key: cord-317608-otd81rvy authors: Corman, Victor M.; Rabenau, Holger F.; Adams, Ortwin; Oberle, Doris; Funk, Markus B.; Keller‐Stanislawski, Brigitte; Timm, Jörg; Drosten, Christian; Ciesek, Sandra title: SARS‐CoV‐2 asymptomatic and symptomatic patients and risk for transfusion transmission date: 2020-05-27 journal: Transfusion DOI: 10.1111/trf.15841 sha: doc_id: 317608 cord_uid: otd81rvy Oral swabs, sputum, and blood samples from 18 asymptomatic and symptomatic patients with SARS‐CoV‐2 infection were examined using RT‐PCR testing in order to assess the risk of transfusion‐related transmission. In asymptomatic patients as well as patients with flu‐like symptoms and fever, no SARS‐CoV‐2 RNA could be detected in the blood or serum despite a clearly positive result in all throat swabs. As patients with symptoms of infectious disease will not be admitted to blood donation, the risk for transfusion transmission of SARS‐CoV‐2 seems to be negligible. • In asymptomatic patients as well as patients with flulike symptoms and fever, no SARS-CoV-2 RNA could be detected in the blood or serum despite a clearly positive result in all throat swabs. • As patients with symptoms of infectious disease will not be admitted to blood donation, the risk for transfusion transmission of SARS-CoV-2 seems to be negligible. A s of March 2020, the SARS-CoV-2 pandemic that originated in Wuhan, Hubei Province, China, is quickly spreading in many countries of the world. Huang et al. 1 reported RNAemia in 6 of 41 symptomatic Wuhan patients (15%) with laboratory-confirmed SARS-CoV2 infection. Zhang et al. 2 showed for 15 Wuhan patients diagnosed with viral pneumonia caused by SARS-CoV-2 that shedding may occur through multiple routes (respiratory, fecal-oral, or body fluids); 6 out of the 15 patients (40%) were blood positives. In addition, Kim et al. 3 reported on intermittently positive blood RT-PCR (real-time reverse transcription polymerase chain reaction) results in 2 SARS-CoV-2 patients in South Korea with mild and moderate symptoms. In Germany, blood donors have to be at least 18 years old and should not be older than 65 years of age. In addition, volunteers will not be admitted to blood donation if they show signs and symptoms of an infection (e.g., fever, flu-like symptoms). With these requirements and the additional donor screening, a high national safety standard with regard to the prevention of transfusion-related viral infections has been achieved in recent years. 4 However, with respect to the safety of blood donation, the questions arise whether Corona virus disease 2019 (Covid-19) can be transmitted through blood and how long SARS-CoV-2 positive patients with minimal symptoms have to be deferred from blood donation. We report on molecular detection of SARS-CoV-2 in 18 patients, 2 of whom were infected in China and evacuated to Germany on February 1. 5 In 16 patients, the transmission in Germany is most likely. 6 Information on the patient population was published elsewhere 5,6 and SARS-CoV-2 testing targeting the E and RNA-dependent RNA polymerase gene was performed as previously described by Corman et al. 7 In patients with minor symptoms, laboratory tests were carried out during the two-week quarantine period, in those with severe symptoms, tests were done during inpatient treatment. Twelve of the 18 patients were males and six were females. Three patients were asymptomatic, seven presented with flu-like symptoms, five had flu-like symptoms as well as fever, two suffered from pneumonia, and one patient needed artificial respiration because of acute respiratory distress syndrome (ARDS) ( Table 1 ). Three of the 18 patients fulfilled the requirements for blood donation in Germany. Whereas oral swabs or sputum from the lower respiratory tract were tested RT-PCR positive in all patients, RNAemia was only detected in one out of eight serum/plasma samples taken from the patient with ARDS. We presented data on 18 SARS-CoV-2 infected patients, 3 patients without specific symptoms and 15 with symptoms of different severity. SARS-CoV-2 genomes were only detected in 1 of 77 blood samples examined. The patient with RNAemia suffered from ARDS and was artificially ventilated in an intensive care unit. In asymptomatic patients who are eligible for blood donation as well as patients with flu-like symptoms and fever, no SARS-CoV-2 RNA could be detected in the blood or serum despite a clearly positive result in all throat swabs. Our findings are in line with published data 8 and confirm that SARS-CoV-2 infection may go without noticeable manifestation of clinical symptoms. Furthermore, Chen et al. 9 detected SARS-CoV-2 genome in the blood of 6 out of 57 Chinese patients and found RNAemia to be associated with a more severe clinical picture. In addition, detectable serum SARS-CoV-2 RNAemia was found to be closely linked to an elevated interleukin 6 (IL-6) level in critically ill Covid-19 patients. 10 Since there is currently no recognized external standardization of the SARS-CoV-2 RT-PCR methods, a direct comparison of the results of Chinese and German studies is not possible. Of note, RNAemia is not equivalent to infectiousness, i.e., despite the presence of RNA it is unknown whether blood can harbor intact viruses that are able to infect tissues and, when transfused, can cause hematogenous transmission. Hitherto, similarly to the other two coronaviruses that have emerged over the past 20 years (SARS, the Severe Acute Respiratory Syndrome Coronavirus 11,12 and MERS-CoV, causing Middle East Respiratory Syndrome, 13 no hematogenous transmissions have been documented for SARS-CoV-2. Due to a lack of evidence indicating a risk for transfusion transmission of SARS-CoV-2, the American Association of Blood Banks (AABB), the Food and Drug Association (FDA), and the Centers for Disease Control and Prevention (CDC) are not recommending any action by blood collection establishments at this time (March 3, 2020). 14 Our data support this recommendation. Among 18 patients with RT-PCR confirmed SARS-CoV-2 infection included in our study only one critically ill individual had RNAemia. Based on these limited data, there is no measurable risk for SARS-CoV-2 transmission through blood components in asymptomatic SARS-CoV-2 infected individuals. As no cases of transmission due to transfusion of blood products have been reported for SARS, MERS-CoV, and SARS-CoV-2, and considering that patients with symptoms of infectious disease will not be admitted to blood donation in Germany, the risk for transfusion transmission of SARS-CoV-2 is supposed to be negligible. However, wellpowered studies are needed to further evaluate the potential risk of hematogenous transmission and to determine the appropriate referral time for blood donation of recovered SARS-CoV-2 patients. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes Viral load kinetics of SARS-CoV-2 infection in first two patients in Korea Haemovigilance reports of the Paul-Ehrlich-Institut Evidence of SARS-CoV-2 Infection in Returning Travelers from Wuhan, China Transmission of 2019-nCoV infection from an asymptomatic contact in Germany Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR Asymptomatic cases in a family cluster with SARS-CoV-2 infection Detectable 2019-nCoV viral RNA in blood is a strong indicator for the further clinical severity Detectable serum SARS-CoV-2 viral load (RNAaemia) is closely associated with drastically elevated interleukin 6 (IL-6) level in critically ill COVID-19 patients Outbreak of severe acute respiratory syndrome-worldwide Identification of a novel coronavirus in patients with severe acute respiratory syndrome MERS coronavirus: diagnostics, epidemiology and transmission Coronavirus and Blood donation -talking points The authors have disclosed no conflicts of interest.