Tuesday, April 28, 2009

Following Swine Flu Online

Tracking and communications could play a key role in combating a pandemic.

By Michael Day

Flu flow: HealthMap, created by Google and the CDC, annotates a global map with news articles, official medical alerts, and other data in real time. Credit: Google Credit: Google

RESOURCES: HealthMap CDC WHO

The World Health Organization (WHO) admitted on Tuesday that it's too late to contain swine flu, and experts say that it is now vital to track the spread of the virus in order to mitigate its effects. Vaccines and antivirals will be crucial to the effort, but tracking and communications technologies could also play a key role in monitoring the virus, distributing accurate health information, and quelling outbreaks.

Bloggers and social-networking sites were among the first to follow the outbreak's rapid spread from its epicenter in Mexico--where swine flu has been linked to more than 150 deaths--to cities across the United States and on to Europe, Israel, and New Zealand.

The need for fast information has seen the Centers for Disease Control and Prevention (CDC) build up a large following on Twitter. Groups ranging from fellow federal institutions, such as the National Institute for Occupational Safety and Health, to local Red Cross divisions, as well as many regular Twitter users, are employing the service to receive updates. Some experts, however, warn that Twitter can just as easily spread misinformation and panic. According to data from the medical tracking site Nielson, conversations related to swine flu reached 2 percent of all messages on Twitter over the weekend. By contrast, Google's Flu Trends, a site that aims to spot flu outbreaks by monitoring search queries related to flu symptoms and treatment, has shown little increase in activity in recent days.

Some Twitter users have also been criticized for spreading misinformation by, for example, warning friends and followers against eating pork, which is not related to the spread of swine flu. Evgeny Morozov, a fellow at the Open Society Institute, in New York, wrote in a blog post on Saturday, "Having millions of people wrap up all their fears into 140 characters and blurt them out in the public might have some dangerous consequences, networked panic being one of them."

Meanwhile, other Internet tools are helping to track the spread of the virus geographically. HealthMap, which was created by researchers from Children's Hospital Boston with support from Google, the CDC, the National Library of Medicine, and the Canadian Institute of Health Research, adds real-time news alerts, official medical information, and other data to a global tracking map.

Susan Perkins, a specialist in microbial evolution at the American Museum of Natural History, in New York, NY, who has previously applied geographical information systems to the study of how viruses evolve, hopes that Internet technology and "the new field of info-epidemiology" can make a difference in future epidemics, if not in the current swine-flu outbreak. "Sites like HealthMap or Google Earth are a good new way to visualize data," she says. "These readily accessible platforms also let people in diverse fields--public health, evolutionary biology, et cetera--share the same information."

Perkins believes that being able to process viral genomes more quickly could make a big difference: "In the future, I would hope that diseases will be able to be better tracked with software that can combine genomic information with real geographic information. That will give us the most power to solve--and then hopefully break--transmission patterns."

Others say that tracking the spread of the virus could help reveal how deadly it is, how easily it spreads, whether drug resistance is emerging, and how to target precious public-health resources. Jeffrey Herrmann, an applied mathematician and software engineer at the University of Maryland, has developed software that can analyze the spread of a disease and pinpoint the best locations for treatment or mass vaccination. He says that this approach "could be used by local public-health departments to determine how many sites and how many staff they need to dispense antiviral medication or vaccinate people."

The WHO's Pandemic Influenza Task Force decided on Monday to raise the alert to level 4 on the pandemic scale. This means that confirmed human-to-human transmissions are now causing community-level outbreaks.

"We might expect up to 30 percent to 40 percent of the population to become ill in the next six months," says Neil Ferguson, a member of the WHO task force and a professor of epidemiology at Imperial College London. He adds that the virus appears less lethal than H5N1 bird flu--but crucially, it's more contagious. In the six years since its emergence in 1993, H5N1 has killed 257 people; swine flu has already killed 150 in a matter of weeks. The last pandemic, Hong Kong flu, killed about 700,000 (1 in 1,000 of its victims) in 1968.

So far, no deaths have been reported outside of Mexico, but the consensus among virologists is that it is too early to say whether suggestions that the death rate is higher in Mexico will be borne out. Some have suggested that better treatment in the United States has made infections there less dangerous. Or it could be that the much greater number of cases seen so far in Mexico--there are now more than 2,000 suspected--has made some deaths there more likely.

Pharmaceutical firms, meanwhile, have begun the race to produce a vaccine. Switzerland's Novartis said on Tuesday that it had received the genetic code of the new virus strain, enabling it to begin work in earnest. The WHO estimates that an effective inoculation is still six months away, but this might be in time for a second wave of infection later in the year.

Peter Dunnill, a professor of biochemical engineering at University College London, warns that even if a vaccine is produced, not everyone will have access to it. "Based on calculations done in relation to H5N1, the global capacity for providing a vaccine at its most optimistic is less than 10 percent of the world's people," he says.

Antiviral drugs are likely to provide the first line of defense. In the United States, Homeland Security Secretary Janet Napolitano said recently that she will release a quarter of the 50 million courses of antiviral drugs in the national stockpile. She added that the Defense Department has another 7 million courses ready. But their effectiveness could be short lived--particularly if they are used now, and the virus resurfaces later in the year. Professor of immunology Peter Lachmann of the University of Cambridge says, "Tamiflu resistance is extraordinarily widespread and develops very quickly. We would be very lucky if this virus does not develop resistance."