ABSTRACT
Studies evaluating the relationship between microbes and human health at non-point source beaches are necessary for establishing criteria which would protect public health while minimizing economic burdens. The objective of this study was to evaluate water quality and daily cumulative health effects (gastrointestinal, skin, and respiratory illnesses) for bathers at a non-point source subtropical marine recreational beach in order to better understand the inter-relationships between these factors and hence improve monitoring and pollution prevention techniques. Daily composite samples were collected, during the Oceans and Human Health Beach Exposure Assessment and Characterization Health Epidemiologic Study conducted in Miami (Florida, USA) at a non-point source beach, and analyzed for several pathogens, microbial source tracking markers, indicator microbes, and environmental parameters. Analysis demonstrated that rainfall and tide were more influential, when compared to other environmental factors and source tracking markers, in determining the presence of both indicator microbes and pathogens. Antecedent rainfall and F+ coliphage detection in water should be further assessed to confirm their possible association with skin and gastrointestinal (GI) illness outcomes, respectively. The results of this research illustrate the potential complexity of beach systems characterized by non-point sources, and how more novel and comprehensive approaches are needed to assess beach water quality for the purpose of protecting bather health.
Subject(s)
Bathing Beaches , Gastrointestinal Diseases/microbiology , Respiratory Tract Infections/microbiology , Seawater/microbiology , Water Microbiology , Coliphages/isolation & purification , Enterococcus/isolation & purification , Enterovirus/isolation & purification , Environmental Exposure/adverse effects , Environmental Monitoring/methods , Epidemiological Monitoring , Florida/epidemiology , Gastrointestinal Diseases/epidemiology , Humans , Rain , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/transmissionABSTRACT
A comparative assessment of the virulence of Babesia bovis clones that adhere or not to bovine brain endothelial cells was done using two clones of B. bovis: (1) a clone phenotypically characterized as virulent (2F8) and (2) a clone of reduced virulence (RAD). Of these subpopulations, we selected those that had adhesive characteristics (a) or nonadhesive characteristics (na) in cultured endothelial cells. Twenty Holstein cattle, 12 months of age or older, were used in this study, and these cattle were randomly assigned to five groups of four animals each. The clones and their respective subpopulations were inoculated via intramuscular injection at a 0.5 x 10(7) infected erythrocyte dosage. Group A was inoculated with aRAD, group B with naRAD, group C with a2F8, group D with na2F8, and group E remained as a control. All inoculated animals showed a decrease in the packed cell volume (PCV), with group D showing the largest decrease (39.53%) and longest time (7 days) with rectal temperature above 39.5 degrees C. Babesia was observed in stained blood smears from only six cattle. While the four parasite subpopulations were pathogenic, significant differences were not noted among them, despite that the subpopulations considered to be virulent caused the greatest reduction in PCV per individual.
