Public health officials now have a better way to study the migratory behavior of pandemics such as the swine (H1N1) flu virus. A new tool allows them to visually follow a virus’s movements around the world.

Researchers at Ohio State University linked several computer systems together into a Web-based application called Routemap to analyze enormous amounts of genetic data collected from all publicly available health sources. The results are then mapped on Google Earth in plots similar to airline routes.

“We not only use the power of supercomputers to take into account an ever-growing database of genetic sequences for influenza, but also present information visually that is easy to understand and use for medical intelligence,” said Ohio State biomedical informatics professor Daniel Janies.

Other systems, including Janies’ earlier Supramap, attempt to map the evolution and spread of influenza over the globe using a single evolutionary tree. That worked fine for strains such as the avian flu (H5N1), because avian flu is easier to track, as the strains have slowly crept around Eurasia the past 13 years.

But H1N1 is different, and one tree is not enough.

“We can project H1N1 lineages, but the pattern of their spread is much more complex, as humans are carrying the lineages around the world so fast in so many directions,” Janies said.

Janies told Homeland1 that the solution to the H1N1 tracking problem is to no longer try to project a single tree.

“In Routemap we take into account patterns of spread implied in many trees based on large amounts of genetic data,” he said.

While some groups scour the Internet and map news data to track disease outbreaks, the Janies method maps real genetic and biological pathogen data.

“We prefer to work with data rather than news,” Janies said.

From this pool of trees, based on 461 full H1N1 genomes, many different routes the virus has taken, Mexico to California, say, or California to New Zealand, can be tracked.

The user can also select a particular place of interest and see whether viral strains are coming into and being exported from that place. Lines are colored differently depending on whether they indicate an incoming (red) or outgoing (green) virus to or from a specific location.

“We are also honest about any uncertainty in the data and use colors to represent that uncertainty,” Janies said, “but even with partial data, we can infer much about a virus in an area based on its sources.”

Routemap’s medical intelligence can also benefit homeland security. Routemap normally analyzes nucleotide sequences of viral DNA, but it can also work with protein sequences in other pathogens.

Routemap can display other features of interest to public health or homeland security professionals, such as genetic changes, pathogenicity or emerging drug resistance.