Avian influenza A (H5N1) in 10 patients in Vietnam.
BACKGROUND
Recent outbreaks of avian influenza A (H5N1) in poultry throughout Asia have had major economic and health repercussions. Human infections with this virus were identified in Vietnam in January 2004.


METHODS
We report the clinical features and preliminary epidemiologic findings among 10 patients with confirmed cases of avian influenza A (H5N1) who presented to hospitals in Ho Chi Minh City and Hanoi, Vietnam, in December 2003 and January 2004.


RESULTS
In all 10 cases, the diagnosis of influenza A (H5N1) was confirmed by means of viral culture or reverse transcriptase-polymerase chain reaction with primers specific for H5 and N1. None of the 10 patients (mean age, 13.7 years) had preexisting medical conditions. Nine of them had a clear history of direct contact with poultry (median time before onset of illness, three days). All patients presented with fever (temperature, 38.5 to 40.0 degrees C), respiratory symptoms, and clinically significant lymphopenia (median lymphocyte count, 700 per cubic millimeter). The median platelet count was 75,500 per cubic millimeter. Seven patients had diarrhea. In all patients, there were marked abnormalities on chest radiography. There was no definitive evidence of human-to-human transmission. Eight patients died, one patient has recovered, and one is recovering.


CONCLUSIONS
Influenza A (H5N1) infection, characterized by fever, respiratory symptoms, and lymphopenia, carries a high risk of death. Although in all 10 cases the infection appears to have been acquired directly from infected poultry, the potential exists for genetic reassortment with human influenzaviruses and the evolution of human-to-human transmission. Containment of influenza A (H5N1) in poultry throughout Asia is therefore urgently required.
Hospital for Tropical Diseases, Health Service of Ho Chi Minh City, Vietnam.
Tinh Hien
TH
Tran
Thanh Liem
TL
Nguyen
Thi Dung
TD
Nguyen
Thi San
TS
Luong
Phuong Mai
PM
Pham
van Vinh Chau
vV
Nguyen
Thi Suu
TS
Pham
Cong Dong
CD
Vo
Thi Quynh Mai
TQ
Le
Thi Thi
TT
Ngo
Bach Khoa
BK
Dao
Phuc Phat
PP
Le
Thanh Truong
TT
Nguyen
Thuy Long
TL
Hoang
Viet Tung
VT
Cao
Truong Giang
TG
Le
Dac Tho
DT
Nguyen
Hong Nga
HN
Le
Kim Tien
KT
Nguyen
Hoang San
HS
Le
Van Tuan
VT
Le
Dolecek
D
Christiane
Tan Thanh
TT
Tran
de Jong
de J
Menno
Constance
C
Schultsz
Peter
P
Cheng
Wilina
W
Lim
Peter
P
Horby
Jeremy
J
Farrar
D000293:Adolescent; D000328:Adult; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D002645:Chickens / Q000821:virology; D002648:Child; D002675:Child, Preschool; D004372:Ducks / Q000821:virology; D005260:Female; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype; D009980:Influenza A virus / Q000235:genetics / Q000302:isolation & purification; D005585:Influenza in Birds / Q000635:transmission*; D007251:Influenza, Human / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy / Q000821:virology*; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D012367:RNA, Viral / Q000032:analysis; D011859:Radiography; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome; D014744:Vietnam / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D012367:RNA, Viral