In April, 2009, a novel H1N1 virus of swine-origin capable of human-to-human transmission likely emerged in Mexico and was first isolated from patients enrolled in two separate surveillance activities in Southern California [5] . The emergence and spread of 2009 H1N1 to over 168 countries has led U.S. officials [6] and the World Health Organization (WHO) [7] to declare a public health emergency; on June 11, 2009 the WHO raised the influenza pandemic alert from phase 5 to phase 6, the official declaration of a pandemic [8] . Early published results from the CDC showed that 2009 H1N1 bears the amantadine-resistance associated S31N mutation in the M2 ion channel, but remains susceptible to oseltamivir and zanamivir [9] . More recently, however, the CDC has reported that ten 2009 H1N1 isolates tested in the United States have been found to be resistant to oseltamivir, raising the concern that dually resistant viruses may become prevalent [4] .