About

Dr. Carey Farquhar, MD, MPH, is a professor at the University of Washington in the Departments of Global Health, Medicine, and Epidemiology. She received her MD from Harvard Medical School and completed her residency and chief residency in internal medicine, as well as a fellowship in infectious disease, at the University of Washington, where she also earned a Masters in Public Health. Her research focuses on HIV epidemiology and prevention in Africa, heterosexual and vertical HIV transmission, HIV and HCV diagnosis and access to treatment among persons who inject drugs, and non-communicable diseases among persons living with HIV. She conducts research in Kenya and mentors trainees from the US and Kenya. Dr. Farquhar is the Director of the UW Kenya Research and Training Center and the International AIDS Research and Training Program (IARTP). She teaches courses on HIV and Responsible Conduct of Research in the School of Public Health and sees patients at Madison Clinic and Harborview Medical Center.

Research topics

• Internal medicine
• Medicine
• Pediatrics
• Intensive care medicine
• Immunology
• Cardiology
• Pathology

Selected publications

• HIV viral non-suppression and drug resistance among persons who inject drugs on dolutegravir antiretroviral therapy in Kenya

  medRxiv · 2026-03-02

  articleOpen accessSenior author

  Background: )-based regimens. We evaluated PWID taking DTG to assess longitudinal rates of viral non-suppression and emergence of drug resistance mutations in Kenya. Methods: ) every 6 months for 2 years. We used univariable Cox proportional hazards to assess longitudinal risk for viremia (VL >200 copies/ml). Plasma specimens with viremia were genotyped for HIV drug resistance, including minority variants, using a lab-developed PacBio sequencing assay, and referenced by the Stanford HIVdb program. Results: Among 250 participants, 125 were receiving methadone, 199 (79.6) reported heroin use, 70% were male, and median age was 39 years. 194 (77.6%) participants completed all five study visits, 41 (16.4%) were lost to follow-up and 15 (6.0%) died. Across all study visits, 166 (66.0%) of the 250 participants were always suppressed, and 84 (33.6%) were viremic at least once during follow-up, including 8 (3.2%) who were always viremic and 76 (30.4%) who were intermittently suppressed. Living in an improvised shelter or outdoors was significantly associated with a higher risk of viremia (HR=4.35, 95% CI: 1.52-12.53). 93 specimens had drug resistance genotyping, 27 (29%) of which were from participants with incomplete follow-up. NNRTI resistance was frequent (37-41% across visits), whereas major resistance mutations were infrequent to tenofovir (4.3%), lamivudine (7.5%), and DTG (1%, minority variant S153F detected at 1% frequency). Accessory DTG mutations, which do not independently reduce susceptibility, were more common, observed in 41% (38/93) of genotyped specimens, most often T97A, E138K, and L74M. Conclusion: Among PWID living with HIV on TLD in Kenya, one-third had intermittent or sustained viral non-suppression across two years of follow-up. While NNRTI resistance was common, DTG resistance mutations were rare. Improving viral suppression among PWID living with HIV will reduce transmission risks and improve clinical outcomes.

  PublisherOA PDFDOI

• Oral Pre‐Exposure Prophylaxis (PrEP) Awareness and Acceptability Among Persons Who Inject Drugs (PWID) in Kenya: A Qualitative Investigation

  Advances in Public Health · 2026-01-01

  articleOpen access

  Background People who inject drugs (PWIDs) are disproportionately affected by HIV despite the availability of multiple efficacious biomedical prevention interventions including oral pre‐exposure prophylaxis (PrEP). Little is known about the knowledge, acceptability, and uptake of oral PrEP among this population in Kenya. To inform the development of oral PrEP uptake optimization interventions for PWID in Kenya, we conducted a qualitative assessment to establish oral PrEP awareness and willingness to take PrEP by this group in Nairobi City. Methodology Guided by the capability, opportunity, motivation, and behavior (COM‐B) model of health behavior change, we conducted eight focus group discussions (FGDs) among randomly constituted samples of PWID in four harm reduction drop‐in centers (DICs) in Nairobi in January 2022. Although the FGDs were conducted in the harm reduction DICs, only few of the participants were utilizing DICs services. The domains explored were perceived risks (behavior), oral PrEP awareness and knowledge (capability), motivation to use oral PrEP (behavior), and perceptions on community uptake (motivation and opportunity). Completed FGD transcripts were uploaded to Atlas.ti version 9 and thematic analysis was conducted through an iterative process of review and discussion by two coders. Findings There was a low level of oral PrEP awareness with only four of the 46 PWID having heard of PrEP; only few participants had ever used oral PrEP, and they were no longer using it, indicating a low capacity to make decisions on oral PrEP. Study participants were aware of the risk posed by unsafe drug injection and expressed willingness to take oral PrEP. Participants demonstrated low understanding of the role oral PrEP plays in complementing condoms in HIV prevention, presenting an opportunity for awareness creation. While the PWID were eager to learn more about oral PrEP, they favored DICs as places where they would like to obtain information and oral PrEP if they chose to use it, identifying an opportunity for oral PrEP programming interventions. Conclusion Creation of oral PrEP awareness among PWID in Kenya is likely to improve uptake since the PWID are receptive. Oral PrEP should be offered as part of combination prevention approaches, and effective messaging through DICs, integrated outreaches, and social networks are recommended to mitigate displacement of other prevention and harm reduction practices by this population. Trial Registration ClinicalTrials.gov identifier: STUDY0001370

  PublisherOA PDFDOI

• HIV risk and oral pre-exposure prophylaxis (PrEP) among people who inject drugs (PWID) in Nairobi: a cross-sectional study

  BMC Infectious Diseases · 2026-01-05

  articleOpen access

  Persons who inject drugs (PWID) in Kenya face a high HIV burden (18% prevalence). Although oral pre-exposure prophylaxis (PrEP) is effective for HIV prevention among PWID, its awareness and use remain low. This study assessed HIV acquisition risk, oral PrEP knowledge, and uptake among PWID in Nairobi, Kenya. HIV-negative PWID were recruited from four drop-in centers in Nairobi (February–March 2022). HIV risk from sexual and injection practices was measured using the National Drug and Alcohol Research Centre’s HIV Risk-Taking Behavior Scale (HRBS). Oral PrEP awareness and uptake were assessed using the Low PrEP Awareness and Use among PWID tool. Analyses included descriptive statistics, unpaired t-tests (HRBS scores), chi-square tests (PrEP awareness and use), logistic regression (factors associated with PrEP awareness), and Fisher’s exact tests (PrEP uptake), conducted in SPSS version 24. Among 256 participants, 82.0% were male, 30.1% were on methadone, and 99.2% injected heroin. Mean HIV risk scores indicated moderate risk from injection practices (8.35/25) and sexual practices (11.59/30), totaling 19.94/55. HRBS scores were not associated with PrEP awareness (P = 0.493) or use (P = 0.727). Sexual HIV risk was higher among women than men (12.44/30 vs. 7.3/30; P < 0.001), and among those aged 18–24 versus 25–55 years (23.00/55 vs. 19.35/55; P = 0.016). PrEP awareness was 59.4%, but only 3.9% had ever used PrEP. Men were more likely than women to be aware of PrEP (84.8% vs. 53.8%; P < 0.001) and to have used it (13.0% vs. 1.9%; P < 0.001). PWID in Nairobi have a moderate HIV risk, with young and female PWID disproportionately affected. Despite moderate awareness, PrEP uptake is very low. Targeted PrEP education, gender-responsive outreach, and integration of PrEP into harm reduction services are needed to improve uptake. ClinicalTrials.gov Protocol Record STUDY0001370.

  PublisherDOI

• Improving HIV assisted partner services outcomes by eliciting additional partners after the initial encounter

  PLOS Global Public Health · 2026-02-03

  articleOpen accessSenior author

  Most assisted partner services (APS) programs elicit partners at the time of HIV diagnosis when index clients may be reluctant to name all partners. Little is known about the benefits of ongoing partner elicitation after the initial visit. We utilized data collected in an APS implementation study across 31 facilities in western Kenya from August 2019 to June 2022. HIV testing service providers offered APS to consenting female index clients and asked them to name their male partners both at initial diagnosis and during follow-up clinic visits for 12 months. Partners were traced and offered HIV testing. Using multivariable Poisson Generalized Estimated Equation models, we compared characteristics of index clients who did and did not name additional partners and assessed HIV diagnoses and characteristics of partners named during initial versus follow-up visits. The 872 female index clients who accepted APS named 3461 male partners, of whom 2920 (84%) were successfully contacted and HIV tested. Of 1819 male partners named at the initial visit, 430 (23.6%) were previously diagnosed and 90 (4.9%) were newly diagnosed with HIV. Of 1101 male partners named at follow-up visits, 335 (30.4%) were previously diagnosed and 193 (17.5%) were newly diagnosed with HIV. Among partners tested, those named at follow-up visits were 3.9 times more likely to be newly diagnosed with HIV than those named at the initial visit (Relative Risk = 3.88, 95%CI = 3.00-4.98) and were more likely to report behaviors associated with HIV transmission, including having sex with >1 partner (p < 0.001) and with a partner at risk of HIV or with unknown HIV status (p = 0.01). Continuing partner elicitation for APS for 12 months after the initial visit was associated with a higher likelihood of identifying male partners at increased HIV risk compared to those initially named and increased the number of new HIV diagnoses.

  PublisherDOI

• The Association of Mild Kidney Disease With Coronary Artery Disease Is Stronger for People Living With HIV

  JAIDS Journal of Acquired Immune Deficiency Syndromes · 2025-09-25

  articleOpen access

  OBJECTIVE: To examine the association between mild kidney disease and coronary plaque parameters using coronary computed tomography angiography in people living with HIV (PWH) compared with people without HIV in Uganda. DESIGN: Cross-sectional secondary analysis. METHODS: We studied 165 participants aged >45 years with ≥1 cardiovascular risk factor (78 PWH on stable antiretroviral therapy, 87 HIV-negative). Kidney function was assessed using estimated glomerular filtration rate (eGFR) and albumin-creatinine ratio (ACR). Coronary artery disease (CAD) was characterized by segment involvement score (SIS), segment stenosis score (SSS), and coronary artery calcium score. Multivariable Tobit regression assessed associations of kidney function measures with CAD parameters, testing for differences by HIV status. RESULTS: The median (interquartile range) age was 57.0 (53-62) years, 62.4% of subjects were female, and 87.3% had hypertension. Among PWH, mildly impaired eGFR (<90 mL/min/1.73 m2) was associated with higher SIS [β 3.31, 95% confidence interval (CI): 0.41 to 6.21, P = 0.03] and SSS (β 5.95, 95% CI: 0.54 to 11.36, P = 0.03). The association with SIS remained significant after adjusting for age, gender, and 10-year ASCVD score (β 2.58, 95% CI: 0.10 to 5.06, P = 0.04). Associations of ACR with coronary plaque were not statistically significant for participants with or without HIV (all P > 0.07). CONCLUSION: In PWH, mildly reduced eGFR was associated with greater coronary plaque burden (SIS, SSS) but not coronary artery calcium; ACR showed no associations with any CAD measures. Incorporating kidney function measures into cardiovascular risk assessment may be valuable in HIV care.

  PublisherOA PDFDOI

• Early structural cardiovascular disease, HIV, and tuberculosis in East Africa (ASANTE): cross-sectional study protocol for a multimodal cardiac imaging study in Nairobi, Kenya

  BMJ Open · 2025-07-01

  articleOpen access

  INTRODUCTION: Persons living with HIV (PLWH) have an augmented risk of cardiovascular disease, including atherosclerosis and myocardial dysfunction, despite effective viral suppression with antiretroviral therapy. Despite the majority of PLWH residing in sub-Saharan Africa, there are limited reports from the region on structural cardiovascular changes due to this residual risk. METHODS AND ANALYSIS: The Early Structural Cardiovascular Disease, HIV, and Tuberculosis in East Africa (ASANTE) cross-sectional study will be conducted in a public hospital in Nairobi, Kenya. It will enrol 400 participants (50% women, 50% PLWH) to undergo cardiovascular phenotyping using multimodal imaging (coronary CT angiography (CCTA) and echocardiography) and banking of biological samples (whole blood, peripheral blood mononuclear cells, plasma and urine). We will define the prevalence of subclinical coronary atherosclerosis by CCTA and subclinical myocardial dysfunction by transthoracic echocardiography and evaluate both traditional and non-traditional risk factors, including endemic infections such as latent tuberculosis. This study will contribute important data on phenotypes of and risk factors for HIV-associated cardiovascular disease in this understudied region. ETHICS AND DISSEMINATION: Ethical approval for the ASANTE study was granted by the University of Nairobi-Kenyatta National Hospital Ethical Review Committee, Nairobi, Kenya, and the University of Washington Institutional Review Board, USA. Results will be submitted for publication in peer-reviewed journals.

  PublisherDOI

• HIV Resistance to Dolutegravir Varies With Coadministered Agents

  Clinical Infectious Diseases · 2025-08-30 · 2 citations

  articleOpen access

  We hypothesized that HIV-dolutegravir resistance is more frequent when coadministered with nucleos(t)ides with shorter intracellular half-lives. Multivariable analysis of 183 viremic (≥200 c/mL) participants from 4 cohorts (N = 660 participants) found dolutegravir resistance in 21 (11.5%). Dolutegravir resistance was greater with dolutegravir + lamivudine + zidovudine/(1 on stavudine) (odds ratio [OR] = 19.4, 95% confidence interval [CI]: 5.1-74.3) or dolutegravir + lamivudine +abacavir (OR = 5.4, 95% CI: 1.1-25.8), compared with dolutegravir + lamivudine + tenofovir.

  PublisherOA PDFDOI

• Low Prevalence of Coronary Artery Calcium in High Cardiometabolic Risk Kenyan Adults with and Without HIV: The ASANTE Study

  Global Heart · 2025-01-01

  articleOpen access

  Co-first

  PublisherOA PDFDOI

• Early Structural Cardiovascular Disease, HIV, and Tuberculosis in East Africa (ASANTE): Cross-sectional study protocol for a multimodal cardiac imaging study in Nairobi, Kenya

  medRxiv · 2025-03-17 · 1 citations

  preprintOpen access

  Abstract Introduction Persons living with HIV (PLWH) have an augmented risk of cardiovascular disease, including atherosclerosis and myocardial dysfunction, despite effective viral suppression with antiretroviral therapy (ART). Despite the majority of PLWH residing in sub-Saharan Africa, there are limited reports from the region on structural cardiovascular changes due to this residual risk. Methods and analysis The Early Structural Cardiovascular Disease, HIV, and Tuberculosis (ASANTE) cross-sectional study will be conducted in a public hospital in Nairobi, Kenya. It will enroll 400 participants (50% female, 50% PLWH) to undergo comprehensive cardiovascular phenotyping using multimodal imaging (coronary CT angiography [CCTA], echocardiography) and banking of biological samples (whole blood, peripheral blood mononuclear cells, serum, and urine). We will define the prevalence of subclinical coronary atherosclerosis by coronary CT angiography (CCTA) and subclinical myocardial dysfunction by transthoracic echocardiography, and evaluate both traditional and non-traditional risk factors, including endemic infections such as latent tuberculosis. This study will contribute important data on phenotypes of and risk factors for HIV-associated cardiovascular disease in this under-studied region. Ethics and dissemination Ethical approval for the ASANTE study was granted by the University of Nairobi-Kenyatta National Hospital Ethical Review Committee, Nairobi, Kenya. Results will be submitted for publication in peer-reviewed journals. Key messages What is already known on this topic In studies from high-income countries, HIV infection is an independent risk factor for structural cardiovascular abnormalities (atherosclerosis, myocardial remodeling) and corresponding incident cardiovascular events. Emerging data from sub-Saharan Africa suggest there may be a unique epidemiological profile, in which HIV and traditional cardiometabolic risk factors (e.g., hypertension, diabetes, overweight/obesity, smoking) are not associated with coronary atherosclerosis. Unique endemic risk factors for cardiovascular disease in HIV have yet to be defined in sub-Saharan Africa. What this study adds We will define the prevalence of and risk factors for subclinical coronary atherosclerosis and myocardial disease in a cohort of Kenyan adults with and without HIV who have been enriched for cardiometabolic risk factors using multimodal imaging (coronary CT angiography, speckle tracking echocardiography). We will assess the contribution of latent tuberculosis infection as a potential endemic risk factor for subclinical cardiovascular abnormalities identified on multimodal imaging. How this study might affect research, practice, or policy Delineating the burden, phenotypes, and unique risk factors for early cardiovascular disease in this setting will facilitate tailored interventions for screening, monitoring, and management among persons with HIV. Developing multimodal cardiac imaging infrastructure in this resource-limited setting will expand tools for understanding the natural history of cardiovascular disease among persons with HIV in this unique setting. This study will yield a diverse collection of stored biological samples, including peripheral blood mononuclear cells, plasma, whole blood RNA, and urine. In combination with the cardiac imaging repository, this biobank will facilitate future collaborative efforts to identify mechanisms underlying phenotypes of cardiovascular disease in this population.

  PublisherOA PDFDOI

• Abstract 4359851: Low prevalence of coronary and thoracic aortic calcium in high-cardiometabolic risk Kenyan adults with and without HIV: The ASANTE Study

  Circulation · 2025-11-03

  article

  Background: HIV is thought to be an independent risk factor for atherosclerotic cardiovascular disease (ASCVD), including coronary atherosclerosis, based on studies from high-income countries. However, there are limited data on the epidemiology of atherosclerosis from sub-Saharan Africa, where there is a high burden of HIV. Methods: Early Structural Cardiovascular Disease, HIV, and Tuberculosis in East Africa (ASANTE) is an ongoing cross-sectional study evaluating coronary atherosclerosis in Kenyan adults with chronically treated/suppressed HIV (PWH) and HIV-uninfected controls. We enroll participants &gt; 45 years old with &gt; 1 cardiometabolic risk factor (hypertension, diabetes, dyslipidemia, smoking, overweight/obesity), targeting a sample of n = 200 (50% female, 50% PWH). Participants undergo comprehensive exposure assessments and non-contrast cardiac CT. We quantify coronary artery calcium (CAC) as a measure of coronary atherosclerosis, thoracic aortic calcium (TAC), and valvular calcium using Agatston scores . We report interim results on clinical characteristics, CAC, TAC, and valvular calcium. We also compare CAC prevalence and estimated 10-year ASCVD risk in ASANTE to other published geographic cohorts. Results: We included 52 PWH and 37 HIV-uninfected control participants who completed CT imaging in this analysis ( Table 1 ). The mean age among all participants was 57 years, and 48% were female. The mean 10-year ASCVD risk score was 12.6% (10.2% in PWH, 17% in controls). Prevalence of diabetes and statin therapy for hyperlipidemia was higher among controls (p &lt; 0.01), while low-density lipoprotein levels were higher among PWH (p = 0.003). Prevalence of CAC &gt;0 by Agatston score was 18% (15% in PWH, 22% in controls; p = 0.63). Prevalence of CAC scores by category are shown in Figure 1 . Valvular and thoracic aortic calcium prevalence was lower than CAC, ranging from 2% to 8% among all participants. Despite having high mean 10-year cardiovascular risk, ASANTE participants had lower CAC prevalence compared with lower-risk cohorts in the United States (p = 0.02 and p &lt;0.001 for ASANTE vs. USA-CAC Consortium and ASANTE vs. USA-SoCal, respectively; Figure 2 ). Conclusion: Despite enriching for cardiovascular risk factors, CAC is less common in the East African population, regardless of HIV status, compared with lower-risk cohorts in high-income settings. Further studies are needed to identify potential atheroprotective exposures and mechanisms in this region.

  PublisherDOI

Recent grants

• SITAWI: Turning the Tide for Women and HIV

  NIH · $4.1M · 2015–2030

• NIH Grant K24AI087399

  NIH · $647k · 2016

• NIH Grant R01HD075108

  NIH · $684k · 2016

• NIH Grant R21TW010459

  NIH · $338k · 2019

• NIH Grant R03HD057773

  NIH · $203k · 2011

Frequent coauthors

• Grace John‐Stewart

  University of Washington

  198 shared

• Yohana Mashalla

  Hubert Kairuki Memorial University

  169 shared

• Rose Bosire

  Kenya Medical Research Institute

  157 shared

• Barbra A. Richardson

  University of Washington

  157 shared

• James Kiarie

  World Health Organization

  153 shared

• Wendy M. Green

  Cleveland State University

  144 shared

• Theresa Odero

  University of Washington

  125 shared

• Onesmus Gachuno

  University of Nairobi

  119 shared

Labs

• Student Epidemic Action Leaders (SEAL) TeamPI