This winter, the simultaneous epidemic of the new coronavirus and influenza is a concern.
The ban on general sales of antigen test kits that can simultaneously check whether they are infected has been lifted.
What is a simultaneous test kit?
What are the benefits?
What are the precautions when using it at home?
I will explain in detail.
Q. What is a “simultaneous test kit”?
I think that there are many people who have used the antigen test kit for the new corona, but the "simultaneous test kit" can check the presence or absence of infection with both the new corona and influenza in a single test. is similar to a corona test kit.
Simultaneous test kits have so far been available only at medical institutions.
However, amid concerns about simultaneous epidemics, there was an opinion that a system should be established that allows testing at home in order to prevent medical institutions from being overwhelmed.
Under these circumstances, the Ministry of Health, Labor and Welfare held an expert subcommittee on the 28th and decided to lift the ban on selling to the general public based on the discussions.
Q. Wasn't the simultaneous test kit already in use?
Already used in the medical field.
At the fever outpatient clinic of "Tamura Clinic" in Suginami Ward, Tokyo, in November, patients with influenza in addition to the new corona have begun to appear, but since it is difficult to determine which one based on symptoms alone, it is difficult to use a simultaneous test kit. progressing.
In this fever outpatient clinic, more than 280 people have been diagnosed with the new coronavirus this month, and 16 people, mainly children, have been diagnosed with influenza.
On the 24th of this month, patients continued to visit, and in the morning alone, 15 people were diagnosed with the new coronavirus and one with influenza.
Of these, a 9-year-old girl had a fever of over 38 degrees, and she was found to be infected with influenza type A when examined with a simultaneous test kit.
In addition, a 30-year-old man was diagnosed with the new corona when using a simultaneous test kit because he had fever symptoms but no one in his family was infected.
Q. How do I use it at home?
We interviewed Dr. Akifumi Tokita, a member of the Public Health Committee of the Japan Pediatrician Association and also in charge of the fever outpatient clinic in Minato-ku, Tokyo, about what points to be aware of when actually using a simultaneous test kit at home. Did.
[Point 1] After 12 hours or more after fever
Both corona and influenza may be "false negative" instead of "positive" immediately after fever.
In particular, it takes time for influenza to become positive after fever, so if you use a simultaneous test kit at home, you should wait about 12 hours or more after fever before testing.
(*You may be able to get tested early at a medical institution, so please consult with us.)
Dr. Tokita said, "I understand the feeling of wanting to be tested right away when you have a sore throat or a fever. Even if the test result is negative, do not go to work, rest at home, see how things are, and wait for a while. I want you to check it again," he said.
[Point 2] Do not cool the test kit too much
The storage temperature of the test kit is 2 degrees to 30 degrees.
If you store it in a refrigerator or use it in an unheated room in winter, the reaction will not progress and there are cases where you get a false negative.
Dr. Tokita said, "It's a small thing, but temperature also has an effect. Conversely, if you use a test kit that you obtained in the middle of summer and left unattended, it may result in a false positive, so please use it properly." was
[Point 3] Rotate the cotton swab and carefully collect
At medical institutions, samples are collected by inserting a cotton swab into the nasopharynx, a place deep in the nose where many viruses are found. is to be taken from
For this reason, according to Dr. Tokita, the sensitivity is about 10% lower than when performed at a medical institution.
When testing at the tip of the nose, insert the cotton swab as far as possible within the range described in the package insert, rotate the swab firmly the specified number of times, and carefully collect the sample. I want you to
[Point 4] Thoroughly dissolve the sample
After collecting the specimen, insert the cotton swab into the attached container containing the solution and dissolve it, but there is a point here as well.
It is important to swirl the cotton swab in the solution or rub it over the container several times to dissolve it well.
Dr. Tokita says, "It is recommended that you pinch the container and rotate the cotton swab at least 10 times. You can't overdo it, so if you dissolve it thoroughly, the results will be quite different." I was.
[Point 5] Focus on the color of the result judgment line
Drop the solution containing the sample on the test kit, and a line will appear to determine whether it is positive or not.
The higher the viral load, the darker the line, but the important thing here is the color.
For each test kit, if a color different from the positive color specified appears, there is a possibility of a "false positive" reaction even though it is not positive.
Dr. Tokita says, ``There are cases where a false positive occurs due to the ingredients in the runny nose, and in that case, for example, a pink line may appear, but a gray line may appear.It is not the original color. Or if the line is thin and you can't judge it, please consult a medical institution."
[Point 6] Understand and use the difference in accuracy
In addition to the sampling method, sampling site, and timing of sampling, whether the fever is high, whether the vaccine has been administered, and the storage conditions of the kit all affect the test results.
Dr. Tokita emphasizes that even with the same simultaneous test kit, there is a difference in accuracy between testing at a medical institution and testing at home.
For this reason, it should be used only as a supplementary measure when the fever outpatient is urgent, and do not think that the test result is everything, especially when you have symptoms but it is negative, do not go out without worrying about the result. that is important.
On top of that, it is said that it is important to read the package insert carefully and keep the points of usage firmly in mind so that you can get as close to the correct results as possible when using it at home.
Young children are especially susceptible to a variety of infections with similar symptoms, some of which can have serious consequences.
For this reason, it is important not to feel relieved even if corona or influenza is negative, and to see a family doctor directly if you have any uneasy symptoms.
Q.Can you secure stock?
Whether the supply of test kits required by the market can be secured is an issue.
Currently, 12 products from 10 companies are approved for manufacture and sale by the Ministry of Health, Labor and Welfare.
Of these, 5 products from 4 companies have been approved for sale to the general public, meeting the conditions such as being able to collect specimens from the nostrils inside the nostrils.
One of these four companies will sell to the general public, and the timing and price at which sales can start will be considered in consideration of the infection situation.
The remaining three companies say that it is difficult to sell to the general public at this time in order to secure inventory to supply to medical institutions.
Regarding simultaneous test kits, the Ministry of Health, Labor and Welfare says that each manufacturer has an inventory of 39 million tests for medical institutions, but for the general public, the supply is expected to decrease for the time being.
Q.Is the number of people infected with influenza increasing?
As of November 20, 546 cases were reported nationwide from medical institutions throughout the week.
When the number of patients per week per medical institution exceeds 1 nationwide, it is said to be a "nationwide epidemic", but at the moment it is far below 0.11.
Since the spread of the new coronavirus, influenza infection has not spread in 2020 and 2021, but as of the 20th of this month, patients have been reported in 31 prefectures nationwide, and the number of patients per medical institution has increased. The number has gradually increased to 0.55 in Kyoto, 0.51 in Osaka, and 0.30 in Tokyo.
It has slightly increased from the previous week, and experts are calling attention to the possibility that the number of patients will increase in the future.
Q. What do experts think?
Professor Kazuhiro Tateda of Toho University, who is a member of the government's subcommittee on countermeasures against the new coronavirus, said, ``If the number of corona-infected people and fever patients increases explosively, the fever outpatient site will be under pressure. If it is possible to determine whether it is coronavirus or influenza with a simultaneous test kit, people with a low risk of becoming seriously ill will receive a prescription for medicine through online medical treatment and receive medical treatment at home, and outpatients with a high risk of becoming seriously ill will be prioritized. , so it is very significant," he said.
On the other hand, Professor Tateda said, ``It should be noted that the timing of positive results for the coronavirus and influenza is slightly different. Even if it's negative, it's necessary to test again the next day, and if you're not feeling well, you need to be careful not to go outside and spread the infection."