False-positive AI result in Trinidad and Tobago

Routine poultry screening in uncovered a sample that tested positive for bird flu, but the latest tests show that the result was a false positive.

The sample was collected during August by the nation’s Ministry of Agriculture Poultry Surveillance Unit.

“Samples were subsequently forwarded for confirmatory testing at the veterinary Laboratories Agency laboratory at Weybridge, England,” a release from the Agriculture Ministry said.

All samples tested negative for AI at the lab, which is a reference lab for the World Organisation for Animal Health.

The Ministry said false positive results were not unusual for screening tests since they are very sensitive.

In the US, for example, there have been more than a dozen initial screening tests that have shown potential H5N1 infection, but confirmatory tests have shown these samples to be free from bird flu, or infected with a low-pathogenic strain that is not harmful to humans.

Because of the likelihood of false-positive initial testing, the US recently changed its rules for reporting bird flu.