Of all the public health tools that could be used to control or eradicate the outbreak of a highly contagious disease, whether intentional – e.g., caused by a terrorist attack – or natural, what is described as “social distancing” may be one of the most effective but least understood defensive instruments available to leaders, planners, and the public at large.
Disease-carrying microbes have finite life spans. Moreover, they are susceptible to destruction by the environment, and are not invincible. The epidemiology of outbreaks follows a rather predictable pattern, in fact, in which the rate of transmission declines with each successive generation of new patients – and once the transmission rate (referred to as “Ro”) falls below 1.0, the outbreak is destined to burn out. The population of a community experiencing an outbreak falls into one of five categories: Susceptible; Exposed (but not yet ill); Ill; Removed (due to death or post-infection immunity); or Vaccinated. In an unvaccinated population, the majority of the population will fall into the Susceptible category relatively early in the outbreak, and it is in protecting that group that social distancing can be most effective. The most obvious application of social-distancing techniques is through the cancellation not only of schools, ranging from kindergartens to major universities, but also of mass-gathering events such as sporting events, movies, and various cultural activities – e.g., concerts and plays. However, these closures in and of themselves may not solve the problem entirely, and may in fact create secondary effects that could dwarf the actual public-health ramifications of the outbreak.
Caveats and Codicils
Used properly, though, social distancing does work. However, there are several caveats that must be kept in mind. Following are a few of the most important of those caveats:
Social distancing must be accompanied by a robust public information and education campaign. Good hygienic practices will greatly reduce the spread of most contagious diseases. The frequent washing of hands, covering one’s face with a sleeve or handkerchief when sneezing and coughing, staying home when ill – all of these have proven positive effects. Most members of the public intuitively understand these concepts, but may need to be frequently reminded to practice them, and other personal measures, to protect themselves and those around them.
- To be effective, social distancing must be instituted early in the outbreak. A comparison of the effects of the 1918 Spanish Influenza Pandemic in a number of different U.S. metropolitan areas revealed that large cities – e.g., St. Louis and San Diego – that instituted social-distancing practices early in the pandemic had significantly lower morbidity and mortality rates than other cities that waited until they were suffering from the full effect of the disease. Here it should be noted that there will almost certainly be an economic downside to social distancing for any community practicing it, but in most if not all situations the economic losses will be preferable to the consequences of failing to institute social-distancing measures.
- Coerced/draconian implementation and enforcement of community-wide social-distancing measures not only may be counter-productive but also might greatly increase the “collateral damage” done to a community’s critical infrastructure. Social proximity outside the nuclear family usually occurs in four primary settings – work, school, elective social functions, and activities of daily living. The curtailment or elimination of any of these settings would almost certainly have a huge negative impact on the community – and, in at least some cases, could not be implemented without some adverse secondary effects as well. A small business might close down, for example, but the economic impact on the workers and staff could be significant. One can only imagine the effect that the closure of metropolitan water-treatment plants and/or communications systems might have on a community. A select few work centers are of such global importance that even a relatively short interruption in services would have far-reaching effects that could take years to recover from. Fortunately, there usually are enough creative solutions available that this need not occur. As an example, several grocery chains already provide curb service – which, although instituted primarily as a “convenience perk” for customers, obviously would also significantly reduce the risk of person-to-person contact and, therefore, the spread of contagious diseases. Moreover, schools may close, but so-called “distance learning” is now so prevalent throughout the United States that there is no reason that a one-month (or longer) closure of a school would necessarily result in a total halt to the learning process. Even in work centers that must stay open, providing clean breaks between shifts, furloughing a portion of the staff, the judicious use of minimal personal protective equipment, and some modification of processes in the work environment are among the measures available that could collectively result in effective social distancing. More, and more effective, worker screening – ranging from passive surveys and questionnaires through temperature screening and more sophisticated testing – can serve as a layered approach to mitigate the outbreak’s effects in the work environment.
- Few people can sustain self-sufficiency for any length of time if critical infrastructures are not maintained. People need food, water, environmental protection, and access to healthcare, and have grown so dependent on a host of other urban/community necessities (communications systems, firefighting and police services, etc.) that even a temporary disruption in the availability of these basic amenities will probably have far-reaching effects. Many of the services mentioned, of course, are provided through government agencies – but, directly or indirectly, also require participation by the private sector to maintain continuity of operations. It is therefore in the community’s best interest to maintain as many services in as close to normal operations as possible.
Much has been written on social distancing, and many U.S. communities have developed notional plans of when, how, and under what conditions to implement a social-distancing plan. Relatively few of those same communities, though, have worked through the various “triggers” that would be needed for instituting the social-distancing practices required, and even fewer have actually tested any of the minor components of the social-distancing mechanisms likely to be implemented. There are, in short, significant gaps in most community preparedness plans, and these should certainly be evaluated – and, perhaps, significantly revised – before social distancing becomes a practical necessity rather than a theoretical academic concept.
Dr. Jerry Mothershead is the Physician Advisor to the Medical Readiness and Response Group of Battelle Memorial Institute. An emergency medicine physician, he also is adjunct faculty at the Uniformed Services University of the Health Sciences in Bethesda, Md. A graduate of the U. S. Naval Academy, Dr. Mothershead served on active duty in the U.S. Navy in a broad spectrum of clinical, operational, and management positions for over 28 years, and has served in an advisory capacity to numerous local, state, and federal agencies in the fields of antiterrorism, disaster preparedness, and consequence management.