Mass thermal screening is “ineffective” in limiting the spread of Covid-19 because of asymptomatic or pre-symptomatic cases, research has found.
Evidence published by the Health Information and Quality Authority (HIQA) shows that screening programmes using non-contact devices were not found to be effective in identifying infectious people and limiting spread of disease.
The detection rates, it said, were consistently low across studies.
HIQA looked at whether non-contact thermal screening could be used to effectively identify cases of Covid-19.
It has urged the Government to give “careful consideration” to the cost-benefit of such measures.
Our new evidence summary on non-contact thermal screening found that mass thermal screening programmes, using non-contact devices, at airports were not effective in identifying people with #COVID19. Read it here: https://t.co/m6xUavsl46 pic.twitter.com/xdI7U6HRDp— HIQA (@HIQA) August 6, 2020
HIQA identified 11 primary studies, three rapid reviews and one systematic review relating to Covid-19 and other respiratory virus pandemics.
The studies were conducted in the context of points of entry, including airports, so their relevance to other community settings, such as schools, is uncertain.
The evidence summaries were developed by HIQA following requests from the National Public Health Emergency Team (NPHET) Clinical Expert Advisory Group.
The evidence suggests that thermal screening is resource intensive and, due to a high proportion of asymptomatic or pre-symptomatic cases, results in low detection rates.— HIQA (@HIQA) August 6, 2020
Dr Mairin Ryan, HIQA’s deputy CEO and director of health technology assessment, said: “Thermal screening has been used in other respiratory infectious disease outbreaks, such as the 2009 H1N1 influenza pandemic (swine flu) in Asia and Australia, to improve detection and reduce the time to isolation of infected individuals.
“It typically involves a combination of fever screening, such as temperature testing, alongside self-reporting of exposure risk and or symptoms.
“However, the evidence clearly shows that this type of test is likely to be ineffective in limiting the spread of Covid-19.
“Thermal screening is noted to be high cost and resource intensive. 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 HIQA also published its evidence summary on the immune response, and potential immunity, following infection with Covid-19 or other human coronaviruses.
We have also updated our evidence summary on the immune response, and potential immunity, following infection with COVID-19 or other human coronaviruses. pic.twitter.com/7i6nyu1PE7— HIQA (@HIQA) August 6, 2020
The research reveals that it is unclear whether long-term immunity to Covid-19 is possible.
Dr Ryan added: “Covid-19 antibody was detected in nearly all individuals up to three months after they were infected, and over 90% of patients had developed a neutralising antibody response, which protects against viral infectivity.
“However, a handful of new studies suggest that it may be possible to be reinfected with SARS-CoV-2. HIQA will continue to monitor the evidence on immunity and update our summary as required.”