It seems as if everyone is an
epidemiologist these days. So it’s worth considering epidemiology’s
history and the role it should be playing in public policy, preventing
disease and promoting health.
When U.S. President Donald Trump and
reporters get into arguments about infections, testing and death rates,
they’re engaging in an epidemiological discussion.
Not everyone who discusses disease and human health is qualified. But most of us are discussing, asking questions expressing concerns and offering opinions in this pandemic, including around the dinner table.
The term epidemiology was first used by Spanish physician Joaquin de Villalba in his 1802 work Epidemiología Española.
But the roots of this field are much
older. In 400 BC, Hippocrates theorized that human ailments had a
natural rather than supernatural cause, which was a helpful development
for medicine and epidemiology.
This meant factors that caused
disease could be measured, understood and possibly acted upon to alter
the course of disease. Measuring and quantifying these factors held
great promise to improve human health, so we could begin to understand
who got sick, who died and why.
A major breakthrough for the field occurred in the mid-19th
century – and this is a story told to all epidemiology students. A
physician named John Snow demonstrated the power of properly enumerating
the distribution of disease in the midst of a deadly cholera outbreak
in London. He believed that contaminated water caused people to get
To prove this, he visited houses and calculated how many cholera cases there were, cleverly mapped out these sicknesses and identified a water pump in the centre of the outbreak. Snow persuaded city officials to remove the handle of the water pump so no one could drink the water, and watched as the number of sick people dwindled.
This contains all the aspects of
modern epidemiology: collecting data, determining the cause of disease
and disease patterns, and implementing action to solve the outbreak. And
Snow did this all without a computer or knowing the name or exact
nature of the germ (the bacteria vibrio cholera).
And the scientific discipline was just getting started.
Epidemiologists have since made
tremendous contributions to polio, sudden infant death syndrome,
HIV/AIDS, cancer, cardiovascular disease, smoking and even automobile
accidents, acts of violence and mental health, among countless others.
Technology is transforming
epidemiology. Machine learning and artificial intelligence methods
applied to population health give new insights. And the massive storage
of health data from countries, counties and clinics provides tremendous
opportunities for discovery.
But classical principles of study
design, data collection, quality control and analysis remain pillars of
all epidemiologic investigations.
There has always been a deep curiosity to know the cause and outcome of disease, with the intent to eventually intervene and alter the course of disease development. For researchers, it’s often easier to discover causes and identify high-risk populations than it is to intervene and change things.
As German poet Johann Wolfgang von Goethe wrote: “knowing is not enough; we must apply … willing is not enough; we must do.”
At some point in the research, it
becomes clear that stopping smoking is more important than knowing even
more details about the dangers contained in cigarettes. As many smokers
will tell you, learning about the dangers of smoking is far easier than
quitting cigarettes for good.
So how do we go from quantifying health risks to developing preventive measures and treatments?
This huge undertaking requires a
multi-disciplinary approach. University of California, San Francisco,
professor of epidemiology and biostatistics Robert Hiatt, said that
“epidemiology has a central role in team science, no matter what the
health issue at hand.” Moyses Szklo, a professor of epidemiology at
Johns Hopkins University, defined translational epidemiology as an
“effective transfer of new knowledge from epidemiologic studies into the
planning of population-wide and individual-level disease control
programs and policies.”
For clinical research to be applied
to population health, epidemiology should be involved in all phases,
including the development of new interventions to implementing and
evaluating those interventions.
It’s fair to say that the goals of
translational epidemiology have not been fully realized. Knowing more
doesn’t necessarily mean helping more. Knowledge needs to be applied in
the real world to make a difference. Epidemiologists and health
professionals can do better.
Researchers may publish in
inaccessible or obscure journals, but that information doesn’t get into
mainstream media or to the public. When the public does find out,
there’s often conflicting information in various research papers and
that confuses. Contradictory information is a natural consequence of the
scientific discovery process, but we need to have conversations to
explain what happened and why.
So it’s time to take the next step in
science and epidemiology. That next step is a plain-speaking way to
improve human health. It’s getting science out of labs and white coats
and down to the street level where sick people are.
The good news is that we already know
a lot about this pandemic. Treatments are improving as doctors and
nurses get more skilled at managing COVID-19. Campaigns for safety,
testing, isolating and tracing are largely well-received, and multiple
vaccines are being developed at unprecedented speeds.
But this pandemic has also shown that
there are challenges to improving human health other than the
scientific ones. Funding was cut during the lull before this crisis.
Necessary supplies weren’t stockpiled so we had a confusing public
debate about wearing masks. For many issues and messages, there was
little collaboration from governments, public and global health
organizations and academics, which led to a lot of confusion and angst.
And the public is wondering why it takes a year and a half to develop,
test and distribute a vaccine.
So what’s the average person to do with all this information and even conflicting advice?
The lesson Snow’s actions taught and
the purpose of translational epidemiology is to make good decisions and
take precautionary actions, even when the details haven’t been fully
worked out. John Snow didn’t have proof that the germ was in the water
and he didn’t even know that the germ was bacteria, but he took action
based on the information at hand.
Our job is to use our common sense,
built upon generational knowledge about disease transmission, for good
public health practices. Listen to the public health messages and think
about reasonable ways to follow them. Deal with the ‘pump handles’ in
our homes to disrupt the flow of the virus. We should spend our energy
keeping ourselves and our loved ones safe.
We’ve known for a long time that
washing hands is one of the best ways to reduce disease. We don’t need
another study to prove this. We don’t need a debate about whether
COVID-19 can live on fish, meat, eggs or plates. Cleanliness is its own
reward. Children’s clothes, toys and the surfaces on which they play
should also be clean.
We also don’t need a study to
determine whether going to a crowded pub for two hours increases your
risk of infection by 50 or 55 per cent. These differences don’t matter –
the danger does. Places and events with lots of people breathing,
sneezing and talking on top of each other are simply risky.
We already know good safety practices
from our grandmother – but are we courageous and persistent enough to
follow them, for ourselves, our families and our communities?
More and new information on this
virus is coming out daily. It’s interesting and sometimes helpful. But
more information should not delay action right now. There’s lots we can
do to keep families safe at home, in cars and in public while the debate
is going on.
There’s no downside to cleanliness, keeping a distance, having a smaller social bubble, wearing a mask, and working on all the habits we already know promote good health.
by Derek Ng, Deborah Prabhu and Allan Bonner. Originally published by Troy Media.