In an initiative that should complement the efforts of infection preventionists (IPs), the Centers for Disease Control and Prevention (CDC) has launched on online interactive training network on infection control aimed at both frontline healthcare workers and other personnel.

“Project Firstline [is] a comprehensive infection control program designed to help prevent the spread of infectious diseases in U.S. healthcare settings,” according to the CDC website.1 “Project Firstline will reach healthcare workers in all healthcare settings, including hospitals, outpatient clinics, dialysis centers, and nursing homes. Core training is posted to address immediate workforce infection control training needs, delivered via short and accessible training videos. The site also includes practical tools to support everyone working in a healthcare facility as they implement infection control protocols and procedures throughout their workday.”

In addition to supporting the efforts of IPs nationally, the training should help to clarify and reinforce CDC guidelines on COVID-19 and other infectious threats.

“It is exciting to see, because this content and information will go a long way to support and emphasize infection prevention across the continuum,” says Connie Steed, MSN, RN, CIC, FAPIC, president of the Association for Professionals in Infection Control and Epidemiology (APIC). “Their focus is on frontline providers and staff, and I think that this is long overdue, quite honestly. It’s hard and challenging, many times, to grasp the rationale of basic IP prevention practices.”

The educational materials are designed to be concise 10-minute videos that do not require a certain level of training or educational background to understand. There are interactive features through periodic “knowledge checks” during training.

“If you look at what they have online, they have a general one on hand hygiene, and then their focus right now is long-term care and dialysis,” says Steed, director of infection prevention and control at Prisma Health in Greenville, SC. “I think that, in the future, they will get into some other topics. Right now, their focus is on COVID and the basics of hand hygiene and things like that. If you look at the dialysis links, they put a lot of other things in there besides COVID — like central-line infection reduction — and they made sure that that material is available via easy links.”

Steed has shared the training on long-term care and dialysis with those units in her facility.

“I see them using it as support and validation for what needs to be done,” she said. “These short videos are excellent. They can be used at a staff meeting and are accessible from any computer. In my organization, we have a long-term care facility IP and director of nursing who already have the [site] access and the information. We have dialysis units and the information is being shared with them. I see IPs using this to help strengthen the messaging and the work that is being done at the frontlines.

The CDC established a coalition of healthcare and academic partners, as well as 64 state and local health departments and labs. Although the site already is online, a training session called “COVID-19 and Infection Control: The Basics,” was expected to be released in mid-November.

Mike Bell, MD, deputy director of the CDC’s division of Healthcare Quality Promotion, recently gave a preview of this topic in a webinar session hosted by one of the project’s sponsors, the American Medical Association. Bell fielded questions on COVID-19 from clinicians. Some of his answers are included here and have been edited for length and content.

90% of Americans Susceptible

Question: Can you comment on droplet and airborne transmission of COVID-19?

Bell: We generate much more than big droplets when speaking and talking — and we are learning more and more about singing and shouting. We generate a wide range of small and big droplets. Many of those small droplets can float around for minutes. That is not the same with tuberculosis and measles, which can float around for hours and stay infectious. But even with something like COVID-19, [with] those small droplets that float around, minutes is long enough if I am face-to-face, within about six feet, for me to inhale something. It is probably a spectrum of exposure that includes a little bit of direct splashing, but also a bit of near-range inhalation. This is something you can’t tease apart just by the epidemiologic data. When something is transmitted like measles, then an entire building will become at least seropositive or actively sick.

With these respiratory viruses, like the original SARS [severe acute respiratory syndrome], MERS [Middle East respiratory syndrome], and SARS-CoV-2, there’s another factor that I want to underscore about how to think about transmission: That is that we don’t have an effective viral treatment and we don’t have a vaccine yet. That means that there [is] a larger portion of people who could become very sick without resource to any very easy treatment. Also, the number of people who are still susceptible — we have seroprevalence even from heavily affected locations of about 5% — which means over 90% of Americans are still susceptible.

What that means for our hospital systems and those of you who are actually manning the frontline in acute care centers, emergency departments, and ICUs [intensive care units] — you are seeing that our healthcare system is already very stretched. So, we take more precautions when it comes to recommending respiratory protection, for example, for those types of infections where we don’t have a safety net.

[In contrast], for seasonal flu, we tend to have residual population immunity, we have vaccines that vary in effectiveness, and also antiviral treatment. There is not much likelihood of seasonal flu absolutely stopping our health system or affecting huge numbers of people and not allowing us to take care of them. I wanted to give you that background of how we are thinking about this. This isn’t a black and white, cut and dried, “We’ve changed our mind,” kind of situation. This is an evolution of understanding. When something can be severe and untreatable, we are concerned. If you go back to these very concerning outbreaks, we are consistently recommending the use of something like a respirator when you are taking care of somebody who is infectious. That is because there is the possibility of inhalation with close range.

Question: Going from distance to time, is there any validity to limiting time spent in the rooms of these patients to minimize the likelihood of transmission?

Bell: Absolutely. The risk of infection is a combination of how much infectious material is being generated — this is a reflection of whether the individual who is ill is manifesting symptoms. We have data that some people are able to generate a lot more droplets and aerosols even when they are speaking quietly — not even from coughing. We have all seen the range of sneeze and cough behaviors. That’s one factor — people generating a lot of [viral] material. Related to that is the pathophysiology of the infected individual themselves. Is there a large enough infectious virus being generated — are they making a lot and projecting a lot. That’s the source piece.

The environment piece is the second step. Are you in a very ventilated outdoor location or are you in a small space with very little air exchange? Those are the two extremes. In the former, the risk is much lower; in the latter category, the risk is much higher. What we are seeing is that in enclosed places with poor air exchange, we are much more likely to see transmission from cases to multiple individuals. The examples we have seen so far include exercise classes that were in small, not well-ventilated locations, where one person who was shouting and breathing hard during exercise managed to infect a large proportion of people in that small space. We don’t see that systematically, but we do when the conditions are right. Similarly, in a choir practice — we have seen this in a couple of examples now — places without great air exchange, somebody who is aggressively generating aerosols by singing was able to infect a large number [of people who] were nearby. So, the environment you’re in is the second factor.

The third factor is what sort of mitigation actions are being taken. If the patient who is the source is wearing a mask, that vastly reduces the efficiency of [viral] release. Also, if you are wearing a mask — even if it is not a fit-tested N95 respirator — there is some effect. We are starting to see data that goes from really great [protection] with a respirator to something like 40% to 50% with surgical masks. There is some benefit to wearing protection as well as keeping from exposing others to your own secretions. There are other factors, like inherent susceptibility based on your genetic makeup, but those are the factors that I think about.

With these in mind, the time that you spend in that context is also related to your likelihood of receiving enough of a dose to initiate an infection. The longer you are in that exposed setting, the more likely you are to be infected. We use the number 15 minutes, and this was originally proposed as a 15-minute [exposure] time. There is this question now — and we will be saying more about this in the coming weeks — that is related to an outbreak that occurred at a prison setting. What we saw there was a relationship with time, but it wasn’t just once. It was cumulative. It makes sense that cumulative series of exposures to shorter periods would add up to be a greater risk. It’s not as if you breathe for 14.99 minutes and only once you cross that threshold you become infected — that’s not how it works So sequential exposures — basically, if you think about it from a probability perspective — if you are spending two minutes with eight patients, there is possibility that one of those people [is] going to be shedding coronavirus and you might be unlucky enough to be infected in that two-minute segment. So, a lot of segments are probably as bad as having one big one.

Fomites and Respirators

Question: Is there still concern about transmission from fomites?

Bell: In the beginning of this outbreak, we paid a lot of attention to surfaces and contaminated equipment — we still think it is important. The virologic evidence shows that COVID-19 can actually persist and be infectious for many minutes; in some cases, hours or longer. So that is true. On the other hand, if we think about what needs to happen for a surface contamination source to create a risk in terms of catching a respiratory virus, you would really need to pick that up and inoculate your eyes, nose, or mouth. We are not seeing anything like hantaviruses — where we know that sweeping or aerosol generation by hosing out the back of a truck [could be infectious]. We are not seeing examples of that kind of transmission. We believe it is possible if you touch a surface, don’t clean your hands and rub your eyes, nose, or mouth you could self-inoculate. And frankly, because there are so many things that are transmitted that way as well and we really don’t want to be picking up other cold viruses or anything else right now. So, breaking the transmission chain from the surface to your face is really all about common sense things — hand hygiene, proper glove removal. If you see colleagues wearing gloves and not taking them off afterward, that is an escalation of risk. They can touch their faces and contaminate surfaces around them and put other healthcare workers and patients at risk.

Question: What are the current recommendations for masks and respirators?

Bell: There are certain things where you should always be using an N95, assuming you have them. Full disclosure: We are painfully aware of the supply chain challenges that many of the facilities are experiencing. This is a very frustrating situation in the context of something like the COVID pandemic. There are currently recommendations that say if for any reason you are not able to use respirators in a single-use disposal kind of way, we have available crisis standards that are not intended to be normal practice. But if you are up against the wall and you are needing to do something, we have suggestions for how to extend the use of respirators. In other words, [keeping] them on and going from patient to patient, or if you are absolutely out, using surgical masks as a temporary alternative. They are not as good, but they are definitely better than nothing. We have some of those crisis recommendations on our website.2,3

Getting back to the current recommendations, we do recommend N95 respirators or powered air purifying respirators, elastomerics — whatever you are using and are fit-testing — for any aerosol-generating procedures like bronchoscopies, induced sputum, and that kind of thing. In addition, if you are taking care of a patient that you think or know has COVID, then we recommend an N95 respirator in addition to eye protection. That having been said, surgical masks for routine patient care when you don’t think the person has COVID-19 are fine. If you are in a place where the community incidence has been high or the prevalence is high, then we recommend using eye protection as well, just because you are likely to bump into somebody who is not symptomatic yet but could be infectious.


  1. Centers for Disease Control and Prevention. Project Firstline. Aug. 10, 2020.
  2. Centers for Disease Control and Prevention. Strategies for optimizing the supply of N95 respirators. Updated June 28, 2020.
  3. Centers for Disease Control and Prevention. Strategies for optimizing the supply of facemasks. Updated June 28, 2020.