High SARS-CoV-2 seroprevalence in blood donors from Romania after the third COVID-19 pandemic wave

Figures & data

Table 1. Seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antibodies in Romanian blood donors by age, gender, area of residence, ABO blood types, and Rhesus blood groups, July–September 2021.

Variables	Nr. positive /Nr. tested (%)	OR (95% CI)	p value
Age groups (years)
18–29	262/644 (40.68)	–	–
30–49	581/1419 (40.94)	1.01 (0.84–1.22)	0.911
50–64	140/332 (42.17)	1.06 (0.81–1.39)	0.655
Gender
Male	579/1448 (39.99)	1.12 (0.95–1.32)	0.193
Female	404/947 (42.66)	–
Area of residence
Urban	663/1660 (39.94)	0.862 (0.72–1.03)	0.099
Rural	320/735 (43.54)	–
ABO blood type
O	340/874 (38.90)	–	–
A	399/955 (41.78)	1.13 (0.93–1.36)	0.210
B	157/374 (41.98)	1.14 (0.88–1.45)	0.309
AB	87/192 (45.31)	1.30 (0.95–1.78)	0.101
Rhesus blood group
Rh positive	813/1999 (40.67)	1.10 (0.88–1.36)	0.404
Rh negative	170/396 (42.93)
Total	983/2395 (41.04)	NA	NA

OR: odds ratio; CI: confidence interval; NA: not applicable.

Table 2. Seroprevalence of SARS-CoV-2 nucleocapsid antibodies in blood donors (tested in 2020 and 2021) and the rate of confirmed COVID-19 reported cases in Timis County, Romania.

Nr. positive/ Nr. tested (%) in 2020*	Nr. positive/ Nr. tested (%) in 2021**	Nr. reported cases/ Nr. inhabitants (%), 19 July 2021***
32/ 2,115 (1.51)	983/ 2,395 (41.04)	54,393/ 705,113 (7.71)

*Tests were performed between 8 July 2020 and 1 September 2020.

**Tests were performed between 2 July 2021 and 2 September 2021.

***Confirmed COVID-19 cases reported in Timis County on 19 July 2021, two weeks before the midpoint of sample collection.