Clinical features of human influenza A (H5N1) infection in Vietnam: 2004-2006.
BACKGROUND
The first cases of avian influenza A (H5N1) in humans in Vietnam were detected in early 2004, and Vietnam has reported the second highest number of cases globally.


METHODS
We obtained retrospective clinical data through review of medical records for laboratory confirmed cases of influenza A (H5N1) infection diagnosed in Vietnam from January 2004 through December 2006. Standard data was abstracted regarding clinical and laboratory features, treatment, and outcome.


RESULTS
Data were obtained for 67 (72%) of 93 cases diagnosed in Vietnam over the study period. Patients presented to the hospital after a median duration of illness of 6 days with fever (75%), cough (89%), and dyspnea (81%). Diarrhea and mucosal bleeding at presentation were more common in fatal than in nonfatal cases. Common findings were bilateral pulmonary infiltrates on chest radiograph (72%), lymphopenia (73%), and increased serum transaminase levels (aspartate aminotransferase, 69%; alanine aminotransferase, 61%). Twenty-six patients died (case fatality rate, 39%; 95% confidence interval, 27%-51%) and the most reliable predictor of a fatal outcome was the presence of both neutropenia and raised alanine aminotransferase level at admission, which correctly predicted 91% of deaths and 82% of survivals. The risk of death was higher among persons aged < or =16 years, compared with older persons (P < .001), and the risk of death was higher among patients who did not receive oseltamivir treatment (P = .048). The benefit of oseltamivir treatment remained after controlling for potential confounding by 1 measure of severity (odds ratio, 0.15; 95% confidence interval, 0.026-0.893; P = .034).


CONCLUSIONS
In cases of infection with Influenza A (H5N1), the presence of both neutropenia and raised serum transaminase levels predicts a poor outcome. Oseltamivir treatment shows benefit, but treatment with corticosteroids is associated with an increased risk of death.
National Hospital of Pediatrics, Ho Chi Minh City, Vietnam.
Nguyen Thanh
NT
Liem
Cao Viet
CV
Tung
Nguyen Duc
ND
Hien
Tran Tinh
TT
Hien
Ngo Quy
NQ
Chau
Hoang Thuy
HT
Long
Nguyen Tran
NT
Hien
Le Quynh
le Q
Mai
Walter R J
WR
Taylor
Heiman
H
Wertheim
Jeremy
J
Farrar
Dinh Duy
DD
Khang
Peter
P
Horby
D000293:Adolescent; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000209:etiology; D005260:Female; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007223:Infant; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000821:virology; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008231:Lymphopenia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D053139:Oseltamivir / Q000627:therapeutic use; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D000637:Transaminases / Q000097:blood; D016896:Treatment Outcome; D014744:Vietnam; D055815:Young Adult
D000998:Antiviral Agents; D053139:Oseltamivir; D000637:Transaminases