Friday, August 17, 2012

H3N2v: CDC Update & ECDC Risk Assessment

 

 

# 6500

 

Friday means the weekly CDC FluView report is out, and right now, the only flu to talk about in the U.S. is H3N2v. We also have a risk assessment from the ECDC  today on this emerging virus, and another state (Pennsylvania) to add to the list of places reporting human infections (4 confirmed, 6 suspected)

 

First stop though, is the CDC’s H3N2v update page, where the latest state totals are listed. Since last week Pennsylvania, Wisconsin, West Virginia, and Michigan have reported their first cases.

 

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There you will also find the CDC’s assessment of this virus, and the risks it currently poses to the public’s health.

 

CDC Assessment

It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur. While there is no evidence at this time that sustained human-to-human transmission is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread. So far, the severity of illnesses associated with this virus in people has been similar to the severity of illnesses associated with seasonal flu virus infections. Limited serologic studies indicate that adults may have some pre-existing immunity to this virus while children do not. CDC is closely monitoring human infections with all novel influenza viruses, including H3N2v viruses, and will provide more information as it becomes available.

 

 

An assessment that is in-line with the latest risk assessment from the ECDC, which finds the risk to public health from this virus to be very low at this time.

 

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ABSTRACT

Following recent increased reporting of human infections in the US with an influenza A(H3N2) variant virus of swine origin (A(H3N2)v), ECDC has updated its risk assessment. It concludes that the swine-origin influenza A(H3N2)v viruses do not currently pose a serious risk to human health in general and Europe in particular. Should increased pathogenicity and/or transmissibility be acquired this assessment will be revised as well as further developments presented on the ECDC web-site.

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Conclusions and recommendations


The swine-origin influenza A(H3N2)v viruses do not currently pose a serious risk to human health in general and Europe in particular. Should increased pathogenicity and/or transmissibility be acquired this assessment will be revised as well as further developments presented on the ECDC web-site. 

 

 

Beyond a few hundred cases of H3N2v, flu activity around the country remains at inter-seasonal low levels, as illustrated by these FluView Reports.

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Today’s FluView contained the following statement on H3N2v.

 

Novel Influenza A Virus:

Novel Influenza A Virus: From July 12 through August 16, 2012, a total of 224 infections with influenza A (H3N2) variant (H3N2v) viruses have been reported in eight states (Hawaii [1], Illinois [3], Indiana [138], Michigan [1], Ohio [72], Pennsylvania [4], West Virginia [3], and Wisconsin [2]). So far during the current outbreaks, eight confirmed cases have been hospitalized as a result of their illness; no deaths have occurred. At this time no ongoing human-to-human transmission has been identified. Public health and agriculture officials are investigating the extent of disease among humans and swine, and additional cases are likely to be identified as the investigation continues. Because of reporting deadlines, the state totals reported by CDC may not always be consistent with those reported by state health departments. If there is a discrepancy between these two counts, data from the state health departments should be used as the most accurate number.

 

CDC is required to report all cases of human infection with novel (non-human) influenza viruses – including influenza viruses of swine origin – to the World Health Organization (WHO)External Web Site Icon as part of the International Health Regulations (IHR)External Web Site Icon. Domestically, CDC reports these cases in this report and on its website. Early identification and investigation of human infections with novel influenza A viruses is critical in order to evaluate the extent of the outbreak and possible human-to-human transmission. Additional information on influenza in swine, variant influenza infection in humans, and strategies to interact safely with livestock can be found at http://www.cdc.gov/flu/swineflu/influenza-variant-viruses-h3n2v.htm.

 

 

While it may not serve to sell newspapers or drive web traffic, this virus is a long way from being any kind of serious public health threat. 

 

That could change over time, of course.

 

Viruses are constantly evolving, and what was true yesterday about H3N2v may not be true next week, or next year. 

 

So we’ll continue to watch these outbreaks with interest. Not because they necessarily portend a pandemic, but because they can teach us a lot about how variant viruses develop and spread.