Clinical manifestations, therapy and outcome of pandemic influenza a (H1N1) 2009 in hospitalized patients
Authors: Mikic Dragan , Nozic Darko , Kojic Miroslav , Popovic Svetlana , Hristovic Dejan , Rajic-Dimitrijevic Radmila , Curcic Petar , Milanovic Milomir , Glavatovic Rade , Begovic-Kupresanin Vesna , Veljovic Milic , Djordjevic Dragan , Kuljic-Kapulica Nada , Cekanac Radovan , Stefanovic Dara 
Published: March 2011

Background/Aim. Increasing number of epidemiological and clinical studies to
date showed that the pandemic influenza A (H1N1) 2009, by its
characteristics, significantly differs from infection caused by seasonal
influenza. Therefore, the information about clinical spectrum of
manifestations, risk factors for severe form of the disease, treatment and
outcome in patients with novel flu are still collected. Methods. A total of
98 patients (mean age 32 ? 15 years, range 14-88 years) with the signs and
symptoms of novel influenza were treated in the Clinic for Infectious and
Tropical Diseases, Military Medical Academy. There were 74 (75.5%) patients
with suspected influenza A (H1N1) 2009, 10 (10.2%) with the likelihood and 14
(14.3%) with the confirmed influenza. In all the patients we registered the
basic demographic data, risk factors for severe disease, symptoms and signs
of influenza, laboratory tests and chest radiography. We analyzed antiviral
therapy use and disease outcome (survived, died). Results. The average time
from the beginning of influenza A (H1N1) to the admission in hospital was 3
days (0-16 days) and from the moment of hospitalization to the Intensive Care
Unit (ICU) admission was 2 days (0-5 days). There were 49 (50.0%) patients,
20-29 years of age and 5 (5.1%) patients older than 65. A total of 21 (21.4%)
patients were with underlying disease, 18 (18.4%) were obese, 19 (19.4%) were
cigarette smokers. All of the patients had fever, 81 (82.6%) cough, while
dyspnea and diarrhea were registered in ? of the patients. In more than 75%
of the patients laboratory tests were within normal limits. The realtime
polymerase chain reaction (PCR) test for identification of influenza A (H1N1)
2009 was positive in 14 (77.8%), while pneumonia was verified in 30 (30.7%)
of the patients. Six (6.1%) patients, mean age of 45 ? 14 years (31-59 years)
were admitted to the ICU, of whom five (5.1%) had Adult Respiratory Distress
Syndrome (ARDS). Risk factors were registered more frequently in the patients
with acute respiratory failure (14.2% vs 4.9%, p < 0.05). A total of 67
(68.4%) patients received oseltamivir, 89 (90.1%) was applied to antibiotics
and 64 (65.3%) were treated with a combined therapy. Antiviral therapy was
applied to 43 (43.3%) patients in the first 48 hours from the onset of the
disease, of whom only one (3.4%) developed ARDS. Fatal outcome was noted in
2.0% of the patients (2 of 98 patients) and in 33.3% of the patients treated
in the ICU. Conclusion. Novel influenza A (H1N1) is most commonly manifested
as a mild acute respiratory disease, which usually affects young healthy
adults. A small number of the patients develop severe illness with acute
respiratory failure and death. Patients seem to have benefit from antiviral
therapy especially in first 48 hours.