By Johnnie Rosario
(Yigo, Guam) If you've been suspicious about the hundreds of nearly-100-percent daily COVID-19 negative test results from the public health laboratory, the manufacturer of the testing machine they use has confirmed your suspicions.
The Department of Public Health and Social Services and the Governor's Office released a statement on April 23, when local media asked whether the government would retest people who had tested negative for the virus via the Abbott ID Now machine used in the public health lab. The inquiry followed an April 14 urgent notice from Abbott Laboratories, the manufacturer of the testing machine, telling users that transporting test swab specimens in a vial with a dilution liquid prior to inserting the swab into the machine may yield a false negative.
"The [Guam Public Health Laboratory] was updated on April 14 by the Abbott Point-of-Contact Technical Consultant Trainer that there are some false negatives due to how the specimens may be stored through the Viral Transport (3ML) Medium (VTM) Collection System. Dilution of swabs immersed in 3mL liquid/medium may have caused false-negatives. GPHL ran its validation tests using 1mL liquid/medium. The Abbott Technical Consultant Trainer acknowledged that GPHL's 'validations went very well but that could be due in part to the fact that you're only using 1mL of VTM for each swab (whereas many of our customers are using 3mL). The GPHL will continue to accept 1 mL of VTM for each swab, which will minimize negativity of the result and will yield higher accuracy and less false negativity." (emphasis added)
We didn't trust the government was telling the people of Guam the truth. So, we tweeted Abbott Laboratories directly on April 30, "Is it acceptable to use a 1ml transport solution with the swabs when running tests on the ID Now machine?"
Abbott responded today:
"The use of viral transport media can reduce the sensitivity of the test through dilution. We have instructed our customers not to use this method."
All of the tests conducted by DPHSS (including the hundreds that have been swabbed at village drive throughs), have been diluted in the VTM and transported to and tested later at the GPHL in Tamuning, where the Abbott ID Now testing machine is located.
Kandit first raised the concern to DPHSS following a story we ran on April 22, 2020, regarding the misuse of the Abbott ID machine. We asked Bertha Taijeron, DPHSS spokeswoman with the Joint Information Center, "Was the government aware of this problem, and is there now a plan to retest those whose tests were stored in a solution before inserting into the Abbott machine?"
The following day, DPHSS and the Governor's Office responded to the inquiry within JIC Release No. 88, asserting that an Abbott trainer told the government it is okay to use the 1mL dilution VTM; and that it would continue to do so.
Today we asked the Joint Information Center for comment on Abbott's confirmation that it has told its customers, including GovGuam, not to use the dilution VTM:
"We asked Abbott about the 1mL claim made by GovGuam regarding their machines and they responded. Abbott’s response directly contradicts GovGuam’s. May we please have a comment about this?"
There has been no response from the government of Guam as of the publication of this story.
Since DPHSS and the Governor's Office doubled down on using the dilution transport system on April 23, the GPHL alone has run 1,122 tests through the Abbott ID Now machine.
Of those tests, nine came back positive, and 1,113 were negative. All of the people tested were symptomatic for COVID-19.