Current Threats to Public Health Flu Viruses

What are they? The flu viruses are a family of RNA viruses that commonly infect mammals and birds. The three main types of flu viruses are: Influenza A Influenza B Influenza C Flu viruses kill half a million people or more a year.

How are they transmitted? Droplet contact through coughing or sneezing is the most common way the flu virus is spread. Indirect contact from touching an object that has the virus on it is the other way it is transmitted. Direct contact with nasal secretions may also pass on the virus.

What are the symptoms? Flu viruses may cause any of the following: Fever Chills Coughing Fatigue Muscle ache Runny Nose Nausea Shortness of Breath Vomiting Dizziness Diarrhea Headaches Sore throat There is also some correlation between flu viruses and pneumonia.

Preventative Measures Flu viruses mutate (change) quite quickly and therefore vaccines against them are usually in need of a booster shot yearly. Disinfectants, detergents and hand sanitizers all break down the flu virus, therefore good overall cleanliness is an effective preventative measure against the flu.

Influenza C Viruses The most rare flu virus. Only contains one genus and species, Influenza C virus. These viruses are usually found in dogs, pigs and humans Some epidemics, both usually only causes mild symptoms in children.

Influenza B Viruses Again only one genus and species, Influenza B Virus. This one almost exclusively affects humans. More rare than any of the influenza A viruses. This virus mutates much slower than the influenza A viruses and therefore immunity to it can be longer lasting, but still needs a booster shot every few years.

Influenza A Viruses The most virulent flu viruses belong to this genus. At least 10 species affect humans. These viruses are usually found in aquatic birds and they have been known to “jump species” and cause epidemics and pandemics when they “jump” to humans. Avian flu and Swine flu are different species of Influenza A Mutate quickly, therefore annual booster shots are needed to prevent infection.

Avian Flu The H5N1 virus (or Avian Flu) is flu virus common to birds in Southeast Asia. The most common method of transmission is handling infected poultry (chickens, turkeys), although once infected, human to human transmission is possible. Mutates quickly. Very virulent and causes death in 60% of all human cases.

Avian Flu The avian flu kills by over stimulating the immune system causing a massive inflammatory response and higher levels of tissue destroying chemicals. Also leads to pneumonia more often than other flu viruses which can also be deadly. No maintained human strains however, so it is not yet endemic in human populations thankfully!

Avian Flu That being said, a highly contagious strain of H5N1 was created by Ron Fouchier of the Erasmus Medical Center in Holland in September 2011. He described it as “one of the most dangerous viruses you could make”! Subsequent research into the production of vaccines against Avian Flu has come to the forefront of viral technology.

Swine flu versus Avian Flu

Swine Flu The H1N1 virus (or Swine Flu) is a mutant offshoot of the most common flu virus to infect humans, the influenza A virus (H1N2). The 2009 H1N1 flu virus is actually a genetic mix of four different flu viruses: two different swine flu viruses (one NA and one Asian), an avian flu virus and influenza A. The 2009 version is called pandemic H1N1/09 virus.

How is it transmitted? The basic reproduction number (the expected number of healthy, non-immune people an infected individual will transmit to) for the H1N1 virus is 1.75. This is quite high. It has also been seen that humans have transmitted the virus to pigs, turkeys, ferrets and household cats.

How can the virus change hosts and become more deadly?

Who is at risk? The short answer is essentially everyone is at risk for Swine Flu. Some people who have had the flu before 1957 have shown some immunity to the H1N1 virus (antibodies confirmed in blood tests), but not all.

Why should we be concerned? People from every age bracket have died from the H1N1 virus. It is a concern because younger, normally healthy people are dying from the virus. This is different from the seasonal flu virus which kills the very old, very young or immuno-compromised individuals.

When did it become a problem? It was first detected in Veracruz, Mexico in March 2009, where it had already been an epidemic for months! Although the Mexican government shut down the majority of medical clinics in the country to try to prevent the spread of “swine flu”, it crossed the Mexican border and has gone global.

When did it become a problem? On June 11th 2009, the World Health Organization (WHO) declared the H1N1 virus a pandemic. On October 25, 2009 U.S. President Barack Obama officially declared H1N1 a national emergency in the United States. On November 8, 2009 WHO stated that "206 countries and overseas territories/communities have officially reported over 503,536 laboratory confirmed cases of the influenza pandemic H1N1 infection, including 6,250 deaths."

What was the Public Health Agency of Canada’s Response? On May 6th 2009, PHAC announced it had mapped out the genetic code of the H1N1 virus. This has allowed for the production of the H1N1 vaccine, which has since been administered in 16 countries.

How do we prevent ourselves from getting “Swine Flu”? Straight from PHAC: Get both seasonal and H1N1 flu shots. Good hand hygiene is the best way to prevent the spread of all flu viruses. Wash your hands with soap and water thoroughly and often. Keep an alcohol-based hand sanitizer (gel or wipes) handy at work, home and in your car. It needs to be at least 60% alcohol to be effective. Cover your mouth and nose with a tissue when you cough or sneeze and throw the tissue out. Cough into your upper sleeve if you don't have a tissue. Avoid large crowds of people where viruses can spread easily. Stay home when you are sick.     Keep common surfaces and items clean and disinfected.

What are some common questions about the H1N1 Vaccine? Why should I get the vaccine? The pandemic H1N1/09 virus is a new virus, the human body has no immune system protection against it. The vaccine will give you the protection you need. To prevent the spread of the virus. Also vaccines are one of history’s most successful and cost-effective public health tools for preventing serious disease and death! Is the vaccine safe? Yes, it is safe. It is made from an inactivated part of the virus, so it cannot give you the flu. Also there have been only 11 cases of Guillain-Barre syndrome in the 65 million administered doses!

What are some common questions about the H1N1 Vaccine? How does the vaccine work? The vaccine contains inactivated pieces of the virus that act as an antigen, something your body recognizes as foreign. This antigen will be recognized as foreign by your immune system cells and they will get rid of it. Your immune system will also make antibodies, special proteins that remember an invader and will fight it off before you get sick the next time it returns.

What are some common questions about the H1N1 Vaccine? What are some side effects of getting the vaccine? Discomfort at the site of injection Occasionally fatigue, nausea, muscle ache and fever. I heard there is mercury in it, won’t that kill me dead?!?!?! Yes, there is a mercury containing compound called thimersol in the vaccine. However, when this compound breaks down, it breaks down into ethyl mercury which is not the toxic form. There will be less mercury in your body after the vaccine than after you eat a can of tuna!

What can I do if I already have the H1N1 Virus? Basically wait it out and make sure you are staying hydrated and nourished as much as possible. If you are in a high-risk group or have developed a severe case of swine flu, you may be prescribed anti-viral drugs like Tamiflu or Relenza. These are not prescribed to everyone who contracts H1N1 flu in order to prevent drug resistant strains of the virus from emerging.