Giardia and cryptosporidium as biohazard in frozen food products.

Abstract

Giardia and Cryptosporidium commonly cause food and water-borne disease outbreaks worldwide. They occur in both normal and immunocompromised hosts causing both health and economic burdens. The globalization of Free Trade Agreement (FTA) on food products increases the possibility of more extensive transmission. Hazard Analysis Critical Control Point (HACCP) system at present covers only conventional bacteria. As a major seafood exporter to various regions of the world, Thailand is considering to include those protozoa into the HACCP for the frozen food industries. Hazard identification of protozoa was performed in raw materials, food products and water used in the industry. Raw and treated water samples were collected by large volume technique through a filter with 1 micrometer (μm) nominal porosity. Immunomagnetic separation (IMS) for Giardia and Cryptosporidium was then applied to eluted and concentrated water. Identifications were individually performed by immunofluorescent and PCR techniques. In raw water, Giardia was found in 42.8-60% whilst Cryptosporidium was found in 20-35%, but no contamination in treated water samples was found. Giardia was also identified in raw materials and food products. The viability of recovered protozoa was analyzed by the reverse transcriptase polymerase chain reaction (RT-PCR). The giardin beta-subunit mRNA gene was selected as the target. Positive RT-PCR for Giardia recovered from raw materials and food products indicates viability. The effect of various concentrations of ultra violet light and difference in duration of solar exposure to control those viable recovered biohazards was studied.