# 6276
We’ve not heard of any human infections with the novel H3N2v swine-origin flu virus since late last year, but today the Weber-Morgan County Health Department in Utah has announced a new case (a h/t to Ironorehopper for tweeting a media report)
You will probably recall that in 2011 there were 12 other similar cases reported, across five states (see CDC: Variant Influenza Strains). All known cases recovered, and most experienced relatively mild symptoms.
First the press release, and then I’ll return with some background on this rare, slowly emerging flu strain.
Press Release
April 11, 2012WMHD Announces Confirmed Case of Novel Influenza
(Ogden, UT) Weber-Morgan Health Department received confirmation from the Centers for Disease Control and the Utah Department of Health that a Weber County resident has tested positive for a novel flu virus that has been identified in several isolated cases in the United States.
The individual was not hospitalized and recovered at home. As a precaution, all known contacts have been advised to watch for fever, cough and other flu-like symptoms and to contact their physician if necessary.
While considered novel, the virus, A/H3N2v, is genetically similar to those which circulate in pigs. It is common practice for the CDC to monitor diseases that are capable of transmitting from animals to humans, says Gary House, director of the Weber-Morgan Health Department.
Fortunately, this individual is getting better, House says. We know there have been 12 other cases with in the past year in the United States that have also fully recovered. We are working with the CDC, the Utah Department of Health and Utah Department of Agriculture and Food to determine how the individual was exposed to this particular flu virus.
As with all other flu viruses, House reminds the community to take preventive measures such as covering coughs and sneezes, staying at home while ill and washing hands frequently.
'We learned from the H1N1 experience of 2009 that the public’s willingness to follow these simple precautions is the best line of defense.' House says.
From the CDC’s website, a little background:
Key Facts about Human Infections with Variant Viruses (Swine Origin Influenza Viruses in Humans)
Questions & Answers
What is a variant influenza virus?
When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus. This naming convention was first announced in a January 6, 2012 Morbidity and Mortality Weekly Report entitled Update: Influenza A (H3N2)v Transmission and Guidelines — Five States, 2011. (See Box)
Can humans be infected with swine influenza viruses?
Yes. Swine flu viruses do not normally infect humans, however, sporadic human infections with influenza viruses that normally infect swine have occurred. When this happens, these viruses are called “variant viruses.” Most commonly, human infections with variant viruses have occurred in persons exposed to infected pigs (e.g. children near pigs at a fair or workers in the swine industry). In addition, there have been documented cases of multiple persons becoming sick after exposure to one or more sick pigs. Also cases of limited person-to-person spread of variant viruses have occurred.
Although the number of confirmed cases over the past year remains small (now totaling 13), the CDC is obviously concerned and has ordered enhanced surveillance, testing, and reporting around the country as to better gauge the prevalence of this virus.
In December and again in January the CDC released updated guidance on this novel influenza, and you can access those documents at the following links.
UPDATED: Guidance Documents Related to Preventing the Spread of Influenza A Viruses Friday, January 06, 2012 3:35:00 PM
UPDATED: Key Facts about Human Infections with Variant Viruses (Swine Origin Influenza Viruses in Humans) Friday, January 06, 2012 3:34:00 PM
UPDATED: Information on H3N2 Variant Influenza A Viruses Friday, January 06, 2012 3:34:00 PM
UPDATED: Variant (Swine Origin) Influenza Viruses in Humans Friday, January 06, 2012 3:33:00 PM
UPDATED: Information on Swine Influenza/Variant Influenza Viruses Friday, January 06, 2012 3:32:00 PM
While it is likely that there are more cases out there going undetected, the good news is that so far we haven’t seen any explosion of flu cases (of any stripe) this winter - and this H3N2v flu does not appear to be any more virulent than regular flu.
Emerging viruses are important to track and monitor, however, because they can change over time. A relatively benign virus today need not necessarily remain so tomorrow.
So while the public health threat at this moment from this variant virus appears low, the CDC has reminded us repeated in over the past few months:
It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur.
While there is no evidence 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.
Good enough reason to get your flu shot (to cover the other flu viruses out there) when it becomes available each year, and to consistently practice good flu hygiene (cover coughs, wash your hands often, stay home if sick) all year round.
