3.5.1. What Is New in the COVID-19 Pandemic?

Viral diseases in the past have motivated researchers to generate algorithms for donor screening, in order to prevent the use of organs from potentially infected donors, and also to improve recipient management, in order to reduce the chances of viral transmission and disease among recipients [25]. Some of the emerging viruses in the past (SARS-CoV, MERS, etc.) were only limited to a certain geographic area, thus not severely hampering the transplantation/donation procedure as a whole. The current COVID-19 pandemic is of unprecedented magnitude. The virus is highly contagious, crossing borders all over the world. There are over 3,500,000 confirmed cases and over 245,000 deaths, affecting 206 countries [26], and probably many more undiagnosed people with COVID-19. Unfortunately, the widespread occurrence of the virus has a great impact on SOT, requiring preventive and possibly therapeutic measures.

## 3.5.2. Restrictions Concerning Donors, Recipients and Transplantation Centers

Not only does the pandemic restrict the number of potential organs available due to infected donors, but it may also affect recipients on the waiting list or just before transplantation. Donor screening for the presence of the SARS-CoV-2 virus or evidence of disease (COVID-19) is highly recommended, which may lead to possible delays in organ procurement and organ transplantation, depending on testing availabilities. In addition, the large number of COVID-19 patients requiring specialist care, including intensive care unit (ICU) resources, certainly competes with the efforts to transplant severely ill patients in order to enable survival and increase quality of life. The pandemic is therefore restricting the capacity for transplantation in many hospitals. This is also due to the transformation of many general or specialized intensive care units (ICUs) into specialized COVID-19 ICUs with strict isolation measures, and also due to shortages of health care workers relating to COVID-19 care requirements. In addition to the scarcity of ventilator capacity in ICUs, many hospitals have shut down their routine outpatient checkups in order to prevent further spread of the infection, resulting in impaired or absent capacity for evaluating patients for possible SOT. These factors will decrease both the number of potential donors and SOT recipients all over the world. On the other hand, there may be hospitals still evaluating candidates and performing transplantation procedures, thanks to sufficient ICU bed availability. Depending on the resources available, the waiting list mortality may suffer under these circumstances. In these centers, donor organ procurement and transplantation can

possibly be increased, when other centers decide to shut down their SOT programs of solid organ transplantations due to the requirements for COVID-19 care.
