Ambient influenza and avian influenza virus during dust storm days and background days.
BACKGROUND
The spread of influenza and highly pathogenic avian influenza (H5N1) presents a significant threat to human health. Avian influenza outbreaks in downwind areas of Asian dust storms (ADS) suggest that viruses might be transported by dust storms.


OBJECTIVE
We developed a technique to measure ambient influenza and avian influenza viruses. We then used this technique to measure concentrations of these viruses on ADS days and background days, and to assess the relationships between ambient influenza and avian influenza viruses, and air pollutants.


METHODS
A high-volume air sampler was used in parallel with a filter cassette to evaluate spiked samples and unspiked samples. Then, air samples were monitored during ADS seasons using a filter cassette coupled with a real-time quantitative polymerase chain reaction (qPCR) assay. Air samples were monitored during ADS season (1 January to 31 May 2006).


RESULTS
We successfully quantified ambient influenza virus using the filtration/real-time qPCR method during ADS days and background days. To our knowledge, this is the first report describing the concentration of influenza virus in ambient air. In both the spiked and unspiked samples, the concentration of influenza virus sampled using the filter cassette was higher than that using the high-volume sampler. The concentration of ambient influenza A virus was significantly higher during the ADS days than during the background days.


CONCLUSIONS
Our data imply the possibility of long-range transport of influenza virus.
Chen
Pei-Shih
PS
Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung City, Taiwan. pschen@kmu.edu.tw
Tsai
Feng Ta
FT
Lin
Chien Kun
CK
Yang
Chun-Yuh
CY
Chan
Chang-Chuan
CC
Young
Chea-Yuan
CY
Lee
Chien-Hung
CH
D000391:Air Microbiology; D000392:Air Movements; D000393:Air Pollutants; D009980:Influenza A virus / Q000235:genetics / Q000302:isolation & purification*; D009975:Orthomyxoviridae / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction
D000393:Air Pollutants