Clinical and epidemiological characteristics of acute upper respiratory tract infections in organized collectives

Aim: to study the clinical and epidemiological features of acute respiratory infections of the upper respiratory tract in individuals from an organized military unit at the initial stages of its formation in order to improve the quality of antiepidemic protection.

Research objectives: to determine the structure of the causative agents of ARI of the upper respiratory tract, to assess the frequency of clinical symptoms in various etiological variants of the disease, to conduct a comparative analysis of clinical manifestations, and to propose clinical guidelines for the differential etiological diagnosis of acute respiratory infections of the upper respiratory tract at the initial stages of the formation of an organized military unit.

Materials and methods: clinical, epidemiological, and laboratory data of 287 patients who sought medical care for upper respiratory tract infections were analyzed. The etiology of the disease was determined using multiplex PCR and classical bacteriological studies, and the results were used to form groups based on the type of isolated pathogens. The frequencies of clinical symptoms were calculated for each group.

Results: 221 cases (77.0%) were monoinfections, and 66 cases (23.0%) were co-infections. The most common pathogens were rhinovirus (28.6%) and influenza B virus (11.5%). Rhinovirus infection was characterized by a predominance of catarrhal syndrome (rhinorrhea 75.6±4.7%, pharyngitis 65.9±5.1%) with a low frequency of fever (12.2±3.7%). In cases of influenza B and adenovirus infections, fever (36.4±8.8% and 40.0±10.7%, respectively) and cough (78.8±7.1% and 80.0±8.9%) were more common.

Metapneumovirus and respiratory syncytial virus were manifested mainly by cough. Seasonal coronaviruses were mild infections with rhinitis and pharyngitis. SARS-CoV-2 infection had a variable clinical picture without specific signs. Diseases caused by bacterial agents were characterized by more pronounced inflammatory manifestations: Streptococcus pyogenes — typical tonsillitis without catarrhal symptoms, Staphylococcus aureus — intoxication and a purulent component. In co-infections, a combination of symptoms was observed.

Conclusions: the clinical manifestations of ARI URT in members of organized groups may be characterized by certain symptom complexes, due to the etiology of the disease, which allows them to be used for preliminary differential diagnosis in conditions of limited laboratory availability.

1. Kunz AN, Ottolini M. The role of adenovirus in respiratory tract infections. Curr Infect Dis Rep. 2010;12(2):81–87. doi:10.1007/s11908-010-0084-5.

2. Zhang G, Ba L, Liu L, et al. Epidemiological shift and clinical characteristics of rhinovirus genotypes in acute respiratory tract infection cases in Kunming, China, from 2019 to 2023. Front Cell Infect Microbiol. 2025;15:1678343. doi:10.3389/fcimb.2025.1678343.

3. Wang L, Wang Y, Ye D, Liu Q. Review of the 2019 novel coronavirus (SARS-CoV-2) based on current evidence. Int J Antimicrob Agents. 2020;55(6):105948. doi:10.1016/j.ijantimicag.2020.105948.

4. Rasool G, Khan WA, Khan AM, et al. COVID-19: A threat to the respiratory system. Int J Immunopathol Pharmacol. 2024;38:3946320241310307. doi:10.1177/03946320241310307.

5. Nair H, Brooks WA, Katz M, et al. Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis. Lancet. 2011;378(9807):1917– 1930. doi:10.1016/S0140-6736(11)61051-9.

6. Kim KR, Park H, Kim DR, Kim YJ. Changes in epidemiology of parainfluenza virus and respiratory syncytial virus infection during coronavirus disease 2019 pandemic in Korea. Clin Exp Pediatr. 2022;65(6):320–321. doi:10.3345/cep.2021.01823.

7. Panda S, Mohakud NK, Pena L, Kumar S. Human metapneumovirus: review of an important respiratory pathogen. Int J Infect Dis. 2014;25:45–52. doi:10.1016/j.ijid.2014.03.1394.

8. Kaler J, Hussain A, Patel K, et al. Respiratory syncytial virus: a comprehensive review of transmission, pathophysiology, and manifestation. Cureus. 2023;15(3):e36342. doi:10.7759/cureus.36342.

9. Verheul MK, Hendriks M, de Melo CVB, et al. Clinical and serological characteristics of symptomatic infection with seasonal human coronaviruses OC43, HKU1, NL63, and 229E in community-dwelling older adults. Front Virol. 2023;3:1171108. doi:10.3389/fviro.2023.1171108.

10. Zamani S, Dadashi M, Bahonar S, et al. Emerging challenges in Staphylococcus aureus bloodstream infections: insights from coagulase typing, toxin genes, and antibiotic resistance patterns. Adv Med. 2023;2023:7041159. doi:10.1155/2023/7041159.

11. Elabbadi A, Voiriot G, Tristan A, et al. Lower respiratory tract infection with Staphylococcus aureus in sickle-cell adult patients with severe acute chest syndrome. Haematologica. 2021;106(12):3236–3239. doi:10.3324/haematol.2021.278827.

12. Rousogianni E, Perlepe G, Boutlas S, et al. Clinical features and outcomes of viral respiratory infections in adults during the 2023–2024 winter season. Sci Rep. 2025;15:35800. doi:10.1038/s41598-025-19236-8.

13. Shi YR, Yuan K, Yue L, et al. Clinical characteristics of single human rhinovirus infection and co-infection in the respiratory tract of children. Transl Pediatr. 2025;14(3):373–381. doi:10.21037/tp-24-79.