Files
Abstract
Cyclospora cayetanensis is an emerging parasite in the United States. Episodes of cyclosporiasis, a gastrointestinal infection caused by the ingestion of Cyclospora oocysts, are often reported with the Cyclospora National Hypothesis Generating Questionnaire (CNHGQ) form. Surveillance data collected with the CNHGQ form showed evidence of annual cluster cases of Cyclospora in Florida from 2014 to 2018 with 277 clinically linked cases of cyclosporiasis. The annual incidence rate (per 100,000 persons) of Cyclospora in Florida increased from 0.27 in 2014 to 0.51 in 2018, although the highest incidence was in 2017 at 0.59. The data also revealed that 44.8% of the cases were related to non-travelers. New food vehicle associations such as watermelon, pineapples, grapes, lemon/lime, pineapples, raw onions, tomatoes, cucumbers, and raw onions were reported. In addition to helping identify cluster cases of Cyclospora, CNHGQ data was also used to create a fresh produce sampling plan in Florida during the months of May-July of 2019. Variables from the CNHGQ data, Cyclospora’s U.S. seasonality, and composite samples of the fresh produce (100-400 g) were used to increase the specificity of the fresh produce sampling plan. Two hundred sixty-three fresh produce samples were collected and composited into 810 samples. Molecular detection via nested PCR detected 13.3%, 29.9%, 27.1% and 24.2% of the fresh produce samples for months May through August, respectively, were presumptive positives for Cyclospora spp. These results suggest evidence for the increased molecular detection of Cyclospora oocysts with the use of composite samples and the CNHGQ surveillance data. The chemical inactivation of protozoan parasites was also investigated with Salmonella Enteritidis cells and Bacillus subtilis spores as controls. Encephalitozoon intestinalis spores were undetected for different formulations of peracetic acid and a blend of fatty acids tested at 2000 ppm. Slightly acetic electrolyzed water at pH values 6.41 (19.5 °C), 6.03 (19.3 °C), and 5.51 (19.3 °C) and tested at 100 ppm resulted in log reductions of >6 log CFU/mL for S. Enteritidis cells and B. subtilis spores at all exposure times except at 1 minute for B. subtilis spores.