OBJECTIVE: To describe detailed clinical and radiological features of the pandemic H1N1 2009 influenza viral infection among healthy young males in a semi-closed institutionalized setting. MATERIALS AND METHODS: A total of 18 patients confirmed with the pandemic H1N1 2009 influenza virus infection from July 18 to July 30, 2009 were enrolled in this study. Each patient underwent an evaluation to determine detailed clinical and radiological features. RESULTS: All patients presented with high fever (> 38.0degrees C), with accompanying symptoms of cough, rhinorrhea, sore throat, myalgia and diarrhea, and increased C-reactive protein (CRP) values with no leukocytosis nor elevated erythrocyte sedimentation rate (ESR). All patients, including one patient who progressed into acute respiratory distress syndrome, were treated with oseltamivir phosphate and quickly recovered from their symptoms. Chest radiographs showed abnormalities of small nodules and lobar consolidation in only two out of 18 patients. However, six of 12 patients who underwent thin-section CT examinations showed abnormal findings for small ground-glass opacities (GGOs) in addition to poorly-defined nodules with upper lobe predominance. CONCLUSION: In a population of healthy young adults, elevated CRP with normal ESR and white blood cell levels combined with GGOs and nodules on thin-section CT scans may indicate early signs of infection by the pandemic H1N1 2009 influenza virus.
*Disease Outbreaks ; Humans ; *Influenza A Virus, H1N1 Subtype ; Influenza, Human/*epidemiology/*radiography/therapy ; Male ; *Military Personnel ; *Radiography, Thoracic ; Republic of Korea/epidemiology ; Tomography, X-Ray Computed ; Young Adult

BACKGROUND/AIMS: Pandemic influenza A (H1N1) virus infection presents with variable severity. However, little is known about clinical predictors of disease severity. We studied the clinical predictors of severe pandemic H1N1 pneumonia and their correlation with radiological findings. METHODS: We reviewed medical and radiological records of adults with pandemic H1N1 pneumonia. After classification of patients into severe and non-severe groups, the following data were evaluated: demographic data, pneumonia severity index (PSI), CURB65, risk factors, time to first dose of antiviral medication, routine laboratory data, clinical outcome, and radiological characteristics. RESULTS: Of 37 patients with pandemic H1N1 pneumonia, 12 and 25 were assigned to the severe and non-severe groups, respectively. PSI score, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dyhydrogenase (LDH) levels were higher in the severe group than in the non-severe group (p = 0.035, 0.0003, 0.0023, and 0.0002, respectively). AST, ALT, and LDH levels were positively correlated with the radiological findings (p < 0.0001, 0.0003, and < 0.0001, respectively) and with the number of involved lobes (p = 0.663, 0.0134, and 0.0019, respectively). The most common finding on high resolution computed tomography (HRCT) scans was ground-glass attenuation with consolidation (n = 22, 60%), which had a predominantly patchy distribution (n = 31). CONCLUSIONS: We demonstrated a positive correlation between clinical findings, such as serum AST, ALT, and LDH levels, and radiological findings. A combination of clinical and HRCT indicators would be useful in predicting the clinical outcome of pandemic H1N1 pneumonia.
Adolescent ; Adult ; Aged ; Alanine Transaminase/blood ; Antiviral Agents/therapeutic use ; Aspartate Aminotransferases/blood ; Biological Markers/blood ; Chi-Square Distribution ; Clinical Enzyme Tests ; Female ; Humans ; Influenza A Virus, H1N1 Subtype/*pathogenicity ; Influenza, Human/*diagnosis/mortality/radiography/therapy/virology ; L-Lactate Dehydrogenase/blood ; Lung/*radiography/virology ; Male ; Middle Aged ; *Pandemics ; Pneumonia, Viral/*diagnosis/mortality/radiography/therapy/virology ; Predictive Value of Tests ; Prognosis ; Republic of Korea/epidemiology ; Respiration, Artificial ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Severity of Illness Index ; *Tomography, X-Ray Computed ; Young Adult