Many people have become accustomed to using rapid test kits for COVID-19. However, some may unknowingly use the “positive control swab” included in the box, leading to inaccurate results. Let’s explore what this “positive control swab” is and how it affects our test results.
1 What are positive and negative control swabs?
According to Professor Do Van Dung, Head of the Department of Public Health and former Vice Principal of Ho Chi Minh City University of Medicine and Pharmacy:
“The positive control swab contains a pre-applied antigen. If the test result is negative, the kit is faulty. The negative control swab is antigen-free, and testing it should yield a negative result. A positive result indicates a faulty kit.”
These control swabs are not meant for collecting throat or nasal samples but are included to verify the accuracy of the test kit.
Some rapid test kits include two sample swabs for quality control
As reported by Tuoi Tre, some rapid test kits on the market include two types of sample swabs for quality control. However, many individuals unknowingly use one of these swabs for testing, leading to inaccurate results.
Dr. Nguyen Dinh Phuong of Ward 4, District 3, clarifies:
“Some COVID-19 rapid test kits include a positive control swab, which will show a positive result even without a sample or with any liquid applied. The negative control swab will display a negative result.”
References:
2 Distinguishing between positive and negative control swabs in COVID-19 test kits
Some rapid COVID-19 test kits include a positive and a negative control swab. To differentiate between the two, examine the packaging:
-
Positive Control Swab: Look for the text “Positive Control Swab”
-
Negative Control Swab: This swab will be labeled “Negative Control Swab”
Positive Control Swab and Negative Control Swab labels
Note: Not all test kits include these control swabs. Only select brands provide them. Carefully read the instructions and use the correct test kit to ensure accurate results.
Test kits that include positive and negative control swabs are: Flowflex SARS CoV-2 Antigen Rapid Test (China), CareStart COVID-19 Antigen (USA), and Panbio COVID-19 Ag Rapid Test Device (South Korea).
References:
3 Important considerations when purchasing rapid COVID-19 test kits for home use
When performing rapid COVID-19 tests at home, keep the following in mind:
-
Purchase from reputable pharmacies or medical facilities to ensure product quality.
-
Avoid unauthorized or unknown sources to prevent counterfeits and inaccurate results.
-
Carefully read the instructions on the packaging or seek advice from medical professionals.
Considerations when buying rapid COVID-19 test kits for home use
|
No.
|
Test Kit Name
|
Origin
|
Reference Price (VND/test)
|
|
1
|
Flowflex SARSCoV-2 Antigen Rapid Test
|
China
|
109,200 – 185,000
|
|
2
|
Trueline Covid-19 Ag Rapid Test
|
Vietnam
|
100,000
|
|
3
|
Biosynex Covid-19 Ag BSS
|
France
|
135,000
|
|
4
|
V Trust Covid-19 Antigen Rapid Test
|
Taiwan
|
160,000
|
|
5
|
CareStart Covid-19 Antigen
|
USA
|
130,000 – 150,000
|
|
6
|
Espline SARS-CoV-2
|
Japan
|
190,000 – 200,000
|
|
7
|
GenBody Covid-19 Ag
|
South Korea
|
135,000
|
|
8
|
Humasis Covid-19 Ag Test
|
South Korea
|
198,000
|
|
9
|
Asan Easy Test Covid-19 Ag
|
South Korea
|
150,000
|
|
10
|
SARSCoV-2 Rapid Antigen Test
|
South Korea
|
116,800
|
|
11
|
Panbio Covid-19 Ag Rapid Test Device
|
South Korea
|
170,000
|
|
12
|
Panbio™ Covid-19 Ag Rapid Test Device (Nasal)
|
South Korea
|
152,000
|
|
13
|
Standard Q Covid-19 Ag
|
South Korea
|
4,950,000 (box of 25 tests)
|
|
14
|
SGTi-flex Covid-19 Ag
|
South Korea
|
198,000
|
|
15
|
BioCredit Covid-19 Ag
|
South Korea
|
175,000
|
|
16
|
COVID-19 Ag
|
South Korea
|
175,000
|
This article has provided information about positive and negative control swabs found in rapid COVID-19 test kits. Remember to pay attention to these details when purchasing and using home test kits.
