Use of Over-the-counter COVID-19 Test Kits
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The College has noticed that a variety of over-the-counter Coronavirus Disease 2019 (COVID-19) self-test kits are being promoted in the market. We are concerned that the public could be misled by the results of these kits.
These over-the-counter test kits usually utilize pinprick blood samples to detect IgG or IgM antibodies against the SARS-CoV-2 virus. Antibodies are produced over days to weeks after infection; the level and timing of response vary among individuals. The performance of these kits, including sensitivity and specificity (i.e. respectively whether the test can accurately exclude COVID-19 infection and whether a positive result is reliable to indicate actual infection), also varies among assays. Thus, the public must be aware of the risk of false negative and false positive results.
A false negative result may cause a false sense of security, which could potentially increase transmission of the virus to others and result in delay in seeking medical consultation and management. On the other hand, a false positive result will lead to undue anxiety and unnecessary investigations, and even public health measures such as isolation of the person and his or her close contacts.
The College reiterates that the current test of choice for the diagnosis of active COVID-19 infection remains polymerase chain reaction (PCR)-based tests detecting viral nucleic acids. The detection of
antibodies is neither a suitable nor a reliable alternative. The College urges the public to seek advice from medical professionals if COVID-19 infection is suspected.
End / Wednesday / 29 April 2020
Issued at HKT 14:00
Tel: +852 2871 8756
市面上售賣之試劑盒，一般採用針刺血液樣本來檢測 SARS-CoV-2 病毒的 IgM 或 IgG 抗體。抗體於感染後數天至數週方能達至可偵測的水平，抗體之濃度及產生之時間亦因人而異。市場上不同牌子之測試劑,其敏感性 (sensitivity) 和特異性 (specificity) 不盡相同，因此市民應注意有假陰性和假陽性
2020 年 4 月 29 日 (星期三) 2 時正
Tel: +852 2871 8756