Four
people in Indiana have been stricken with H3N3 influenza, a new strain of swine
flu.
The
variant strain, identified as H3N2v, showed up in four people who attended the
state fair where officials have confirmed there were pigs carrying the virus.
Last
year there were 309 cases reported from a number of different states. Sixteen
required hospitalization and one died.
The
epidemiology of this outbreak in Indiana so far seems consistent with what was
seen last summer, when most cases reported exposure to pigs, particularly at
agricultural fairs.
While
most illness was mild, serious illness also was observed; however none of the
cases in Indiana this week were hospitalized and there were no deaths.
Symptoms
of H3N2v have included fever, sore throat, cough and body aches.
No
sustained human-to-human spread of the virus has been detected, though sporadic
limited spread of this virus has occurred in the past.
Steps
to make a vaccine against H3N2v have been taken, but no vaccine is currently
available for H3N2v.
The
2012-2013 and 2013-2014 seasonal flu vaccines are not formulated to provide
protection against H3N2v, but are formulated to protect against seasonal flu
viruses that circulate widely each season. However, the same influenza
antiviral drugs used to treat seasonal flu can treat H3N2v.
The
currently recommended drugs – oseltamivir and zanamivir - are available by prescription
only.
Early
treatment works better and is especially important for people with a high risk
condition. The risk of this virus triggering a full-blown pandemic is
considered relatively low, however, because serology studies have suggested
that significant numbers of adults have some existing immunity against this
virus.
Children
younger than about 10 years old, however, have little to no immunity against
H3N2v virus.
Given
this, a more likely scenario if H3N2v were to become more transmissible among
people would be localized outbreaks in pockets of the population that do not
have immunity against this virus, for example, in day care or school settings.
This information is from the American Society
of Swine Veterinarians.
