Table 3. Risk factors for SARS-CoV-2 infection.

*Adjusted for age, gender and profession.

RR, relative risk; COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2

Variables	Total participants	Follow-up (one month), COVID-19 positive	Unadjusted RR (95% CI)	p-value	Adjusted RR* (95% CI)	p-value
Age (years)
<30	1887 (53.4)	116 (57.7)	Reference		Reference
30-39	1139 (32.3)	61 (30.3)	0.87 (0.64-1.18)	0.370	0.87 (0.65-2.18)	0.392
40-49	358 (10.1)	18 (9.0)	0.82 (0.50-1.33)	0.415	0.95 (0.59-1.54)	0.848
≥50	148 (4.2)	6 (3.0)	0.66 (0.30-1.47)	0.310	0.85 (0.39-1.89)	0.694
Gender
Male	2389 (67.6)	138 (68.7)	Reference		Reference
Female	1143(32.4)	63 (31.3)	0.95 (0.71-1.27)	0.751	0.70 (0.52-0.93)	0.015
Profession
Staff involved in COVID-19 patient care	2567 (72.7)	150 (74.6)	Reference		Reference
Administrative staff	492 (13.9)	24 (11.9)	0.83 (0.55-1.27)	0.399	0.82 (0.54-1.24)	0.354
Students	473 (13.4)	27 (13.5)	0.98 (0.66-1.45)	0.908	1.09 (0.74-1.61)	0.652
Ivermectin prophylaxis
No ivermectin prophylaxis	1147 (32.5)	133 (66.2)	Reference		Reference
Received single-dose ivermectin prophylaxis	186 (5.3)	23 (11.4)	1.07 (0.70-1.61)	0.761	1.04 (0.69-1.58)	0.846
Received two-dose ivermectin prophylaxis	2199 (62.2)	45 (22.4)	0.18 (0.13-0.25)	<0.001	0.17 (0.12-0.23)	<0.001