Department of Population Health Sciences

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Browsing Department of Population Health Sciences by Subject "11 Medical and Health Sciences"

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    Increasing HIV-1 pretreatment drug resistance among antiretroviral-naive adults initiating treatment between 2006 and 2014 in Nairobi, Kenya
    Chung, Michael H.; Silverman, Rachel A.; Beck, Ingrid A.; Yatich, Nelly; Dross, Sandra; McKernan-Mullin, Jennifer; Bii, Stephen; Tapia, Kenneth; Stern, Joshua A.; Chohan, Bhavna; Sakr, Samah R.; Kiarie, James N.; Frenkel, Lisa M. (Lippincott Williams & Wilkins, 2016-06-19)
    Antiretroviral-naïve adults initiating antiretroviral therapy in Nairobi, Kenya were tested for HIV-1 drug resistance at codons K103N, Y181C, G190A, M184V, and K65R using an oligonucleotide ligation assay. Prevalence of pretreatment drug resistance increased from 3.89% in 2006 to 10.93% in 2014 (P < 0.001), and 95% of those with resistance had at least one nonnucleoside reverse transcriptase inhibitor mutation. Resistance to tenofovir (K65R) was found in 2014 but not in 2006.
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    Insecticide-treated livestock: a potential One Health approach to malaria control in Africa
    Ruiz-Castillo, Paula; Rist, Cassidy; Rabinovich, Regina; Chaccour, Carlos J. (Elsevier, 2022-02-01)
    New vector-control tools are urgently needed to reduce malaria in areas where there is significant transmission after deployment of indoor residual spraying (IRS) and insecticide treated nets. Insecticide-treated livestock (ITL) is a potential novel strategy by which zoophagic mosquitos are killed after feeding upon animals treated with an insecticide. Although there are several insecticide candidates in the pipeline with a wide efficacy range against mosquitos, additional field studies with epidemiological outcomes are required to test the impact of this intervention on malaria transmission. Insecticides under consideration have long been used in livestock to improve animal health and productivity, but each has food and environmental safety considerations. Therefore, moving ITL from a concept to implementation will require a One Health framework.
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    Minority and majority pretreatment HIV-1 drug resistance associated with failure of first-line nonnucleoside reverse-transcriptase inhibitor antiretroviral therapy in Kenyan women
    Milne, Ross S.; Silverman, Rachel A.; Beck, Ingrid A.; McKernan-Mullin, Jennifer; Deng, Wenjie; Sibley, Thomas R.; Dross, Sandra; Kiarie, James N.; Sakr, Samah R.; Coombs, Robert W.; Chung, Michael H.; Frenkel, Lisa M. (Lippincott Williams & Wilkins, 2019-05-01)
    Objectives: Among women initiating first-line nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based-ART with and without a history of single-dose nevirapine (sdNVP) with or without zidovudine with or without lamivudine (ZDV with and without 3TC) for prevention of mother-to-child HIV transmission (PMTCT), we hypothesized that pre-ART HIV-drug resistance would be associated with virologic failure. Design/Methods: In a prospectively enrolled study, three genotypic drug-resistance assays [oligonucleotide-ligation-assay (OLA), consensus sequencing, and next-generation sequencing by Illumina] were retrospectively performed to detect pre-ART drug resistance. Minority or majority drug-resistant variants identified in pre-ART RNA and/or DNA, a history of antiretrovirals for PMTCT, and other risk factors were assessed for association with virologic failure. Results: Failure occurred in 38/169 (22.5%) women, and was associated with pre-ART drug resistance detected by any assay (OLA of plasma or PBMC, consensus sequencing of PBMC and/or plasma, and next-generation sequencing of PBMC at frequencies of at least 10% and as minority variants; all P < 0.0001). Failure was also associated with PMTCT using sdNVP and ZDV with or without 3TC, but not sdNVP only; however, the longer time-interval between PMTCT and ART initiation observed for sdNVP-only women showed no interaction with failure. Viral loads and OLA of PBMC in longitudinal specimens demonstrated rapid failure and emergence of drug resistance, particularly among sdNVP and ZDV with or without 3TC-experienced women with pre-ART drug-resistant minority variants by next-generation sequencing but without drug resistance by OLA or consensus sequencing. Conclusion: Pre-ART drug resistance was detected similarly by OLA of PBMC or plasma and by consensus sequencing, and was associated with virologic failure soon after initiation of first-line NVP-based ART. A history of sdNVP and ZDV with or without 3TC for PMTCT or minority variants detected by next-generation sequencing identified additional women with failure. These findings emphasize the value of assessing individual antiretroviral history, particularly nonsuppressive antiretrovirals with at least two drug classes, and testing for pre-ART drug resistance, including minority variants.
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    Persistence of HIV drug resistance among South African children given nevirapine to prevent mother-to-child-transmission
    Kanthula, Ruth; Rossouw, Theresa M.; Feucht, Ute D.; van Dyk, Gisela; Beck, Ingrid A.; Silverman, Rachel A.; Olson, Scott; Salyer, Christen; Cassol, Sharon; Frenkel, Lisa M. (Lippincott Williams & Wilkins, 2017-05-15)
    Objectives: We set out to examine the prevalence and persistence of mutations conferring high-level nonnucleoside reverse transcriptase (NNRTI)-resistance in a cohort of HIV-infected children who had failed prophylaxis to prevent mother-to-child-transmission (PMTCT). Design: A prospective observational cohort study at the Pediatric HIV Clinic at Kalafong Provincial Tertiary Hospital in Pretoria, South Africa. Methods: Children referred for initiation of antiretroviral therapy (ART) were enrolled from July 2010 through February 2013. HIV drug resistance testing was performed using the oligonucleotide ligation assay (OLA) on dried blood spots (DBS) collected at enrolment and monthly follow-up visits for 2 years. Results: South African children who failed HIV-prophylaxis had a high prevalence of NNRTI-resistant HIV (46/88; 52%). Among children with NNRTI-resistance, the frequency of the predominant resistant variant in each child's HIV-quasispecies was high (median 96%) at study entry (median age 7.5 months), and in 26 out of 27 followed a median of 13 months persisted at a high frequency (median 89%). Conclusion: Our finding that infants who fail HIV-prophylaxis frequently have long-lived NNRTI-resistant HIV suggests that resistance will likely persist through 36 months of age, when children qualify for NNRTI-based ART. These children may benefit from HIV drug resistance testing to guide selection of their treatment.
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    Prevalence of Pre-antiretroviral-Treatment Drug Resistance by Gender, Age, and Other Factors in HIV-Infected Individuals Initiating Therapy in Kenya, 2013-2014
    Silverman, Rachel A.; Beck, Ingrid A.; Kiptinness, Catherine; Levine, Molly; Milne, Ross S.; McGrath, Christine J.; Bii, Steve; Richardson, Barbra A.; John-Stewart, Grace C.; Chohan, Bhavna; Sakr, Samah R.; Kiarie, James N.; Frenkel, Lisa M.; Chung, Michael H. (Oxford University Press, 2017-12-15)
    Background: Pre-antiretroviral-treatment drug resistance (PDR) is a predictor of human immunodeficiency virus (HIV) treatment failure. We determined PDR prevalence and correlates in a Kenyan cohort. Methods: We conducted a cross-sectional analysis of antiretroviral (ARV) treatment-eligible HIV-infected participants. PDR was defined as ≥2% mutant frequency in a participant's HIV quasispecies at pol codons K103N, Y181C, G190A, M184 V, or K65R by oligonucleotide ligation assay and Illumina sequencing. PDR prevalence was calculated by demographics and codon, stratifying by prior ARV experience. Poisson regression was used to estimate prevalence ratios. Results: PDR prevalences (95% confidence interval [CI]) in 815 ARV-naive adults, 136 ARV-experienced adults, and 36 predominantly ARV-naive children were 9.4% (7.5%-11.7%), 12.5% (7.5%-19.3%), and 2.8% (0.1%-14.5%), respectively. Median mutant frequency within an individual's HIV quasispecies was 67%. PDR prevalence in ARV-naive women 18-24 years old was 21.9% (9.3%-40.0%). Only age in females associated with PDR: A 5-year age decrease was associated with adjusted PDR prevalence ratio 1.20 (95% CI, 1.06-1.36; P = .004). Conclusions: The high PDR prevalence may warrant resistance testing and/or alternative ARVs in high HIV prevalence settings, with attention to young women, likely to have recent infection and higher rates of resistance. Clinical trials registration: NCT01898754.
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    Sexually Transmitted Disease Partner Services Costs, Other Resources, and Strategies Across Jurisdictions to Address Unique Epidemic Characteristics and Increased Incidence
    Silverman, Rachel A.; Katz, David A.; Levin, Carol; Bell, Teal R.; Spellman, Dawn; St John, Lisa; Manley Rodriguez, Evelyn; Golden, Matthew R.; Barnabas, Ruanne V. (Wolters Kluwer Health, 2019-08)
    Background: Sexually transmitted disease (STD) partner services (PS) are a core component of STD programs. Data on costs are needed to support PS programming. Methods: In Washington State STD PS programs, disease intervention specialists (DIS) conduct telephone-based interviews and occasional field visits, offer expedited partner therapy to heterosexuals with gonorrhea or chlamydia, and promote human immunodeficiency virus (HIV) testing, preexposure prophylaxis, and HIV care. We conducted activity-based microcosting of PS, including: observational and self-reported time studies and interviews. We analyzed cost, surveillance, and service delivery data to determine costs per program outcomes. Results: In King, Pierce, and Spokane counties, respectively, DIS allocated 6.5, 6.4, and 28.8 hours per syphilis case and 1.5, 1.6, and 2.9 hours per gonorrhea/chlamydia case, on average. In 2016, each full-time DIS investigated 270, 268, and 61 syphilis and 1177, 1105, and 769 gonorrhea/chlamydia cases. Greater than 80% of syphilis cases in King and Pierce were among men who have sex with men versus 38% in Spokane. Disease intervention specialists spent 12% to 39% of their time actively interviewing cases and notifying partners (clients), and the remaining time locating clients, coordinating and verifying care, and managing case reports. Time spent on expedited partner therapy, HIV testing, and referrals to HIV treatment or preexposure prophylaxis, was minimal (<5 minutes per interview) at locations with resources outside PS staff. Program cost-per-interview ranged from US $527 to US $2210 for syphilis, US $219 to US $484 for gonorrhea, and US $164 to US $547 for chlamydia. Discussion: The STD PS resource needs depended on epidemic characteristics and program models. Integrating HIV prevention objectives minimally impacted PS-specific program costs. Results can inform program planning, future budget impact, and cost-effectiveness analyses.