Abstract

Background: From the beginning of the epidemic, influenza A (H1N1) infection seemed to have a more severe course and worse outcomes than did infection with seasonal influenza A. In addition, the demographic profile shows that it affected younger age group, and individuals with fewer comorbidities. More severe respiratory involvement was noted, and a large number of patients were admitted to intensive care units with influenza A (H1N1)-associated pneumonia.

Objective: To describe the clinical characteristics and outcome of patient on mechanical ventilator infected with 2015 H1N1 influenza virus.

Materials and Methods: Nasopharyngeal and throat swabs were collected from patients presenting with influenza-like illness (ILI) at Civil Hospital, Ahmedabad, Gujarat, India, outpatient department and indoor patients, and patients admitted to other hospitals of Ahmedabad and nearby areas. From January–March 2015, 6716 specimens were received and were tested by the WHO CDC validated kits and real-time reverse transcription polymerase chain reaction (RT-PCR) for H1N1 and influenza A (seasonal flu).

Result: From January to March 2015, 6716 nasal and throat samples were received from patients of all ages with ILI. ILI was defined as fever (>100 F) with cough and/or sore throat. All the samples were processed by real-time RT-PCR. Out of 6716 samples, 1800 samples were from Civil Hospital, Ahmedabad, from different wards and outpatient department, and 4916 samples were from different private hospitals of Ahmedabad city and nearby areas. In Civil Hospital Ahmedabad, out of 1800 samples, 1054 samples tested positive for H1N1 and 242 were positive for influenza A (seasonal flu). Among them, 676 patients started showing response to oseltamivir whereas 378 patients were hypoxic and required oxygen therapy. Of these, 247 patients required mechanical ventilation, of which 189 patients died and 58 patients recovered.

Conclusion: Patients with suspected influenza A (H1N1) infection should be moved to negative-pressure isolation rooms as soon as possible to avoid transmission of the infection. They should receive continuous oxygen monitoring. Antiviral treatment should not be delayed. This infection requires proactive management.

Key words: Swine flu, mechanical ventilator, outcome