Japa Volchok, DO
This article has been edited. Since it was originally published, the guidelines from the CDC have changed on the use of masks by the general public. These are available here.
We see the national, state, and local agencies, medical societies, and health care systems all creating their own policies and guidelines for infection prevention. These are all well-intended, but they are not always well implemented or even based on good science. We are faced with a global respiratory disease outbreak with as yet unclear mortality rate, transmission routes and true risks.
A recent publication in The Lancet has reviewed mortality rates in China and found they range from 0.9% to well over 3%. It is much too early to make any accurate conclusions for the rest of the world. The WHO recently reported that the global rate is 3.4%, but cautions that this is a crude calculation and does not fully take into account mild cases not identified or reported.
Healthcare workers and the number of infected persons in an area or country do have a direct impact on mortality. More infected, fewer healthcare providers, overwhelmed healthcare facilities, and fewer resources will lead to increased mortality. Incorrect use of personal protective equipment (PPE), hoarding of face masks and other devices is becoming a global problem.
Be sure to practice proper hand hygiene (you are probably doing it wrong). Wet, lather, scrub, rinse, dry, and use alcohol gels only when you can’t wash is the official Centers for Disease Control and Prevention (CDC) guideline.
In this era of instant information, public reality is often driven and directed by social media and becomes skewed and no longer based in fact. We weren’t always this content with this variable in public health. If we look back over the past 20 years, we note that SARS occurred 17 years ago in 2003, while MERS occurred 8 years ago in 2012.
The impact of social media can be wonderful, but it can also fuel hysteria and panic. We didn’t have Twitter until 2006, and Instagram was only 2 years old, with 50 million users when MERS hit the scene. Now we have 330 million Twitter users and over 1 billion users on Instagram. The World Health Organization (WHO) Director-General Dr. Tedros Adhanom Ghebreyesus noted the impact of this when he said, “we’re not just fighting an epidemic; we’re fighting an infodemic.”
For accurate and timely data, Johns Hopkins offers an excellent site that pulls in global data into a graphical map of cases by country.
The flood of constant information, both accurate and inaccurate, is leading to disparate and fragmented infection prevention and control strategies and policies among health officials across the spectrum—including long-term care facilities that saw their first death this week. To combat junk science and hysteria, let us review the basics of infection prevention and control.
Basic Science of COVID-19 Infection Control and Prevention
Infection control and prevention can be summarized into two concepts well known to infection preventionists; these are the chain of infection and the hierarchy of controls. The chain is the pathway that a pathogen, in this case, COVID-19 or coronavirus, follows in causing respiratory illness and disease. There are steps or links in this chain, and infection prevention and infection preventionists target these links and attempt to break them.
The hierarchy of control is a systematic approach to controlling the outbreak of a special pathogen like COVID-19 or novel coronavirus. This model was developed by the National Institute for Occupational Safety and Health (NIOSH) and is known as “prevention through design.” This was originally designed for preventing illness and injury in all workplaces, including respiratory disease outbreak that can affect healthcare personnel and may appear as just a routine cough or sore throat. Reviewing and following these two straightforward yet complicated concepts brings a scientific approach to dealing with COVID-19.
The chain of infection begins with the infectious pathogen or agent that causes the disease, this pathogen then infects or inhabits a reservoir or host, the host has a portal of exit through which the pathogen passes to a susceptible host, a mode of transmission or the method through which the agent is transmitted and finally a portal of entry. So in the case of COVID-19, the agent is a novel coronavirus, the reservoir or host was originally an animal, and now it is infected humans. The portal of exit is respiratory secretions that are primarily coughed or sneezed out after some incubation period. The mode of transmission, to the best of our current knowledge, is through contact with the respiratory secretions of an infected person.
COVID-19 has been identified in multiple body fluids, but it appears at present that only those of a pulmonary source transmit the infection, but this remains uncertain. The portal of entry is through any mucous membrane that is in contact with the pathogen, typically the mouth or nose. The susceptible host is everyone on earth. As a novel coronavirus, COVID-19 exists in an environment in which no one has pre-existing immunity, and this makes it a truly global disease of concern.
The hierarchy of control and infection prevention design can be thought of as an inverted pyramid with the base of the pyramid flipped and placed at the top. Appearing first in this inverted pyramid is the most important element in the elimination of the pathogen. It is the most important because it is the most effective. The next element is substitution or ways to avoid contact or reduce the risk of contact through new methods or new ways to work. Then we have the engineering of the process of how we can create effective barriers between healthcare providers and the pathogen, think airborne infection isolation room.
Next is administration, or how people work around the pathogen, the algorithms and procedures that are followed, the training and policies that can prevent transmission. The last on the list is personal protective equipment (PPE). The idea being that PPE can further reduce or prevent transmission and infection, but the goal and hope is that the first four controls make this last resort unneeded. Some of the Elimination controls look to reduce the number of staff coming into contact with an infected patient, decreasing face to face contact through the use of telemedicine, cross-training of staff so fewer people come into contact with the infected patient, reducing clutter and nonessential items in the room that can’t be disinfected, and the handling of waste.
Some of the substitution controls look to reduce contact with the pathogen, and these can include disposable stethoscopes (single-use are the only ones that enable proper use of N95 masks), double gloves, and modified hand washing process are just a few. To succeed in controlling the spread of COVID-19, we must follow rational approaches based on sound scientific principals and avoid the irrationality of panic and fear. For those of us that are healthcare personnel, we need to be smart, wash our hands with proper hand hygiene, be educated and hope that when we need personal protective equipment, there is still some left.