Emerging Disease Paper: H3N2 Influenza
Cami Johnstonbaugh
The University of Oklahoma Health Sciences Center College of Nursing
February 21, 2015

History of Emergence of Disease H3N2 is a swine virus that first circulated in pigs in 2010 and emerged in humans in 2011 (Centers for Disease Control and Prevention [CDC], 2014a) . This version of the virus has been found to have a variety genes from previous viruses including, “the 2009 H1N1 pandemic virus M gene” (CDC, 2014a). The development of the M gene quality may have something to do with why this virus was able to infect humans. Many precautions are made to contain the spread of this virus and any other new strains of virus that appear each year. According to the CDC (2014a) this virus seems to spread more conveniently from pigs to humans than previous swine influenza viruses.
Description of Disease H3N2v is a strain of influenza that is created in pigs; this is referred to as swine flu. When viruses that ordinarily travel between animals (pigs in this instance) infect humans they are defined as variant viruses (Flu.gov, 2015b). These viruses can be designated by adding the letter “v” to the end of the subtype. Since the appearance of this strain of influenza, there has been 18 hospitalizations in the U.S. and one death reported of an elderly adult in Ohio in 2012 who had various underlying health conditions (CDC, 2014b). H3N2v’s symptoms are comparable to those of the seasonal flu; these include fever, cough, runny nose, body aches, nausea, and diarrhea. Additionally, for those who have other ailments, more adverse events may present themselves.
Transmission
There have been various documented cases of people acquiring the virus after being exposed to infected pigs and a limited amount of cases where it was spread from person to person. Influenza viruses are continually altering and mutating. The process that allows for a strains to blend and create a new subtype is an antigenic shift. An antigenic shift occurs suddenly and is “when two different flu strains infect the same cell and combine” (Flu.gov, b). An example of how this works would be that a strain is given to a host such as a pig in this case, a person would infect the swine with a human strain of Influenza A, and then the viruses would infect the same cell and produce a new strain. This is then passed back to the human. This transmission is done through the same route that seasonal influenza viruses spread between humans, so it is thought; a pig can either cough or sneeze and the infected droplets get inhaled. (CDC, 2014a). There’s also some proof that one could possibly be infected by touching something with the infection on it and then touching one’s mouth/nose.
Distribution Patterns of Disease People who work closely to pigs have the highest risk for contracting the virus. Most cases involved those who had visited county fairs and worked on farms. There have been 343 cases in 13 states in the United States since it surfaced in 2011, none of which were in Oklahoma (CDC, 2014c). There possibly could have been more that were not reported. Information on the prevalence in other countries was not found, but if proper precautions are not put into place this is definitely a possible outcome.
Populations Affected There are many strains of flu that effect millions of people across the globe but there are certain groups of people who are more susceptible and/or have more adverse complications from the disease, whether it is the H3N2v strain or any other strain. Among groups are young children, pregnant women, people with chronic health conditions like asthma, diabetes or heart and lung disease, and people who are age 65 years and older (Flu.gov, 2015). Children are more at risk for acquiring the virus and/or complications of the ailment because their immune systems are not fully developed. Depending on how young they are, a common severe flu-related complication is a seizure. Similarly,