Research in Progress
Our research group uses multi-disciplinary approaches to study how social and environmental conditions impact infectious diseases. We focus on both emerging disease threats and infectious diseases on the edge of elimination. We conduct field-based surveillance, use next generation genomics to understand transmission pathways, and employ analytical methods including infectious disease modeling and machine learning. Our long-term goals are to reduce the burden of the infectious diseases we study through development of improved surveillance tools, with an emphasis on identifying high risk environments and vulnerable populations.
Our work is supported by sources including the National Institutes of Allergy and Infectious Diseases at the National Institutes of Health, the US State Department and the Colorado Department of Public Health and the Environment.
Current projects
Reemergence and persistence of schistosomiasis in China
China
has achieved remarkable progress in the control of schistosomiasis, a
water-borne pathogen that causes liver fibrosis, anemia and can impair
child growth and development. However, schistosomiasis has reemerged and
persisted in some areas, despite aggressive disease control efforts. We
are working with collaborators at the Sichuan Center for Disease
Control and Prevention in order to understand why these pockets of
transmission persist. Our work has demonstrated the concentration of infections in a limited number of individuals, and suggested the practice of using human waste as an agricultural fertilizer (often called night soil) may facilitate transmission. We have recently developed an efficient, method for sequencing large numbers of loci from field-collected S. japonicum miracidia. Current efforts are underway to understand sources of infections in residual transmission hotspots.
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COVID-19 in Colorado
Since the emergence of COVID-19 in Colorado, our team has been collaborating with local experts to advise response to the COVID-19 pandemic in Colorado. Working with a team of public health officials, biostatisticians, clinicians and health policy experts, we have developed infectious disease transmission models designed to estimate health care needs, cases, and fatalities. We have used these models to estimate the impact of social distancing and other policies to date, and to project the future trajectory of the epidemic under different intervention scenarios – including the potential impacts of relaxing social distancing, widespread mask-use, and improved case detection and containment. Our team is working to develop tools to monitor the course of the epidemic in near-real-time, identify early indicators of potential increases in transmission, and reduce exposure in high-risk populations. For example, the team has developed an app for projecting the course of SARS-Cov-2 in Colorado under different intervention scenarios. This work has been used to inform local decision-making.
Impacts of climate change on water-borne disease
Climate change has the potential to impact the distribution of water-borne diseases but the causal pathways are complex, and health impacts likely depend not only on meteorological exposures but other underlying vulnerabilities. We are interested in estimating relationships between predicted changes in climate (such as increased ambient temperature and heavy rainfall events) and water-borne diseases, developing models that explore the extent to which climate-health relationships to vary across factors such as population density, access to safe water and pathogen distribution. Our team has conducted studies aimed at characterizing household water quality in Guatemala, as well as evaluating vulnerability of water sources to rainfall events and local contamination sources. We have also conducted a systematic review, a meta-analysis and developed a framework that characterize the relationships between climate drivers, including temperature, heavy rainfall, flooding, and drought, and their relationship with infectious diarrhea.
Climate change, urbanization, and emerging infections in West Africa
Outbreaks of mosquito-borne viral diseases have increased in frequency and magnitude over the last 20 years as a result of multiple factors including climate change, globalization, and urbanization. The viruses, Zika, Dengue, Yellow Fever, and Chikungunya, and are transmitted by Aedes mosquitoes, which thrive in urban areas where containers such as flower pots, plastic bottles and discarded tires provide breeding habitat. West Africa is at risk of Aedes-born disease outbreaks: Aedes mosquitoes and Yellow Fever have long been present in the region and rapid urbanization may be increasing available habitat for Aedes mosquitoes. But, surveillance is limited. We are studying the association between social and environmental conditions, and the distribution of Aedes mosquitoes in order to identify vulnerable populations and inform surveillance and control measures.
