The aim is to substantiate the concomitant factors of comorbid conditions in patients with the leading etiological feature of acute intestinal infection, determining the structure and frequency of comorbid conditions in elderly. Object and methods of research. The main disease COVID-19 was diagnosed by enzyme-linked immunosorbent assay, PCR test, measurements of pulmonary respiration saturation by pulse oximetry, heart rate, temperature, instrumental methods: spiral computed tomography, foX-ray, which confirm the presence of pneumonia, statistical methods, etc. Results. According to the research methods, concomitant diseases were found in all subjects, according to which no statistically significant differences in the frequency of their manifestation were detected (p=0.47). The results of the study revealed the presence of diseases such as myocardial infarction, heart failure, peripheral vascular disease, transient cerebrovascular disease, gastric ulcer, acute cerebrovascular disease with hemiplegia, diabetes mellitus with/without limb lesions, acute and chronic lymphoma, chronic renal failure with creatinine level more than 3 mg%, chronic nonspecific lung diseases, peripheral vascular lesions, transient cerebrovascular disorders, dementia, bronchial asthma. According to these accompanying factors, a statistically significant difference was proved, taking into account the leading etiological factor of acute intestinal infection in the frequency of detection of 1 (p=0.0006), 2 (p≤0.00001) and 4 (p≤0.00001) comorbid condition, no significant difference when comparing the frequency of 3 comorbidities in certain groups was proved (p=0.42).