Epidemiological analysis of the pandemic influenza A (H1N1) virus in Bhutan

Abstract

Background: In April 2009, a swine origin influenza A (H1N1) virus (S-OIV) was identified in Mexico. The virus has since spread throughout the world and caused an influenza pandemic. Children and young adults appear to those most affected and also those who appear to maintain transmission. Cytokines are important mediators aimed to trigger immune mechanisms responsible for counteracting the microorganisms invade the host. Methods: Totally 61 patients was enrolled with mean age of 10.1±4.2 years. 20 patients with S-OIV pulmonary complication and 41 patients without S-OIV pulmonary complicationwere studied. The concentrations of IL-1 , IL-6, IL-8, IL-10, IFN-g and TNF-a were measured using cytokine cytometric bead assay kits. Stained lymphocytes were analyzed by flow cytometry (Becton Dickinson Immunocytometry Systems). Results: Among the patients who presented with the S-OIV infection, there were no differences in the age, gender, illness day on admission, white blood cell count between patients with pneumonia and those without pneumonia. Level of CRP was higher in patientwithpulmonarycomplications.Amongmeasuredcytokines in the children with the S-OIV infection, the serum levels of TNF, IL-1 and IL-6 in patients with pneumonia were significantly higher than those in patients without pneumonia. Immunophenotypes expression of CD3+, CD8+, and CD16+CD56+ on PBMCs was lower in patients with pneumonia. Conclusion: Peripheral blood mononuclear cells from S-OIV infected patients reveal variability in immune responses of human macrophages in response to S-OIV infections. Acute phase response of cytokines during the 2009 S-OIV infection might have contributed to the pathogenesis of the disease.