SARS-CoV-2 Omicron variant shedding during respiratory activities

BACKGROUND

As the world transitions to COVID-19 endemicity, studies focusing on aerosol shedding of highly transmissible SARS-CoV-2 variants of concern (VOCs) are vital for the calibration of infection control measures against VOCs that are likely to circulate seasonally.

OBJECTIVE

This follow-up G-II aerosol sampling study aims to compare the aerosol shedding patterns of Omicron VOC samples with pre-Omicron variants analyzed in our previous study.

STUDY DESIGN

Coarse and fine aerosol samples from 47 SARS-CoV-2 infected patients were collected during various respiratory activities (passive breathing, talking, and singing) and analyzed via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and virus culture.

RESULTS

Compared to patients infected with pre-Omicron variants, comparable SARS-CoV-2 RNA copy numbers were detectable in aerosol samples of Omicron infected patients despite being fully vaccinated. Omicron-infected patients also showed a slight increase in viral aerosol shedding during breathing activities, and were more likely to have persistent aerosol shedding beyond 7 days post-disease onset.

CONCLUSION

This follow-up study reaffirms the aerosol shedding properties of Omicron, and should guide continued layering of public health interventions even in highly vaccinated populations.

Isolated acute cellular rejection of the liver after simultaneous liver and kidney transplantation: a case report

Simultaneous liver and kidney transplantation (SLKT) is now considered the treatment of choice for patients with concurrent end-stage liver and kidney diseases. Even though the early postoperative mortality rate following SLKT is reported to be high compared to that of liver transplantation alone, the liver graft from the same donor has been argued to induce better kidney graft acceptance as evidenced by a low rate of acute renal rejection episodes. There have been many reports of a low incidence of acute renal rejection following SLKT; however, only a few cases were proven by simultaneous biopsies. The authors experienced a case of biopsy-proven isolated acute cellular rejection of the liver graft following SLKT.