Updated: 8/17/2011 11:30 p.m.

Bayer HealthCare confirmed that it has recalled all retail stock of its Contour 10- and 25-count and Counter TS 10-count diabetes test strips over a "packaging issue" that resulted in inaccurate glucose readings in some of its products.

Bayer’s voluntary recall in the U.S. joins government-recall of all Contour glucose testing strips in Hong Kong. *

During routine quality testing, Bayer found that strips from half of its bottles of low-count strips produced false readings, the Centre for Health Protection of the Hong Kong Dept. of Health reported.

"In-house investigation findings so far point to interaction of the strips with the gas trapped inside the bottles as the cause of the defect," according to the CHP report.

"These actions are not taken as a result of any adverse events reported to Bayer," according to a Bayer press release. "Instead, Bayer is taking this action out of an abundance of caution to address a packaging issue which, under certain conditions, can cause some test strips packaged in some small-count vials to operate outside of US FDA-cleared performance specifications and produce a low-bias reading during blood glucose testing."

The company initiated a voluntary U.S. recall of the affected products from distribution channels and offices of health care providers, Bayer spokesperson Susan Yarin told MassDevice.

No new shipments of the affected tests have been shipped to the U.S. since June, and Bayer expects the remaining quantities in the market to be "really small," according to Yarin.

To make up for the dwindling supply of the lower-count products Bayer upped the shipment of the 50-count boxes, which were unaffected by the packaging error, Yarin told us.

That tactic doesn’t apply to Hong Kong, where the watchdog agency wasn’t so sure that the difference between a 50- and 25-count vial of testing strips was apparent enough to stave off a total recall.

"Given that so far there is no indication that the strip and the packing method for each of the four package sizes is unique and not identical, and the lack of a satisfactory explanation for the sparing of the 50-unit bottles, DH considers it only prudent to advise for a blanket recall of all four package sizes, the 50-unit one included," a Hong Kong Dept. of Health spokesperson said in prepared remarks. "The recall scope will be reviewed on availability of new evidence."

Bayer has informed the FDA of the recall, first reported by Diabetic Investor, and the company has determined that the risk that users may misunderstand the recall and suffer injury from failing to use their glucose testing device is greater than the risk posed by the potentially inaccurate readings from the test strips, Yarin said.

While the FDA has taken no action and no adverse events association with the inaccurate tests have yet been reported, it’s not unheard of for glucose testing strip recalls to receive Class I status, generally reserved for the most serious type of recall that involves situations with a reasonable probability that continued use will cause serious injury or death.

Roche Diabetes Care was slapped with a Class I recall in June for strips distributed in France that reportedly read falsely elevated blood glucose levels.

*Correction, August 11, 2011: This article originally stated that the U.S. recall followed the Hong Kong recall. Bayer reported that it was in discussions with the FDA prior to the Hong Kong recall. Return to the corrected sentence.