Title: Co-pathogens causing respiratory infections in patients with SARS-CoV-2 in Bulgaria

Abstract:

Statement of the Problem: Coinfections with SARS Co-2 and bacterial, fungal, or viral pathogens can worsen the clinical condition and pose challenges to the disease's diagnosis, treatment, and prognosis. This study aims to determine the prevalence and clinical significance of co-infection with SARS-Co-2 and another respiratory pathogen in Bulgaria. Methodology & Theoretical Orientation: Nasopharyngeal swabs from patients with confirmed SARS-CoV-2 infection were prospectively collected from both inpatients and outpatients, with female patients being 55% and male patients being 45%, respectively, and patient ages varied from 45 days to 98 years. RT-PCR was used to detect SARS-Co-2, 8 common respiratory viruses - respiratory syncytial virus(RSV), human metapneumovirus(HMPV), parainfluenza viruses(PIV)1/2/3, rhinoviruses(RV), adenoviruses(AdV), bocaviruses(BoV) and 4 seasonal coronaviruses: OC43, NL63, 229E, and HKU-1. Capillary electrophoresis was used for the detection of three bacterial co-pathogens: Mycoplasma pneumonia(MP), Chlamydophila pneumonia(ChP), and Haemophilus influenza(HI).
Results: From August 2021 to early May 2022, clinical samples from 337 SARS-CoV-2 positive patients were tested for the presence of respiratory co-pathogens, with 42 co-infections detected. Those involving bacterial pathogens were n=23(54.8%) and those involving viral pathogens were n=14(33.3%). The order of evidence of co-pathogens was: HI(n=20; 47.6%), RSV(n=4, 9.5%), ChP(n=3,7.1%), AdV(n=3;7.1%), HI+RSV(n=3;7.1%), BoV(n=2,4;8%), HMPV(n=1;2.4%),PIV-3(n=1;2.4%), RV(n=1;2.4%), HKU-1(n=1;2.4%), NL63(n=1;2.4%), HI+AdV(n=1;2.4%) and HI+PIV2 (n=1;2.4%). Children aged 6-16 years and patients over 65 years had the highest rate of co-infections (37.5%/18.2%). Of the co-infected patients, 32(76%) were hospitalized and three(7.1%) had a fatal outcome. The deaths were in patients co-infected with a bacterial pathogen and SARS-CoV-2.
Conclusion & Significance: In patients positive for SARS-Co-2, the frequency of co-infections with a bacterial pathogen prevailed over that with a viral one. Due to the large proportion of antibiotic-treated patients(83%) with complications due to COVID-19 and the risk of the emergence of resistant strains, timely diagnostics aimed at identifying co-pathogens is of particular importance, which would help in the correct and timely treatment of patients.
Acknowledgments: This abstract is supported by: contracts KΠ-06-H 43/5/30.11.2020/ Molecular-genetic and clinical characteristics of human coronavirus. Study of the role of SARS-CoV-2 in co-infections with other respiratory viruses, NO KΠ-0 6-DK1/7/29.03.2021/ Viral load, cytokines and serum antibody levels depending on the clinical severity of COVID-19 infection and by the European Regional Development Fund through Operational Program Science and Education for Smart Growth 2014–2020, Grant BG05M2OP001-1.002-0001-C04 Fundamental Translational and Clinical Investigations on Infections and Immunity.
Recent Publications: Trifonova I, Christova I, Madzharova I, Angelova S, Voleva S, Yordanova R, Tcherveniakova T, Krumova S, Korsun N. Clinical significance and role of coinfections with respiratory pathogens among individuals with confirmed severe acute respiratory syndrome coronavirus-2 infection. Front Public Health. 2022 Sep 2;10:959319. doi: 10.3389/fpubh.2022.959319. PMID: 36117597; PMCID: PMC947944 IF2021 6.46
Alexiev I, Giovanetti M, Cella E, Ivanov I, Stoikov I, Donchev D, Grigorova L, Gancheva A, Dimitrova R, Korsun N, Trifonova I, Philipova I, Dobrinov V, Grigorova I, Kantardjiev T, Christova I, Ciccozzi M. Initial introduction and spread of the SARS-CoV-2 AY.4.2.1 Delta variant in Bulgaria, a genomic insight. J Med Virol. 2022 Jul 28:10.1002/jmv.28033. doi: 10.1002/jmv.28033. Epub ahead of print. PMID: 35902787; PMCID: PMC9353378. IF2021 20.6
Alexiev I, Ivanov I, Philipova I, Korsun N, Stoikov I, Dimitrova R, Grigorova L, Gancheva A, Trifonova I, Dobrinov V, Grigorova I, Savov A, Asenova B, Ciccozzi M, Kantardjiev T. Postvaccination SARS-CoV-2 Alpha (B.1.1.7) lineage infection among healthcare workers on the background of IgG antibodies. J Med Virol. 2022 Mar;94(3):836-839. doi: 10.1002/jmv.27394. Epub 2021 Oct 20. PMID: 34647629; PMCID: PMC8661687. IF2021 20.6
Korsun NS, Angelova SG, Trifonova IT, Voleva SE, Grigorova IG, Tzotcheva IS, Mileva SD, Perenovska PI. The Prevalence and Genetic Characterization of Human Metapneumovirus in Bulgaria, 2016-2019. Intervirology. 2021;64(4):194-202. doi: 10.1159/000516821. IF2020 1.763
Korsun N, Trifonova I, Voleva S, Grigorova I, Angelova S. Genetic characterization of the influenza viruses circulating in Bulgaria during the 2019-2020 winter season. Virus Genes. 2021 Oct;57(5):401-412. doi: 10.1007/s11262-021-01853-w. IF2020 2.332

Biography:

Iveta Madzharova is a biologist at the National Center for Infectious and Parasitic Diseases, National Laboratory "Influenza and SARS", Sofia, Bulgaria since the beginning of 2022. She has а bachelor’s degree in Biotechnology - Sofia University "St. Kliment Ohridski", Biological Faculty and started a master's degree in 2021 in the field of Microbiology and microbiological control - Sofia University "St. Kliment Ohridski", Biological Faculty. She is developing a master's thesis on the research topic. She participated in two projects related to the research topic. She published one article with impact factor in a reputable journal on the topic "Clinical significance and role of co-infections with respiratory pathogens among individuals with confirmed coronavirus-2 infection with severe acute respiratory syndrome". She participated in an international congress.