Risk Factors associated with COVID-19 Infection among Contacts of Index Cases in Saudi Arabia: A Case-Control Study

Abstract

This study was aimed to determine the risk factors associated with COVID-19 infection among contacts of index cases in Saudi Arabia. This unmatched case-control study was conducted among contacts of confirmed COVID-19 cases in April and May 2020 in Al-Madinah, Saudi Arabia. A total of 118 cases and 115 controls were included in this study. All cases and controls were interviewed via telephone by using a structured questionnaire that included two sections. The first section included participants' personal and demographic information, and the second part included questions on the degree of distancing and the duration of contact prior to the appearance of the first symptom, seasonal influenza vaccination, and the nature of the relationship with the index case patient. The majority of cases (83.1%) and controls (67.2%) were males. The mean standard deviation age for the whole sample was 35.3 (10.6) years, and their ages ranged from 18 to 63 years. In the multivariate analysis, the risk for COVID-19 infection was increased by age [Adjusted Odds Ratio (aOR) = 2.2; 95% Confidence Interval (CI), 1.1-4.8, p = 0.046], and was higher among family members (aOR = 10; 95% CI, 3.3-20.0; p = 0.001), coworkers (aOR = 20.0; 95% CI, 4.4-50.0; p < 0.001), and those who communicated with an index case at a distance of <1.5 m (aOR = 4.3; 95% CI, 1.9-9.8; p = 0.001).