Detection of the first appearance of SARS-CoV-2 virus in Hungary based on retrospective testing of respiratory samples / A SARS-CoV-2 vírus magyarországi megjelenésének kimutatása légúti minták retrospektív vizsgálata alapján.

ABSTRACT

INTRODUCTION: In Hungary, SARS-CoV-2 was first detected in the swab samples of two Iranian patients on March 4, 2020. After finding the first positive cases, the question arose whether the virus had entered Hungary and caused infections before this date. Before March 4, 2020, except for the two above-mentioned samples, none of the 224 swab samples received specifically for SARS-CoV-2 tested positive. AIM: The National Reference Laboratory for Respiratory Viruses of the National Public Health Center aimed to carry out a retrospective study of the swab and other samples taken for testing respiratory virus infections between January 1, and April 19, 2020 sent by sentinel physicians within the influenza surveillance for diagnostic purposes. METHOD: For the study, we used swab samples taken weekly by sentinel physicians of the influenza surveillance service, and other samples received for diagnostic purposes. Tests were performed using real-time PCR. RESULTS: All the 465 swab samples sent by sentinel physicians were found to be SARS-CoV-2 negative. Also, of the 551 samples collected for diagnostic reasons of other respiratory viruses, no SARS-CoV-2 positive was found among those taken before March 4. CONCLUSION: Based on our data, it is very likely that prior to the first cases diagnosed on March 4, 2020, SARS-CoV-2 did not cause clinically symptomatic infections in Hungary. Orv Hetil. 2020; 161(38) 1619-1622.