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EMeRGenS is an NIH-funded research project at the University of California San Diego (UCSD). We plan to use dynamic mathematical modeling to predict and effectively respond to emerging substance use epidemic threats and associated HIV, HCV, and fatal overdose incidence.



The overdose epidemic in the United States has followed an exponential curve since 1979 with no sign of abating. On the contrary, a series of political, economic and technological factors are fueling drug use epidemics in the country. Technological advances have led to an explosion in the emergence of powerful synthetic substances that can be produced with minimal equipment. Inequalities, poor mental health services, and other social issues contribute to an increased susceptibility to drug use disorders. Improved transport and communication infrastructure, including the internet, facilitates the emergence of drug markets. As a result, polysubstance use is diversifying presenting new health risks and new challenges for treatment. In 2017, over 70,000 people died of an overdose and HIV outbreaks were identified in two cities of Massachusetts. Curbing these alarming trends requires preemptive epidemic preparedness and the latter should be based on a rigorous and systematic assessment of the factors influencing drug use epidemics. These factors, however, are dynamic and interacting.


We will use an emerging infectious disease framework and dynamic mathematical modeling methods to predict emerging drug use epidemics in the United States. Mathematical modeling has been used extensively to forecast emerging and reemerging infectious disease epidemics because it allows us to mechanistically represent the different factors determining disease transmission and their dynamics over time. We will develop a mathematical model of drug use in the United States which represents current patterns of drug use across the country and associated HIV, HCV and overdose incidence. It will explicitly represent heterogeneity in susceptibility to drug use disorders in the population, social networks and the influence of drug markets, law enforcement and healthcare services on drug use and associated health outcomes.


We will investigate the value of internet data (Google searches, social media, news) in providing real-time estimates of substance use patterns and associated health harms to complement our models' parameterization and inform timely modeling scenarios.

We will also use online marketing strategies which harness interest for a topic, as expressed by internet searches, to promote harm reduction intervertions among communities identified by our models as being at rish for an impending emerging susbstance use epidemic. 




Annick Bórquez, MSc, PhD

Annick Bórquez, MSc, PhD, is an HIV and substance use epidemiologist at the division of Infectious Diseases and Global Public Health at UCSD. Her research seeks to improve the health of marginalized populations through developing, applying and integrating mathematical modeling, cost effectiveness and qualitative methods. Her focus is on addressing intersecting epidemics of substance use disorders, overdose, HIV, HCV and other associated health harms, with a focus on social and structural determinants of health. She has led multiple studies to inform intervention and policy planning in HIV and substance use among people who inject drugs, justice involved populations, female sex workers, men who have sex with men and transgender women in a range of settings, including Mexico, Peru, West and Sub-Saharan Africa, India, Russia and the United States.
Dr. Bórquez has a background in medical microbiology from the University of Edinburgh and holds an MSc. and a PhD. in epidemiology from the department of Infectious Disease Epidemiology at Imperial College London. 

She is the principal investigator of this NIDA Avenir grant to adapt emerging infectious diseases methods including internet/big data analysis and mathematical modeling, to the field of substance use to predict and respond to emerging substance use epidemics in the United States.


Gabriel Carrasco-Escobar, MPH

Gabriel Carrasco-Escobar completed his master degree in Epidemiology and Biostatistics at Universidad Peruana Cayetano Heredia (UPCH), Peru, and is currently in the Public Health Doctoral Program at the University of California, San Diego (UCSD), USA. His research is focused on the Epidemiology of Tropical Diseases and the intersection with environmental determinants in resource-limited settings. He is particularly interested in epidemiological, spatial and remote sensing methods to understand the distribution and determinants of tropical diseases. In the most recent years, his work was focused on the role of human population mobility in the malaria epidemiology in the Amazon region and the micro-geographic landscape composition as regulator for Malaria transmission dynamics.

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Rocio Carrasco-Hernandez, MSc, PhD

Dr. Rocio Carrasco-Hernandez is a multidisciplinary researcher. Originally from Mexico City, she coursed an BSc and an MSc in Biology, working with research projects on the ecophysiology of plants and microorganisms in volcanic soils and then modelling the ecological niche of bovine rabies disease, using landscape and environmental variables. She then completed a PhD in Environmental Sciences in Manchester, UK; working with physical models of solar radiation in urban environments. Back to Mexico, she obtained a 2yr postdoctoral position at the Faculty of Medicine, UNAM, to study geographical relations that may affect HIV risk among transwomen. Now entering the field of molecular epidemiology, Dr. Carrasco-Hernandez attempts to understand some geographical patterns governing HIV transmission networks, as well as some structural properties of the genetic sequences which may explain the formation of large transmission clusters within a population.

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Derek Johnson, PhD

Derek Johnson is a post-doctoral student at UCSD researching the use of novel data to predict and assess emerging substance abuse. He received his Ph.D. in epidemiology from the University of Alabama at Birmingham and has completed a postdoctoral program in global health at Tufts University. He has previously worked for Médecins Sans Frontières where he worked on HIV related projects in Uganda and Myanmar.


Charles Marks, MPH

Charles Marks is a doctoral student in the SDSU-UCSD Joint Doctoral Program in Interdisciplinary Research on Substance Use and works as a graduate research assistant for PRIMER. Their current research focuses on developing dynamic models of injection initiation which can be utilized to understand various factors related to injection initiation as well as to inform initiation prevention measures. Generally, they are interested in utilizing critical social theory to inform public health policy research addressing health inequities.

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Kaiming Bi, PhD

Kaiming Bi is a post-doctoral researcher in the Division of Infectious Diseases and Global Public Health at UCSD. Before joining UCSD, he received his bachelor's degree in Mathematics at Northeastern University in China and received his Ph.D. degree in Industrial Engineering at Kansas State University. His research background includes disease modeling, simulation, optimal control, and machine learning. Currently, his research interest focus on the modeling of opioid-related drug transmission.

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Thomas Patton, MSc, PhD

Tom Patton is a Postdoctoral Fellow in the NIH T32 Training Program in Substance Use, HIV, and Related Infections at the University of California, San Diego (UCSD). He received an MSc in Health Economics and a Ph.D. in Economics from the University of York (UK). He previously worked as a Research Fellow at the Centre for Health Economics, University of York. His main research interest is in the development of economic evaluations for the assessment of policy interventions aimed at reducing the harms of opioid use disorder.   

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Anh Vo, BS, BA

Anh Vo is a research assistant at UCSD's Division of Infectious Diseases and Global Public Health. Anh's current research focuses on developing mathematical models examining underlying patterns or seasonality of drug epidemics, as well as how the recent COVID-19 pandemic affects and informs changes in drug use. She is also working concurrently on projects that seek to use dynamic modeling to optimize HIV prevention portfolios targeting people who inject drugs. Anh has received her B.S. in Public Health and B.A. in Global Health at UCSD, and her primary interests lie in exploring emerging issues in infectious disease by leveraging biostatistics and mathematical modeling.

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Sharon Park, BA

Sharon is a Program Coordinator for UCSD's Division of Infectious Diseases and Global Public Health. She supports multiple principal investigators working on a variety of research topics including HIV transmission networks, injection drug use, ethno-epidemiology along the US-Mexican border. She received her B.A. in Economics from the University of California Berkeley. 


Consider joining our research team - follow this link to view our current job postings! 

Our Findings


Identifying Counties at Risk of High Overdose Mortality Burden Throughout the Emerging Fentanyl Epidemic in the United States: A Predictive Statistical Modeling Study. The Lancet Public Health

Marks C, Abramovitz D, Donnelly C, Carrasco G. Carrasco-Hernández R, Ciccarone D, González-Izquierdo A, Martin NK, Strathdee S, Smith D, Bórquez A. The Lanncet Public Health 2021. DOI:


Methodological approaches for the prediction of opioid use-related epidemics in the United States: a narrative review and cross-disciplinary call to action.

Marks C, Carrasco-Escobar G, Carrasco-Hernandez R, Johnson D, Ciccarone D, Strathdee SA, Smith D, Bórquez A. Transl Res. 2021 Mar 30:S1931-5244(21)00081-5. doi: 10.1016/j.trsl.2021.03.018. PMID: 33798764.


Impact of cumulative incarceration and the post-release period on syringe-sharing among people who inject drugs in Tijuana, Mexico: a longitudinal analysis.

Rivera Saldana CD, Beletsky L, Borquez A, Kiene SM, Strathdee SA, Zúñiga ML, Martin NK, Cepeda J. Addiction. 2021 Feb 23. doi: 10.1111/add.15445. PMID: 33620749.


Preferences and acceptability of law enforcement initiated referrals for people who inject drugs: a mixed methods analysis.

Olgin GK, Bórquez A, Baker P, Clairgue E, Morales M, Bañuelos A, Arredondo J, Harvey-Vera A, Strathdee S, Beletsky L, Cepeda JA. Subst Abuse Treat Prev Policy. 2020 Oct 2;15(1):75. doi: 10.1186/s13011-020-00319-w. PMID: 33008431; PMCID: PMC7530855.


What is needed to achieve HCV microelimination among HIV-infected populations in Andalusia, Spain: a modeling analysis.

Skaathun B, Borquez A, Rivero-Juarez A, Mehta SR, Tellez F, Castaño-Carracedo M, Merino D, Palacios R, Macías J, Rivero A, Martin NK. . BMC Infect Dis. 2020 Aug 8;20(1):588. doi: 10.1186/s12879-020-05285-z. PMID: 32770955; PMCID: PMC7414743.

Opioid agonist treatment scale-up and the initiation of injection drug use: A dynamic modeling analysis.

Marks C, Borquez A, Jain S, Sun X, Strathdee SA, Garfein RS, Milloy MJ, DeBeck K, Cepeda JA, Werb D, Martin NK.

PLoS Med. 2019 Nov 26;16(11):e1002973. doi: 10.1371/journal.pmed.1002973. eCollection 2019 Nov. 

Free PMC Article

Responding to global stimulant use: challenges and opportunities.

Farrell M, Martin NK, Stockings E, Bórquez A, Cepeda JA, Degenhardt L, Ali R, Tran LT, Rehm J, Torrens M, Shoptaw S, McKetin R.  Lancet (London, England). 2019 November 2;394(10209):1652-1667. PubMed PMID: 31668409; PubMed Central PMCID: PMC6924572; DOI: 10.1016/S0140-6736(19)32230-5.

Integrating HIV preexposure prophylaxis and harm reduction among men who have sex with men and transgender women to address intersecting harms associated with stimulant use: a modelling study.

Bórquez A, Rich K, Farrell M, Degenhardt L, McKetin R, Tran LT, Cepeda J, Silva-Santisteban A, Konda K, Cáceres CF, Kelly S, Altice FL, Martin NK. Journal of the International AIDS Society. 2020 June;23 Suppl 1:e25495. PubMed PMID: 32562365; DOI: 10.1002/jia2.25495.

Modelling integrated antiretroviral treatment and harm reduction services on HIV and overdose among people who inject drugs in Tijuana, Mexico.

Cepeda JA, Bórquez A, Magana C, Vo A, Rafful C, Rangel G, Medina-Mora ME, Strathdee S, Martin NK. Journal of the International AIDS Society. 2020 June;23 Suppl 1:e25493. PubMed PMID: 32562375; DOI: 10.1002/jia2.25493.

Abstracts and Conference Proceedings

To be announced! 

Our Findings
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