Abstract:

Objective To explore the relationship between viral load and clinical characteristics by analyz⁃ ing the early nasal swab viral load of Delta variant of New Coronavirus（SARS ⁃Cov ⁃2）. Methods One hundred and eight patients infected with Delta variant of SARS ⁃ Cov ⁃ 2 treated in Guangzhou Eighth People′ s Hospital， Guangzhou Medical University from May 21 to June 18，2021 were selected. The levels of N gene and Orf1a/b gene of nasal swab virus RNA and the viral nucleic acid of nasal swab were detected by real⁃time polymerase chain reac⁃ tion（RT⁃PCR）. According to the cycle threshold（Ct）value，the patients were divided into high copy group and low copy group，and the clinical characteristics and viral nucleic negative conversion time were compared between the two groups. Results Fifty⁃nine cases were included in high copy group，while forty⁃nine in low copy group. There was no significant difference in terms of gender and age between the two groups（P > 0.05）. Compared with the low copy group，the high copy group had high proportion of throat discomfort，diarrhea，and type 2 diabetes mellitus. The decrease of CD3+，CD4+ and CD8+ T lymphocytes at baseline was common in the two groups，and the CD4+ lymphocyte count in the high copy group was lower than that in the low copy group（P < 0.05）. The decrease of peripheral blood lymphocytes and eosinophils at baseline was also common in the two groups. Compared with those in the low copy group，the lymphocyte and eosinophil counts were lower and recovered slower at the first week in the high copy group（all P < 0.05）. CT value was positively correlated with lymphocytes and eosinophils at the first week（r = 0.261 and 0.333），but negatively with viral nucleic negative conversion time（r = -0.289）. Compared with that in the low copy group，the viral nucleic negative conversion time was longer in the high copy group（20.2 d vs. 16.3 d，P < 0.05），but there was no significant difference in the severe type rate between the two groups（P > 0.05）. Conclusion The early viral load of SARS⁃Cov⁃2 Delta variant is negatively correlated with peripheral blood lymphocytes and eosinophils，but positively with the time of virus negative conversion. The pathophysiological mechanism needs further study. Diabetes may affect viral load，but viral load can′t predict poor prognosis.

Key words:

SARS?Cov?2, clinical features, diabetes, lymphocyte, eosinophil