Summary

Background: Patients with addiction are a vulnerable group in which there is little data on the infection and severity of COVID-19. The objective of this study was to analyze the seroprevalence against SARS-CoV-2 in users in treatment for addictions in Madrid and to describe the factors related to infection in this group.

Methods: Cross-sectional descriptive study (June-October 2020), in a non-probabilistic sample of 473 patients with Substance Use Disorder, from the 8 Addiction Care Centers (CAD) of the Madrid City Council. Demographic, habit and health characteristics, IgM and IgG for SARS-CoV-2, previous PCR, presence of symptoms, contact with COVID-19 cases were described, and multivariate analysis was performed using binary logistic regression.

Results: 5.1% of users had positive serology for SARS-CoV-2 (5.8% in men and 2.7% in women). The patients with the highest percentage of seropositivity were between 50-59 years old (8.3%), with alcohol being the most prevalent main substance consumed (7.4%). Having previous positive PCR showed a significant odds ratio (OR) with respect to being seropositive in the frequentist analysis.

Conclusions: The highest seroprevalence rate occurred among men, with epidemiologically known factors showing the strongest association. The seropositive user profile of the DKA was a man in the 50s, alcohol consumer and without comorbidities. No characteristic related to substance use was found to justify the difference in risk of infection with the general population.