More than 20 flights into Ireland from London in the first three weeks of December contained at least one passenger who subsequently tested positive for Covid-19.
Between December 1 and December 18 one or more confirmed cases were noted on 24 separate flights from the English capital into Irish airports.
The news comes in the wake of Ireland joining the majority of EU countries in halting direct air travel from Great Britain as a new strain of the coronavirus takes hold in the south of the UK.
"The Government should arrange testing for all London passengers from the past fortnight,” a source within Ireland’s contact tracing centres said.
The Department of Health was asked to clarify the number of flights inbound to Ireland thus far in December which have subsequently confirmed cases of the virus, but had not responded at the time of publication.
Typically, only the passengers in the three or four rows both behind and in front of a confirmed case will be reached by contact tracers.
Meanwhile, the standard of data being used by contact tracers here has not improved, despite assurances from management that access would be given to the data contained on passenger locator forms (PLFs) to improve the tracing process.
Earlier in December, the roughly 800 contact tracers currently working were informed that their cohort working specifically on flight tracing would be granted access to the forms ahead of the Christmas travel rush in order to enhance the quality of the data.
However, the move away from flight manifest data provided by the airlines, on which tracing is currently based, has yet to occur in any meaningful fashion, according to several sources.
Last week, the Department of Health confirmed that since August PLFs had been accessed for contact tracing purposes on just five occasions.
In that time, roughly 500,000 of the mandatory forms for passengers inbound on planes and ferries had been filled out, meaning the data contained on the locator forms was used for contact tracing in just 0.001% of cases.
As of November 29, Ireland moved to the EU’s traffic light system, meaning many incoming passengers are not required to self-isolate at all.
Contact tracers said that issue, coupled with the inadequate information available from the airlines, a spike in the number of cases, and the marked increase in traffic due to Christmas could have been enough to overwhelm the tracing system.
The data contained on passenger locator forms is a great deal more comprehensive than that present within flight manifests – comprising name, address of stay, contact number, email, age, flight number, country of departure, length of stay, and departure date.
It is an offence, punishable by a fine of up to €2,500, either to fail to fill in a form or to fill it out with misleading information.