Molecular Detection of H1N1 and Impact of Cytokines among Infected Patients with Respiratory Distress: A Cross-sectional Study

Introduction: Viruses are spread from one individual to another. In respect to the mode of transmission, the majority of them enter the human body by the inward breath of infective respiratory beads. Upper Respiratory Tract Infections (URTI) are infections of the body’s respiratory tract, which include the sinuses, nose, throat, airways, and lungs. The influenza virus has four key structural antigens: the internal Ribonucleoprotein (RNP), the viral envelope Matrix (M), and two surface Glycoproteins (GP), Neuraminidase (NA) and Haemagglutinin (HA). A respiratory virus called swine flu/H1N1 evolved and spread widely around the world. H1N1 outbreaks with various virus strains were noted before the most recent severe pandemic, which occurred in 2009. Seasonal outbreaks that are extremely infrequent since the 2009 pandemic the influenza strain have occurred.

Aim: To assess the prevalence and level of cytokines in H1N1-infected patients with signs and symptoms of respiratory distress.

Materials and Methods: This is a cross-sectional study of viral molecular, immunological and epidemiological parameters. The study was done at the Indian Council of Medical Research (ICMR) at the Department of Health Research (DHR), Virus Research and Diagnostic Laboratory (VRDL), Department of Microbiology, Burdwan Medical College and Hospital (BMCH), Burdwan, India. The duration of the study was seven months, from January 2022- July 2022. Samples in Viral Transport Medium (VTM) were collected from suspected influenza patients with mild or severe Acute Respiratory Distress Symptoms (ARDS) and Influenza Like Symptom (ILS). The RNA samples were isolated and the nucleic acid purified from samples was screened by Real-time Polymerase Chain Reaction (RT-PCR). The extracted clinical Ribonucleic Acid (RNA) samples are then converted into Complementary Deoxyribonucleic acid (cDNA). The HA gene sequences of endemic swine influenza A virus (H1N1) and sequences from a panel of human and avian type A influenza virus strains, including the type A human seasonal strains, were retrieved from the GenBank database in the National Centre for Biotechnology Information (NCBI) portal. The Enzyme-linked Immunoassay (ELISA) method was used to measure the proinflammatory cytokines Interleukin (IL)-8, IL2 and anti-inflammatory cytokine IL10, as well as the IL3 concentration level in severe Acute Respiratory Distress Syndrome (ARDS) +Immediate Life Support (ILS) positive H1N1 infected patients. Analysis of all the data was performed by Statistical Package for Social Sciences (SPSS) software version 22.

Results: In this study, all samples (n=120) were examined using RT-PCR, which revealed that 53 samples were infected with the Influenza A Virus (IAV). Among the total positive 24 were males and 29 were females. the average concentration of IL3 was 1749.49 pg/mL. The increase in IL8 was not as big as the increase in IL2 and IL3. IL8 was identified as a significant proinflammatory factor during angiogenesis, or uncontrolled cell growth.

Conclusion: The prevalence of H1N1 infection was found to be high in children under the age of ten. The concentration of IL-3 in H1N1-infected patients’ samples was higher than the concentrations of the other three cytokines.