Serological surveillance for SARS-CoV-2 antibodies among students, faculty and staff within a large university system during the pandemic

Table 1 Prevalence of coronavirus disease 2019 (immunoglobulin M or immunoglobulin G) according to sociodemographic, behavioral, and clinical characteristics on coronavirus disease 2019 among Brazilian students, professors, and technical employees from a public university, Niteroi, Brazil, 2021, n (%)

Characteristics	Total	Coronavirus disease 2019		P value1
		No (n = 1484)	Yes (n = 164)
Tie to the university	1545			0.3
Students	763 (49.4)	695 (91)	68 (8.9)
Professors	438 (28.3)	391 (89)	47 (11)
Technical employees	344 (22.3)	303 (88)	41 (12)
Gender	1648			> 0.9
Female	962 (58.4)	867 (90)	95 (9.9)
Male	686 (41.6)	617 (90)	69 (10)
Age	1648			0.015
Adolescents (younger than 20 years of age)	48 (2.9)	44 (92)	4 (8.3)
Adults (20–59 years of age)	1499 (91)	1358 (91)	141 (9.4)
Older adults (60 years of age or more)	101 (6.1)	82 (81)	19 (19)
Ethnicity	1648			0.4
Asian	12 (0.7)	12 (100)	0 (0)
Caucasian	710 (43.1)	646 (91)	64 (9.0)
Mixed race	273 (16.6)	242 (89)	31 (11)
Afro-Brazilian	144 (8.7)	133 (92)	11 (7.6)
Non-declared	509 (30.9)	451 (89)	58 (11)
Has a family member in healthcare	1642			0.003
No	1211 (73.7)	1106 (91.3)	105 (8.7)
Yes	431 (26.3)	372 (86)	59 (14)
Adhered to social distancing measures	1601			< 0.001
No	487 (30.4)	419 (86)	68 (14)
Yes	1114 (69.6)	1021 (91.7)	93 (8.3)
Was in contact with a positive result patient	1644			< 0.001
No	700 (42.6)	667 (95.3)	33 (4.7)
Does not know	60 (3.6)	57 (95)	3 (5)
Yes	884 (53.8)	756 (86)	128 (14)
Presented symptoms	1648
Yes	1203 (73)	1064 (88)	139 (12)
Healthcare was needed	1648			< 0.001
No	1216 (73.8)	1126 (93)	90 (7.4)
Does not know	1 (0.1)	1 (100)	0 (0)
Yes	431 (26.1)	357 (83)	74 (17)
Did symptoms make one miss a day of work	1648			< 0.001
No	1410 (85.5)	1299 (92.1)	111 (7.9)
Does not know	1 (0.1)	1 (100)	0 (0)
Yes	237 (14.4)	184 (78)	53 (22)
Was the individual hospitalized	1648
Yes	27 (1.6)	19 (70)	8 (30)
Presence of chronic disease	1648			0.5
Negative	1213 (73.6)	1089 (90)	124 (10)
Positive	435 (26.4)	395 (90.8)	40 (9.2)
Smoker	1643			0.5
Not currently	175 (10.7)	159 (91)	16 (9.1)
Non-smokers	1333 (81.1)	1202 (90)	131 (9.8)
Current smokers	135 (8.2)	118 (87)	17 (13)
The patient is vaccinated against severe acute respiratory syndrome-coronavirus 2	1605			< 0.001
No	1231 (76.7)	1135 (92.2)	96 (7.8)
Yes	374 (23.3)	309 (83)	65 (17)

¹Pearson's χ² test, Fisher's exact test.

Table 2 Multiple logistic regression analysis of the effect of sociodemographic, behavioral, and clinical characteristics on coronavirus disease 2019 among Brazilian students, professors, and technical employees from a public university, Niteroi, Brazil, 2021, (n = 1648)

Characteristic	Odds ratio	95%CI	P value
Gender
Female	1	-
Male	0.97	0.68-1.37	0.9
Age (10 years)	1.16	1.02-1.31	0.024
Social distancing
No	1	-
Yes	0.59	0.41-0.84	0.004
Case positive contact
No	1	-
Yes	3.49	2.34-5.37	< 0.001
Get vaccinated
No	1	-
Yes	2.33	1.61-3.35	< 0.001