Trouble with COVID-19 test kits: Carefully read precautions in advance and use one suitable for the purpose
In the context of preventing the spread of COVID-19 infection, there is a growing interest in COVID-19 test kits, which are used to check for COVID-19 infection when feeling unwell, before traveling or other events. On the other hand, local consumer affairs centers and the like across Japan have received numerous inquiries and complaints about COVID-19 test kits.
In order to prevent problems related to COVID-19 test kits, NCAC would like to share trouble cases and advice for consumers.
Sample cases
- [Case 1]
- I bought a PCR test kit. I've found that test results show whether the infection risk is high or low, instead of positive or negative.
- [Case 2]
- When I used an antigen test kit on the market, test results showed negative. Later, I've found that I am positive.
- [Case 3]
- I didn't know I had to take a blood sample by myself for an antibody test. I was unable to collect it.
- [Case 4]
- I bought a PCR test kit at a convenience store. I can't find a way to send a sample.
- [Case 5]
- I bought test kits for members of a circle and brought their samples to the company concerned. However, I haven't received some of the test results.
- [Case 6]
- I placed an order for an antigen test kit online. However, I haven't received my order yet and I cannot contact the seller.
About test for COVID-19 infection
*The following is based on information as of November 4, 2021.
There are a few ways to test for COVID-19 infection: PCR test, antigen test (qualitative or quantitative), etc. Among COVID-19 test kits on the market, antigen test kits sold as "extracorporeal diagnostic medicines" have been approved by the Japanese government.
Antigen test kits sold as "extracorporeal diagnostic medicines" are intended for self-examination and test results are not equivalent to a diagnosis. You need to visit a medical facility to receive a diagnosis.
Antigen test results show whether a person was infected by COVID-19 in the past, and do not show the status at the time of testing.
Difference between antigen test and PCR test
Qualitative antigen test
| What's inspected | proteins characterizing virus (antigens) |
|---|---|
| For accuracy | a certain viral load is required for detection |
| Place of test | where a sample is taken |
| Time for determination | about 5 to 30 minutes |
Quantitative antigen test
| What's inspected | proteins characterizing virus (antigens) |
|---|---|
| For accuracy | the viral load required for detection is less than that required for the qualitative antigen test |
| Place of test | test equipment required |
| Time for determination | about 30 to 40 minutes |
PCR test
| What's inspected | gene sequences characterizing virus |
|---|---|
| For accuracy | the viral load required for detection is less than that required for the qualitative antigen test |
| Place of test | test equipment required |
| Time for determination | a few hours |
Advice for consumers
- Results from test kits do not determine whether or not a person is infected by COVID-19.
- Check "what can be determined by test results" and "how to take and send a sample" before using a test kit.
- Check seller's information to avoid trading with fraudulent online shopping sites.
- In case of trouble or concern, consult your local consumer affairs center.
