Among 41 patients who were hospitalized from January 2004 through July 2005 and had positive RT-PCR results, 12 were excluded from the study (3 patients whose medical records were unavailable; 2 patients related to persons with confirmed H5N1 subtype pneumonia who were asymptomatic, positive for viral RNA, and treated with prophylactic oseltamivir; and 7 patients who had some illnesses, particularly respiratory diseases, which complicated interpretation of the clinical course or chest radiographic findings). We therefore studied 29 patients with clinically and virologically confirmed influenza A (H5N1) infection.
shows the general characteristics of the patients, and the shows the clinical course from onset of disease to hospitalization and discharge. Patients ranged in age from 14 to 67 years and with a mean age of 35.1 years. A total of 25 patients were given 150 mg/day of oseltamivir, and 15 were treated with methylprednisolone (initial dose 40–160 mg/day, median dose 80 mg/day). Seven (24.1%) of the 29 patients died. No significant associations were found between mortality rates and age (p = 0.57), sex (p = 0.68), history of high-risk exposure (contact with poultry [p = 1.00], contact with sick poultry [p = 1.00], and contact with sick poultry or persons [p = 1.00]). Three of 6 patients from a family infected with H5N1 subtype died, and 4 of 23 patients without such an association died (p = 0.13). Duration between onset of disease and hospitalization was not associated with higher mortality rates (p = 0.98).
Characteristics of 29 patients infected with highly pathogenic avian influenza virus (H5N1), northern Vietnam, 2004–2005*
Figure Clinical course of 29 patients infected with highly pathogenic avian influenza virus (H5N1), northern Vietnam, 2004–2005. Zero days on horizontal axis represent days of hospitalization at the National Institute of Infectious and Tropical Diseases. (more ...)
shows initial laboratory findings at hospitalization. Leukopenia (neutropenia), thrombocytopenia, hypoalbuminemia, and increased AST and urea nitrogen levels were associated with increased deaths.
Initial laboratory and chest radiographic results for 29 patients infected with highly pathogenic avian influenza virus (H5N1), northern Vietnam, 2004–2005*
Five (20.0%) of the 25 patients treated with oseltamivir died, as did 2 (50.0%) of 4 who were not treated (odds ratio 0.25, 95% confidence interval [CI] 0.03–2.24, p = 0.24). To adjust for variation in disease severity among patients, exact logistic regression was performed by using leukocyte counts, platelet counts, AST levels, and urea nitrogen levels. Adjusted odds ratios for deaths among patients treated with oseltamivir were 0.15 (95% CI 0.00–2.57, p = 0.19), 0.16 (95% CI 0.00–2.23, p = 0.17), 0.54 (95% CI 0.02–11.85, p = 1.00), and 0.28 (95% CI 0.01–5.16, p = 0.55), respectively, for the 4 adjustments for disease severity.
The time between the onset of symptoms and initiation of treatment with oseltamivir varied (, ). The mortality rates were 20% (3/15) and 20% (2/10) when treatment with oseltamivir was started within and after 7 days of disease onset.
Methylprednisolone was given to 15 of 29 patients. Five (33.3%) of these 15 patients died, and 2 (14.3%) of 14 patients who were not given this drug died (odds ratio 3.0, 95% CI 0.48–18.93, p = 0.39). Exact logistic regression after adjustment for severity by using leukocyte counts, platelet counts, AST levels, or urea nitrogen levels showed odds ratios for deaths among patients treated with methylprednisolone of 0.74 (95% CI 0.00–9.57, p = 0.82), 1.82 (95% CI 0.18–25.48, p = 0.89), 1.14 (95% CI 0.07–18.92, p = 1.00), and 2.43 (95% CI 0.28–31.69, p = 0.61), respectively.
Thirteen patients were treated with oseltamivir and methylprednisolone. The regression model that included these 2 drugs and interactions did not show effectiveness of either drug.