Urban transmission of mosquito-borne diseases

Urban environments are the fastest growing landscapes on the planet, and transmission of diseases by urban adapted mosquitoes has increased markedly over the past several decades. The EcoGRAPH group is involved in several projects focused on mapping mosquito habitats and microclimates in cities, modeling the distribution of urban disease transmission hotspots, and projecting the future changes in transmission risk resulting from urban growth and climate change. We used satellite remote sensing and in situ microclimate measurements to generate high-resolution maps of temperature and linked them with mechanistic transmission models to estimate the localized patterns of potential dengue transmission in the southeastern U.S. (Wimberly et al. 2020).

We are currently collaborating with Courtney Murdock (Cornell University) and Mercedes Pascual (University of Chicago) to extend these approaches to map neighborhood-level patterns of urban malaria transmission by Anopheles stephensi in the Gujarat province of India. This work will extend existing temperature-trait modeling approaches to incorporate the influences of humidity on water balance in mosquitoes. We are also collaborating with partners in Ethiopia to study the the spread of Anopheles stephensi to East Africa and the resulting implications of malaria control and elimination.

References

Urban expansion in the Global South

The world’s population is contiuing to become more urbanized, particularly in low and middle income countries located in the global South. During the 21st century, urbanization rates in Africa have increased considerably as rapidly growing populations have migrated to cities for economic opportunities. Although research has tended to focus on the largest “megacities”, there are also many rapidly growing secondary cities that are smaller in size but more numerous. The EcoGRAPH group is using is using satellite remote sensing to map historical patterns of urban grow in parts of Africa and India. These data will be used to parameterize spatially explicit urban growth models for making future projections of urban expansion. These projections can be used to assess how expanding cities will interact with the changing climate to influence human exposure to heat and infectious diseases.

Dynamics and impacts of urban greenspace

Built and natural environments have multifarious effects on public health, including physical activity, urban heat islands, air quality, infectious disease transmission, social contacts, and emotional well-being. A critical feature of urban and suburban environments is greenspace, which is broadly defined as open, undeveloped land with vegetation. This definition encompasses a variety of ecological and land use characteristics ranging from local features such as street trees and neighborhood parks to broader regional networks of large parks and natural areas. The EcoGRAPH group uses satellite remote sensing to monitor longer-term changes in the types, amounts, and spatial distribution of greenspace in urban environments. Our overall goal is to develop better characterizations of urban environments and use them to improve our understanding of how greenspace influences of variety of health outcomes.