Identification of thresholds on Sea surface temperature and coastal chlorophyll for understanding environmental suitability of V. vulnificus incidence

Vibrio spp. are pathogenic bacteria native to warm and brackish water. Vibriosis- the disease caused by these pathogens in humans accounts for around 80000 illnesses and 100 deaths annually in the United States. Of all the species, V. vulnificus has the highest mortality rate of all seafood-borne pathogens in the United States. In this context, understanding the environmental conditions that lead to increased V. vulnificus growth and spread can aid in the development of early warning systems and targeted prevention strategies. Besides sea surface temperature (SST), biotic parameters like coastal chlorophyll are also determined to affect V. vulnificus incidence in humans locally. However, the precise role of coastal chlorophyll as a potential confounding variable is understudied. Moreover, the spatial scale to which the data for environmental variables could be obtained also poses characterization constraints for researchers since the commonly employed in-situ sampling-based methods usually work with discrete locations covering a small area. The present study uses the odds ratio analysis to determine SST and chlorophyll-a threshold values critical to V. vulnificus incidence. The analysis reveals a definite positive relationship between remotely derived environmental variables and the odds of V. vulnificus incidence, where a specific statistical value of SST and chlorophyll-a marks a clear distinction between low and high odds of V. vulnificus incidence. This finding translates into a consistent pattern when checked for counties of coastal Florida. We anticipate our methodology to help distinguish between high and low-risk conditions, enabling public health workers to take proactive measures to protect the health and well-being of the public.