Coronavirus: Hong Kong’s decision to stop nasal swabs for PCR tests does not pose risk to residents, experts say
- Switch to throat swabs only could reduce sample collection time by two-thirds and will not pose risk to local pandemic situation, says adjunct associate professor
- Respiratory medicine expert notes change to procedure means sensitivity of PCR tests will drop by one-third
A decision by Hong Kong health authorities to stop taking nasal swab samples for Covid-19 polymerase chain reaction (PCR) tests could allow more imported cases to enter the community, but does not pose a risk to the local pandemic situation, medical experts have said.
But respiratory medicine expert Dr Leung Chi-chiu on Monday said he found it “problematic” for the city’s government to opt for a less sensitive method when it had spent a huge amount of resources on PCR testing.
Authorities earlier announced that from Tuesday they would no longer use both throat and nasal swabs for free PCR tests at government-run sites, including those at the airport, with all screenings to collect throat samples only to boost efficiency and service capacity.
Leung, a former chairman of the Hong Kong Medical Association’s advisory committee on communicable diseases, said the sensitivity of the tests could drop by one-third if only throat swabs were taken, but such a change might have “little effect” on the imported case situation.
The number of daily imported cases in Hong Kong passed the 500 mark for the first time since the pandemic began nearly three years ago, with health officials on Monday reporting 565 infections among inbound travellers.
The figure was among the 5,198 infections logged on the same day, alongside 5 more deaths, bringing the overall tally to 1,952,893 cases and 10,475 related fatalities.
Citing overseas studies, Leung noted that PCR tests conducted using both throat and nasal specimens had a sensitivity of 97 per cent, while screenings which only relied on the former stood at 68 per cent.