The following statements are where I think we are currently on the new swine flu H1N1 influenza A strain. I've also communicated with Drs. Ann Schuchat and Nancy Cox at the CDC, who responded that they agree with these comments.
- The H1N1 influenza A is a new strain - a swine flu strain - with some genetic components that are characteristic of human and bird flu viruses. It bears watching and tracking, as any new influenza does.
- It is spreading human to human, and may have the attack rate of a typical yearly influenza A, but this is particularly difficult to determine because of both the overreporting (everyone thinks they have it), and under reporting (we are not really tracking the full spectrum of disease as we are not testing those with mild symptoms). It is also too early to really determine transmissability, because there are too few cases.
- Virulence appears to be low and if this continues, it will be a mild pandemic at worst. It currently appears to be very transmissible, but the outbreak could wane further if transmissability decreases. A severe pandemic will likely result only if it mutates into a more virulent strain. But assessment of the strain's virulence is also based on a limited number of cases.
- It is worthwhile to begin preparing a vaccine, but we don't yet have the upgraded technology (mammalian cell culture, reverse genetics) in regular use for flu, so we may have to rely on the older technologies (using hen eggs to provide a medium for growing the dead virus). This has yet to be determined.
- It is likely to wane soon due to summer weather, but bears watching carefully over our summer in the southern hemisphere, and mapping carefully for resurgence in the fall.
- Since the WHO designations for pandemic alert don't include severity of illness or even true extent of illness, raising the pandemic alert levels have led to the public misperception that massive deaths are about to occur, which is part of the reason why the fear level is so high. It is best to provide calm accurate contexted information to avoid this, as I point out in "False Alarm; the Truth About the Epidemic of Fear."
Dr. Marc Siegel is an internist and associate professor of medicine at the NYU School of Medicine. He is a FOX News medical contributor and writes a health column for the LA Times, where he examines TV and movies for medical accuracy. Dr. Siegel is the author of "False Alarm: The Truth About the Epidemic of Fear"and "Bird Flu: Everything You Need to Know About the Next Pandemic." Read more at www.doctorsiegel.com
Marc Siegel MD is a professor of medicine and medical director of Doctor Radio at NYU Langone Medical Center. He is a medical analyst and reporter for Fox News since 2008. His upcoming book concerns a mysterious viral outbreak.