A Large-Scale Retrospective Study on the Prevalence of COVID-19 and Urinary Bacterial Coinfections Among Hospitalized Patients in Salmas, Northwest Iran

Background: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2, started with an outbreak of COVID-19 in Wuhan, China, in December 2019, resulting in millions of deaths in the following years. Bacterial coinfections and superinfections are concerns for patients with COVID-19. This study aimed to determine the mortality rate of COVID-19, its associated risk factors, and the bacterial isolates from urine samples of hospitalized patients suspected of having COVID-19 in Salmas, northwest Iran. Methods: The data from 3,733 patients suspected of COVID-19 who were referred to Khatam Al-Anbiya hospital in Salmas, West Azerbaijan, Northwest Iran, from December 2019 to February 2024, were collected and analyzed in a retrospective study. Results: Of the 3,733 patients, 2,172 (58.2%) tested positive for COVID-19, while 1,561 (41.8%) tested negative. Among those who tested positive, 1,210 were females (59.6%), and 962 were males (56.5%). The highest COVID-19 rate was observed in 2021 (72%), whereas the lowest rate was reported in 2024 (13.8%). Of the COVID-19-positive patients, 328 (15.1%) died, and the bacterial isolates from their urine samples included Escherichia coli (68.75%), which was the most prevalent isolate, followed by Klebsiella spp. (12.5%), coagulase-negative staphylococci spp. (10%), Enterobacter spp. (3.75%), nonhemolytic streptococci spp. (2.5%), Pseudomonas aeruginosa (1.25%), and Streptococcus beta-hemolytic spp. (1.25%). Conclusion: Based on the results, the overall mortality rate of COVID-19 over five years was 15.1%. The most important risk factors for COVID-19-related death included older age, chronic kidney and lung diseases, diabetes mellitus, and male gender. Bacterial isolates from the urine samples of COVID-19 patients were E. coli, Klebsiella spp., coagulase-negative staphylococci spp., P. aeruginosa, Enterobacter spp., and non-hemolytic streptococci spp.