Thursday, August 17, 2017

MMWR Reports 3 More Novel Flu Infections (ND, OH, PA)













 

#12,696


Although details remain scant, we have confirmation of at least 3 additional novel flu infections (1 each in OH, PA, & ND) reported in today's MMWR Notifiable Diseases and Mortality Tables. This brings the number of cases reported in the past 30 days to 18, and 2017's total to 19.

https://www.cdc.gov/mmwr/volumes/66/wr/mm6632md.htm?s_cid=mm6632md_w
We should get additional details in tomorrow's FluView, but for now we have the following statement from the North Dakota Health Department reporting two - not one - novel flu cases linked to a local county fair.

One was a local resident, while the other was an out-of-state visitor.

North Dakota Department of Health Reports First Variant Influenza Case
 
BISMARCK, N.D. – The North Dakota Department of Health (NDDoH) reports a confirmed case of variant influenza A H3N2v in a child with exposure to pigs. Influenza viruses that normally circulate in pigs are called variant influenza when the virus is found in people.
Variant influenza viruses are different from typical circulating human influenza A viruses. 
Most cases of variant influenza occur during summer months in people who raise pigs, or who had contact with pigs at agricultural events like fairs. Influenza viruses do not typically move readily between people and pigs, so variant influenza cases are rare.

Symptoms of variant influenza are similar to those of seasonal flu and include fever, cough, sore throat, headache, muscle aches and lack of appetite. People seeing a health care provider for a respiratory illness should let their provider know if they have had recent exposure to pigs. Providers should alert the NDDoH if they suspect variant influenza.


“This is the first time a North Dakota resident has tested positive for variant influenza,” said Jill Baber, an epidemiologist with the NDDoH. “The child visited the North Dakota State Fair in Minot and had direct contact with pigs. The child was hospitalized, but has since been released and is recovering.” A second case associated with the State Fair, in a non-North Dakota resident, has also been identified.


(Continue . . . )

I've found no information on the Pennsylvania and Ohio cases, although there were reports late yesterday that a Child has tested positive for Influenza A after showing A pig at the Henry County Fair, which Closed their Pig Barn Over H1N2 Swine Flu earlier this week.  
Further testing is underway to determine the subtype of the child's infection, so it may or may not be connected to today's report.
Earlier today, in EID Journal: Transmission Of Swine H3N2 To Humans At Agricultural Exhibits - Michigan & Ohio 2016, we looked at the risks of novel flu transmission in these types of venues, including from healthy-looking pigs.
Most years fewer than a dozen `swine variant' infections are reported in the United States, mostly involving farm or livestock workers. Most are mild, but it is likely that many others go undiagnosed.
During the summer of 2012 we saw our largest outbreak to date, with 10 states reporting more than 300 confirmed cases, nearly all linked to county or state fair attendance (see H3N2v Update: CDC Reports 52 New Cases, Limited H2H Transmission).

With state and county fair season continuing over the summer and into fall, it would not be unexpected to see additional, scattered reports of swine variant infection. While most cases are mild, the CDC pays close attention whenever a flu virus jumps species. 

CDC Assessment

Sporadic infections and even localized outbreaks among people with variant influenza viruses may occur. All influenza viruses have the capacity to change and it's possible that variant viruses may change such that they infect people easily and spread easily from person-to-person. The Centers for Disease Control and Prevention (CDC) continues to monitor closely for variant influenza virus infections and will report cases of H3N2v and other variant influenza viruses weekly in FluView and on the case count tables on this website