793 research outputs found
Establishing a cohort at high risk of HIV infection in South Africa: challenges and experiences of the CAPRISA 002 acute infection study.
No full textOBJECTIVES: To describe the baseline demographic data, clinical characteristics and HIV-incidence rates of a cohort at high risk for HIV infection in South Africa as well as the challenges experienced in establishing and maintaining the cohort. METHODOLOGY/PRINCIPLE FINDINGS: Between August 2004 and May 2005 a cohort of HIV-uninfected women was established for the CAPRISA 002 Acute Infection Study, a natural history study of HIV-1 subtype C infection. Volunteers were identified through peer-outreach. The cohort was followed monthly to determine HIV infection rates and clinical presentation of early HIV infection. Risk reduction counselling and male and female condoms were provided. After screening 775 individuals, a cohort of 245 uninfected high-risk women was established. HIV-prevalence at screening was 59.6% (95% CI: 55.9% to 62.8%) posing a challenge in accruing HIV-uninfected women. The majority of women (78.8%) were self-identified as sex-workers with a median of 2 clients per day. Most women (95%) reported more than one casual sexual partner in the previous 3 months (excluding clients) and 58.8% reported condom use in their last sexual encounter. Based on laboratory testing, 62.0% had a sexually transmitted infection at baseline. During 390 person-years of follow-up, 28 infections occurred yielding seroincidence rate of 7.2 (95% CI: 4.5 to 9.8) per 100 person-years. Despite the high mobility of this sex worker cohort retention rate after 2 years was 86.1%. High co-morbidity created challenges for ancillary care provision, both in terms of human and financial resources. CONCLUSIONS/SIGNIFICANCE: Challenges experienced were high baseline HIV-prevalence, lower than anticipated HIV-incidence and difficulties retaining participants. Despite challenges, we have successfully accrued this cohort of HIV-uninfected women with favourable retention, enabling us to study the natural history of HIV-1 during acute HIV-infection. Our experiences provide lessons for others establishing similar cohorts, which will be key for advancing the vaccine and prevention research agenda in resource-constrained settings
Anaemia in acute HIV-1 subtype C infection.
No full textBACKGROUND: The high prevalence of anaemia and the increased morbidity and mortality associated with anaemia during AIDS has been well described yet there has been little information about anaemia and changes in haemoglobin levels during acute and early HIV-1 infection. METHODS: HIV-negative women (n = 245) were enrolled into an observational cohort as part of the Centre for the AIDS Programme of Research in South Africa (CAPRISA) Acute Infection Study. Acute infection was diagnosed following a positive HIV RNA PCR in the absence of antibodies, or detection of HIV-1 antibodies within 3 months of a previously negative antibody test. Haemotologic parameters were assessed before infection and at regular intervals in the first twelve months of HIV infection. RESULTS: Fifty-seven participants with acute HIV infection were identified at a median of 14.5 days post-infection (range 10-81) and were enrolled in the CAPRISA Acute Infection cohort at a median of 41 days post-infection (range 15-104). Mean haemoglobin prior to HIV-1 infection was 12.7 g/dL, with a mean decline of 0.46 g/dL following infection. The prevalence of anaemia increased from 25.0% prior to HIV-1 infection to 52.6% at 3 months post-infection, 61.1% at 6 months post-infection, and 51.4% at 12 months post-infection. CONCLUSIONS: Haematologic derangements and anaemia with a trend towards iron deficiency are common with acute HIV-1 subtype C infection in this small cohort. The negative impact of anaemia concurrent with established HIV infection upon morbidity and mortality has been well documented but the prognostic potential and long-term effects of anaemia during acute HIV-1 infection remain unknown
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.
No full textCAPRISA, 2014.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
Impact of antiretroviral therapy on health-related quality of life among South African women in the CAPRISA 002 acute infection study.
No full textCAPRISA, 2014.Abstract available in pdf
Additional file 1 of Application of quantile mixed-effects model in modeling CD4 count from HIV-infected patients in KwaZulu-Natal South Africa
No full textAdditional file 1. R package qrLMM() sample output using CAPRISA 002 Acute Infection Study data across fitted quantile levels
Additional file 2 of Application of quantile mixed-effects model in modeling CD4 count from HIV-infected patients in KwaZulu-Natal South Africa
No full textAdditional file 2. Graphic overview of convergence for model parameters across all fitted quantiles, produced from the qrLMM package using the CAPRISA 002 AI Study data
Establishing a cohort at high risk of HIV infection in South Africa: Challenges and experiences of the CAPRISA 002 acute infection study
No full textOBJECTIVES: To describe the baseline demographic data, clinical characteristics and HIV-incidence rates of a cohort at high risk for HIV infection in South Africa as well as the challenges experienced in establishing and maintaining the cohort. METHODOLOGY/PRINCIPLE FINDINGS: Between August 2004 and May 2005 a cohort of HIV-uninfected women was established for the CAPRISA 002 Acute Infection Study, a natural history study of HIV-1 subtype C infection. Volunteers were identified through peer-outreach. The cohort was followed monthly to determine HIV infection rates and clinical presentation of early HIV infection. Risk reduction counselling and male and female condoms were provided. After screening 775 individuals, a cohort of 245 uninfected high-risk women was established. HIV-prevalence at screening was 59.6% (95% CI: 55.9% to 62.8%) posing a challenge in accruing HIV-uninfected women. The majority of women (78.8%) were self-identified as sex-workers with a median of 2 clients per day. Most women (95%) reported more than one casual sexual partner in the previous 3 months (excluding clients) and 58.8% reported condom use in their last sexual encounter. Based on laboratory testing, 62.0% had a sexually transmitted infection at baseline. During 390 person-years of follow-up, 28 infections occurred yielding seroincidence rate of 7.2 (95% CI: 4.5 to 9.8) per 100 person-years. Despite the high mobility of this sex worker cohort retention rate after 2 years was 86.1%. High co-morbidity created challenges for ancillary care provision, both in terms of human and financial resources. CONCLUSIONS/SIGNIFICANCE: Challenges experienced were high baseline HIV-prevalence, lower than anticipated HIV-incidence and difficulties retaining participants. Despite challenges, we have successfully accrued this cohort of HIV-uninfected women with favourable retention, enabling us to study the natural history of HIV-1 during acute HIV-infection. Our experiences provide lessons for others establishing similar cohorts, which will be key for advancing the vaccine and prevention research agenda in resource-constrained settings
Human immunodeficiency virus-specific gamma interferon enzyme-linked immunospot assay responses targeting specific regions of the proteome during primary subtype C infection are poor predictors of the course of viremia and set point.
No full textIt is unknown whether patterns of human immunodeficiency virus (HIV)-specific T-cell responses during acute infection may influence the viral set point and the course of disease. We wished to establish whether the magnitude and breadth of HIV type 1 (HIV-1)-specific T-cell responses at 3 months postinfection were correlated with the viral-load set point at 12 months and hypothesized that the magnitude and breadth of HIV-specific T-cell responses during primary infection would predict the set point. Gamma interferon (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay responses across the complete proteome were measured in 47 subtype C HIV-1-infected participants at a median of 12 weeks postinfection. When corrected for amino acid length and individuals responding to each region, the order of recognition was as follows: Nef > Gag > Pol > Rev > Vpr > Env > Vpu > Vif > Tat. Nef responses were significantly (P < 0.05) dominant, targeted six epitopic regions, and were unrelated to the course of viremia. There was no significant difference in the magnitude and breadth of responses for each protein region with disease progression, although there was a trend of increased breadth (mean, four to seven pools) in rapid progressors. Correlation of the magnitude and breadth of IFN-gamma responses with the viral set point at 12 months revealed almost zero association for each protein region. Taken together, these data demonstrate that the magnitude and breadth of IFN-gamma ELISPOT assay responses at 3 months postinfection are unrelated to the course of disease in the first year of infection and are not associated with, and have low predictive power for, the viral set point at 12 months
Fluidity of HIV-1-specific T-cell responses during acute and early subtype C HIV-1 infection and associations with early disease progression.
No full textDeciphering immune events during early stages of human immunodeficiency virus type 1 (HIV-1) infection is critical for understanding the course of disease. We characterized the hierarchy of HIV-1-specific T-cell gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay responses during acute subtype C infection in 53 individuals and associated temporal patterns of responses with disease progression in the first 12 months. There was a diverse pattern of T-cell recognition across the proteome, with the recognition of Nef being immunodominant as early as 3 weeks postinfection. Over the first 6 months, we found that there was a 23% chance of an increased response to Nef for every week postinfection (P = 0.0024), followed by a nonsignificant increase to Pol (4.6%) and Gag (3.2%). Responses to Env and regulatory proteins appeared to remain stable. Three temporal patterns of HIV-specific T-cell responses could be distinguished: persistent, lost, or new. The proportion of persistent T-cell responses was significantly lower (P = 0.0037) in individuals defined as rapid progressors than in those progressing slowly and who controlled viremia. Almost 90% of lost T-cell responses were coincidental with autologous viral epitope escape. Regression analysis between the time to fixed viral escape and lost T-cell responses (r = 0.61; P = 0.019) showed a mean delay of 14 weeks after viral escape. Collectively, T-cell epitope recognition is not a static event, and temporal patterns of IFN-γ-based responses exist. This is due partly to viral sequence variation but also to the recognition of invariant viral epitopes that leads to waves of persistent T-cell immunity, which appears to associate with slower disease progression in the first year of infection
An Economic Analysis of Electron Accelerators and Cobalt-60 for Irradiating Food
No full textAverage costs per pound of irradiating food are similar for the electron accelerator and cobalt-60 irradiators analyzed in this study, but initial investment costs can vary by $1 million. Irradiation costs range from 0.5 to 7 cents per pound and decrease as annual volumes treated increase. Cobalt-60 is less expensive than electron beams for annual volumes below 50 million pounds. For radiation source requirements above the equivalent of 1 million curies of cobalt-60, electron beams are more economical.food irradiation, electron accelerators, cobalt-60, cost comparison, economies of size, Food Consumption/Nutrition/Food Safety,
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