Epidemiology
Chris Barker
VM: Pathology, Microbiology and Immunology
Mosquito-borne diseases, Epidemiology, Surveillance
My program focuses on the epidemiology and ecology of mosquito-borne diseases, primarily those caused by West Nile, chikungunya, and dengue viruses, and including other livestock diseases such as Rift Valley fever and bluetongue. My research combines laboratory studies and epidemiological methods to understand the environmental drivers of disease outbreaks, and I oversee the UC Davis component of the statewide surveillance program for mosquito-borne viruses.
STAR project opportunities in my lab include: Summer field trial testing administration of ivermectin to wild birds as a novel control strategy for West Nile virus.
Dr. Barker can be reached via email at cmbarker@ucdavis.edu.
Jennifer Cassano DVM, PhD
VM: Medicine & Epidemiology
(See also: Translational Medicine, Behavior/Animal Welfare)
Dr. Cassano is an equine field service clinician in the Department of Medicine & Epidemiology with a 50% clinical appointment in the VMTH. As the director of the Regenerative Medicine Laboratory part of the Veterinary Institute for Regenerative Cures, Dr. Cassano oversees the preparation of all the stem cells used in various clinical trials underway at UC Davis. Her research seeks to better understand how modulation of the immune response can be harnessed in therapeutic treatments, combining the areas of immunology and regenerative medicine. Potential projects include evaluating mesenchymal stem cells antibacterial and antifungal properties in feline, canine, and equine species as well as evaluating mitochondria as a regenerative medicine treatment in osteoarthritis and metabolic disorders.
Dr. Cassano hopes to mentor highly motivated students interested in getting involved in clinically oriented research. Students will be involved with the following projects: Barriers to veterinary care survey of horse owners: Assist in survey design, distribution, statistical analysis and manuscript preparation. Valley Fever Epidemiology survey: lateral flow assay test, statistical analysis, manuscript preparation. If interested, regenerative medicine modality projects with more benchtop and animal opportunities.
For more information and to discuss potential projects please contact Dr. Cassano at jmcassano@ucdavis.edu.
Christine Kreuder Johnson, VMD, PhD
One Health Institute
(See also: Global Health, Wildlife/Zoonoses)
Dr. Kreuder Johnson is a Professor of Epidemiology and Ecosystem Health in the School of Veterinary Medicine and Director of the EpiCenter for Disease Dynamics at the One Health Institute at UC Davis. Her research focuses on wildlife population health and the impact of ecological processes on species at risk and patterns of disease transmission in marine and terrestrial wild animal populations. Recent activities investigate zoonotic disease spillover dynamics, viral host shifts, further characterization of the animal-human interface, and epidemiologic patterns facilitating zoonotic disease transmission and spread. She provides epidemiologic support to federal and state agencies during unusual outbreak events and directs global surveillance activities for the Emerging Pandemic Threats PREDICT program.
Contact info: ckjohnson@ucdavis.edu
Gaby Maier, DVM, MPVM, PhD
(See also: Food Animal Medicine & Food Safety)
Not taking students in 2025
Dr. Gaby Maier (DVM, MPVM, PhD) is an Assistant Specialist in Cooperative Extension for Beef Cattle Herd Health & Production where her research is focused on finding solutions to health challenges in California beef production units with a focus on cow-calf operations. Challenges in beef production include control of infectious diseases such as infectious bovine keratoconjunctivitis, better known as pinkeye, anaplasmosis, trichomoniasis or bovine respiratory disease. With the increasing concern about antimicrobial resistance in both humans and animals, fresh approaches to the treatment and management of many infectious diseases in livestock will become more important. Her research using epidemiological study design and field work focuses on the quantification of common practices, and new or untested techniques to diagnose, treat or prevent disease. Trace mineral supplementation is another area where many beef producers struggle and research into effective trace mineral supplementation is a further research interest. Beyond her research, Dr. Maier is extending knowledge in the form of workshops and seminars for beef ranchers, hobby farmers and the public.
Potential 10-week projects:
Cross-sectional survey of antimicrobial resistance in fecal pathogens in cow-calf operations in California
Survey of anthelmintic usage on cow-calf operations in California
Please contact Dr. Maier via email at gumaier@ucdavis.edu
Beatriz Martinez-Lopez, DVM, MPVM, Ph.D.
Quantitative epidemiology, risk assessment, spatial epidemiology, modeling
VM: Medicine & Epidemiology
Dr. Beatriz Martínez López (DVM, MPVM, PhD) is Assistant Professor in the Department of Medicine and Epidemiology, Agricultural Experiment Station (20%) faculty and Director of the UC Davis Center for Animal Disease Modeling and Surveillance (CADMS). Her research is focused on the development and implementation of novel epidemiological methods to gain knowledge about the evolution, spread and economic impact of infectious diseases and to support policies. She uses risk assessment, spatial epidemiology methods, molecular epidemiology, modeling or social network analysis to identify individuals, areas and time periods at higher risk of becoming infected and to detect the most important factors contributing to such risk. She is also working in the integration of these and other methods (i.e. data mining, time-series analysis) in operational, web-based, platforms (i.e., Disease BioPortal, http://bioportal.ucdavis.edu/) with the aim to provide a near real-time monitoring and early warning systems for better prevention and control of transboundary, emerging and re-emerging infectious diseases at a global and local scale. She has been working with diseases affecting domestic and/or wild animal populations such as foot-and-mouth disease, African swine fever, classical swine fever, bovine tuberculosis, Aujeszky´s disease, African horse sickness, bluetongue, avian influenza, West Nile, Rift Valley Fever and diseases affecting aquatic organisms. Many of those diseases are considered to be emerging or re-emerging due to globalization, climate, land use and management changes. CADMS provides a coordinated, interdisciplinary, dynamic environment to develop methods, models and surveillance systems to better prevent, control and eradicate infectious diseases. Currently, CADMS, which accounts with approximately 16 personnel including faculty, analysts, programmers, veterinarians, administrative staff and graduate students, is a FAO Reference Center for modeling and epidemiology and offers diverse opportunities for collaborations in research activities both locally and internationally.
Contact Dr. Martinez-Lopez at beamartinezlopez@ucdavis.edu.
Emmanuel Okello, BVM, MSc, PhD
VMTRC
(see also: Microbiology/Parasitology, Genetics and Genomics)
Dr. Emmanuel Okello is an Assistant CE Specialist in Antimicrobial Stewardship at UC Davis, School of Veterinary Medicine. The goal of his research and extension program is to develop antimicrobial stewardship guidelines and best management practices that reduce antimicrobial resistance while maintaining the health and welfare of the herds and flocks. Okello’s specific areas of interest include the use of alternatives to antibiotics to control infectious diseases in livestock, development and evaluation of vaccines and rapid diagnostics tests, and improved management practices for disease prevention.
Please contact Dr. Okello for prospective STAR projects (eokello@ucdavis.edu). Website: https://www.vetmed.ucdavis.edu/faculty/emmanuel-okello
Richard Pereira, DVM, PhD
SVM: Population Health and Reproduction
(See also: Food Animal Medicine/Food Safety, Microbiology/Parasitology, Genetics/Genomics)
Dr. Pereira research focuses on evidence based medicine on antimicrobial resistance in livestock and judicious use of antimicrobials through interventions that promote livestock health and well-being. Maintaining the effectiveness of antimicrobial drugs to treat infections is of relevance to the health of both animal and human populations. Recent project investigated enteric microbiota of calves using metagenomic sequencing approaches, and herd management impacts on prevalence of resistant enteric bacteria, including evaluation of drug use, feeding practices, and housing management of dairy calves and heifers.
Epidemiology is the foundation of his research which also employs statistics, microbiology, and molecular and genomic approaches. Using these tools, some current research projects include investigating and identifying risk factors for selection and spread of antimicrobial resistance in Salmonella from livestock, and investigating impacts on drug resistance and animal health from feeding pre-weaned calves waste milk (milk containing drug residues) with the aim of identifying interventions to reduce unwanted impacts from this practice.
Previous projects accomplished include:
Spatial-temporal trends in antimicrobial resistant Salmonella isolates recovered from Northern California dairy cattle at a veterinary microbiology laboratory between 2002 and 2017.
Potential 10 week projects for Summer students:
Antimicrobial resistance in bacteria causing metritis in dairy cows.
Evaluation of on-farm factors affecting antimicrobial drug on the dairy farms.
Contact information: rvpereira@ucdavis.edu
Woutrina Smith, DVM, Ph.D.
Infectious disease epidemiology (see also: microbiology, global health)
VM: Medicine & Epidemiology
Dr. Smith is an infectious disease epidemiologist with a special interest in One Health and the molecular epidemiology of zoonotic diseases. She works at local and global study sites where interactions among humans, animals and their environments lead to research questions that can be addressed using laboratory and fieldwork approaches to characterize and manage health at an inidividual, population, and ecosystem level. Her research involves zoonotic protozoa such as Cryptosporidium, Giardia, and Toxoplasma, as well as bacteria that include Mycobacterium, Salmonella, and Campylobacter.
Dr. Smith can be reached via email at wasmith@ucdavis.edu.
Michael Ziccardi, DVM, MPVM, PhD
VM: Karen C. Drayer Wildlife Health Center and VM: Medicine & Epidemiology
(See also: Wildlife/Exotic Animal Medicine/Zoonoses, Aquatic Health/Ecotoxicology)
Dr. Michael Ziccardi DVM MPVM PhD is Executive Director of the One Health Institute, and Director of the Oiled Wildlife Care Network (OWCN) and California Veterinary Emergency Team (CVET). His work focuses on global oiled wildlife preparedness, response, and research as well as statewide domestic animal and livestock disaster response. Ziccard's clinical and research areas of expertise are in free-ranging wildlife health, with an emphasis on epidemiology. His current research focus is on the effects of petroleum on marine species.
Please email Dr. Ziccardi for more information at: mhziccardi@ucdavis.edu.