Meral Candan / DUVAR
The World Health Organization (WHO) General Directorate Tedros Adhanom Ghebreyesus recently called on countries engaged in the fight against the coronavirus pandemic to increase the number of tests being conducted. Every country has been prioritizing different strategies. On this subject, it appears that South Korea and Hong Kong have emerged at the front of the pack in terms of the numbers of tests conducted and the other methods they have utilized.
In Turkey, the 20,000 tests that have been conducted to date just barely reach the daily number of tests that were conducted in South Korea. Based on the figures shared every day by Minister of Health Fahrettin Koca, as the number of tests increase, so do the number of cases. Speed is very important when it comes to determining whether one has the highly-infectious coronavirus. For this reason, a number of countries are using testing kits that provide results within 15 minutes.
Koca said on March 19 that these faster test kits would begin to be used throughout in Turkey within a few days and that the target was to test 10-15,000 people a day. So what do we know about these tests? For this answer and more, we spoke to Dr. Serhan Ünal and Dr. Özlem Kurt Azap, who are both currently working on the virus.
Polymerase Chain Reaction (PCR) tests have been used a fundamental method in Turkey and throughout the world. The tests, used in a laboratory, take between 1-4 hours to yield results. With PCR, samples from a person's respiratory system are taken and it is determined whether or not there is a presence of the virus' DNA. According to Dr. Kurt Azap, the PCR tests are a method that had been used prior to the emergence of corona, and that many people apply to receive one and it that is more expensive that the faster tests.
The most common method to emerge among testing devices is the 15 minute antigen test. This test also takes respiratory samples but instead of looking at the virus' DNA, like the PCR test, it focuses whether or not the virus has left a trace in the body. Based on Koca's announcement, the antigen test will be used in Turkey in the upcoming days. The antibody test, which is used less often, takes samples from blood in the finger and determines if there are responses to the virus in the body based on antibodies.
At the moment, the PCR tests used in Turkey are produced locally. In fact, Koca said in a recent statement that half a million of these tests had been sold to the United States. 2,000,000 of the antibody tests that are soon to be used in Turkey were purchased from China.
To what extent the tests are reliable has become a major topic of curiosity over the past few days. Following the death of retired general Aytaç Yalman, Koca's statements on the subject created a flurry of question marks. Yalman had tested negative for coronavirus only to subsequently test positive for it.
“In this type of situation can a case appear negative at the beginning and then appear positive? This is possible. We are just now identifying this. There are cases that are positive in the beginning, then negative three days later, then positive seven days later,” Koca said.
Commenting on the margin of error on these these tests, Dr. Ünal said that the PCR test, by looking at the genetic structure of the virus, comes up with a definitive result.
“The rapid test kits also absolutely detect positive results. When the result is negative it is almost completely certain that it is negative. In terms of the positive results, there is something called a false positive and it is witnessed to a clear extent. For that reason the negative and positive results from the rapid test kits are separated and the positive ones are sent to a laboratory for the purpose of confirming their accuracy,” Ünal said.
According to Dr. Kurt Azap, negative results also have to be confirmed for their accuracy: “This is the case with the flu, and we are expecting it to be as such with this virus.”
Giving the example of the deceased general Aytaç Yalman, while speaking on a television program, journalist Muharrem Sarıkaya said that 90-95 pct. of the tests conducted in China revealed an accurate result, and those showing symptoms were tested again three days later.
Based on figures released on March 22, 20,345 tests have been conducted, revealing 1236 cases of coronavirus. Based on figures gleaned from official sources pertaining to countries that have conducted more than 100,000 tests, Oxford University's Our World in Data indicated that China revealed 80,967 cases with 320,000 tests, South Korea recorded 8652 cases after conducting 316,664 tests, Russia came up with 199 positive results from 143,519 tests, Australia reported 709 cases from 113,615 tests, while the United States conducted 103,945 tests, resulting in 14,250 positive cases.
Having conducted upwards of 20,000 cases up until now, Turkey is behind many countries in this area. However, authorities plan to increase the number of daily tests to 10-15,000. Dr. Kurt Azap said that what the Turkish Medical Association (TBB) wants is comprehensive testing to be implemented immediately.
“At this current juncture it is not possible to say whether testing 15,000 people a day is sufficient. This will change in accordance with the speed in which new cases emerge,” Kurt Azap said.
“We are in the middle of a war. It is not only healthcare workers that can fight this war,” Ünal said, adding that everyone is responsible for protecting themselves and those around them.