Temperature scanning at ports and airports is ineffective in identifying incoming passengers infectious with Covid-19 and in limiting the spread of the disease, according to a new report.
Thermal screening is high cost and resource intensive, and detection rates are low, the report by the Health Information and Quality Authority (Hiqa) states.
There have been numerous calls for the screening of incoming passengers at points of entry to the State as a way of curbing the spread of Covid-19. Mass screening has been used in some countries in other infectious disease outbreaks – such as in Australia and some Asian countries during the 2009 swine flu pandemic.
However, the evidence review by Hiqa says this type of screening is likely to be ineffective in limiting the spread of Covid-19.
“Detection rates are very low due to large proportion of cases that have no symptoms, are infectious before showing any symptoms or who do not present with fever,” the report says.
The report says not all cases present with fever, a substantial proportion are asymptomatic and about 25 per cent of symptomatic cases never develop a fever.
In addition, some cases may “evade detection” by taking common medicines that reduce body temperature.
Using thermal screening could result in a false sense of safety and reduce the number of trained healthcare staff available to work in other areas of pandemic management, the report says.
The report finding on the effectiveness of thermal screening relates to point-of-entry only and its applicability to other settings, such as schools, is uncertain, the authors say.
Separately, Hiqa has published an evidence summary on potential immunity following infection with Covid-19 or other coronaviruses.
Its review of available international research finds that antibodies were detected in nearly all people up to three months after infections, and more than 90 per cent of patients had developed a neutralising antibody response, which protects against further infection.
However, a handful of new studies suggest it may be possible to be re-infected with Sars-CoV-2, the virus that causes Covid-19.
“It remains unclear whether long-term immunity to Sars-CoV-2 is possible,” according to Dr Máirín Ryan, Hiqa’s deputy chief executive and director of health technology assessment.
Currently, passengers arriving in Ireland are required to complete a passenger locator form indicating where they will stay for the following 14 days, and to self-isolate at this address for the period.