Mortality predictors of H1N1 influenza outbreak in 2015–A cross-sectional study

Background & Aim H1N1 pandemic has been associated with increased morbidity and mortality. In India, a recent outbreak of H1N1 influenza has posed a serious challenge for health services with rapid spread across various states causing panic among public. The present outbreak data correlates clinico-laboratory findings with mortality. Method In a prospective observational study at a tertiary care centre in Northern India, data was collected from 1st January 2015 to 28th February 2015 related to H1N1 mortality in all patients tested positive using real-time reverse-transcription polymerase chain reaction testing on nasopharyngeal swabs. Results Data of 151 patients was analyzed. Age ranged from 3 months to 85 years with 47.6% females and 55%above 40 years. Comorbidity was seen in 52.9% (diabetes mellitus Type 2- 23.8%, hypertension - 25.8%) of the patients. The time between onset of symptoms and hospitalization ranged from 1 to 25days. Documented clinical features were fever - 96.6%, dry cough - 86.09%, productive cough - 13.01% and dyspnea - 80.7%. Management included oseltamivir and antibiotics if indicated along with 66.8% of the patients who required oxygen support, 22.5% required intensive care, 14.5% mechanically ventilated and 8% maintained on non invasive ventilation. Mortality was 8.6%. logistic regression were used to explore factors influencing mortality in H1N1 infection; the significant risk factors were- rising age (OR=1.041), longer hospital stay (OR=1.092), raised serum aspartate transaminase (OR=1.013), raised serum alanine transaminase (OR=1.027), raised total leukocyte count (OR=1.115) and raised bilirubin (OR=1.389) levels Conclusion The mortality rate in our study was 8.6%. H1N1 influenza patients who were older with deranged hepatic parameters and raised total leukocyte count had poor prognosis.