The Voice of Epidemiology

    
    


    Web EpiMonitor

► Home ► About ► News ► Job Bank Events ► Resources ► Contact
 


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.  ■

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.   ■

 


Reader Comments:
Have a thought or comment on this story ?  Fill out the information below and we'll post it on this page once it's been reviewed by our editors.
 

       
  Name:        Phone:   
  Email:         
  Comment: 
                 
 
       

           


 

 
 
 
      ©  2011 The Epidemiology Monitor

Privacy  Terms of Use  Sitemap

Digital Smart Tools, LLC