In June 2009, the World Health Organization (WHO) declared a global pandemic of novel Influenza A (H1N1) virus. Since the first cases were reported in April 2009, lots of cases have been described in many countries, causing hospitalizations and some deaths. In the United States we have been seeing cases throughout the summer, most of them reporting mild symptoms and recovering without complications. Over the last few months we had the opportunity of learning about the behavior of the new virus. We know how to use our diagnostic tools and the validity of those tools; we also know more about the impact of the antiviral medications available against the flu virus.

One of the main concerns for the medical community is how the new virus is going to behave when co-mingling with the seasonal influenza virus in the fall. We are observing the Southern Hemispheres, where they are right now going through their winter months and learning from their experience. We are learning and getting prepared. Since this is a new pandemic, coordination of efforts and following recommendations is going to be of utmost importance during the upcoming flu season.

Initially, the novel virus was referred to as the “swine flu” because some of the genes found in the new virus resembled those found in the flu virus affecting pigs (swine) in the United States. Further studies showed that the virus is very different from the pig virus; it actually contains genes present in bird flu (also known as avian flu) and also in human flu. The new virus causes symptoms similar to the seasonal flu and it is spread the same way, mainly from human to human through droplets released while coughing or sneezing. Touching a surface with the virus on it, and then touching our eyes or nose can also transmit the virus.

The symptoms associated with the virus include fever, sore throat, headache, congestion, body aches and fatigue. Some patients have reported vomiting and diarrhea.

The new virus is reported to produce mild symptoms in some patients, but is also responsible for hospitalizations and deaths. We know that a sector of the population is at High Risk for complications of the regular seasonal flu: those age 65 years or older, those younger than 5 years, pregnant woman, and patients with chronic conditions. The novel flu virus seems to produce complications in high-risk patients as well, mainly patients who are pregnant or suffer from diabetes, asthma, heart disease and kidney disease. Those over 60 years of age seem to be protected against the virus. It is believed that this age group has some natural antibodies from previous contacts with similar viruses. We must remember that the novel virus is a relative of the one causing the flu pandemic in 1918, of which we had outbreaks up until 1957. For this reason, the CDC thinks the new virus may cause a most serious disease burden to those younger than 25 years of age. At this time, there are fewer cases and fewer deaths reported in patients older than 65 years of age, which is contrary to the behavior of the seasonal flu.

People who suffer from Influenza A (N1H1) infection are contagious from 1 day before the appearance of symptoms to 7 days after. It is recommended to stay home for 7 days or 24 hours after the disappearance of fever, whichever is longer. As for measures to minimize the spread of the virus, they are not different from the universal advice given for seasonal influenza:

• Cover your mouth when coughing or sneezing.
• Wash your hands often with water and soap, or use alcohol based wipes.
• Avoid contact with sick people.
• Avoid touching your eyes, nose and mouth.

The virus may live on a surface for up to 8 hours. It is killed by heat, chlorine, hydrogen peroxide, soap and alcohol. There is no risk associated with eating or preparing pork, since the virus is not spread by food. So far there has been no description of virus spread from drinking water.

A new vaccine for the Influenza A (H1N1) virus is going to be available this fall. It is recommended to get the seasonal influenza vaccine as soon as it becomes available, and follow the CDC recommendations for the new vaccine. The population groups included in the recommendations for the new vaccine are:

• Pregnant women.
• People in households with infants under 6 months of age.
• Healthcare workers and Emergency Care workers.
• Young people between the ages of 6 months and 24 years.
• Nonelderly adults with underlying risk conditions such as diabetes and chronic lung disease.

For more information, check these two websites:

-         www.cdc.gov/h1n1

-         http://h1n1.nejm.org

About Dr. Marta Katalenas M.D.

Dr. Marta Katalenas is a Board Certified Pediatrician specializing in childhood obesity and owns the Pediatric Center of Round Rock located in Round Rock, Texas. Dr. Katalenas is a professional speaker and author of the upcoming book "From Scratch", a guide to healthy cooking and eating for busy families.

This entry was posted on Tuesday, September 1, 2009 at 12:48 pm and is filed under Influenza (Flu). You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.