after antiretroviral therapy (ART) initiation is increasingly recognized, little is known about pre-treatment losses to care (PTLC) after an initial positive HIV test. Our objective was to determine PTLC in newly identified HIV-infected individuals in South Africa. METHODOLOGY/PRINCIPAL FINDINGS: We assembled the South African Test, Identify and Link (STIAL) Cohort of persons presenting for HIV testing at two sites offering HIV and CD4 count testing and HIV care in Durban, South Africa. We defined PTLC as failure to have a CD4 count within 8 weeks of HIV diagnosis. We performed multivariate analysis to identify factors associated with PTLC. From November 2006 to May 2007, of 712 persons who underwent HIV testing and received their test result, 454 (64%) were HIV-positive. Of those, 206 (45%) had PTLC. Infected patients were significantly more likely to have PTLC if they lived > or = 10 kilometers from the testing center (RR = 1.37; 95% CI: 1.11-1.71), had a history of tuberculosis treatment (RR = 1.26; 95% CI: 1.00-1.58), or were referred for testing by a health care provider rather than self-referred (RR = 1.61; 95% CI: 1.22-2.13). Patients with one, two or three of these risks for PTLC were 1.88, 2.50 and 3.84 times more likely to have PTLC compared to those with no risk factors. CONCLUSIONS/SIGNIFICANCE: Nearly half of HIV-infected persons at two high prevalence sites in Durban, South Africa, failed to have CD4 counts following HIV diagnosis. These high rates of pre-treatment loss to care highlight the urgent need to improve rates of linkage to HIV care after an initial positive HIV test.

Who starts antiretroviral therapy in Durban, South Africa?... not everyone who should.

OBJECTIVE: To evaluate rates of antiretroviral therapy (ART) initiation within 12 months of a new HIV diagnosis in Durban, South Africa. DESIGN: Prospective observational cohort. METHODS: Adults (>or=18 years) were enrolled before HIV testing at two outpatient clinics into the South African Test, Identify and Link cohort. Both sites offer comprehensive HIV care. HIV test results, CD4 cell counts, dates of ART initiation and dates of death were collected from medical records and 12-month patient/family interviews were conducted. ART eligibility was defined as a CD4 cell count less than 200 cells/microl within 90 days of HIV diagnosis. The primary endpoint was ART initiation within 12 months for ART-eligible subjects. RESULTS: From November 2006 to October 2008, 1474 newly diagnosed HIV-infected outpatients were enrolled, 1012 (69%) of whom underwent CD4 cell count testing within 90 days. The median CD4 cell count was 159 cells/microl (interquartile range 65-299). Of those who underwent CD4 cell count testing, 538 (53%) were ART-eligible. Only 210 (39%) eligible enrollees were known to have initiated ART within 12 months. Among ART-eligible subjects, there were 108 known deaths; 82% occurred before ART initiation or with unknown ART initiation status. Men [rate ratio (RR) 1.3, 95% confidence interval (CI) 1.1-1.5] and subjects without an HIV-infected family member/friend (RR 1.3, 95% CI 1.1-1.7) were more likely not to start ART. CONCLUSION: Less than half of ART-eligible subjects started ART within 12 months. Substantial attrition and mortality follow HIV diagnosis before ART initiation in Durban, South Africa. Major efforts directed towards earlier HIV diagnosis, effective linkage to care and timely ART initiation are urgently needed.

Loss to care and death before antiretroviral therapy in Durban, South Africa.

OBJECTIVE: To examine the loss to care and mortality rates before starting antiretroviral therapy (ART) among ART eligible HIV-infected patients in Durban, South Africa. DESIGN: Retrospective cohort study. METHODS: We reviewed data from ART eligible adults (> or = 18 years) at an urban HIV clinic that charges a monthly fee from July to December 2006. ART eligibility was based on CD4 count < or = 200 cells per microliter or clinical criteria and a psychosocial assessment. Patients who did not start ART and were lost within 3 months were phoned. Correlates of loss to care were evaluated using logistic regression. RESULTS: During the study period, 501 patients registered for ART training. Mean time from initial CD4 count to first ART training was 3.6 months (interquartile range 2.3-3.9 months). Four hundred eight patients (81.4%) were in care and on ART at 3-month follow-up, and 11 (2.2%) were in care but had not initiated ART. Eighty-two ART eligible patients (16.4%) were lost before ART initiation. Of these, 28 (34.1%) had died; two thirds of deaths occurred before or within 2 months after the first ART training. Despite multiple attempts, 32 patients (39%) were unreachable by phone. Lower baseline CD4 counts (< or = 100 cells/microL) and unemployment were independently associated with being lost. CONCLUSIONS: Loss to care and death occur frequently before starting ART at an HIV clinic in Durban, South Africa. This delay from CD4 count to ART training, even among those with the lowest CD4 counts, highlights the need for interventions that improve linkage to care and prioritize ART initiation for those with low baseline CD4 counts.

Extensive intrasubtype recombination in South African human immunodeficiency virus type 1 subtype C infections.

Recombinant human immunodeficiency virus type 1 (HIV-1) strains containing sequences from different viral genetic subtypes (intersubtype) and different lineages from within the same subtype (intrasubtype) have been observed. A consequence of recombination can be the distortion of the phylogenetic signal. Several intersubtype recombinants have been identified; however, less is known about the frequency of intrasubtype recombination. For this study, near-full-length HIV-1 subtype C genomes from 270 individuals were evaluated for the presence of intrasubtype recombination. A sliding window schema (window, 2 kb; step, 385 bp) was used to partition the aligned sequences. The Shimodaira-Hasegawa test detected significant topological incongruence in 99.6% of the comparisons of the maximum-likelihood trees generated from each sequence partition, a result that could be explained by recombination. Using RECOMBINE, we detected significant levels of recombination using five random subsets of the sequences. With a set of 23 topologically consistent sequences used as references, bootscanning followed by the interactive informative site test defined recombination breakpoints. Using two multiple-comparison correction methods, 47% of the sequences showed significant evidence of recombination in both analyses. Estimated evolutionary rates were revised from 0.51%/year (95% confidence interval [CI], 0.39 to 0.53%) with all sequences to 0.46%/year (95% CI, 0.38 to 0.48%) with the putative recombinants removed. The timing of the subtype C epidemic origin was revised from 1961 (95% CI, 1947 to 1962) with all sequences to 1958 (95% CI, 1949 to 1960) with the putative recombinants removed. Thus, intrasubtype recombinants are common within the subtype C epidemic and these impact analyses of HIV-1 evolution.

Mutually exclusive T-cell receptor induction and differential susceptibility to human immunodeficiency virus type 1 mutational escape associated with a two-amino-acid difference between HLA class I subtypes.

The relative contributions of HLA alleles and T-cell receptors (TCRs) to the prevention of mutational viral escape are unclear. Here, we examined human immunodeficiency virus type 1 (HIV-1)-specific CD8(+) T-cell responses restricted by two closely related HLA class I alleles, B*5701 and B*5703, that differ by two amino acids but are both associated with a dominant response to the same HIV-1 Gag epitope KF11 (KAFSPEVIPMF). When this epitope is presented by HLA-B*5701, it induces a TCR repertoire that is highly conserved among individuals, cross-recognizes viral epitope variants, and is rarely associated with mutational escape. In contrast, KF11 presented by HLA-B*5703 induces an entirely different, more heterogeneous TCR beta-chain repertoire that fails to recognize specific KF11 escape variants which frequently arise in clade C-infected HLA-B*5703(+) individuals. These data show the influence of HLA allele subtypes on TCR selection and indicate that extensive TCR diversity is not a prerequisite to prevention of allowable viral mutations.

Motif inference reveals optimal CTL epitopes presented by HLA class I alleles highly prevalent in southern Africa.

HIV-specific CTL play a central role in immune control of HIV. The basis for understanding the success or failure of this immune response requires identification of the specific epitopes targeted by CTL. However, in populations most severely affected by the global epidemic, this fundamental knowledge is hindered by the lack of characterization of many of the HLA class I alleles highly prevalent in such populations. Overall, the peptide-binding motif has been determined for a small minority (9%) of HLA class I alleles, with a strong bias toward those alleles prevalent in Caucasoid populations. These studies therefore set out to define, in a South African Zulu/Xhosa population at the epicenter of the epidemic, the epitopes presented by alleles highly prevalent, but for which the peptide-binding motif had not been characterized. Using a method of motif inference, epitopes presented by four such alleles prevalent in the Zulu/Xhosa population of Durban, South Africa, namely, B*3910, B*4201, B*8101, and Cw*1801, are described. Importantly, this approach may additionally facilitate optimization of epitopes in certain instances where conflicting reports in the literature exist regarding the peptide-binding motif, such as for HLA-A*2902, also highly prevalent in southern African populations. These data indicate that the previously anomalous position of HLA-A*2902 among HLA-A alleles, outside any recognized HLA-A supertype, is artifactual, and the true position of the A*2902 motif overlaps those of the A1 and A24 supertypes.

Fitness cost of escape mutations in p24 Gag in association with control of human immunodeficiency virus type 1.

Mutational escape by human immunodeficiency virus (HIV) from cytotoxic T-lymphocyte (CTL) recognition is a major challenge for vaccine design. However, recent studies suggest that CTL escape may carry a sufficient cost to viral replicative capacity to facilitate subsequent immune control of a now attenuated virus. In order to examine how limitations can be imposed on viral escape, the epitope TSTLQEQIGW (TW10 [Gag residues 240 to 249]), presented by two HLA alleles associated with effective control of HIV, HLA-B*57 and -B*5801, was investigated. The in vitro experiments described here demonstrate that the dominant TW10 escape mutation, T242N, reduces viral replicative capacity. Structural analysis reveals that T242 plays a critical role in defining the start point and in stabilizing helix 6 within p24 Gag, ensuring that escape occurs at a significant cost. A very similar role is played by Thr-180, which is also an escape residue, but within a second p24 Gag epitope associated with immune control. Analysis of HIV type 1 gag in 206 B*57/5801-positive subjects reveals three principle alternative TW10-associated variants, and each is strongly linked to concomitant additional variants within p24 Gag, suggesting that functional constraints operate against their occurrence alone. The extreme conservation of p24 Gag and the predictable nature of escape variation resulting from these tight functional constraints indicate that p24 Gag may be a critical immunogen in vaccine design and suggest novel vaccination strategies to limit viral escape options from such epitopes.

Dominant influence of HLA-B in mediating the potential co-evolution of HIV and HLA.

The extreme polymorphism in the human leukocyte antigen (HLA) class I region of the human genome is suggested to provide an advantage in pathogen defence mediated by CD8+ T cells. HLA class I molecules present pathogen-derived peptides on the surface of infected cells for recognition by CD8+ T cells. However, the relative contributions of HLA-A and -B alleles have not been evaluated. We performed a comprehensive analysis of the class I restricted CD8+ T-cell responses against human immunodeficiency virus (HIV-1), immune control of which is dependent upon virus-specific CD8+ T-cell activity. In 375 HIV-1-infected study subjects from southern Africa, a significantly greater number of CD8+ T-cell responses are HLA-B-restricted, compared to HLA-A (2.5-fold; P = 0.0033). Here we show that variation in viral set-point, in absolute CD4 count and, by inference, in rate of disease progression in the cohort, is strongly associated with particular HLA-B but not HLA-A allele expression (P < 0.0001 and P = 0.91, respectively). Moreover, substantially greater selection pressure is imposed on HIV-1 by HLA-B alleles than by HLA-A (4.4-fold, P = 0.0003). These data indicate that the principal focus of HIV-specific activity is at the HLA-B locus. Furthermore, HLA-B gene frequencies in the population are those likely to be most influenced by HIV disease, consistent with the observation that B alleles evolve more rapidly than A alleles. The dominant involvement of HLA-B in influencing HIV disease outcome is of specific relevance to the direction of HIV research and to vaccine design.