Pediatrics at Whitlock, P.C. 707 Whitlock Avenue Suite D30 Marietta, GA 30064 USA (770) 499-8909
Swine Flu
This information is provided by the Center for Disease Control
What is novel H1N1 (swine flu)?
Novel H1N1 (referred to as swine flu early on) is a new influenza virus causing
illness in people. This new virus was first detected in people in the United States
in April 2009. This virus is spreading from person-to-person worldwide, probably
in much the same way that regular seasonal influenza viruses spread. On June 11,
2009, the World Health Organization (WHO) signaled that a pandemic of novel H1N1
flu was underway.
Why is novel H1N1 virus sometimes called swine flu?
This virus was originally referred to as swine flu because laboratory testing showed
that many of the genes in this new virus were very similar to influenza viruses
that normally occur in pigs (swine) in North America. But further study has shown
that this new virus is very different from what normally circulates in North American
pigs. It has two genes from flu viruses that normally circulate in pigs in Europe
and Asia and bird (avian) genes and human genes. Scientists call this a "quadruple
reassortant" virus.
Spread of novel H1N1 virus is thought to occur in the same way that seasonal flu
spreads. Flu viruses are spread mainly from person to person through coughing or
sneezing by people with influenza. Sometimes people may become infected by touching
something such as a surface or object with flu viruses on it and then touching their
mouth or nose.
What are the signs and symptoms of this virus in people?
The symptoms of novel H1N1 flu virus in people include fever, cough, sore throat,
runny or stuffy nose, body aches, headache, chills and fatigue. A significant number
of people who have been infected with this virus also have reported diarrhea and
vomiting. As with seasonal flu, severe illnesses and death have occurred as a result
of illness associated with this virus.
How severe is illness associated with novel H1N1 flu virus?
Illness with the new H1N1 virus has ranged from mild to severe. While most people
who have been sick have recovered without needing medical treatment, hospitalizations
and deaths from infection with this virus have occurred.
In seasonal flu, certain people are at high risk of serious complications. This
includes people 65 years and older, children younger than five years old, pregnant
women, and people of any age with certain chronic medical conditions. About 70 percent
of people who have been hospitalized with this novel H1N1 virus have had one or
more medical conditions previously recognized as placing people at high risk of
serious seasonal flu-related complications. This includes pregnancy, diabetes, heart
disease, asthma and kidney disease.
One thing that appears to be different from seasonal influenza is that adults older
than 64 years do not yet appear to be at increased risk of novel H1N1-related complications
thus far. CDC laboratory studies have shown that no children and very few adults
younger than 60 years old have existing antibody to novel H1N1 flu virus; however,
about one-third of adults older than 60 may have antibodies against this virus.
It is unknown how much, if any, protection may be afforded against novel H1N1 flu
by any existing antibody.
How does novel H1N1 flu compare to seasonal flu in terms of its
severity and infection rates?
With seasonal flu, we know that seasons vary in terms of timing, duration and severity.
Seasonal influenza can cause mild to severe illness, and at times can lead to death.
Each year, in the United States, on average 36,000 people die from flu-related complications
and more than 200,000 people are hospitalized from flu-related causes. Of those
hospitalized, 20,000 are children younger than 5 years old. Over 90% of deaths and
about 60 percent of hospitalization occur in people older than 65.
When the novel H1N1 outbreak was first detected in mid-April 2009, CDC began working
with states to collect, compile and analyze information regarding the novel H1N1
flu outbreak, including the numbers of confirmed and probable cases and the ages
of these people.
The information analyzed by CDC supports the conclusion that novel H1N1 flu has
caused greater disease burden in people younger than 25 years of age than older
people. At this time, there are few cases and few deaths reported in people older
than 64 years old, which is unusual when compared with seasonal flu. However, pregnancy
and other previously recognized high risk medical conditions from seasonal influenza
appear to be associated with increased risk of complications from this novel H1N1.
These underlying conditions include asthma, diabetes, suppressed immune systems,
heart disease, kidney disease, neurocognitive and neuromuscular disorders and pregnancy.
How long can an infected person spread this virus to others?
People infected with seasonal and novel H1N1 flu shed virus and may be able to infect
others from 1 day before getting sick to 5 to 7 days after. This can be longer in
some people, especially children and people with weakened immune systems and in
people infected with the new H1N1 virus.
Information regarding influenza is available through the Centers for Disease Control
and Prevention (CDC) Web site at CDC Flu Information.
State and local health departments can be contacted for information regarding the
availability of the influenza vaccine, access to vaccination programs, and information
about state or local influenza activity.
