To understand the seroprevalence against antibodies to SARS-CoV-2 in Zhejiang, in order to find the key point of subsequent antibody monitoring.

The results of novel coronavirus serum antibodies in 120 245 cases were retrospectively analyzed. The single-positive rate of IgG serum antibody, single-positive rate of IgM serum antibody and double positive rate of IgG and IgM serum antibody in Zhejiang area were investigated according to the sample source, age, and gender.

Among the 120 245 study subjects in Zhejiang area, fever clinics, new hospitalizations and accompanying persons accounted for the most. The age was mainly 30~50 years old. The single positive rate of IgG antibody was 0.11%, the single positive rate of IgM antibody was 0.15%, and the double positive rate of IgG and IgM antibody was 0.13%. Grouped according to the sample source, the single positive rate of IgG and IgM serum antibodies for newly hospitalized and accompanying persons in fever clinics was the highest, and the double positive rate of IgG and IgM serum antibodies for people in isolation points was the highest (0.16%). Grouped by age and gender, the single positive rate of IgG in the female group compared with IgG and IgM, the double positive rate was higher than that of the male group, and the difference was statistically significant. Compared with the group more than 50 years old, the other groups had lower IgG single-positive rates, IgM single-positive rates, IgG and IgM double-positive rates, and the difference was statistically significant. In Wenzhou area with high detection rate, the single positive rate of serum antibody IgG (0.14%), the single positive rate of IgM (0.15%), and the double positive rate of IgG and IgM (0.25%) were all higher than the provincial level. In addition, the IgM single-positive rate and the IgG, IgM double-positive rate of the personnel at the isolation point were statistically different from those of the medical institution staff. The male serum antibody IgG single-positive rate, IgM single-positive rate, IgG, IgM double-positive rate were all higher than those of women. The age group showed that the positive rate of people aged 30-50 is higher than that of the whole province.

Although the positive rate of new coronavirus seroantibodies was low in Zhejiang, the positive rate of quarantine personnel and new hospitalized and accompanying persons in fever clinics is relatively high, especially in people over 50 years old. In order to avoid another outbreak, epidemic prevention and control work still requires great attention.