Covid-19 screening tests are evolving. French researchers have just developed a new method. In particular, it could make it possible to discover, from a PCR test, whether a patient is still contagious or not. This new method could also detect possible serious forms, reports The echoes, Wednesday.
Today, a PCR test can only detect traces of the virus in a person’s nose. But in a press release, the Assistance publique-Hôpitaux de Paris (AP-HP) says that it would be possible to better distinguish patients. According to the researchers, this would require measuring type I interferon (IFN-I), a protein that acts against the coronavirus during contamination.
Thanks to a new innovative technology, the measurement could be performed directly on the swab taken for the PCR test. In a work published in the Journal of Experimental Medicine, scientists state that the level of interferon is proportional to the presence of the infectious virus. Therefore, a high level of this protein would mean that the virus is active and that the patient can potentially infect other people.
“If there is a small virus and there is no IFN-I in your sample, you have been sick but you are no longer contagious. On the contrary, if there are a large number of viruses and IFN-I, this calls for isolation, ”explains Dr. Sophie Trouillet-Assant, associate researcher who signed the study. Furthermore, the French researchers made another discovery, still related to type I interferon.
Patients in intensive care with a severe form of Covid-19 had too little of this protein to be detected. In fact, these patients would produce anti-IFN-I autoantibodies, which thus act against the antiviral action of the protein. Thus, during PCR testing with interferon analysis, it might be possible to detect possible severe forms in upstream patients. And even more specific treatments could be developed.