By Joseph Hazan, M.D., FACOG
Influenza viruses are a group of
RNA viruses. They belong to
the viral family Orthomyxoviridae.
This group is divided into
Influenza A, B and C.
Influenza C generally causes
only mild respiratory illness.
A and B strains cause seasonal
viral flu and the main strains
are included in the yearly flu
shots.
Influenza A is divided into subtypes
based on the expression patterns of
two viral antigens, H and N.
H stands for Hemagglutinin and this
is the viral antigen that causes the
virus to attach itself.
There are 16
H variants.
On the other hand the N stands for
Neuraminidase which is the viral
antigen that causes the virus to be
released.
There are 9 of the N variants.
H1N1 refers to a subtype of Influenza A.
THE CURRENT PANDEMIC started in
early April 2009 in Mexico as a
disease that mostly affected the young
and caused symptoms of pneumonia.
By the time the WHO ( World Health
Organization) raised the pandemic
level to 5 on April 29 there were 2
fatalities in the U.S.
On May 20, 2009 the CDC (Centers for
Disease Control and Prevention), published
the 20 cases and 1 fatality and drew attention
to the severity of shortness of breath in
pregnant cases.
Also, fever, sore throat,
cough, runny nose, headaches, aches,
pains,nausea, vomiting, diarrhea were seen.
By May 20, 2009 there were 10.000
cases of H1N1 globally.
On June 6, 2009 the WHO announced
a level 6 pandemic which is the highest
level in 41 years. By then there were
about 94.000 cases in over 100 countries.
Pregnant women are more susceptible
to more severe symptoms, higher
complication and mortality from H1N1.
It is also more dangerous to the fetus.
TESTING is done by a rapid influenza
antigen test.
To confirm the diagnosis,
a RT-PCR ( Reverse Transcription-
Polymerase Chain Reaction) test is
done.
TREATMENT is done with antivirals and
ISOLATION face masks are used.
PREVENTION is also with antivirals.
Vaccination has recently become
available.
Leave a Reply