© Sinopix / Rex FeaturesAt Hong Kong airport, a screen shows the location of a person in the airport, while immigration and health inspectors check the temperature and travel routes of visitors to see if they have the H1N1 virus.
Future pandemics will almost certainly be spread via air travel, with flights capable of carrying a pathogen across the world in hours. The UN's Convention on International Civil Aviation requires nations to "prevent the spread of communicable diseases by means of air navigation". That is easier said than done, especially in poorer regions.
Enter CAPSCA - the Cooperative Arrangement for the Prevention of the Spread of Communicable diseases by Air travel. CAPSCA aims to help airports in developing nations prepare for a pandemic, and its schemes are now getting off the ground in the Americas, Asia-Pacific and Africa.
"When an aircraft arrives with a suspected disease case on board, CAPSCA will make sure you've thought about where you are going to park the plane, how you will deal with the luggage and how are you going to keep in touch with the passengers that haven't got any symptoms," Evans says. You also have to work out which people on the plane are most likely to be infected and whether they need prophylactic treatment or admission to hospital. How will you protect customs officers? Careful planning is crucial and CAPSCA will promote that, Evans explains.
At present these plans rely on aircrew identifying any sick passengers by their symptoms. It would be far better to have an automatic system that can detect infected people as they pass through a gate or wander around an airport, but there is still no reliable technology to do that.
Since the SARS scare in 2003, some airports have used infrared cameras to pinpoint passengers with high temperatures, Turkey spotted its first swine flu case this way. It is an imperfect solution, however, because different viruses are infectious at different stages: flu is infectious about a day before fever arrives, whereas with SARS the two coincide. "So cameras were better at picking up SARS cases before an infected person got on a plane," Evans says.
Ideally, he'd like to see a test that reveals when somebody is infected before they even develop symptoms - perhaps based on a breath test. But such technology remains far-off.
One infection-spotting technique that might be practical in the near future is the cough detector. Biorics, a spin-off from the Catholic University of Leuven in Belgium, is hoping to use cheap networks of microphones in airports to detect and locate people with persistent coughs. The firm has developed software that by analysing the pattern of frequencies can tell the difference between someone merely clearing their throat and a sickly cough. Once a cougher has been detected, the microphone array can then be used to triangulate their position and identify them, perhaps with the aid of CCTV, so they can then be checked for infection.
"It is not clear for which human infections the technique will be reliable. That needs more research," says Biorics director Daniel Berckmans. The firm also believes its acoustic cough detector can monitor animal health on the kind of massive pig farms where the new H1N1 flu is thought to have emerged. In tests with seven microphones in pens of 100 pigs, the Biorics system was able to identify sick pigs 82 per cent of the time within 3 hours of infection.
Beyond the realm of aviation, pandemic detection could harness the distributed sound and location sensors we all carry: cellphones. Biorics says its algorithms could be built into phones, alerting health authorities when a suspect cough is sensed, even revealing whether it is the phone user who is sick or if somebody else is coughing in the background.
Comment: This begs the question, what defines a 'suspect cough'?
Last week, the Japanese government kicked off a 2000-person trial based on GPS-enabled phones. Cellphone users will receive a warning text if their GPS history suggests they may have been in contact with another user later diagnosed with flu.
Both these ideas have the potential to infringe privacy. But in the face of a 1918-style potential pandemic, health authorities are likely to echo the words of Sun Microsystems boss Scott McNealy, when faced with the onslaught of the internet: "Forget privacy."
Ceramic coating makes short work of viruses
Viruses lurking on solid surfaces could be killed by a new coating based on ceramic nanoparticles, which is undergoing trials in the US.
The technology follows from work by virologist John Oxford and his colleagues at Queen Mary, University of London. The team discovered that certain silicon and metal carbide ceramics destroy any viruses they came into contact with, as long as the substances are in the form of fine particles no more than 100 nanometres across.
"It kills 99.9 per cent of viruses in less than an hour. It's better than wiping the surface with acetic acid," says Joseph Rugaso of Intrinsiq Materials in Farnborough, UK, which is now developing the coating.
No one is yet sure how it works, however. Originally, it was thought that the nanoparticles physically damaged surface proteins on the virus, but the researchers now suspect the particles have a chemical effect akin to that of an acid.
Intrinsiq makes its coating by mixing a plasma of silicon and carbon ions and condensing them as carbide nanoparticles. Backed by defence company Qinetiq, also in Farnborough, Intrinsiq is working to build its antiviral material into aviation air filters, face masks, shopping cart handles, cash machines and even banknotes.
"Most available face masks work by filtering out virus particles based on their size, but don't deactivate the virus," says Rugaso. "Our masks, and cabin air filters will provide the added benefit of virus deactivation." After all, he says, a face mask or filter that has merely trapped viruses is still a biohazard.
Reader Comments
to our Newsletter