Q-229. Pathogen Measurements in the St. Lucie River Estuary

H. Solo-Gabriele1, A. Abdelzaher1, M. Wright1, Y. Deng1, C. Ortega1, L. Stark2;
1Univ. of Miami, Coral Gables, FL, 2Florida Dept. of Hlth., Tampa, FL.

A sampling effort was initiated to measure pathogens within the St. Lucie River Estuary, FL, USA, due to concerns about elevated fecal indicator levels within the waterway after the 2004 hurricane season. A total of 18 measurements were conducted at seven sites. These measurements included the analysis of physical-chemical parameters (pH, salinity, temperature, and turbidity), and measurements of bacterial indicators (enterococci, fecal coliform, E. coli, and total coliform), viral indicators (somatic and MS2 coliphage), viral pathogens (enterovirus by culture and enterovirus, adenovirus, hepatitis A, norovirus by PCR), and protozoan pathogens (Cryptosporidium and Giardia). Results showed that bacterial and viral indicator levels were within typical ranges (101 to 102 and < 102, respectively) for urban watersheds, with higher levels typically observed within more inland sites characterized by lower salinities. All pathogen results were negative with the exception of one. This one sample tested positive for culturable virus (8.5 MPN/100 L), subsequently confirmed specifically as a reovirus. Notable physical-chemical parameters for the sample that measured positive for reovirus included low salinity (<1 ppt) and high water temperature (31 oC). Indicator bacteria and indicator virus levels for this sample were within average values typically measured within the current study for the St. Lucie River Estuary and were relatively low for low salinity sites. Overall results suggest that low salinity relates to elevated levels of bacterial and viral indicators. Further measurements are recommended within low salinity sites of the St. Lucie River Estuary, with an emphasis on identifying the persistence and source of reovirus. A risk assessment is also recommended in order to better establish the human health significance of the positive reovirus measurement.