[Which sampling method for the upper respiratory tract specimen should be taken to diagnose patient with COVID-19?]

Coronavirus disease 2019 (COVID-19) is raging in China, especially in Hubei Province, which has resulted great dangers in people's life and national economy. According to the guidelines drafted by China's Center for Disease prevention and Control (CDC), the positive nucleic acid test is need to the diagnosis of patient with COVID-19. Upper respiratory tract specimens are the main sources for nucleic acid detection. However, based on international guidelines of COVID-19 , no recommended level of upper respiratory tract sampling method is proposed. Therefore, which kind of sampling methods should be chosen to help the COVID-19 diagnosis and which way is the most secure for doctors and nurses is our concern. In this review, we analyzed a total of 10 literatures on the sampling methods of upper respiratory tract related to infectious diseases such as severe acute respiratory syndrome coronavirus (SARS), middle east respiratory syndrome coronavirus (MERS), and influenza A (H1N1), which were spread worldwide in past years. Literatures were collected from the three dimensions of sampling method, sampling time, and sampling safety. It was found that among all the upper respiratory sampling methods, nasopharyngeal aspirate (NPA) had a higher positive rate within 2 weeks of symptom onset, while combined nasal and oropharyngeal swabs (NS + OPS) was the least harmful to medical staff during sampling. We wish this review is helpful for the prevention of COVID-19.