Thermal Scanner – Credit Wikipedia
The announcement yesterday morning of two H5N1 cases in the south-central Chinese province of Guizhou (see China: Two H5N1 Cases Reported In Guiyang) has once again raised alerts over the potential spread of avian flu.
While no additional cases have been reported, we often see increased vigilance across Asia whenever H5N1 makes the news.
An example comes today from Taiwan’s Central News Agency (CNA), on their CDC’s order to screen arrivals from China for fever or flu-like illness, and to take and test specimens from travelers showing symptoms.
(Central News Agency reporter Lin Honghan) -
The CDC today said that the Chinese mainland the Guizhou outgoing diagnosed two cases of H5N1 influenza, has asked the airport, port personnel to strengthen passenger fever, to investigate the history of bird contact.
Department of Health, Centers for Disease Control press release said that the birds history of exposure to inbound travelers from mainland China have flu-like symptoms, quarantine officers will adopt a specimen for examination, and self-health management 10 days.
The CDC called for local Taiwanese businessmen go travelers with the plan, you should pay attention to personal hygiene, strengthen wash their hands, do not touch the birds, to avoid infection; return, such as a fever or flu-like symptoms, consult a doctor immediately should wear a mask.
While the screening of inbound passengers for disease symptoms is quite often the first visible public health response when an emerging pathogen threatens, its track record of preventing disease entry into countries is spotty at best.
Last April, in EID Journal: Airport Screening For Pandemic Flu In New Zealand, we saw a study that found the screening methods used at New Zealand’s airport were inadequate to slow the entry of the 2009 pandemic flu into their country, detecting less than 6% of those infected.
New Zealand did not employ thermal scanners, although countries that did, didn’t fare much better.
In December of 2009, in Travel-Associated H1N1 Influenza in Singapore, I blogged on a NEJM Journal Watch article on of a new study that has been published, ahead of print, in the CDC’s EID Journal entitled:
Epidemiology of travel-associated pandemic (H1N1) 2009 infection in 116 patients, Singapore. Emerg Infect Dis 2010 Jan; [e-pub ahead of print]. Mukherjee P et al
Airport thermal scanners detected only 12% of travel-associated flu cases; many travelers boarded flights despite symptoms.
While the success rate is likely to be low, there may be some value in trying to limit the number of infected persons arriving into a country, for that may slow the spread of the illness and might allow more time to develop and deploy a vaccine.
Fortunately, we aren’t at the point with the H5N1 virus that it poses a serious global public health threat.
That could change, of course, if the virus evolves into a more human-adapted pathogen.
The sobering truth is that vast oceans and extended travel times no longer offer us the kind of protection they once did, and we possess no technological shield that would keep an emerging pandemic virus out.
All of which makes the funding and support of international public health initiatives, animal health initiatives, and global disease surveillance increasingly important.
No matter where on this globe you happen to live.