Researchers have found that an unusual new coronavirus diagnostic tool can detect viruses days before standard PCR tests identify them,media BGR reported. According to the report, trained dogs can detect the specific odors of COVID-19 patients, identify infected people correctly early, and they do not make mistakes.
Doctors from all over the world began training dogs a few months ago to detect the smell of COVID-19 patients and began to get results. Researchers in Finland have realized that dogs have a big advantage over conventional PCR tests because they can detect disease before traditional tests detect viruses.
The report from The Times explained that researchers were initially confused about dogs that could “sniff out” COVID-19. The animals identify sick passengers at the airport. When tested with a normal PCR, the result is negative. At first, the dogs gave false positive results. A few days later, people who tested negative began to show symptoms, proving that the dog’s test results were correct. What the animals did was discover the virus before PCR testing found it.
“They actually found PCR negatives, which would become PCR-positive within a week,” said Dr. Anna Hielm-Björkman. She added that researchers in other countries that use dogs for COVID-19 screening have observed the same behavior. This is a problem when you have a test that is much better than the gold standard because you can’t validate it in any normal way. “PcR (false negative results) is about 70 percent,” the researchers said. A good dog is never less than 100%. “
If COVID-19 is tested prematurely after exposure to the virus, the results are likely to be negative. It takes several days for the virus to begin to multiply before it can return a positive result. In fact, the patient in the first few days of symptoms have been contagious, when the patient’s virus test results are likely to be positive. If contagious, the patient ejects virus particles when they talk, cough, or sneeze. The same particles eventually appear on the nasal swab.
Previous reports have explained that the dogs do not actually come into contact with passengers for safety reasons. They get a wipe cloth that passengers use on their skin. As shown in the image above, the wipe cloth is placed in a container with three other samples next to it. The dog then indicates that the sample is positive by “calling, sticking out, or lying down.”
Getting dogs to spot COVID-19 patients before PCR testing would be a good screening tool. These animals can be used in crowded places such as airports to quickly identify potential asymptomatic transmitters. The problem with this resource is that it is not fully scalable. Dogs need to be trained to detect odors, and they need to be protected. There have been cases where owners can transmit the new coronavirus to dogs.
However, the study does make a good point that COVID-19 can be diagnosed earlier than current PCR tests. It is not clear how PCR testing can be improved to provide results faster.