Friday, June 12, 2009

H1N1 "Swine" flu

AMedivision Editorial

Image of the newly identified H1N1 influenza virus from the CDC Influenza Laboratory.

When the current novel H1N1influenza virus first made its public debut in April 2009, splashing across worldwide news headlines like a herald of impending Armageddon, many people reacted in understandable panic. Political figuresincited media flurries about the use of public transportation, there was talk ofclosing the US/Mexican border, and in Egypt officials embarked on the less than noble task ofmassacring their country's entire pig population based on the unfortunate misnomer of “swine flu”. But the outcry soon subsided, partially in thanks to the predominating worries over a global economic crisis and the fact that the majority of people infected with novel H1N1 simply recover. In truth, as soon as H1N1 was discoveredThe World Health Organization (WHO) andThe Centers for Disease Control and Prevention (CDC) instigated emergency response measures which undeniably limited the spread of the virus. For now.

Why a Pandemic?

On June 11 2009,WHO declared H1N1 a phase 6 pandemic. This essentially means that the virus is spreading in at least 3 countries by verified human-to-human transmission and that a global pandemic is under way, not that the virus has become more severe or more deadly. However, it is hoped that the new designation will help speed production of avaccine. To put things in perspective, ordinary influenza viruses -the kind that spread around the office every season- infect about 1 billion people worldwide and kill an estimated 500,000 each year. To date there are about28,774 cases of H1N1 reported globally, with 147 reported fatalities.
However it should be noted that influenza activity typically does not reach its peak in the U.S. until January or February.

Why is it so Dangerous?
The frightening aspect of any new influenza virus is the possibility that it mayevolve into something more deadly, more contagious or more drug resistant. In 1889 between 1 and 4 million people died from aH2N2 influenza strain: in 1918 another strain of H1N1, the"Spanish flu" killed between 50 and 100 million people and infected almost one third of the world's population. As recently as 1969 anH3N2 strain of influenza killed an estimated 1 million people.

This version of H1N1 is a novel strain of influenza which we have never been vaccinated or naturally immunized against. Health officials have warned that the virus could mutate into a more virulent form, putting greater numbers of people at risk. In May 2009WHO declared that the virus must be closely monitored especially in the southern hemisphere, as it could mix with ordinary seasonal influenza and change in unpredictable ways:a leading virologist from the University of Hong Kong has described the new H1N1 influenza virus as "very unstable", meaning it could mix and swap genetic material when exposed to other viruses, and the CDC reminded us that the 1918 flu epidemic which killed hundreds of thousands in the United States alone was preceded by a mild "herald" wave of cases in the spring, followed by devastating waves of illness in the fall.

Fortunately, current analysis shows that the virus is most similar to strains that cause mild symptoms in humans leading experts to suggest that it is unlikely to cause severe symptoms for most people. And as of early June 2009, the CDC reported "encouraging news" regarding any mutations to date by announcing thatsamples of the virus from points around the globe are still "genetically identical" to the strain found in the United States.

About H1N1:
H1N1 is a subtype of influenza virus A and the most common cause of influenza (flu) in humans. Virus strains are categorized according to two proteins found on the surface of the virus: hemagglutinin (H) and neuraminidase (N): strains are assigned an H and N number based on which forms of these proteins the strain contains. Only H 1, 2 and 3, and N 1 and 2 are commonly found in humans.
The current strain, on which this attention is focused, is thought to be a mutation -or reassortment- of four already known strains: one endemic in humans, one endemic in birds, and two endemic in pigs. The outbreak was first detected in Mexico on March 18, 2009.

Protecting Yourself:
The signs of infection with this strain of H1N1 are currently similar to other forms of influenza, and include fever, coughing, headaches, pain in the muscles or joints, sore throat, chills, fatigue and runny nose. Diarrhea and vomiting have also been reported in some cases. People at higher risk of serious complications included people age 65 years and older, children younger than 5 years old, pregnant women, and people of any age with underlying medical conditions, such as asthma, diabetes, obesity, heart disease, or a weakened immune system.
In children, emergency warning signs that need urgent medical attention include:
  • Fast breathing or trouble breathing
  • Bluish or gray skin color
  • Not drinking enough fluids
  • Severe or persistent vomiting
  • Not waking up or not interacting
  • Being so irritable that the child does not want to be held
  • Flu-like symptoms improve but then return with fever and worse cough
In adults, emergency warning signs that need urgent medical attention include:
  • Difficulty breathing or shortness of breath
  • Pain or pressure in the chest or abdomen
  • Sudden dizziness
  • Confusion
  • Severe or persistent vomiting
  • Flu-like symptoms improve but then return with fever and worse cough

  • The CDC has advised sick people to stay home from work, school, or social gatherings and to generally limit contact with others to avoid infecting them.
  • Little data is available on the risk of airborne transmission specific to this particular virus. Masks may be of benefit in "crowded settings" or for people who are in "close contact" with infected persons, but this hasn’t been proven.
  • Infection can be caused by touching a surface contaminated with flu viruses and then touching the eyes, nose, or mouth. The CDC has advised avoiding such contact and frequent washing of hands with soap and water or with alcohol-based hand sanitizers, especially after being out in public.
  • The leading international health agencies stressed that the "influenza viruses are not known to be transmissible to people through eating processed pork or other food products derived from pigs”.
Take these everyday steps to protect your health:
  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective.
  • Avoid touching your eyes, nose or mouth. Germs spread this way.
  • Try to avoid close contact with sick people.
  • Stay home if you are sick for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. This is to keep from infecting others and spreading the virus further.