Severe acute respiratory syndrome coronavirus 2 infection in hematopoietic stem cell transplant recipients in Mexico City.

Abstract

Hematopoietic stem cell transplant (HSCT) recipients are among patients with highest risk of adverse coronavirus disease 2019 (COVID-19) outcomes. We compared clinical outcomes in post-HSCT patients with COVID-19 before and during the Omicron period. This was a retrospective study including patients post-HSCT with severe acute respiratory syndrome coronavirus 2 infection from April 2020 to March 2023 at Instituto Nacional de Cancerología, Mexico City. We describe their clinical characteristics and report the variables associated with severe clinical disease, hospitalization, and death. Fifty-three patients were included; 31 (58.5%) from the pre-Omicron period and 22 (41.5%) from the Omicron period. Median age was 42-years old (interquartile range 26-53), and 31 patients (59%) were men. Only four patients (16%) had received a vaccine prior to COVID-19 diagnosis in the pre-Omicron period versus 20 (91%) in the Omicron period (p<0.001). COVID-19 severe cases were more common before Omicron: seven patients (23%) versus two patients (9%). Only one patient (3%) received an antiviral in the pre-Omicron period compared to 11 patients (50%) during the Omicron period (p<0.01). COVID-19-associated mortality was almost double in the pre-Omicron period (16%vs. 9%, p=0.6). This study reports patients with a high proportion of severe outcomes during the first 2 years of the pandemic. Outcomes improved during Omicron with better access to vaccines and antivirals and no in-hospital cases. Variables associated with worse outcomes were similar to other reports. Strengthening infection control measures in the hospital and better access to preventive strategies and therapeutic options are mandatory in these high-risk patients.