Disinfectants and COVID-19; Transmitting Without Symptoms: It’s TTHealthWatch!

TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week. A transcript of the podcast is below the summary.

This week’s topics include the value of large scale interventions to reduce COVID-19, the impact on convalescent sera on COVID-19 infection, use of disinfectants and cleaners in households, and asymptomatic transmission of SARS-CoV-2.

Program notes:

0:40 Convalescent sera in treating COVID-19

1:40 Only 100 patients enrolled

2:43 Monoclonal antibodies being made

3:01 Impact of large scale anticontagion policies

4:01 These kinds of interventions keep number down

5:01 Keep below epidemic levels

6:01 Balance things economically

6:31 Asymptomatic COVID infection

7:31 May actually have mild symptoms

8:31 Don’t have longitudinal studies

8:51 Household cleaners and disinfectants and SARS-CoV-2

9:52 Application of bleach to food

10:51 Was in fact harmful

11:51 Hydroxychloroquine for post-exposure

12:46 End

Transcript:

Elizabeth Tracey: What’s the effect of large-scale anti-contagion policies on COVID-19?

Rick Lange, MD: How often do we say, “Asymptomatic COVID infection?”

Elizabeth: What do people know about safe practices regarding cleaning and disinfection for SARS-CoV-2 prevention?

Rick: Can people who recovered from COVID infection help those that have active infection?

Elizabeth: That’s what we’re talking about this week on TT HealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a Baltimore-based medical journalist.

Rick: I’m Rick Lange, President of Texas Tech University Health Sciences Center in El Paso, where I’m also Dean of the Paul L. Foster School of Medicine.

Elizabeth: Rick, I’d like to turn first to the Journal of the American Medical Association, this look at antibodies that are produced by people when they are convalescent from COVID-19 infection, and whether — I’m going to call it — harvesting those antibodies can help people who are currently infected.

Rick: Elizabeth, you summarized it well, and this is based upon studies that were done in the Spanish influenza in 1918, and even with SARS and MERS, where the suggestion that giving antibodies of people that have recovered from the infection and developed antibodies from it, giving it to people with active infection to see if we can help their recovery.

This is the first randomized trial to look at it. We’ve had some observational studies and this was conducted in Wuhan, China. It’s a little disappointing in that they planned to have 200 patients treated… that is to identify 200 people that recovered, harvest their antibodies in sufficient quantity, large numbers, and then give it to 200 individuals who were actively infected.

The unfortunate part was — I say that tongue in cheek — they had so few infections at the end of the study that they couldn’t complete it, so they only had 100 patients enroll. 50 were standardly treated and 50 received antibodies. What they discovered was that the 50 that received antibodies did not have a significant improvement.

Now, it was a small number of patients, but then they looked a little bit further. They looked at those that just had severe disease versus those that have life-threatening disease — life-threatening meaning they were in shock — and what they did discover is that the people that had severe disease did seem to receive a benefit.

Now, it’s a post-hoc analysis and it’s a small number of individuals, but it suggests that if convalescent serum is going to be effective, then it should probably be given in those individuals that had severe disease instead of waiting for a life-threatening disease.

The only other caveat about this was the average time from when patients had symptoms to when they received the antibodies was 30 days, so that’s pretty long. More to come because there are more studies in the works.

Elizabeth: Unquestionably, there’s lots of studies that are underway and I also saw a report that was really interesting that it’s possible to use cows to raise these antibodies so we don’t have to rely entirely upon volunteers coming forward and saying, “Sure, you can plasma freeze me.”

Rick: In the future, they’re making monoclonal antibodies, the part that is specific to the virus that can manufacture and attach it to it, so there are a number of those going on as well in terms of studies.

Elizabeth: I guess we’re going to wait and see what some of these other very large studies that are enrolling here in the US. Why don’t we go to Nature, a journal we don’t talk about very often? I thought this one was noteworthy and I’m going to reveal that this one is not peer-reviewed. But this is the effect of large-scale, anti-contagion policy, so what do governments and localities implement, and how have they impacted on COVID-19 infection.

All of these interventions are things — over 1,700 of them, by the way — such as travel restrictions, school closures, quarantine of positive cases, prohibiting large-scale things like concerts, and so forth, where people get together in very large numbers, across China, France, Iran, Italy, South Korea, and the US.

It uses statistical modeling. They estimate that these policies have prevented 62 million confirmed infections, or 530 million total infections, across the 6 countries. In a second study, they estimate that between 3% and 4% of the populations of 11 European countries have been infected with SARS-CoV-2.

They suggest that these kinds of interventions, especially lockdowns, have markedly kept the numbers down and suggest that continued interventions should be considered. This is in light of the fact that around the world everyone is reopening.

Rick: This is an interesting study because it used econometric methods. They knew what the growth was, as exponential growth, and then among over the 1,700 local, regional, and national policies were able to follow after that how that changed the growth curve, or reproducibility, of the viral infection. As you suggested, roughly an estimated 530 million total infections were averted.

Another article, and it has just to do with Europe, used a different method, but came to roughly similar conclusions in that these shutdowns saved approximately 3.1 million lives in 11 European countries and it dropped the average infection rate by about 82%. What these measures do is help drive the contagion below epidemic levels so we have the hospital resources, staff, and PPE to meet the needs of the infected individuals.

Elizabeth: I’m going to ask you to reflect personally on two things we talked about before we started to record, one that Texas’s rate of infection is increasing and many more infections are turning up there. How do you juxtapose — because we’ve talked before about — the economic impact, which is toxic also, of shutting down against this contagion?

Rick: There are now 13 states, as of this week, who have had an increase in number of cases — 13 states in the US — because they’ve relaxed some of their restrictions and that was inevitable. We’re not going to out chase this virus, it’s not going away, and the economic harms that you suggest by shutting down are real. It affects the individual. People lose their jobs, they lose their insurance, they can’t afford medications, they don’t have access to healthcare, and they become some of the most vulnerable individuals with regards to infection.

It’s balancing the knowledge that there will be some people that infected. You don’t want to overwhelm the hospital system so we can’t take care of those individuals. You still balance things economically so people are not losing their jobs, they do have access to healthcare, and they can afford to have medications. But no doubt about it, as we relax restrictions, the number of infections will increase.

Elizabeth: I guess I would just add that public health message, which is try to keep your distance, wash your hands, and wear your mask.

Rick: Yeah. One of the things is I think we’ve become more complacent in terms of these healthy measures the longer the infection goes on. What I’m trying to tell people is the health measures that you stressed, please don’t become complacent about.

Elizabeth: Let’s move on. It’s your next one and that’s from Annals of Internal Medicine.

Rick: It talks about the prevalence of asymptomatic COVID infection. It’s an interesting article because you’d like to say, “Well, give me a number, like how often does this occur?” But instead what they did was they reported on 16 different cohorts that talked about the infection rate and what percentage of those were asymptomatic.

The populations that they reported on were drastically different. One was as simple as over 13,000 patients that were surveyed in Iceland, just random individuals, and then some on cruise ships, or people that were incarcerated, or people in a nursing home. There is no way to combine all those into a single number, so I’ll talk about kind of general themes.

First of all, when we talk about asymptomatic infections, we have to realize that some of those are truly asymptomatic. The individual has the infection and they never developed symptoms. Some of the people who were reported as asymptomatic, it means they have an infection, but they haven’t developed symptoms yet. Those are presymptomatic. Then there are some individuals that we call asymptomatic that actually had symptoms. They are just mild symptoms, something as simple as fatigue or diarrhea.

Nevertheless, what they reported is that in some populations as many as 40% or 50% of the individuals that have COVID infection may, in fact, be asymptomatic. What percentage of those go on to develop symptoms?

In a nursing home facility, 90% of them went on to develop symptoms. That is they were presymptomatic. In individuals that were incarcerated, a younger population, only about 10% or 15% went on to develop symptoms.

One of the things that people have espoused is that, “Well, the people that are asymptomatic are less likely to spread infection.” These cohorts would suggest that that’s not the case. Being asymptomatic or presymptomatic does not mean that you’re less likely to pass it on to somebody else.

Elizabeth: That’s just such an important point with all this confusion about the WHO and their, I’m going to call it, misspeak regarding, “Hmm, maybe we don’t have to worry so much.” That was the take home for me anyway.

Rick: One of the reasons we have trouble really ascertaining the true prevalence of asymptomatic infection is we don’t have good longitudinal studies. You’d like to test somebody and then test them again two or three of four weeks later, and during that time find out whether they develop symptoms. But we really don’t have good longitudinal studies at this point. We hope to have some in the future, and when we do, we’ll report it to our listeners.

Elizabeth: No doubt. I can’t even imagine the wealth of retrospective analyses that are going to take place. We’ll be talking about it.

Finally, let’s turn to Morbidity and Mortality Weekly Report, a survey by the CDC that took a look at what do people know about disinfecting practices and what are they doing when it comes to safe household cleaning and disinfection for COVID-19 prevention.

This is what they call an opt-in Internet panel survey of 502 US adults, conducted in May, to ask people about their knowledge and practices regarding household cleaning and disinfection. This was secondary to a sharp increase in reports to the National Poison Control Centers regarding household cleaners and disinfectants. They said, “Okay, what are people doing? Let’s go out there and look.”

39% of the respondents reported engaging in non-recommended high-risk practices with the intention of preventing SARS-CoV-2 transmission. This included application of bleach to food items like fruits and vegetables — 19% of people did that — use of household cleaning and disinfectant products on hands and skin, 18% of these folks said they did that, misting their body with a cleaning or disinfectant spray, inhalation of vapors from these things, and drinking or gargling diluted bleach solution, soapy water, and other cleaning and disinfectant solutions. Of the number who engaged in these practices, 25% of them reported at least one adverse health effect regarding employing these kinds of practices in their home.

Rick: It’s an interesting study because one of the first questions they ask these individuals is, “Do you think you know how to properly and safely disinfect your home?” Specifically, “Do you know how to safely disinfect it against the COVID virus?” 80% of individuals said, “Oh, yeah. I got this. I know what to do.”

Then when they drill down, as you describe, what they were doing was not what was recommended and was in fact harmful. Proper hand hygiene, cleaning, and disinfecting high-touch surfaces is what’s recommended and not many of the practices that, Elizabeth, you already mentioned.

Elizabeth: I think it’s really kind of upsetting and concerning that people are employing these kinds of things. It reminds me of the couple in Arizona, who one of them died and one of them was harmed by ingesting a chloroquine-containing fish tank product.

Rick: Absolutely. By the way, Elizabeth, I’m going to just take a little tangent here for a second because you talked about hydroxychloroquine, and we reported on that earlier — and just to make our listeners aware — is that those studies have since been retracted because the data weren’t available for scrutiny. What I want our listeners to know is that we are aware that the studies we reported on have been retracted.

There has been a subsequent study just published, or available, in the New England Journal of Medicine that shows that when they used hydroxychloroquine for post-exposure prophylaxis — that is to prevent infection — it doesn’t appear to be helpful. That study has not been withdrawn. Those data right now look like they’re pretty sturdy, but the other ones have been.

Elizabeth: I guess we just need to mention, of course, that even today we talked about something that had not undergone peer review. There is an accelerated publication schedule for almost every one and that inevitably is going to result in some kinds of circumstances like this one.

Rick: These studies were peer-reviewed, but then they go back and say, “Okay, we reviewed this study, but let’s look at the baseline data. Let’s get really in the weeds.” That’s when they discovered they weren’t willing to share that information with the New England Journal of Medicine and with Lancet, so they said, “Well, if you won’t share with us, then we can’t validate the study. We’re pulling it.” Kudos to ’em.

Elizabeth: On that note, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.

Rick: I’m Rick Lange. Y’all listen up and make healthy choices.