H5N1 Virus Changes in Northern Vietnam
Author Information
Author(s): Le Mai T. Q., Wertheim Heiman F. L., Nguyen Hien D., Taylor Walter, Hoang Phuong V. M., Vuong Cuong D., Nguyen Hang L. K., Nguyen Ha H., Nguyen Thai Q., Nguyen Trung V., Van Trang D., Ngoc Bich T., Bui Thinh N., Nguyen Binh G., Nguyen Liem T., Luong San T., Phan Phuc H., Pham Hung V., Nguyen Tung, Fox Annette, Nguyen Cam V., Do Ha Q., Crusat Martin, Farrar Jeremy, Nguyen Hien T., de Jong Menno D., Horby Peter
Primary Institution: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
Hypothesis
What are the characteristics and antiviral susceptibility profiles of H5N1 viruses infecting humans in northern Vietnam in 2007?
Conclusion
In 2007, H5N1 clade 2.3.4 viruses replaced clade 1 viruses in northern Vietnam and were susceptible to amantadine but showed reduced susceptibility to oseltamivir.
Supporting Evidence
- Eight patients were diagnosed with H5N1 in 2007, and five of them died.
- Phylogenetic analysis showed that clade 2.3.4 H5N1 viruses replaced clade 1 viruses in northern Vietnam.
- Four human H5N1 strains had eight-fold reduced in-vitro susceptibility to oseltamivir compared to clade 1 viruses.
- All patients presented with fever, cough, and dyspnea.
- Seven patients required mechanical ventilation early after admission.
Takeaway
Some sick people in Vietnam got a new type of bird flu virus that was harder to treat with one medicine but could still be treated with another.
Methodology
Patients suspected of H5N1 infection were tested using RT-PCR and virus isolates were characterized by genome sequencing and drug susceptibility testing.
Potential Biases
Potential bias due to the limited geographical area and the specific patient demographics.
Limitations
The study was limited to a small sample size of eight patients and may not represent the broader population.
Participant Demographics
Six males and two females, median age 23 years, with exposure to poultry.
Statistical Information
P-Value
0.021
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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