Wednesday, February 26, 2014

Has the CDC Detected An Imported H7N9 Case Via Chinese New Year Travel? We'll Find Out Soon Enough

IF a H7N9 case entered the USA via international travel related to Chinese New Year Celebrations, AND IF it was detected, we are in the time frame in which a public H7N9 announcement would be expected. Those are a lot of IFs. It's also a big IF if it would have any immediate impact.

What draws our eyes to this question is recent BARDA activity related to PERMAVIR stockpiles, HHS's desire to track all TWEETS about H7N9, and CDC's recent positioning to let large orders for mechanical ventilators.

Frankly we believe it's likely H7N9 entered San Francisco by Valentine's day, carried in by Americans returning home from Chinese New Year celebrations in Mainland China. The best place for H7N9 to initially have spread in the USA would have been during the Chinese New Year parade and activities in San Francisco on 2/15 -2/16.
"According to a recent survey, this year plans to travel abroad for Chinese respondents, 29% of people choose to travel to the United States. Among them, 46 percent plan to the United States as a destination for Chinese tourists to California, 31 percent plan to go to New York, there are some Chinese tourists planning to go to Boston."

Did H7N9 make it into the USA? Our best guess is yes, BUT we think the odds of detection are low as the Bay Area is swamped with a H1N1 outbreak and deaths. The real point of concern would be if H7N9 made it into the Bay Area wild life, as its river delta and surrounding large human population fit the profile of outbreak locations in China.

Unfortunately, research studies of the Bay Area have shown that
 "Waterfowl in California can spread the avian influenza virus (AIv) during summertime when wetland temperatures are warm and waterfowl densities are low.
Researchers with the USGS and partners found low pathogenic (LP) AIv in water and waterfowl fecal samples collected in the California Central Valley during summer, indicating on-going infections in resident waterfowl, persistent shedding and active transmission of AIv.
Despite previous research suggesting that colder temperatures and increased bird densities as waterfowl congregate during migration are most favorable to the survival of these viruses, the recent findings suggest that high summer water temperatures do not prevent its circulation.l"
this means if H7N9 is imported into the Bay Area it can persist to seed a Fall 2014 H7N9 outbreak.
Other locations fitting that profile are Houston, and possibly New Orleans.

Of course this doesn't mean that we should hold our breath for an imminent announcement from the CDC that H7N9 has been detected in the USA, it only means that you should not be surprised if that is what happens (this year or next).


Technical Announcement:Low Pathogenic Avian Influenza Transmitted During Summer in California Wetlands

US-Chinese New Year rush off New York "shopping" in Massachusetts visiting campus


Pandemic Alert! CDC Desires Info On H7N9 & MERS TWEETS in Real Time AND 5 Years Historical

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