Antech study says KeyScreen PCR found twice the parasites of antigen testing plus flotation

Antech's KeyScreen GI Parasite PCR found parasites in twice as many fecal samples as IDEXX's Fecal Dx antigen panel and centrifugal flotation combined, according to a study published in Parasites & Vectors. The blinded comparison covered 1,013 dog and cat samples.

Authors came from Antech Diagnostics, Colorado State University and Universidad Nacional de Colombia. Antech said several authors are its employees, and KeyScreen is an Antech product. Antech is a Mars Science & Diagnostics company.

KeyScreen out-detected both antigen testing and flotation

Against the Fecal Dx Antigen Profile with Giardia, KeyScreen detected 1.6 times more positives across the same six parasite groups, Antech said. Flotation, the in-clinic microscope method, found parasites in 6 of the 1,013 samples (0.6%) that KeyScreen missed.

Jimmy Barr, DVM, DACVECC, Antech's chief medical officer, said a screening test "is only as good as what it can find." Antech's takeaway is that PCR should be the primary fecal screen, with flotation kept for selected cases.

The Giardia numbers carry much of the argument. About 9 in 10 Giardia-positive samples were not the A or B assemblages, the two types Antech flags as potentially zoonotic. Among samples KeyScreen typed as A or B, the Fecal Dx panel detected Giardia in 4 of 10. Benzimidazole-resistance markers showed up in about 1 in 5 hookworm positives, a result that bears on which dewormer a clinic reaches for.

The test already sits inside Antech's reference lab menu

KeyScreen is not new. Antech introduced it in January 2022 at the VMX conference in Orlando, as dvm360 reported at the time, and its product page lists 20 intestinal parasites, including hookworms, roundworms, whipworm, Giardia, coccidia, three tapeworm groups and Toxoplasma. The sample is 0.15 grams of feces that can be refrigerated for up to 10 days. Results come back in 24 hours for most customers and within 48 hours for the rest, per the page.

The product page also cites a 2023 comparison in which KeyScreen reported 2.5 times more co-infections than in-clinic flotation alone. The new paper adds the antigen comparison to that flotation result.

IDEXX sells the other side of the matchup. Its Fecal Dx antigen testing page says the test can identify infections missed by other methods, including in pets that receive preventives. IDEXX and Antech now trade peer-reviewed claims on more than one product line. In October, Antech said a JAVMA study found its Accuplex panel caught more Ehrlichia positives than IDEXX's SNAP 4Dx Plus, and our coverage of that paper noted that five of its seven authors work for Antech.

Practices will weigh a send-out PCR against in-house antigen panels

For practice owners, the choice is a send-out test with a one to two day wait against an antigen or flotation result in the exam room. KeyScreen adds assemblage typing and a resistance marker, which matter most when a Giardia case or a stubborn hookworm case comes back. Practice groups with in-house labs and rival reference labs both have a stake in how clinics read the paper.

Antech sits inside a larger Mars diagnostics and care stack, covered in our look at the Mars periodontal AI model. A fecal screen repeats for many dogs and cats each year, so the share of that screen that moves from flotation to PCR is the number rival labs will track.

Antech's product page does not list a price, so the cost per sample against antigen panels is the figure clinics will need from a sales rep. Clinics will decide whether the extra detection justifies the wait.

Source: Antech via Business Wire