Swine Flu H1N1 Virus

It is not known at this time how severe the H1N1 Swine Flu virus will be in the general population. In the seasonal flu, there are certain people that are at higher risk of serious flu-related complications. This includes people that are 65 years and older, children younger than 5 years old, pregnant women, and people of any age with certain chronic medical conditions. Early indications are that pregnancy and other previously recognized medical conditions that increase the risk of influenza-related complications, like asthma and diabetes, also appear to be associated with increased risk of complications from the H1N1 Swine Flu virus infection as well.

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 H1N1Swine Flu-related complications thus far in the outbreak. The Center for Disease Control is conducting laboratory studies to see if certain people might have natural immunity to this virus, depending on their age. Early reports indicate that no children and few adults younger than 60 years old have existing antibody to the H1N1Swine Flu virus; however, about 1/3 of adults older than 60 may have antibodies against this virus. It is unknown how much, if any, protection may be afforded against H1N1 Swine Flu by any existing antibody.

The Center for Disease Control is still learning about the severity of the H1N1 Swine flu virus. At this time, there is not enough information to predict how severe the H1N1 Swine flu outbreak will be in terms of illness and death or how it will compare with seasonal influenza.

With the 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 in some people. Each year, in the U.S., on average, about 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.

So far, with the H1N1 Swine flu, the largest number of H1N1 Swine flu confirmed and probable cases have occurred in people between the ages of 5 and 24-years-old. At this time, there are few cases and no deaths reported in people older than 64 years old, which is unusual when compared with the 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 the H1N1 swine flu virus.

At the current time, the Center for Disease Control believes that this virus has the same properties in terms of spread as the seasonal flu viruses. With the seasonal flu, studies have shown that people may be contagious from 1 day before they develop symptoms to up to 7 days after they get sick. Children, especially younger children, might potentially be contagious for longer periods. The Center for Disease Control is studying the virus and its capabilities to try to learn more and will provide more information as it becomes available.