Last data update: Jul 01, 2024. (Total: 47134 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Sexton CJ [original query] |
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Evaluation of SMARTube to detect HIV infection before seroconversion using standard methods
Feldblum PJ , Chen PL , Fischer SJ , Sexton CJ . AIDS Res Hum Retroviruses 2016 32 1067-1071 The acute phase of HIV infection carries substantial risk of transmission; identification of acute-phase infections may offer opportunities to reduce that risk. SMARTube incubation of blood specimens is designed to stimulate in vivo-primed HIV-specific lymphocytes to produce HIV antibodies in vitro. The resulting supernatant (S-plasma) can be tested to identify acute infections with commercially available HIV assays. We assessed the performance of the SMARTube to identify acute HIV infections in studies at three developing country sites. We conducted HIV incidence studies in Ho Chi Minh City, Vietnam, and Bloemfontein and Rustenburg, South Africa. We estimated HIV incidence in cross-sectional samples and measured prospective incidence in uninfected women followed for up to 12 months. We incorporated SMARTube into the HIV testing algorithm at cross-sectional screening and monthly follow-up visits. We tested 1,384 persons in Vietnam, 1,145 women in Bloemfontein, and 538 persons in Rustenburg. Cross-sectional samples from 11 participants that tested positive with SMARTube after an initial unincubated negative test result (11 of 2,472; 0.4% of all specimens) were considered "potential acute" infections. Matching samples from 3 of the 11 (27.3%) were confirmed by polymerase chain reaction (PCR) testing. In follow-up of 355, 401, and 223 uninfected women in Vietnam, Bloemfontein, and Rustenburg, respectively, 11 seroconversions occurred in Bloemfontein and Rustenburg. In four of these incident infections (36.4%), SMARTube testing had resulted in earlier detection of HIV infection than the eventual seroconversion visits. In our field studies, pretreatment with SMARTube allowed the identification of acute HIV-1 infection in some new infections, but with a positive predictive value of 27%. Larger studies are needed to evaluate SMARTube as an alternative to technically challenging and costly enzyme immunoassay and PCR testing to detect acute HIV infection. |
Progressing beyond SLMTA: are internal audits and corrective action the key drivers of quality improvement?
Maina RN , Mengo DM , Mohamud AD , Ochieng SM , Milgo SK , Sexton CJ , Moyo S , Luman ET . Afr J Lab Med 2014 3 (2) 222 BACKGROUND: Kenya has implemented the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme to facilitate quality improvement in medical laboratories and to support national accreditation goals. Continuous quality improvement after SLMTA completion is needed to ensure sustainability and continue progress toward accreditation. METHODS: Audits were conducted by qualified, independent auditors to assess the performance of five enrolled laboratories using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) checklist. End-of-programme (exit) and one year post-programme (surveillance) audits were compared for overall score, star level (from zero to five, based on scores) and scores for each of the 12 Quality System Essential (QSE) areas that make up the SLIPTA checklist. RESULTS: All laboratories improved from exit to surveillance audit (median improvement 38 percentage points, range 5-45 percentage points). Two laboratories improved from zero to one star, two improved from zero to three stars and one laboratory improved from three to four stars. The lowest median QSE scores at exit were: internal audit; corrective action; and occurrence management and process improvement (< 20%). Each of the 12 QSEs improved substantially at surveillance audit, with the greatest improvement in client management and customer service, internal audit and information management (> 50 percentage points). The two laboratories with the greatest overall improvement focused heavily on the internal audit and corrective action QSEs. CONCLUSION: Whilst all laboratories improved from exit to surveillance audit, those that focused on the internal audit and corrective action QSEs improved substantially more than those that did not; internal audits and corrective actions may have acted as catalysts, leading to improvements in other QSEs. Systematic identification of core areas and best practices to address them is a critical step toward strengthening public medical laboratories. |
Correlation of prospective and cross-sectional measures of HIV type 1 incidence in a higher-risk cohort in Ho Chi Minh City, Vietnam
Sexton CJ , Costenbader EC , Vinh DT , Chen PL , Hoang TV , Lan NT , Feldblum P , Kim A , Giang LT . AIDS Res Hum Retroviruses 2012 28 (8) 866-73 The primary aim of this study was to estimate HIV incidence within a high-risk population in Ho Chi Minh City (HCMC), Vietnam using both cross-sectional and prospective methodologies. A secondary aim was to develop a local correction factor for the BED and avidity index incidence assays. The research study design consisted of three phases: (1) cross-sectional, (2) prospective, and (3) BED false recent (BED FR). A total of 1619 high-risk, sexually active individuals were enrolled in the cross-sectional phase and 355 of the opiate-negative, HIV-negative women were subsequently enrolled in the prospective phase. Four-hundred and three men and women with known HIV infection duration of greater than 12 months were enrolled in the BED FR phase. The HIV prevalence for all participants in the cross-sectional phase was 15.8%. HIV incidence in the cross-sectional group was estimated using the BED IgG capture assay and AxSYM avidity index assay for recent HIV infection and incidence within the prospective cohort was determined by observations of HIV seroconversion. HIV incidence in opiate-negative women was estimated using the BED assay to be 0.8% unadjusted and 0.5% after applying the locally derived BED false recent rate of 1.7%; no seroconversions were observed in the prospective cohort. We also screened the cross-sectional samples for evidence of acute infection using nucleic acid testing, 4th generation HIV EIA, and SMARTube coupled with Genscreen and Determine diagnostic tests; no confirmed acute infections were identified by any method. HIV incidence within this opiate-negative study population was low and incidence estimates from the two methods compared favorably with each other. Incidence estimates and false recent rates using the AxSYM assay were higher: AI FRR of 2.7% and adjusted incidence of 1.7% per year (95% CI, 0.6, 2.8). By comparison, both HIV prevalence and incidence estimates for the opiate-positive group were higher. |
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