The World Health Organization in June of this year declared that the novel H1N1 virus (formerly called “swine flu”) had reached pandemic proportions.
The Centers for Disease Control say the H1N1 virus was originally called “swine flu” because laboratory testing showed many of the genes in this new virus resembled influenza viruses that normally occur in pigs in North America. But further study has shown this new virus is very different from that which normally infects North American pigs. It has two genes from flu viruses that normally circulate in pigs in Europe and Asia, as well as bird and human genes. Scientists call this
a “quadruple reassortant” virus. Because
it is new, it is called a “novel” virus.
The Centers for Disease Control and Prevention offer the following information about the virus.
Contagion and Severity
The H1N1virus is thought to spread in the same way as seasonal flu: through coughing or sneezing by people with influenza. People may become infected by touching a surface or object with flu viruses on it and then touching their mouth or nose.
People infected with seasonal and novel H1N1 flu shed virus and may be able to infect others from one day before getting sick to five to seven days after –
or even longer for some people, especially children, people with weakened immune systems and people infected with the new H1N1 virus.
Studies have shown that influenza virus can survive on environmental surfaces and can infect a person for two to eight hours after being deposited there. Influenza virus is destroyed by heat (167-212°F [75-100°C]). Chlorine, hydrogen peroxide, detergents (soap), iodophors (iodine-based antiseptics) and alcohols are also effective if used in proper concentration for a sufficient length of time.
Illness with the new H1N1 virus has ranged from mild to severe. While most infected people have recovered without medical treatment, hospitalizations and deaths have occurred. About 70 percent of people who have been hospitalized with this novel H1N1 virus have had one or more medical conditions that place people at “high risk” of serious seasonal flu-related complications. These conditions include pregnancy, diabetes, heart disease, asthma and kidney disease.
H1N1 appears to differ from seasonal influenza in that adults older than 64 years do not thus far appear to be at increased risk of novel H1N1-related complications. While no children, and very few adults younger than 60 years old, appear to have existing antibodies to novel H1N1 flu virus, about one-third of adults older than
60 may have such antibodies. It is unknown what protection any existing antibody may afford against novel H1N1 flu.
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. Severe illnesses and death have occurred from illness associated with this virus.
Prevention and Treatment
A novel H1N1 vaccine is currently in production and may be ready for the public in the fall. As always, a vaccine will be available to protect against seasonal influenza. Other precautions include the following:
Covering the nose and mouth with a tissue when coughing or sneezing, then immediately disposing of the tissue.
Washing hands often with soap and water for at least 15 seconds or using alcohol-based hand cleaners, especially after coughing or sneezing;
Avoiding touching eyes, nose or mouth.
Trying to avoid close contact with sick people.
Staying home for at least 24 hours after the temperature is normal.
Following public health advice regarding school closures, avoiding crowds, and other social distancing measures.
Keeping a supply of over-the-counter medicines, alcohol-based hand rubs, tissues and other related items.
In children, emergency warning signs that need urgent medical attention:
Fast breathing or trouble breathing
Bluish or gray skin color
Failure to drink enough fluids
Severe or persistent vomiting
Inability to wake up or interact
Such irritability that the child does not want to be held
Improvement of flu-like symptoms followed by return of fever and worse cough
In adults, emergency warning signs that need urgent medical attention:
Difficulty breathing or shortness of breath
Pain or pressure in the chest or abdomen
Severe or persistent vomiting
Flu-like symptoms improve but then return with fever and worse cough
Additional information is available at www.cdc.gov/h1n1flu/qa.htm.