Breathomix's Covid breath test cleared infected people — health boards shelved it

The SpiroNose, a coronavirus breath test developed by Leiden company Breathomix, was introduced in Amsterdam on 29 January 2021 on the advice of the government's Outbreak Management Team, intended for dozens of locations nationwide as an alternative to the nasal cavity test.

The rollout hit its first wall within weeks: a number of people cleared of having coronavirus by the breath test later confirmed positive via PCR. After an internal investigation the system was reinstated and described as 'very reliable', but faith in it kept draining.

By July 2021, regional health boards were refusing to use the system, the Volkskrant reported: checks at three test centres found that for the vast majority of people the results were so unreliable that they needed another test anyway. Most of the units, bought with a multi-million euro investment, were languishing in storage, and the cabinet was expected to ditch the project shortly.

False negatives are the worst failure mode for a screening tool: every one that surfaces publicly undoes the premise of screening at all.

The reinstatement after the internal investigation — 'very reliable' — did not survive contact with the health boards' own control tests.

The system scaled ahead of proof: units were bought for dozens of locations on the strength of early advice, before field reliability was established.

Once several boards independently demanded control tests, the test's reputation was gone regardless of what the data eventually said.

For a diagnostic tool, trust is the product: field reliability, not a celebrated launch, decides whether the system keeps using you.

Regional health boards refused the system and insisted on control tests that showed it too unreliable for most users; Breathomix said it was consulting with health boards and the ministry about 'the best strategy for further rolling out' the test, while the cabinet was expected to drop the project.