Nasty epidemic, neat science
Five years ago this month, one of the first U.S. outbreaks of the H1N1 virus swept through the Washington State University campus, striking some 2,000 people. A university math and biology professor has used a trove of data gathered at the time to gain insight into how only a few infected people could launch the virus's rapid spread across the university community.
The fall 2009 semester hadn't even started when the first cases came in to the university's Health and Wellness Services clinic—11 one day, and just two days later, 47. Not two weeks later, doctors and nurses in the clinic saw 164 H1N1 patients, attending to a total of nearly 1,000 sick people, plus hundreds more by phone. They ran out of Tamiflu, an antiviral medication.
The flu wasn't as intense as feared. People felt awful for three or four days and were close to normal within a week. No one died.
Still, WSU took on the national distinction of having one of the first and largest H1N1 outbreaks at an American college. The epidemic also gave Elissa Schwartz, an assistant professor of both math and biological sciences, an ideal phenomenon for scientific study.
At the time, Schwartz was teaching students about the behavior of epidemics in a closed population. She had her students search the scientific literature looking for studies that tracked actual epidemics in closed populations, which have no movement in our out. They found very few.
But they had a fairly closed population in Pullman, more specifically College Hill, where many students live, often in shared housing. When they do leave the house, they're on campus, in close proximity to more people. With the exception of semester breaks and the occasional road trip, they rarely leave.
"We thought, 'Oh, if we can get data on this, then that will be real live data, not simulated data, on the actual number of infections in this community,'" Schwartz recently told Washington State Magazine. "And it turned out that the Health and Wellness Services was tracking it, which was great."
To analyze the numbers, Schwartz used a computer model called FluTE, which can simulate the transmission of an influenza virus across a population and tease out things like how many became infected, how many carriers first had it and what strategies would make the biggest difference in containing its spread.
Transmissibility is measured by the R0, or R naught, a term made somewhat popular in the movie "Contagion." It's the average number of people infected by one person in a fully susceptible population.
Schwartz pegged the R naught for the Pullman outbreak at 2.2, meaning one infected person ended up passing his or her infection on to roughly two others. That's close to the rate attributed to the massive 1918 flu pandemic, which killed more people than the bubonic plague.
Schwartz's analysis also suggests the outbreak was started by as few as 20 people initially infected by the virus. It's a remarkably low number of people given the number of people who ultimately got sick.
"But given that it was spreading as fast as it was," Schwartz said, "and people were living in close proximity as they were, which means the contact rate is really high, then perhaps the number of carriers wasn't low."
Finally, Schwartz wondered what strategy might have worked best to contain the outbreak, from vaccinations to isolation to quarantines, or all of the above. Sick people were asked to isolate themselves from others, but that is difficult, Schwartz said. A sick person can still share a bathroom with others.
A quarantine would contain potentially exposed people, she said. But it would be difficult to carry out because it's unclear how to define a sick person's 'nearest neighbors' when many live in large shared houses such as fraternities, sororities or dormitories.
"Our analysis does show, though it may sound obvious, that vaccination would be the best way to control these types of infections," said Schwartz. Her study was published last year in the Journal of Biological Systems and she presented her findings in July at the Society for Mathematical Biology Annual Meeting in Osaka, Japan.
Elissa Schwartz | Eurek Alert!
Discovery of a novel gene for hereditary colon cancer
29.07.2016 | Rheinische Friedrich-Wilhelms-Universität Bonn
New evidence: How amino acid cysteine combats Huntington's disease
27.07.2016 | Johns Hopkins Medicine
Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.
To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...
A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology
On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...
Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.
While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.
Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.
Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...
Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases
Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...
29.07.2016 | Event News
15.07.2016 | Event News
15.07.2016 | Event News
29.07.2016 | Power and Electrical Engineering
29.07.2016 | Life Sciences
29.07.2016 | Event News