Influenza A/H5N1 virus infection in humans in Cambodia.
BACKGROUND
Between January 2005 and April 2006, six patients of influenza A/H5N1 virus infection were reported in Cambodia, all with fatal outcome.


OBJECTIVE
We describe the virological findings of these six H5N1 patients in association with clinical and epidemiologic findings.


METHODS
Broncho-alveolar lavage, nasopharyngeal, throat and rectal swabs and sera were cultured for virus isolation and viral load quantified in clinical specimens by real-time RT-PCR. We compared sequences obtained from different body sites within the same patient to detect viral quasi-species.


RESULTS
H5N1 virus strains isolated in Cambodia belong to genotype Z, clade 1 viruses. H5N1 viruses were isolated from serum and rectal swab specimens in two patients. The haemagglutinin gene sequences of the virus in different body sites did not differ. Amino acid substitutions known to be associated with a change in virus binding were not observed.


CONCLUSIONS
The high frequency of virus isolation from serum and faecal swabs highlights that H5N1 is likely to be a disseminated infection in humans and this has implications for antiviral treatment, biosafety in clinical laboratories and on risks for nosocomial and human-to-human transmission. There were no tissue-specific adaptive mutations in the HA gene from viruses isolated from different organs.
Buchy
Philippe
P
Institut Pasteur in Cambodia, 5 Monivong blvd, P.O. Box 983, Phnom Penh, Cambodia. pbuchy@pasteur-kh.org
Mardy
Sek
S
Vong
Sirenda
S
Toyoda
Tetsuya
T
Aubin
Jean-Thierry
JT
Miller
Megge
M
Touch
Sok
S
Sovann
Ly
L
Dufourcq
Jean-Baptiste
JB
Richner
Beat
B
Tu
Phan Van
PV
Tien
Nguyen Thi Kim
NT
Lim
Wilina
W
Peiris
J S Malik
JS
Van der Werf
Sylvie
S
D000328:Adult; D000818:Animals; D001769:Blood / Q000821:virology; D002160:Cambodia / Q000453:epidemiology; D002460:Cell Line; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005260:Female; D005838:Genotype; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000821:virology; D008297:Male; D012367:RNA, Viral / Q000032:analysis / Q000302:isolation & purification; D012137:Respiratory System / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014776:Virus Cultivation
D012367:RNA, Viral