Gert Uves van Zyl
Affiliation: University of Stellenbosch
Country: South Africa
- Low lopinavir plasma or hair concentrations explain second-line protease inhibitor failures in a resource-limited settingGert Uves van Zyl
Division of Medical Virology, Department of Pathology, NHLS Tygerberg and Stellenbosch University, Tygerberg, South Africa
J Acquir Immune Defic Syndr 56:333-9. 2011..In resource-limited settings, many patients, with no prior protease inhibitor (PI) treatment on a second-line, high genetic barrier, ritonavir-boosted PI-containing regimen have virologic failure...
- It is time to consider third-line options in antiretroviral-experienced paediatric patients?Gert U van Zyl
Division of Medical Virology, Stellenbosch University, and National Health Laboratory Service Tygerberg, Parow, Cape Town, South Africa
J Int AIDS Soc 14:55. 2011..The historic use of full-dose ritonavir as part of an unboosted protease inhibitor (PI)-based antiretroviral therapy regimen in some South African children contributes to the frequent accumulation of major PI resistance mutations...
- Antiretroviral resistance patterns and factors associated with resistance in adult patients failing NNRTI-based regimens in the Western Cape, South AfricaGert U van Zyl
Division of Medical Virology, Stellenbosch University, Tygerberg, Cape Town, South Africa
J Med Virol 83:1764-9. 2011..Major protease inhibitor mutations were not detected. A delayed response to ART failure may risk accumulation of TAMs in patients on an NNRTI-based regimen. The use of NVP rather than EFV was associated with ETV resistance...
- Pooling strategies to reduce the cost of HIV-1 RNA load monitoring in a resource-limited settingG U van Zyl
Division of Medical Virology, Stellenbosch University, and National Health Laboratory Service, Tygerberg, South Africa
Clin Infect Dis 52:264-70. 2011..Recently, the use of pooling strategies with a clinically appropriate viral load threshold was shown to be accurate and efficient for monitoring when the prevalence of virologic failure is low...
- NucliSens EasyQ HIV-1 V1.2 system: Detection of human plasma-derived background signalG U van Zyl
Division of Medical Virology, National Health Laboratory Service and Stellenbosch University, Tygerberg 7505, South Africa
J Virol Methods 165:318-9. 2010..In this case HIV-negative human plasma should be included routinely in addition to NTCs, which would allow rapid detection of a background signal...
- Surveillance of transmitted resistance to antiretroviral drug classes among young children in the Western Cape Province of South AfricaGert U van Zyl
Division of Medical Virology, Stellenbosch University, Tygerberg, South Africa
Pediatr Infect Dis J 29:370-1. 2010..The estimated NRTI and protease inhibitor transmitted antiretroviral resistance prevalence is low (<5%), predicting good therapeutic response in Western Cape infants...
- Protease inhibitor resistance in South African children with virologic failureGert U van Zyl
Centre for Infectious Diseases, Division of Medical Virology, Tygerberg and Stellenbosch University, Cape Town, South Africa
Pediatr Infect Dis J 28:1125-7. 2009..We explored antiretroviral resistance mutations in pediatric patients failing PI-based antiretroviral therapy and the predictors of major PI resistance mutations (MPIRM) in these patients...
- Zidovudine with nevirapine for the prevention of HIV mother-to-child transmission reduces nevirapine resistance in mothers from the Western Cape, South AfricaG U van Zyl
Faculty of Health Sciences and National Health Laboratory Service NHLS Tygerberg, Division of Medical Virology, Department Pathology, Stellenbosch University, Cape Town, South Africa
J Med Virol 80:942-6. 2008..1%, 95% confidence interval: 8.7-25.6%), which appears to be lower than in studies with sd NVP alone (37.5%, 95% confidence interval: 23.0-50.6%)...
- Extraction buffer contaminated bacterially as a cause of invalid HIV-1 viral load results on the NucliSens EasyQ systemM Claassen
Division of Medical Virology, National Health Laboratory Service Tygerberg Department of Pathology, Faculty of Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
J Virol Methods 150:80-1. 2008..This experience underlines the necessity of state-of-the-art assay design incorporating adequate internal controls and calibrators...
- Pitfalls with rapid HIV antibody testing in HIV-infected children in the Western Cape, South AfricaM Claassen
Discipline of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Stellenbosch and NHLS, Tygerberg 7505, South Africa
J Clin Virol 37:68-71. 2006..CONCLUSIONS: The Capillus test had an unexpectedly low sensitivity in a South African population of HIV-infected children that had access to antiretroviral treatment, posing a risk of false negative HIV testing...