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Deadly Failure To
Control Transmission Of SARS-CoV-2 In The US Triggers Proposals For
New Strategies Or Better Use Of Existing Countermeasures
The deadly failure of
the US to achieve control of the current coronavirus pandemic has
frustrated and angered many experts as well as everyday Americans. It
has sent some infectious disease and policy experts back to the
drawing boards to formulate alternative approaches or reinvigorate old
ones that have the best chance of success at this relatively late
phase in the pandemic in the United States.
Lessons Learned
A comprehensive review
of the experiences of many US states as well as that of several other
countries by the Center for American Progress entitled
“A New
Strategy to Control the Coronavirus” has identified several lessons
learned. Based on these analyses and the success achieved by New York
and other Northeast states in maintaining low incidence levels, the
Center has proposed the following strategy to prevent future waves of
cases in the coming year.
1. Close
indoor dining and bars.
Experience has shown that these locations are foci of transmission and
they should be kept closed or reclosed if reopened, particularly in
hotspots. Support with good unemployment insurance should be provided
for workers as well as financial support to cover the fixed costs of
businesses forced to close.
2.
Monitor other potentially high-risk venues
Other
potentially important sources of transmission such as gyms and places
of worship could be closed or other measures used to lower risk such
as requiring capacity limits, moving outdoors, or requiring masks.
Nail and hair salons have not been linked to outbreaks but are
inherently risky and should be monitored closely for breaches in
compliance with face coverings. Public education about avoiding any
indoor gatherings such as parties especially without masks is needed.
3.
Mandate masks
This
recommendation calls on governors and mayors to implement state and
local mask mandates. Financial assistance to businesses should require
mask mandates before the aid is provided.
4. Adopt
cluster-based contact tracing.
The goal
of cluster -based tracing is to study the patterns in chains of
transmission to identify sources that can produce a large number of
cases. These types of sources are super-spreading events and the focus
should be on identifying and preventing them rather than tracing all
chains of transmission. Bars are an example of such sources but
contact tracing may identify others. According to the Center, the
model for this approach is Japan which finds patterns in
cluster-based contact tracing and uses the information to identify
sources that could become major outbreaks.
Think
Differently About Test Sensitivity
Another
new strategic approach is being advocated by Michael Mina,
professor of epidemiology at the Harvard School of Public Health. He
was interviewed recently on the podcast This Week in Virology where he
made the case for a different way of thinking about testing.
Heretofore, the focus has been on having highly sensitive tests that
are able to accurately determine if an individual is infected with
SARS-CoV-2. This for the most part has meant relying on polymerase
chain reaction or PCR tests to diagnose individuals. However, the PCR
test is very sensitive and can even detect virus fragments that may
not be capable of spreading and causing transmission to other persons.
These tests are relatively expensive and are not easy and
straightforward to carry out. Also there has been a long delay in
reporting the test results which have made some contact tracing work
ineffective because it is too late to halt transmission.
New Approach
A different approach
argues Mina is to lower the bar for how sensitive tests need to be and
to focus instead on other kinds of tests that are cheap, easy to carry
out, and provide results in minutes rather than days. The type of test
Mina is calling for utilizes a thin paper strip that only requires a
saliva sample and can deliver results in 15 minutes or less. This type
of test will be less sensitive but may be considered sensitive enough
to detect infectious persons. In this way of thinking, false negatives
are of no concern because they are unlikely to be contagious and the
test is good enough to be considered sensitive in picking up persons
who are likely to transmit. Thus, if made widely available at low
cost, these “contagiousness tests” could become ubiquitous and could
serve to quickly determine if someone should be admitted to school or
work or into any other environment where the risk of transmission
exists. Positive persons would be kept away from others. And the test
could be repeated daily if necessary to keep close monitoring of each
situation.
Test, Test, Test
Mina’s idea was also
explained recently in a feature article in the Atlantic. It described
Mina’s idea this way. “Test negative, and you many enter the public
space. Test positive, and you are sent home. In other words: Mina
wants to test nearly everyone, nearly every day.”
Real Lockdown
Another idea has been
put forward by Michael Osterholm at the Center for Infectious
Disease Research and
Prevention (CIDRAP)
and Neel Kashkari, president of the Federal Reserve in
Minneapolis. In an op-ed piece in the New York Times, Osterholm and
Kashkari call for a second more rigid lockdown throughout the US. They
believe the earlier lockdown was not carried out well enough and that
the only way to get the virus under control now is to get serious
about keeping everyone at home for six weeks. The goal of the new
lockdown would be to get reported cases to a level as low as 1 case
per 100,000 because at that level public health control measures have
a possibility of being effective. As rates stand now, the volume of
cases is too large for effective testing and contact tracing,
according to the authors.
New York Example
Failing such a
rigorous intervention, Osterholm believes that another coronavirus
“forest fire” will spread out of control in the US in future months.
In one of the regular podcasts from CIDRAP, Osterholm said the US
could look to the situation in New York State to envisage how the new
lockdown could drive the seven day average numbers of cases and deaths
lower.
New York had
approximately 9800 cases and 921 deaths as of April 10. By June the
cases had fallen to 662 and deaths to 39. By August 10, cases were at
651 and 8 deaths and the averages have been flat since June. According
to Osterholm, New York has done what the rest of the country can and
should now do.
Since we have to get
through at least 6-8 months without a vaccine, according
to Osterholm, the number of cases is going to get much worse. We
should take our medicine now and get ready to manage the smaller
caseload that will emerge after a rigorous lockdown, he said. It is a
pay now or pay me later situation he believes. He is hopeful their
proposed strategy can earn discussion and support.
NY Times
Editorial Board
In
perhaps a less surprising new strategy, the New York Times Editorial
Board has proposed making better use of the tools the US has to
achieve a higher level of control that has eluded it. In its view, the US has
never really had a true lockdown compared to other countries. It
estimated that the US only closed down or “shuttered” half of the
country rather than the 90% that was attained in other areas.
Consequently the US never achieved the dampening effect that other
countries were capable of producing.
The
Board proposed a new strategy consisting of the following key steps:
1. Clear
and consistent messaging.
Because
of the confusion that has been sown, it is now important to coordinate
messaging at every level, especially from the top---masks are
essential, and social distancing is a civic responsibility.
2.
Better Use of Data
Obtaining and sharing more information about how the pandemic is
unfolding in various populations and places and how it is being
managed could allow public health officials to provide better
forecasts of what is coming so that people could adjust their plans
accordingly.
3.
Smarter shutdowns.
Alert
levels could be created to warn people about what behaviors are
permissible and which are not at different risk levels or at different
levels of transmission in the community. Shutdowns would not need to
be equally aggressive in all communities. Such color coded alert
systems have been developed in Harris County Texas as an example. (See
next article).
4.
Testing, Tracing, Isolation, and Quarantine
The US
has failed at all of these. The Times calls for more effective and
rapid diagnostics and the federal government should compel companies
to make the needed tests available. Once testing is taking place at a
high enough volume, then the other public health measures can be made
effective to control the outbreak.
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From Harris County Website
readyharris.org
Harris County
COVID-19 Threat Level System
The
Harris County COVID-19 Threat Level system advises four levels of
transmission:
Level
1: Stay Home (Current
Level)
Level one
signifies a severe and uncontrolled level of COVID-19 in Harris
County, meaning outbreaks
are present and worsening and
that testing and contact tracing capacity is strained or exceeded. At
this level, residents take action to minimize
contacts with others wherever possible and avoid
leaving home except for the most essential needs like
going to the grocery store for food and medicine.
Level
2: Minimize
ALL Contacts
Level two
signifies a
significant and uncontrolled level
of COVID-19 in Harris County, meaning that there is ongoing
transmission of the virus and that testing and contact tracing
capacity is likely sufficient to meet demand. At this level, residents
should minimize
contact with others, avoiding any medium or large
gatherings and only
visiting permissible businesses that follow public
health guidance.
Level 3: Stay
Vigilant
Level three signifies a
moderate, but controlled level
of COVID-19 in Harris County, meaning a demonstrated reduction in
transmission and the local healthcare system is within capacity.
Residents should
remain
vigilant, but
resume contact with others and resume leaving home.
Level 4: Resume
Normal Activity
Level four signifies a minimal
and controlled level of
COVID-19 in Harris County, meaning new chains of transmission are
limited and quickly broken or a vaccine and/or treatment has been
developed and widely deployed. At this level, residents may
resume
normal contact with others unless
sick.
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