Cooperative Fish and Wildlife Research Units Program: Massachusetts
Education, Research and Technical Assistance for Managing Our Natural Resources

Hosts and their pathogens exist in spatiotemporally variable thermal environments, and temperature has been repeatedly shown to impact critical disease quantities, such as contact rates, vector abundance, and recruitment of susceptible hosts. Predicting how a changing climate will impact infectious disease dynamics requires a better understanding of the mechanistic impact of temperature on host-pathogen interactions. Our proposal is focused on how temperature and climate influences in-host infection dynamics in seasonal environments when hosts are sensitive to environmental temperature. Specifically, we will focus on how seasonal temperature variation influences host immune function, pathogen transmission, and host behavior; processes that may be determinants of the timing, magnitude, and extent of seasonal disease outbreaks. We will use the amphibian-Batrachochytrium dendrobatidis (Bd) system, where both host (the Eastern red-spotted newt, Notopthalmus viridescens) and pathogen are sensitive to temperature, to determine the functional relationship between environmental temperature and host and pathogen responses and parameterize models to predict the timing and magnitude of seasonal infection outbreaks. To accomplish these goals, we combine manipulative field experiments with a robust set of field observations (including a 5-year pilot study) to identify mechanisms that underlie the complex temperature relationships in this system. We will develop statistical and mathematical tools that combine data types, account for observation uncertainty, and allow for prediction and validation. Our results will contribute to disentangling the role of host- (i.e., immune response, behavior) and pathogen-related (i.e., development, growth) contributions to the timing and magnitude of seasonal outbreaks.