Developing countries have reported lower molecular diagnostic testing levels due to a lack of resources. Therefore, antibody tests represent an alternative to detect exposure to SARS-CoV-2 and analyze possible risk factors. We aimed to describe and compare the clinical-epidemiological characteristics and the quality of food intake in Mexican individuals with a positive or negative test to antibodies against SARS-CoV-2. We carried out antibody tests and applied a survey to 1799 individuals; 42% were positive, and diabetes was more prevalent in these cases (p < 0.01). No differences were identified in the blood type nor influenza vaccination between groups. Coughing, respiratory distress, muscle pain, joint pain, and anosmia were the most prevalent symptoms among seropositive cases (p < 0.0001). Food intake quality was similar in both groups, except for the most consumed type of fat (p = 0.006). In conclusion, this study supports the association of diabetes as a principal risk factor for SARS-CoV-2 infection in the Mexican population. The results do not support previous associations between blood group or influenza vaccination as protective factors against SARS-CoV-2 infection. However, frequent consumption of polyunsaturated fats is highlighted as a new possible associated factor with COVID-19, which more studies should corroborate as with all novel findings.

Background: Developing countries have reported lower molecular diagnostic testing levels due to a lack of infrastructure and resources. Therefore, antibody tests represent an alternative to detect exposure to SARS-CoV-2 and analyze possible risk factors in them. This study aimed to describe and compare the clinical and epidemiological characteristics and the quality of food intake between individuals with a positive or negative test to antibodies against SARS-CoV-2.Methods: Mexican individuals of diverse ages and sex, that attended to detect anti-SARS-CoV-2 antibody seropositivity from July to November 2020 were included. A survey was applied to identify the clinical and epidemiological characteristics and food intake quality in negative and positive individuals for anti-SARS-CoV-2 antibodies. These variables were compared using the Chi-square test, Kruskal Wallis, Fisher's exact test, or t-student.Results: In this study, a total of 1,799 individuals participated; 42% were positive for SARS-CoV-2. It was found that seropositive subjects were older and that diabetes was more prevalent in them (p <0.01). No differences were identified in the blood type nor vaccination against influenza between seronegative and seropositive cases. Cough, respiratory distress, muscle pain, joint pain, and anosmia were more prevalent in seropositive cases than in those seronegative (p<0.0001). The IgM or IgM+IgG seropositive cases presented anosmia more frequently than those with only IgG antibodies (p<0.05). The dietary patterns and individual food intake habits were similar in both groups, except for the most consumed type of fat (p = 0.006). Seronegative cases showed to consume monounsaturated fats more frequently than other types of fats, whereas seropositive subjects have more regular consumption of polyunsaturated fats.Conclusion: This study confirms the association between being anti-SARS-CoV-2 seropositive with older age and the presence of diabetes mellitus. Furthermore, it suggests muscle and joint pain could also be considered major criteria for discriminating patients with suspected COVID-19 seropositivity. Moreover, the results suggested polyunsaturated fats as a possible new risk factor associated with COVID-19, and anosmia as a marker of active disease. This finding will be of interest to investigate in further studies regarding the type of fat consumed and the risk of infection by SARS-CoV-2.