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.