Healthcare Hygiene magazine September 2020 September 2020 | Page 14

TRANSMISSION DYNAMICS AND COVID-19
Well-designed engineering controls can be highly
effective in protecting workers and will typically be
independent of worker interactions to provide this
high level of protection.”
this high level of protection. The initial cost of engineering controls
can be higher than the cost of administrative controls or PPE,
but over the longer term, operating costs are frequently lower,
and in some instances, can provide a cost savings in other areas
of the process.”
Finally, when it comes to administrative controls and PPE,
NISOH says they are “frequently used with existing processes
where hazards are not particularly well controlled. Administrative
controls and PPE programs may be relatively inexpensive to
establish but, over the long term, can be very costly to sustain.
These methods for protecting workers have also proven to be
less effective than other measures, requiring significant effort by
the affected workers.”
Dooley and Frieden (2020) explain that, since the source
of infection is persons with SARS-CoV-2 infection, prospective
COVID-19 patients with symptoms of mild illness should test,
isolate and monitor their condition and only seek in-person care
if symptoms worsen, as well as use telemedicine options.
For patients requiring in-person care, the authors say that
transmission risk can be mitigated through the following steps:
● having all persons wear facemasks when on premises
● identifying all persons with COVID-19 symptoms before they
enter the facility and separating them from other patients
● moving persons who are coughing to a well-ventilated area
separate from other patients
● isolating persons admitted with known or suspected COVID-19
in well-ventilated, single-person rooms with doors closed
● implementing and maintaining droplet precautions for 10
days after symptom onset and three days after recovery
(resolution of fever without use of fever-reducing medications
and improvement in respiratory symptoms)
● for persons with known or suspected COVID-19, performing
aerosol-generating procedures in airborne infection
isolation rooms
For COVID-19 and any other potentially airborne infections,
Dooley and Frieden (2020) recommend the following engineering-control
measures:
● create directional air flow to move air away from uninfected
persons
● dilute the air to reduce the concentration of airborne infectious
particles
● remove such particles from the air by high-efficiency particulate
air (HEPA) filtration or effective UV light installation
● prevent recirculation of potentially contaminated air
These airborne-control measures should be accompanied by
“meticulously cleaning and disinfecting potentially contaminated
Transmissions Dynamics and COVID-19
Tom Frieden, MD, MPH, president and CEO of
Resolve to Save Lives, an initiative of Vital Strategies,
and former director of the CDC, addresses how the
pandemic is reshaping the conversation around how
to best protect patients and healthcare personnel.
HHM How significantly is COVID-19 changing the way
we think about transmission dynamics and the need for
infection prevention and control?
Tom Frieden (TF): There are differences in transmission
patterns and infectiousness of pathogens, but with a novel virus
such as SARS-CoV-2, which causes COVID-19 disease, we are
learning more every day. SARS-CoV-2 is transmitted primarily via
exhaled respiratory droplets, as we would normally expect with
a respiratory disease. However, we weren’t expecting such high
levels of infectiousness among people who are been infected
but not ill – up to 40 percent of disease may be transmitted by
infected people who are asymptomatic – something that is less
common with infectious diseases. We are learning that we can’t
rely on past experience to make assumptions about how a new
pathogen will behave, so we need to ensure that the full hierarchy
of established infection control protocols – source control (the
removal or mitigation of infection sources), engineering and
environmental controls, administrative controls, and personal
protective equipment – are rapidly and rigorously implemented
in all areas of all healthcare settings.
HHM What is your overall sense of IP&C readiness in
hospitals pre-pandemic, and how is the ongoing response
and IP&C implementation?
TF: There is always room to improve IP&C protocols in the
United States and around the world. In the United States, in an
average year, at least 70,000 people are killed by infections they
contract in healthcare facilities. Globally, more than one-quarter
of all facilities lack running water. After the SARS outbreak in
2003, and more recently in the successful effort to reduce the
burden of hospital-acquired infections including MRSA and
Staphylococcus, IP&C protocols were strengthened throughout
health systems globally. With COVID-19, one major problem is
not the IP&C protocols themselves, but the availability of personal
protective equipment such as N95 masks, gloves, and gowns. Early
in the pandemic, we were shocked to see how many healthcare
personnel were forced to resort to makeshift PPE such as plastic
trash bags and homemade masks. Although more supplies of
PPE available in many places, there are still important shortages.
HHM What do you think is the future of IP&C, post-COVID?
Will hospitals finally be better prepared to face other
emerging threats?
TF: We need to rethink many of our IP&C strategies to make sure
that we aren’t caught by surprise again. In case of a new pathogen,
we must protect against all possible modes of transmission until
we understand how it is spread. We can’t allow supply chain
issues to hinder ready access to sufficient quantities of PPE. And
the healthcare system must implement the full hierarchy of IP&C
measures in all areas of all facilities, including in nonclinical areas
such as staff break rooms, and including at long-term care facilities
where diseases often spread.
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