Combatting Circulating Infectious Diseases in California: Evaluating New Approaches to Surveillance and the Costs of Outbreaks on Public Health Agencies
The costs of circulating infectious diseases in California and the need for better approaches to surveillance are major challenges for surveillance laboratories tasked with controlling and preventing the spread of disease. This is particularly true for respiratory pathogens and measles. Although vaccines are widely available for common respiratory tract pathogens as well as measles, outbreaks of both still occur, straining California local and state public health agencies on an annual basis. In the first part of this thesis, I critically evaluate the utility of multiplex molecular diagnostics for public health surveillance of respiratory pathogens and provide recommendations for the development of new assays that better meet the needs of the surveillance community. Next, I present a case study in which multiplex assays were used to study respiratory infections in nursing homes in California. This case study demonstrates the utility of multiplex assays for studying correlations between environmental contamination and human illness and suggests that this approach could be an effective tool for infection control in healthcare settings. Last, I present a study in which we modeled the epidemiological and economic impact of two recent measles outbreaks in California (the 2014-15 U.S. multi-state and the 2016-17 measles outbreak). The results of this study suggests that, at the county level, population density and the distance from the epicenter of the outbreak are the best predictors of contact counts and costs for these two measles outbreaks. In addition to providing insights into the true costs of prior measles outbreaks, this model also could be used prospectively by local health departments to better manage future outbreaks. Collectively, these studies provide important insights and tools for improving surveillance of respiratory pathogens, more effective controlling respiratory infections in healthcare settings, and decreasing costs of outbreaks.