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 therefore you should get your vaccine against them 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. H5 and N1 are cell surface markers on the virus’ protein coat (capsid)

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 often which can be deadly Reported April 5, 2013 (3 days ago) human cases have been confirmed in China

Swine flu versus Avian Flu

Swine Flu The H1N1 virus (or Swine Flu) is a mutant 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? A NEW TERM: basic reproduction number is the expected number of healthy, non-immune people that an infected individual will transmit to This number is 1.75 for the H1N1 virus (this is quite high) It has also been seen that humans have transmitted the virus to pigs, turkeys, ferrets and household cats.

When did it become a problem? FYI (no need to write this ) 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."

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 became global.

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.

H1N1 Update – from PHAC On August 10, the WHO (World Health Organization) declared that HINI was in the “post-pandemic” stage Epidemiologist found that H1N1 was circulating at lower levels – behaving like seasonal influenza It continues to circulate in Canada at low levels

Who is at risk for contracting flu? Essentially everyone is at risk for getting Flu Individuals who are at higher risk for complications while infected with flu virus include: Adults over 65 Infants and young children People with chronic conditions (e.g diabetes, cancer)

Why should we be concerned? All flu viruses mutate quickly, which can result in new strains that humans lack immunity to (e.g. H1N1) People from every age bracket have died from the H1N1 virus. It is difficult to predict the characteristics of future strains of flu virus

How do we prevent ourselves from getting Flu? From PHAC: Get flu shots Good hand hygiene is the best way to prevent the spread of all flu viruses. 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. Use your cough corner  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.

Reactionary treatment for the flu Usually: rest, drink lots of fluids to avoid dehydration, stay nourished (eat what you can) 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.