1) Recent Research: Flu Virus in Ontario and Toronto – Teaching Notes
i.
The Recent Research Article: Flu Virus in Ontario and Toronto falls under the category of
Nature of Science.
ii.
Ministry Curriculum Expectations:
Overall Expectations:
F2. Investigate the characteristics of population growth, and use the models to calculate the
growth of populations within an ecosystem.
F3. Demonstrate an understanding of concepts related to population growth, and explain
the factors that affect the growth of various populations of species.
Specific Expectations
F3. Understanding Basic Concepts:
F3.1 Explain the concepts of interaction (e.g., competition, predation, defense mechanism,
symbiotic relationship, parasitic relationship) between different species.
F3.2 Describe the characteristics of a given population, such as its growth, density (e.g.,
fecundity, mortality), distribution, and minimum viable size.
F3.3 Explain factors such as carrying capacity, fecundity, density, and predation that cause
fluctuation in populations, and analyse the fluctuation in the population of a species of
plant, wild animal, or microorganism.
iii.
DiGiuseppe, M. (2003). Biology 12. (1st ed.). Toronto (ON): Nelson Thompson Learning.
Pagliaro, J. (2012, February 21). Cases of flu virus in Ontario and Toronto at five-year low.
The Toronto Star; Sect D:4 (col 4).
iv.
Teaching notes:
a. Distribute one article to each student.
b. Ask students in class to read article aloud by paragraph.
c. Students answer analysis questions independently.
d. Allow 20 minutes class time for completion; 10 minutes for debriefing.
e. Students are to keep articles for test review.
Cases of flu virus in Ontario and
Toronto at five-year low
February 21, 2012
Jennifer Pagliaro
Staff Reporter
After riding the wave of the 2009 H1N1 pandemic, Ontario
residents appear to have avoided the seasonal onslaught of
coughing and sneezing — so far.
The number of laboratory-confirmed cases of the flu by the
end of January was the lowest it’s been in the past five
years, according to data from the Ontario Ministry of Health
and Long-Term Care.
In Toronto there were only 64 confirmed cases of influenza
since September. Sixteen were part of an institutional
outbreak in the last week of January. At the same point last
year, Toronto had already seen 1,106 confirmed cases of
the flu. In York, Peel and Durham regions, there were 55
confirmed cases of influenza total compared to 97 last year.
Across the province 191 confirmed cases of the flu were
reported, compared to 3,059 at this point last year.
“So far we’ve had a very unremarkable flu season,” said
Ontario’s Chief Medical Officer of Health Dr. Arlene King.
When you’re talking about the flu, unremarkable is a good
thing. Not only are the numbers low, but King said the virus
strains we are currently seeing are the ones planned for,
including the H1N1 pandemic strain.
She said the season low thus far can be attributed to a
combination of environmental and host (that’s us) factors.
“A combination of immunization and immunity related to
illness may have resulted in very, very high levels of
immunity in our population to begin with,” she said. Our
immunity may be especially high this year, after the 2009
outbreak of the H1N1 strain saw high levels of both infection
and vaccination.
Experts say the current vaccine is extremely effective,
making it the best defence we have. King said the uptake
for vaccinations across Ontario happened quicker than
predicted this year. After ordering 3.9 million doses, another
400,000 were ordered to keep up with demand, she said.
And since the virus survives better in cold, dry
temperatures, Toronto’s mild weather may also be a factor,
King said. “The environment influences how people behave as well, so they may be less cloistered up
together for prolonged periods of time, encouraging transmission between people,” she said. But
experts were quick to warn that the number of cases hasn’t peaked for this flu season and still could
in February or in March.
Toronto’s associate medical officer of health Dr. Irene Armstrong said it’s hard to know what causes
the change in outbreaks from season to season. “A lot of what we know about influenza is just based
on observation,” she said. But overall, the numbers recorded could be much lower than the actual
number of people with the flu, since many stay home and never get tested, Armstrong said.
In Toronto, 31,257 people were immunized at 46 Toronto Public Health community clinics, falling into
the average of 30,000 to 35,000 people immunized at TPH clinics each year. “We do know that
influenza is inevitable,” King said. “We encourage everyone to get a flu shot every year.”
Recent Research: Flu Virus in Ontario and Toronto
1. One reason cited for the decline in confirmed flu diagnoses is the milder weather, resulting in
fewer people congregating indoors which can increase the potential for the virus to spread. In
which population dispersion pattern (clumped, uniform or random) do you believe this year’s flu
viruses are found? Explain your answer.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
2. Do flu viruses typically grow geometrically or exponentially? Why?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
3. Viruses are able to mutate and change, leading to antibiotic-resistant disease such as
Methicillin-resistant staphylococcus aureus (MRSA) and other “super-bugs”. If the H1N1 flu virus
was able to mutate and become resistant to its vaccine, what potential consequences might be
observed?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
4. From the 2009/2010 flu season to the 2010/2011 flu season, confirmed cases of the flu in
Toronto dropped from 2,430 to 1,106. Calculate the growth rate of the flu over these years.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Recent Research: Flu Virus in Ontario and Toronto – Answer Key
1. One reason cited for the decline in confirmed flu diagnoses is the milder weather, resulting in
fewer people congregating indoors which can increase the potential for the virus to spread. In
which population dispersion pattern (clumped, uniform or random) do you believe this year’s flu
viruses are found? Explain your answer.
This year’s flu is likely clumped (i.e. in households, schools or hospitals). This is likely due to the
high rates of vaccination (minimizing spread of the virus) and lower prevalence of residents
clustered indoors. Instead, the flu likely infects immune-compromised individuals (hospital
patients) or non-vaccinated households.
2. Did the flu virus grow geometrically or exponentially from 2009/2010 to 2010/2011? Why?
The growth rate during this time period was exponential, as the virus spread was not limited by
vaccinations or hosts to infect.
3. Viruses are able to mutate and change, leading to antibiotic-resistant disease such as
Methicillin-resistant staphylococcus aureus (MRSA) and other “super-bugs”. If the H1N1 flu virus
was able to mutate and become resistant to its vaccine, what potential consequences might be
observed?
If the H1N1 virus was able to resist its vaccine, a higher prevalence of people could become
infected. It would lead to a higher number of immuno-compromised individuals becoming sick
(i.e. elderly or sick) and may cause changes in death rates and life expectancy if left unchecked
over time as was witnessed with the Spanish Flu epidemic.
4. From the 2009/2010 flu season to the 2010/2011 flu season, confirmed cases of the flu in
Toronto dropped from 2,430 to 1,106. Calculate the growth rate of the flu over these years.
Δ
= (b + i) – (d + e) / n x 100
= (-1324 – 0) / 2430 x 100
= -1324/2430 x 100
= -54.4
The growth rate was negative 54.4