Publications by authors named "Katzenstein D"

Background: The WHO HIV testing algorithm for high prevalence populations recommends the use of three different serologic assays, though this approach may lead to diagnostic misclassification. The study objective was to compare dried blood spot (DBS)-based HIV-1 nucleic acid detection methods to determine their suitability to confirm the diagnosis of HIV-1 in adults generally with suppressed or low-level plasma HIV-1 RNA.

Methods: Four methods were evaluated: Cepheid Xpert HIV-1 Qual Assay (Xpert), Hologic Aptima HIV-1 Quant Dx assay (Aptima), Roche Cobas Ampliprep/Cobas TaqMan HIV-1 test, v.

View Article and Find Full Text PDF

Remote sensing observations of Searles Lake following the 2019 moment magnitude 7.1 Ridgecrest, California, earthquake reveal an area where surface ejecta is arranged in a repeating hexagonal pattern that is collocated with a solution-mining operation. By analyzing geologic and geotechnical data, here we show that the hexagonal surface ejecta is likely not a result of liquefaction.

View Article and Find Full Text PDF

Background: In Zimbabwe, children, adolescents and young adults living with HIV (CALWH) who are on public health antiretroviral therapy (ART) have inadequate viral load (VL) suppression. We assessed whether a clinic-based VL monitoring could decrease 12-month virologic failure rates among these CALWH.

Methods: The study was registered on ClinicalTrials.

View Article and Find Full Text PDF

Background: Molecular epidemiological approaches provide opportunities to characterize HIV transmission dynamics. We analyzed HIV sequences and virus load (VL) results obtained during routine clinical care, and individual’s zip-code location to determine utility of this approach. Methods: HIV-1 pol sequences aligned using ClustalW were subtyped using REGA.

View Article and Find Full Text PDF

Tenofovir disoproxil fumarate, lamivudine, and dolutegravir (TLD) as a safe and more effective single daily dose regimen is rolling out in Africa for people living with HIV. Although access to viral load (VL) testing is improving, patients may still be transitioned to TLD with virological failure and potential drug resistance. We reviewed annual VL test results of 390 children and adolescents who had enrolled in a community-based antiretroviral therapy program in rural Zimbabwe between 2018 and 2019.

View Article and Find Full Text PDF

HIV-1 pol sequences from antiretroviral therapy (ART)-naive and ART-experienced people living with HIV-1 are fundamental to understanding the genetic correlates and epidemiology of HIV-1 drug resistance (HIVDR). To assess the public availability of HIV-1 pol sequences and ART histories of the individuals from whom sequenced viruses were obtained, we performed a systematic review of PubMed and GenBank for HIVDR studies published between 2010 and 2019 that reported HIV-1 pol sequences. 934 studies met inclusion criteria, including 461 studies of ART-naive adults, 407 of ART-experienced adults, and 66 of ART-naive and ART-experienced children.

View Article and Find Full Text PDF

We conducted a 24month prospective follow-up study, at a primary health care clinic in Harare, Zimbabwe, to determine cumulative mother-to-child transmission of HIV-1 (MTCT) rate and the contributions of intrauterine (IU), intrapartum (IP), and postpartum (PP) to MTCT, as well as maternal and infant mortality rates in the era of Option B combination antiretroviral therapy (cART). Plasma for viral load (VL) quantitation was obtained from 475 mothers enrolled into the study. VL was quantified at enrolment and every 6 months thereafter up to 24 months using the Cepheid GeneXpert HIV-1 Quantitative test.

View Article and Find Full Text PDF

Introduction: pre-treatment drug resistance (PDR) can compromise the 3 95-95-95 global target for viral load suppression. The high complexity and cost of genotyping assays limits routine testing in many resource limited settings (RLS). We assessed the performance of a rapid HIV-1 drug resistance assay, the Pan Degenerate Amplification and Adaptation (PANDAA) assay when screening for significant HIV-1 drug resistance mutations (DRMs) such as K65R, K103NS, M184VI, Y181C and G190A.

View Article and Find Full Text PDF

Previously used as part of salvage therapy, integrase strand transfer inhibitors (INSTIs) have become part of the preferred antiretroviral therapy (ART) first-line regimen in most low- to middle-income countries. With the extensive use of dolutegravir in first-line ART, drug resistance mutations to INSTIs are inevitable. Therefore, active monitoring and surveillance of INSTI drug resistance is required.

View Article and Find Full Text PDF

Objectives: The aim of this study was to determine the contributions of intrauterine (IU), intrapartum (IP), and postpartum (PP) transmission to mother-to-child transmission of HIV-1 (MTCT) and infant mortality in the first 6 months of life, in the era of Option B Plus combination antiretroviral therapy.

Methods: Plasma for virus load (VL) quantitation was obtained from 451 women enrolled into the study. VL was quantified using the Cepheid GeneXpert HIV-1 quantitative test.

View Article and Find Full Text PDF

Background: Suboptimal adherence to antiretroviral therapy (ART) is responsible for most virologic failure among adolescents with HIV. Methods for objectively measuring adherence to ART are limited. This study assessed the association between ritonavir concentrations in hair and self-reported adherence and modified directly administered ART on virologic outcomes among HIV-infected adolescents who were virologically failing second-line ART in Harare, Zimbabwe.

View Article and Find Full Text PDF

Objective methods of measuring antiretroviral adherence are limited. We assessed the relationship between tenofovir disoproxil fumarate (TDF) hair concentrations, self-reported adherence, and virological outcomes in HIV-infected adolescents in Harare, Zimbabwe. HIV-infected adolescents on atazanavir/ritonavir-based second-line treatment for >6 months with viral load (VL) ≥1,000 copies/mL were randomized to either modified directly administered antiretroviral therapy (mDAART) or standard of care.

View Article and Find Full Text PDF

Introduction: Maintaining virologic suppression of children and adolescents on ART in rural communities in sub-Saharan Africa is challenging. We explored switching drug regimens to protease inhibitor (PI) based treatment and reducing nevirapine and zidovudine use in a differentiated community service delivery model in rural Zimbabwe.

Methods: From 2016 through 2018, we followed 306 children and adolescents on ART in Hurungwe, Zimbabwe at Chidamoyo Christian Hospital, which provides compact ART regimens at 8 dispersed rural community outreach sites.

View Article and Find Full Text PDF

Pretreatment drug resistance (PDR) can compromise antiretroviral therapy (ART) efficacy and undermine the WHO targets to end the AIDS epidemic as a public health threat by 2030. Thus, we examined the level of PDR in Harare, Zimbabwe. Eligible study participants were adults who were ART naive or individuals with previous ART exposure reinitiating treatment, recruited between October 2018 and February 2020 in a HIV ART treatment clinic, in Harare.

View Article and Find Full Text PDF

Background: Women in low- and middle-income countries are at the highest risk of cervical cancer yet have limited access to and participation in cervical cancer screening programs. Integrating self-collected, community-based screening offers a potential primary screening method in areas of limited resources. In this paper, we present a study evaluating knowledge, attitudes, and practices of cervical cancer and Human Papilloma Virus (HPV) in rural Zimbabwe.

View Article and Find Full Text PDF

HIV drug resistance (HIVDR) is a barrier to sustained virologic suppression in low- and middle-income countries (LMICs). Point mutation assays targeting priority drug resistance mutations (DRMs) are being evaluated to improve access to HIVDR testing. In a cross-sectional study (June 2018 to September 2019), we evaluated the diagnostic accuracy of a simple and rapid HIVDR assay (the pan-degenerate amplification and adaptation [PANDAA] assay targeting the mutations K65R, K103NS, M184VI, Y181C, and G190A) compared to Sanger sequencing and next-generation sequencing (NGS).

View Article and Find Full Text PDF

Human papillomavirus (HPV) types differ by geographic location and the ethnicity of the human host, which may have implications for carcinogenicity. HPV35 is one of the least frequently identified high-risk types in North America and Europe but was the most common high-risk HPV (hrHPV) infection in a cohort in rural Zimbabwe. Whole genome analysis is limited for HPV35; no such studies have been performed in Zimbabwe.

View Article and Find Full Text PDF

Objective: To define sepsis syndromes in high-HIV burden settings in the antiretroviral therapy (ART) era.

Methods: We characterized a prospective cohort of adults presenting to a tertiary emergency department in Harare, Zimbabwe with suspected community-acquired sepsis using blood and urine cultures, urine tuberculosis lipoarabinomannan (TB LAM), and serum cryptococcal antigen (CrAg) testing. The primary outcome was 30-day all-cause mortality.

View Article and Find Full Text PDF

Barriers to sustainable virologic suppression (VS) of HIV-infected adolescents and young adults include drug resistance mutations (DRMs) and limited treatment options, which may impact the outcome of second-line antiretroviral therapy (ART). We sequenced plasma viral RNA from 74 adolescents and young adults (16-24 years) failing first-line ART at Newlands Clinic, Zimbabwe between October 2015 and December 2016. We evaluated first-line nucleoside reverse transcriptase inhibitor (NRTI) susceptibility scores to first- and second-line regimens.

View Article and Find Full Text PDF

Objectives: The integrase strand inhibitor dolutegravir (DTG) combined with tenofovir and lamivudine (TLD) is a single tablet regimen recommended for 1st, 2nd and 3rd-line public health antiretroviral therapy (ART). We determined drug resistance mutations (DRMs) and evaluated the predictive efficacy of a TLD containing regimen for viremic adolescents and young adults in Harare, Zimbabwe.

Methods: We sequenced plasma viral RNA from HIV-1-infected adolescents and young adults on 1st and 2nd-line ART with confirmed virologic failure (viral load >1000 copies/ml) and calculated total genotypic susceptibility scores to current 2nd, 3rd line and DTG regimens.

View Article and Find Full Text PDF

Background: South Africa has the largest public antiretroviral therapy (ART) programme in the world. We assessed temporal trends in pretreatment HIV-1 drug resistance (PDR) in ART-naïve adults from South Africa.

Methods: We included datasets from studies conducted between 2000 and 2016, with HIV-1 sequences from more than ten ART-naïve adults.

View Article and Find Full Text PDF

Background: In low- and middle-income countries (LMIC), women have limited access to and uptake of cervical cancer screening. Delayed diagnosis leads to poorer outcomes and early mortality, and continues to impede cancer control disproportionately in LMIC. Integrating self-collected, community-based screening for High Risk-Human Papilloma Virus (HR-HPV) into existent HIV programs is a potential screening method to identify women at high risk for developing high-risk cervical lesions.

View Article and Find Full Text PDF

Background: Efavirenz (EFV)-based regimens select broad drug resistance to nonnucleoside reverse-transcriptase inhibitors (NNRTIs), limiting the effectiveness of EFV and other NNRTIs. The duration, persistence, and decay of drug resistance mutations (DRMs) in the proviral reservoir is not well defined.

Methods: Participants with virologic failure of EFV-based regimens and drug-resistant viremia with the K103N mutation in plasma ribonucleic acid (RNA) were identified from AIDS Clinical Trials Group (ACTG) studies A364 and A5095.

View Article and Find Full Text PDF

Objectives: High-risk human papilloma viruses (hrHPV) are the causative agents of cervical cancer, the leading cause of cancer deaths among Zimbabwean women. The objective of this study was to describe the hrHPV types found in Zimbabwe for consideration in cervical cancer screening and vaccination efforts.

Design And Methods: To determine hrHPV prevalence and type distribution in Zimbabwe we implemented a community-based cross-sectional study of self-collected cervicovaginal samples with hrHPV screening using near-point-of-care Cepheid GeneXpert HPV.

View Article and Find Full Text PDF