Researchers map the global spread of drug-resistant influenza
By Claudia Adrien
In last fall’s movie “Contagion,” fictional health experts scramble to get ahead of a flu-like pandemic as a drug-resistant virus quickly spreads, killing millions of people within days after they contract the illness.
Although the film isn’t based entirely on reality, it’s not exactly science fiction, either.
“Certain strains of influenza are becoming resistant to common treatments,” said Ira M. Longini, Ph.D., a UF professor of biostatistics in the College of Public Health and Health Professions, the College of Medicine, and the Emerging Pathogens Institute. “We’ve been able to map out globally how this phenomenon is happening.”
Longini is among a team of researchers who published an article in the Royal Society journal Interface and explain how seasonal H1N1 influenza became resistant to oseltamivir, otherwise known as Tamiflu, the most widely used antiviral agent for treating and preventing flu. The scientists say that a combination of genetic mutations and human migration through air travel can lead to the rapid global spread of drug-resistant strains.
“If you see resistant strains in parts of the world where no one is taking antiviral drugs, that’s the smoking gun that the resistant strain must be transmitting,” said Longini, who also worked on this research at the Fred Hutchinson Cancer Research Center in Seattle.
In some situations, drug-resistant bacteria and viruses can spread when drugs are overused. The scientists explored this theory using a mathematical model that simulates the spread of influenza across 321 cities connected by air travel. Using this model, they found that oseltamivir use had not been nearly widespread enough to promote the spread of antiviral resistance after it arose. The resistant strain probably originated in one person taking the drug.
“For the next pandemic, we should have all the available drugs at our disposal as a first line of defense to both prevent infection and to treat the most vulnerable,” Longini said. “Or else, the chance that the next pandemic influenza strain is resistant goes up. We know something like ‘Contagion’ could happen for influenza.”