Pre-Existing Allergies Patients with Higher Viral Load and Longer Recovery Days Infected by SARS-CoV-2 Omicron BA.2 in Shanghai, China, 2022.

BACKGROUND

It is not known whether the viral load and the number of days to negative nucleic acid increased in patients with a history of allergy during the COVID-19 pandemic.

OBJECTIVE

To investigate the impact of allergy labels on SARS-CoV-2 Omicron outcomes.

METHODS

This retrospective cohort study included 62,293 patients with mild Omicron infection between April 9, 2022, and May 31, 2022. Using 1:2 propensity score matching, we identified 2177 COVID-19 patients with a history of allergy and 4254 COVID-19 patients with no history of allergy. The differences in viral load, days to nucleic acid turning negative, and clinical symptoms were compared between the two groups.

RESULTS

Compared with the group with no allergies, the number of days before negative nucleic acid conversion of COVID-19 patients with allergies was significantly higher, the viral load was significantly higher, and the cumulative negative conversion rates at 5-10 days were all lower ( < 0.01). Patients with a history of allergy to antibiotics had higher viral load and more days with negative nucleic acid levels ( < 0.001). Subgroup analysis revealed that the viral load in penicillin-allergic and cephalosporins-allergic patients was significantly compared to patients without any history of allergies ( < 0.05).

CONCLUSION

Patients with a history of allergy have a more significant viral load and a longer duration of nucleic acid negative conversion upon COVID-19 infection, particularly those allergic to antibiotics.