Methods Specified in Revised French Standard NF T90-455 for Enumeration of Cryptosporidium and Giardia in Drinking Water

IDEXX (USA) recently announced that its unique methodologies, Filta-Max and Filta-Max xpress, for the enumeration of Cryptosporidium and Giardia in water, have been specified as standard methods within the revised French standard NF T90-455, “Qualité de l'eau - Echantillonage et/ou dénombrement des oocystes de Cryptosporidium et des kystes de Giardia - Méthode de concentration et de dénombrement.”

The move by the French regulatory agency, AFNOR, specifies the IDEXX Filta-Max systems as one of only two standard technologies to sample Cryptosporidium and Giardia in a number of water matrices including finished or raw water. Once sampled, the enumeration of levels of Cryptosporidium and Giardia can be undertaken using an immunomagnetic separation technique.

“This latest regulatory milestone is great news for IDEXX,” commented Andrew Headland, Senior Business Manager, for IDEXX EMEA. “Already, more Cryptosporidium and Giardia tests are conducted worldwide using the Filta-Max system than all other filtration technologies combined, and this approval is a step forward in our plans to further expand the use of the method into new global markets.”

The IDEXX Filta-Max xpress system was launched as an automated system designed specifically for efficient and rapid elution of Cryptosporidium and Giardia. Using the unique capture and recovery technology first implemented in Filta-Max, the xpress filter module is constructed of 40 reticulated foam discs with a diameter of 5.5 cm (with an 1.8 cm diameter hole), and 39 discs with a diameter of 4.0 cm stacked alternately to a height of 79 cm and then compressed to a height of 3.0 cm. The pressurised water sample is pushed through the filter module, trapping the target organisms within the foam architecture. The filter module is then eluted by a buffer solution using pressurised air, and the resulting sample is concentrated before the enumeration process to determine the level of target organisms.

Filta-Max and Filta-Max xpress are accepted by the U.S. Environmental Protection Agency (EPA) under Methods 1622 and 1623 and is referenced in the UK Guidelines “The Microbiology of Drinking Water (2010) - Part 14”. Filta-Max is referenced in the international standard ISO 15553 (2006).