Acute-Care Psychiatry During the Pandemic

in the early days of this century, I spent a lot of time in Avian Influenza Task Force meetings. I was on two separate task forces and at the same time working on an acute care inpatient psychiatric unit. One of the meetings took up four hours in the afternoon and I would have to go back to my unit and make up those four hours. I made the mistake of that not saving all the documentation from those meetings. There were hundreds of pages. The main focus of one task force was on “surge suppression” or helping with crowd control to prevent emergency departments from being overwhelmed by people who did not really have the viral infection. The other meeting was more about the actual response to the viral infection. I was always skeptical of what I heard. We kept hearing that if there was an epicenter of infection, large pallets of Tamiflu would be on the way. We saw presentations with pictures of those pallets under plastic wrap. At the same time there was discussion about morgues and refrigerated trucks that have become part of the current crisis.

I was more concerned about what would happen to inpatient psychiatry units. I kept hearing that the medical and surgical beds would be overwhelmed. When I suggested that we increase the capacity of negative airflow rooms and rooms vented directly to outside air, I was told that was impossible. One expert gave the opinion that if there is an airborne virus in the hospital: “The minute you walk into the hospital you should be wearing an N95 mask”.

That was about 2005 and I had never heard of an N95 mask before that. I had certainly worn masks for painting, dust protection, and various chemical and biological experiments that I did in the course of education and research. I went out and bought a small package of N95 masks. I fitted them per the instructions and noticed a couple of things. The fit was extremely snug due to upper and lower elastic bands (that have a much smaller circumference than a human head or neck), the circular contour of the mask providing a suction fit to some extent, and a flexible metal band that bends over the bridge of the nose to effectively seal that area. When you are wearing an N95 mask your voice is muted and you are breathing against resistance. If you wear it long enough, it becomes soaked with exhaled droplets. I rapidly concluded that it would be nearly impossible to conduct a psychiatric interview wearing this mask.

I never really learned at the time whether there was a plan to shut down inpatient psychiatry and use all the beds for avian influenza patients. Thankfully it never got to that point. Flashing forward 15 years a real pandemic is upon us and the problems remain unsolved. Inpatient psychiatric units and residential drug and alcohol treatment units are considered necessary services in most states and they remain open. Very recent information from the authorities now suggest that SARS-CoV-2, the virus causing COVID-19 is airborne and that there are a significant number of asymptomatic carriers.

I have been using telepsychiatry at this point for two weeks and it seems to be going well. There are definite constraints compared with face-to-face interviews. I have noticed more constraints since my original post on this topic. I put a couple of questions out there on social media today to see how my colleagues who are still actively engaged in acute care are adapting to the changing parameters of this pandemic. Before putting those questions out, I had the thought that telepsychiatry could be used over the short distances in inpatient settings. As a resident I had the experience of observing psychotherapy firsthand and being observed from adjacent rooms that also had microphones for communication between those rooms. I was interested in seeing whether or not anyone had implemented those solutions.  I was pleased with the feedback that I have so far.

One of the first responses was that psychiatric staff were using surgical facemasks and face shields in some settings. In other settings, adjacent rooms and telepsychiatry both on-site and off-site were being used for acute-care units. The most unique solution I heard of was a consultation liaison team using iPads to interview medical and surgical patients remotely where possible. That reminded me that some people have joined my telepsychiatry sessions using smart phone apps. It was generally very suboptimal if the phone was not completely stabilized.  I also had the experience this week of getting a link sent to me from a colleague who worked for a large healthcare system. It was an invitation to open up a video session with him even though I am not registered in his clinic.  It was very similar to a Zoom session that I did for a podcast. All this information shows that there are technologies available right now that are effective and actively being used. They have also been very rapidly deployed or are in the process of being deployed. There is some potential that this sudden change in the delivery of psychiatric services may be a more permanent one.

I asked the question about whether or not the services were saving personal protective equipment (PPE). The response to that question was somewhat mixed. I am not clear on what it means but speculate that some of the staff still need to have direct patient contact at some point during the day. Most acute-care staff at this point have been assigned PPE. The PPE specifics seem to vary from place to place but it is clearly rationed. If I was designing a survey of acute-care psychiatric facilities I would like to see the specifics of how many people had N95 masks and other kinds of protective gear.

Preadmission screening remains a question mark.  There is general agreement that there is an asymptomatic carrier state for SARS-CoV-2 (1,2).  Carriers may have a lower viral load and be partially symptomatic. Most people admitted to inpatient psychiatric units these days require intensive nursing care for their own safety. If there were environments where patients with COVID-19 could be safely segregated and treated that would be ideal, but I doubt those kinds of environments exist on inpatient psychiatric units. Even then the asymptomatic carriers would require the same psychosocial interventions as non-carriers.  The general screening done is to ask about contact with known cases and daily temperatures. I am not aware of any screening procedures that involve trying to identify the virus and carrier state.

My overriding concern is that medical and psychiatric staff everywhere have adequate protection. We have known since my days on the avian influenza task forces that airborne viruses are difficult to contain. They can infect through surface contamination, droplet contamination, and traveling on air currents. Working to cancel all those routes of infection is a tall order especially on an inpatient psychiatric unit.

The only practical way to maintain the level of communication necessary and minimize risk of infection is through some type of electronic communication. Some of the early methods have been listed in this post. Having worked in these settings for a large part of my adult life I am very concerned about the staff with daily direct patient contact including nursing, nursing assistants, and occupational therapy.  Housekeeping staff also have a vital role and are directly exposed to most contaminated surfaces. I have seen large numbers of inpatient staff come down with seasonal respiratory viruses and I know that vulnerability is there. They all need PPE. We need additional innovation in these settings to protect all staff and patients.  

And we have needed that innovation for a long time.

George Dawson, MD, DFAPA




References:


1: Lai CC, Liu YH, Wang CY, Wang YH, Hsueh SC, Yen MY, Ko WC, Hsueh PR. Asymptomatic carrier state, acute respiratory disease, and pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): Facts and myths. J Microbiol Immunol Infect. 2020 Mar 4. pii: S1684-1182(20)30040-2. doi: 10.1016/j.jmii.2020.02.012. [Epub ahead of print] Review. PubMed PMID: 32173241.

2: 1: Hu Z, Song C, Xu C, Jin G, Chen Y, Xu X, Ma H, Chen W, Lin Y, Zheng Y, Wang J,Hu Z, Yi Y, Shen H. Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China. Sci China Life Sci. 2020 Mar 4. doi: 10.1007/s11427-020-1661-4. [Epub ahead of print] PubMed PMID: 32146694.

Supplementary 1:

I am very interested in what you are doing at your facility to contain this virus while continuing to go to work every day and treat patients.  I am also very interested in whether you have enough PPE.  I am interested in hearing from everybody staff psychiatrists, residents, social workers, occupational therapists, nurses, nursing assistants, and housekeeping staff.  Please post in the comments section below and feel free to remain anonymous. 


Graphic Credit:

Shutterstock per their standard agreement.

New Twist On An Old Method To Kill The Flu Virus

Right after posting the previous article on the latest confirmation that influenza virus is airborne, I came across and article in Nature that had me thinking back to my childhood.  I remember walking into an insurance office on Main Street in our small town.  There was something strange about the environment.  Up next to the ceiling were ultraviolet lights.  The lights were shielded so that they only reflected up toward the ceiling.  I asked my parents what they were and got the answer: "They are there to kill germs."  My head was spinning from that answer: "There are germs in the air? They are up next to the ceiling? What kills the germs that are down here next to me?" Yes - I was a neurotic little kid.

Over time I learned a little about the nature of ultraviolet light, especially that it could cause eye damage if you looked right at it. As I got into the 1970s, the hippie era, and psychedelia that because less important.  There were UV lights everywhere - blacklight posters and the detergent residues in clothing phosphorescing white light after it has been activated by UV light.  In some environments everyone was bathed in UV light.

Today most Americans are aware of UV light because of sunscreen and eyeglass applications.  Long and medium wavelength (UVA and UVB) and not absorbed by the ozone layer.  It is recommended that glasses block 100% of the UVA and UVB for maximum eye protection.  That can also be designated as UV400 because they block all UV light from 280-400 nm.  The part of the UV spectrum is also important in sunscreens.  UVA penetrates the skin to a deeper level and is responsible for damaging keratinocytes, cataracts and causing premature aging.  UVB is responsible for burning and carcinogenesis.  UVA and UVB are considered both carcinogenic and carcinogenic.  Even those UV light has been known to be germicidal for over 80 years that human toxicity has limited the application.

UVC (100-280 nm) is blocked by the ozone layer and therefore is not a consideration in either eye or skin protection.  It is considered to be the part of the spectrum that is potentially germicidal and that is where the latest application begins.  In this report the authors used filtered 222-nm light sources in an experiment to see if they could inactivate aerosolized H1N1 influenza virus.  They were able to accurately measure the light dose and estimate virus inactivation using an epithelial cell model that measured infected cells by fluorescence.  The authors aerosolized the virus into a UV irradiation chamber.  The chamber had a total volume of 4.2 liters and had a characteristic particle distribution of 87% < 0.3 - 0.5 μm, 11% 0.5 - 0.7 μm, and 2% > 0.7 μm.  Those are characteristic particle distributions of airborne droplets that occur with breathing, talking, and coughing.

An air flow of 12.5 L/min through the chamber was noted and they calculated that this meant a single droplet passed through the chamber in about 20 seconds.  I think that is significant because it in unlikely in a typical building that a person would be standing in an air current moving that quickly. In other words, if the aerosolized virus can be inactivated in an airstream moving that quickly - it might have practical applications in most environments.  The authors were able to construct a dose response curve showing that at a dose of 2 mJ/cm² viral survival is negligible.

I found this to be extremely impressive work because it clearly shows that airborne influenza virus can be inactivated using a far-UV source that is much safer to humans than previous germicidal UV sources.  Furthermore the sampling and intervention characteristics seem to be very realistic in terms of what might be encountered in public facilities.  The real question seem to be whether any commercially available air cleaner/purifiers come close to matching the characteristic of this experiment.  A preliminary search of these devices shows that the airflow characteristics are typically not listed, very few use far-UVC light sources (most use germicidal 254-nm sources shielded in the device), and none are certified in terms of how much virus they kill. They typically suggest that germicidal UV light is all that is needed for air purification.  There is also the question of whether using a device in your office at work confers any degree of protection once you leave that office and start walking down the hallways.  My speculation is that it would not, but the amount of virus generated in your office may be a significant variable.

The authors themselves suggest that if their results are confirmed far-UVC represent a significant opportunity to limit the transmission of airborne disease and that it could be widely used in medical offices and buildings as well as public areas where disease transmission is common like airports and airplanes.

I am hoping that this areas of research yields rapid results and broad implementation.

George Dawson, MD, DFAPA 


Reference:

1:  David Welch, Manuela Buonanno, Veljko Grilj, Igor Shuryak, Connor Crickmore, Alan W. Bigelow, Gerhard Randers-Pehrson, Gary W. Johnson, David J. Brenner.  Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases.  Scientific Reportsvolume 8, Article number: 2752(2018).  doi:10.1038/s41598-018-21058-w

Graphics Credit:

Table 1, Figure 1, and Figure 2 are all used from reference 1 per the Creative Commons Attribution 4.0 International License.

Viruses Are In The Air - Protection From Airborne Viruses

Today was a good day.  I got up this morning and there on the morning news was a headline that I had been waiting to hear for at least 20 years.  There on CBS This Morning, Gail King was saying: "The flu can spread just by breathing so that is kind of scary."  That is kind of scary.  It is even scarier if you know that fact and listen to 20 years of how hand washing will prevent the flu. Hand washing is good only for surface contamination.  It does nothing for airborne viruses.  There is no known protection from airborne viruses other than biohazard environments.

I did not come by the knowledge easily.  Before medical school, I was a research assistance in a plant tissue culture lab.  Our job was to try to clone Loblolly Pine (Pinus taeda) and Douglas Fir (Pseudotsuga menziesii) trees from elite seed.  That required a sterile environment for tissue and media manipulations.  I spent much of the day working in a laminar flow hood bathed in sterile air.  We were not concerned at all about viruses at the time, but there were always experiments lost due to yeast and fungal contamination of the culture medium.  From there it was off to medical school and observations about just how contagious airborne viruses could be.  On some rotations the entire team was ill with respiratory infections.  I notice there is some movement today on telling physicians to stay home if they are sick.  If all of the people who were sick on one of these teams stayed home - there would be nobody there to take care of patients.  I did work with one attending physician who wore a surgical mask in a medicine clinic as a barrier to viruses.  Today we know that these masks are ineffective in blocking viruses.

The real eye opener came in practice.  For over 20 years I worked in an inpatient environment that was designed in the 1960s.  According to the HVAC experts I have consulted with, the environments in those days were designed to preserve heat.  They were not designed to provide fresh air in a manner that would minimize the risk of airborne virus infections.  All of the rooms in that environment had individual radiators equipped with fans.  The room air was recirculated.  At the top of each room was a 12" x 12" square vent that moved the air down  the length of the building to a few air shafts that traveled up and down between floors.  I was reassured that there was adequate air flow and that it was measured.  I was provided with some diagrams that did not really show any solid data.

In that environment, airborne viral infections ran rampant.  They were acute care psychiatric units - so many of the patients directly admitted had influenza.  It was just a matter of time before it was picked up by the staff and then transmitted from person to person.  Getting one or more of these infections predictably was quite depressing.  As anyone knows - a severe case of the flu disrupts your entire life.  The polypharmacy that the staff was subjected to was also impressive.  Long complicated courses of antibiotics for secondary infections after the flu had passed.  Exposure to prednisone and methylprednisolone for post-viral bronchitis and asthma exacerbations.  All of the infected staff were schooled in proper handwashing techniques by Infection Control.  During flu season we were basically adrift in tight confines - breathing contaminated air.  It is well documented by studies in hospital and other building environments that there are a significant amount of viral and other pathogens in the air that can be collected by a number of means (2).

The other enlightening experience involved my participation in two Avian Influenza task forces.  Practically all of the work that I saw being done seemed to ignore the issue of airborne spread.  That was probably at least in part due to the fact that the hospital capacity of negative air pressure rooms would be immediately overwhelmed.  At that point, I heard one expert say: "You need to have an N95 respirator mask on as soon as you walk through the door of the hospital."  The efficacy of those masks in preventing flu transmission is limited but probably offers some moral support when you are walking into an environment that is full of highly lethal influenza virus. Most of the planning done on the task forces seemed to be designed to prevent a large surge of patients going to the emergency department, providing psychological support to the overwhelmed, and hoping the military really did have that palette full of Tamiflu that they keep showing us in the PowerPoint presentations.

One of the questions I frequently get is - what about the vaccine?  Designing an effective flu vaccine is part science and part speculation.  It involves anticipating the viral strains of the next epidemic and that is difficult to know with certainty.  This is the first year that I can recall public health officials coming out with the actual numbers.  Most Americans have heard that this years vaccine is about 30% effective and that the most effective vaccines are 50-60% effective.  The argument is that the vaccine improves herd immunity and decreases the spread of the virus.  Exactly how much of that is cancelled out by broad exposure to an airborne virus is unknown, but I do think that is sufficient reason to always get the vaccination.  I was my own experiment for about 30 years.  I reacted to an anti-rabies duck embryo vaccine in my 20s and did not get the vaccine for the subsequent years.  I finally saw an allergist/immunologist about 7 years ago and have been getting the vaccine since.  Since then there has been no detectable change in the number or intensity of flu-like illnesses that I have developed.  During the time unvaccinated, I had the experience of developing an acute fever after being exposed to a colleague with the flu, taking Tamiflu (oseltamivir) and having the symptoms resolve within 24 hours.  There is a chance that a universal flu vaccine can be designed and I hope that is true.  In the meantime we are left dealing a number of airborne viruses and altering the environment seems like the best approach.   

Flashing forward to this morning.  Part of the story focused on Donald K. Milton and the work he did in designing a machine to sample flu viruses in a natural setting.  Other sampling techniques have typically involved subjects breathing according to protocol into a device.  The large reverse megaphone type of device that this group is using allows air flow past the face at a regular rate.  It allows research subjects to breath normally and sample their expired air for influenza virus.  The sample in this case was a group of healthy 19-21 year old college students with a high asthma prevalence (21%) and a low influenza vaccination rate.  Nasopharyngeal (NP) sampling and RNA detection was used to diagnose influenza and RNA copies.

The subjects were asked to breathe, talk, cough, and sneeze into the sampling device with no constraints on that activity.  They were asked to recite the alphabet at 5, 15, and 25 minutes.  Coarse droplets (> 5 μm ) and fine droplets (≤ 5 μm and >0.05 μm) were collected separately. Influenza virus was recovered from 89% (N=150) of the NP swabs and 39% (N=52) of the fine aerosol sample. This is positive proof that just breathing (tidal volume breathing) results in dispersing infectious viral particles into the air.  The influenza cases did not sneeze during the collection period. Viral shedding was greater for men.  Women coughed more frequently but shed significantly less virus per cough.  Increased BMI produced increased viral shedding in the fine aerosol and the speculation was that increased BMI causes a tendency for small airway collapse and that may lead to increased shear forces that produce the fine aerosol.  Since sneezing was not observed - it was not considered necessary to produce the fine or coarse aerosol.  Coughing was present and was a significant predictor of both coarse and fine aerosols.

 
This is a critical paper that I hope that all public health officials, administrators and architects will take note of.  It takes more than handwashing and coughing into your sleeve to protect people against influenza virus.  It takes recognition that this is an airborne virus and it is aerosolized by breathing.  Physicians are on the front lines when it comes to virus exposure and we need better barrier methods to prevent exposure.  During flu season I sit in a 8 x 10 foot office and talk with people who sit about 4-5 feet away from me.  I talk with most of them for 20-30 minutes or about the length of time of the experiment.  The symptoms listed in the severity scale below are incorporated into my review of systems and there are some days when 100% of the people I see have a respiratory infection.  If they all have influenza, 30% will leave aerosolized virus in my office just from talking with me.  Is there a better way to do things to minimize exposure?

I think it starts with building design.  Rooms that are all individually vented to the outdoors on both the intake and exhaust side.  Heat exchangers exist today and can be used for this purpose.  Starting with influenza as the model and optimizing air flow and humidity to decrease infection rates is a start.  Interviewing people across barriers or using television cameras is another possibility especially if vulnerable populations need to be protected from consultants who may be carriers. The tremendous lack of psychiatric infrastructure compounds the problem.  Although the building that I refer to was ultimately replaced and torn down - psychiatric services are typically housed in the oldest and most run down buildings.  Today jails have replaced psychiatric hospitals and the jail infrastructure is no better.  It is common to see patients who are acutely ill with influenza in these settings.  Psychiatric beds need to be in an environment that reduces the transmission of infectious diseases including airborne viruses.   

The work does not stop at that level.  The ways hospitals and buildings are cleaned needs to be thoroughly investigated.  Carpet and floor cleaning equipment clearly leads to the dispersion of particles in the carpeting or on the floor.  I am not aware of any initiative to make sure that cleaning the surfaces in buildings does not leave the air contaminated.

My advice is to spread the word and this reference to anyone who is unsure about airborne viruses. I am hopeful that at some point over the next 10-20 years the environmental aspects of the problem will be addressed.  That will change the nature of influenza transmission as well as a host of other viruses that get sampled in the HVAC systems of old buildings - probably long after the occupants have been infected by them.



George Dawson, MD, DFAPA


References:


1:  Yan J, Grantham M, Pantelic J, Bueno de Mesquita PJ, Albert B, Liu F, Ehrman S, Milton DK; EMIT Consortium. Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community. Proc Natl Acad Sci U S A. 2018 Jan 30;115(5):1081-1086. doi: 10.1073/pnas.1716561115. Epub 2018 Jan 18. PubMed PMID: 29348203; PubMed Central PMCID: PMC5798362

2:  Airborne Virus Monitoring: unedited search



Supplementary:

Image at the top uses a crowd infographic from Shutterstock per their licensing agreement.

Supplementary 2:

This is the approach the authors used to scoring the flu symptoms severity in their paper (my interpretation) (click to enlarge):

Is It Time To Quarantine Air Travelers?

My wife and I just got back from Alaska on August 10, 2015 and within a few days became progressively symptomatic with an influenza-like illness that appears to be peaking today on day 5.  I know exactly how we were infected.  There were several ill passengers, particularly in close proximity who had not mastered coughing into the crook of the arm and who were actually coughing and sneezing over the top of the arm.  The plane was packed as usual.  We had paid an extra $100 to be able to sit in "economy comfort class".  In fairness there was about an extra 4 inches between my knees and the back of the seat in front of me (and I m 5'10'' on a good day).  Even that could not make up for the severe ergonomic problems of airplane seating.  I would quickly describe those as a lack of upright, even in the upright position.  Upright is at least 15-20 degrees from upright and over the course of a 5 hour flight that can create quite a bit of pain in anyone with a back problem.  This problem has been studied to some extent as evidenced by bullet point 3 on this web page.  The economy comfort class also comes with free alcoholic beverages, and I saw one passenger who was clearly uncomfortable rapidly down 4 drinks.  The other ergonomic problem is an ill defined seat.  It felt like sitting on 5 or 6 tennis balls all the way.

But back to the focus on viruses.  From discussing the problem with friends and family it is almost a universal experience that people get viral illnesses on their flight back from a recreational or work destination.

When I boarded a cruise ship recently I was screened for GI symptoms and asked if I had any recent illnesses as part of the check-in procedure.  That did not happen at any point when I got on either of the direct flight to or from Minneapolis.  In addition to the screening procedures there was hand sanitizer being actively and passively dispensed throughout the ship and on the ships TV channel the following message played continuously on a 24/7 basis:

Please wash your hands often and use the sanitizer stations provided throughout the ship especially when you are coming from ashore.  Always use a fresh cup when using beverage dispensers and refrain from using personal containers directly or on common beverage stations.  To stay healthy wash your hands with soap and warm water frequently.

 In comparing respiratory infections from air travel to Norovirus infections on cruise ships there are important differences.  The Norovirus infections occur in a well defined captive population in  very specific time period.  If an outbreak occurs it can become widely known, to the public relations detriment of that cruise line.  If a respiratory virus is contracted on a flight, everyone leaves the plane after arrival in a few hours and the total number of people infected is unknown.  There have been studies that look at the attack rates of people who have been on a flight where there is an index case of influenza and also the effects of using masks prophylactically when there are known index cases onboard.  There are no cautions to the passengers about how to prevent the spread of respiratory infections and (to my knowledge) no easy way for them to cancel in the event that they develop an acute upper respiratory in infection.  The CDC has some limited guidance on air travel, including some information on influenza transmission cabin air conditioning including the fact that it is partially recirculated and HEPA filtered 15-20 times per hour.  The most interesting study in microbial diversity in commercial aircraft that I could find was by Osman, et al (1) who compared conventional culture techniques to available molecular probes in 2008 in samples from 16 domestic and international flights.  They conclude that the molecular probe techniques demonstrated a much greater microbial diversity than culture techniques and that microbes varied significantly from domestic to international flights.  The molecular probe techniques identified 12 classes and 100 species of bacteria in cabin air, but in sufficiently low concentrations to not present a health hazard.  I am aware of studies in the past that have done viral cultures for respiratory viruses on filters in buildings but could not find similar data for commercial aircraft.  There have already been simulations about what happens when a person sneezes on an commercial aircraft, and those results are eye-opening.  I posted that in a look at the issue of hand washing and respiratory viruses.

Rather than go into excessive detail about the limited research that has been done so far, let me summarize a few facts and my conclusions.  Respiratory viruses can be transmitted during commercial air travel.  The attack rate for influenza virus has been estimated to be 2 - 4%.  There has been at least one study that shows masks can prevent infection.  There have been several simulations of how air travel potentially increases the world wide spread of airborne viral infections and some of these infections like corona virus and SARS outbreaks puts a significant burden on the international public health community.  Furthermore, the public health burden in terms of both morbidity and mortality is huge.  Influenza virus alone kills about 20,000 people annually in the United States or the equivalent of 5 large cruise ships in terms of total lives.  By comparison, there if far more press coverage of a Norovirus outbreak on a cruise ship and that virus is much less fatal.  Every American contracts about 2 - 3 respiratory viruses per year of varying severity.  That probably amounts to about 2-6 weeks of illness per year, associated with a disruption of work and daily activities as well as increased infection risk for those in the sphere of that person's routine.  There is also a risk for exacerbation of chronic illnesses like asthma and chronic obstructive pulmonary disease.

All of these considerations lead me to suggest (at the minimum) - the following measures:

1.  Intensification of study of airborne diseases especially respiratory viruses:  The technology is certainly there and there is no reason that molecular technologies cannot be applied to samples from commercial aircraft and I think that the HEPA filters are a logical place to start.  I would really like to see this become a focus of a private research fund, because it seems like the federal government has created numerous monitoring systems but no practical ways to detect high risk scenarios and disrupt disease transmission.  It seems like that is likely to occur only after an outbreak of a highly fatal respiratory virus occurs.

2.  Passenger education is critical:  The airline industry needs to adopt the methodologies that are currently employed in the cruise industry - educating everyone on the plane, screening for passengers at risk and quarantining them if necessary.  A critical piece of the education process is that while hand washing is necessary, it is not sufficient to prevent the spread of airborne respiratory viruses.  That public needs more awareness of that concept and what else can be done.  The method of quarantine is debatable and would probably need some flexibility based on passenger needs and acceptability and the severity of the problem.  It could include grounding until the infection clears, use of masks to block airborne infection, or possibly a section of the passenger cabin with more intensive HEPA filtering (altering air flow and humidity can affect the likelihood of virus transmission).

3.  Developing a culture to reduce the risk of respiratory virus infection:  Everywhere that I look we have practices in place that encourage the transmission of respiratory viruses.  Most Americans do not let respiratory viruses stop them from carrying on their business as usual.  In the past few days, I have personally walked through clouds of sneezed droplets because I happened to be following a fellow customer or coworker too closely at the wrong time.  I can't recall exactly when it happened, but getting rid of sick and vacation time and replacing it with paid time off or PTO days is an incentive for going to work sick.  Most of that sickness is respiratory viruses.

The American attitude to the common cold is far too casual.  It does not take into account the spectrum of symptom severity and the fact that many of these viruses can cause influenza-like illnesses and very severe syndromes.  Even a cold of moderate severity generally curtails a lot of activities and produces significant morbidity.  I don't understand how the medical and consumer community has come to this level of acceptance and denial of this collection of more-than-just-a-nuisance pathogens, but I would like to see it stop.

The American attitude toward the bad ergonomics of airline seating is another issue.  I think it is unfortunate that most passengers these days have never flown on a 747.  I may be overidealizing the flying of my youth, but planes today seem like dismal narrow aluminum tubes by comparison.



George Dawson, MD, DFAPA



References:

1: Osman S, La Duc MT, Dekas A, Newcombe D, Venkateswaran K. Microbial burden and diversity of commercial airline cabin air during short and long durations of travel. ISME J. 2008 May;2(5):482-97. doi: 10.1038/ismej.2008.11. Epub 2008 Feb 7. PubMed PMID: 18256704.

Supplementary 1:

For a graph of the URI I contracted on the Alaska vacation and most likely on the flight home follow this link.


Attribution:

The graphic at the top of the blog is directly from the CDC and one of their pages on Middle East Respiratory Virus Coronavirus.  Photographic credit is given to Jennifer L. Harcourt.  The picture depicts coronavirus particles in the cytoplasm of an infected cell.

Hand Washing

I washed my hands 40 times yesterday and used disinfectant hand cleaner at least 10 times when I did not have immediate access to water and soap.   My hand washing technique was validated by  an infection control nurse who was trained to monitor appropriate hand washing.   I also wiped down the table in my office and the chair about 3 times with disinfectant wipes.  I am careful not to touch my food or my face.  I have an air cleaner running in that office from about 8AM to 6PM that has a UV lamp designed to kill viruses.  Despite all of that I am in day #5 of a flu-like illness (cough, myalgias, fatigue, but no fever).

I don't have obsessive compulsive disorder.  I live in Minnesota and it is peak season for the annual influenza epidemic.  I actually take more precautions.  During flu season, I avoid the public.  I used to belong to a gym, but set up my basement so I could do my workout routine at home.  Exercise equipment is a known reservoir of viruses and bacteria.  I have also been in a gym when it sounded more like a hospital ward due to the hacking and coughing.  I avoid movie theaters for the same reason.  I have been doing these same rituals for the past twenty years, initially because I thought I was allergic to influenza vaccine and did not want to catch the flu.  I have been fairly  successful in avoiding the flu, but not so successful in avoiding practically every other respiratory virus.  For twenty three years I worked in an old building that was designed to contain heat rather than clear respiratory viruses.  In that environment, once a virus is introduced there is a predictable epidemic (sometimes within a few days) affecting the entire staff.   Modern employment disincentives (the finite paid time off with no sick time system) keeps all of the ill people working.  They would rather work than lose vacation time.  That keeps the epidemic going.

 Throughout the flu season people at risk are told the same things.  Wash your hands, cough into your sleeve, stay at home if your are ill and get the flu shot.  Unfortunately all of these measures is not enough to prevent infection by airborne viruses.  Face masks help.  A study of college dormitory dwellers showed that hand washing and wearing a mask only offered modest protection against influenza like illness relative to a control group.  They used the term modest, but I would call about a 10% difference in infection rates weak at best.  In their study they looked at three groups of students in college dormitories.  The groups and the attack rates of flu-like illness (FLI) included controls (no intervention) 117/552, face mask only 99/378, and face mask and hand hygiene 92/367.   The authors tried to control as many measures as possible but there are a lot of reasons why experimenting on college students is problematic.  In terms of the basic methods hand washing or use of hand disinfectants is considered to have a small but significant effect on the transmission of respiratory viruses.  The effectiveness of masks depends on the fit of the mask, the physical characteristics of the environment and the virus itself.  One study (4) showed that a tightly sealed N95 respiratory mask would block 94.8% of influenza virus and a poorly fitting mask blocked only 56.6% of the virus.  

The process of creating infectious droplets is an interesting physical process.  There are  current estimates that show normal breathing for 5 minutes creates a few droplets through the process of atomization.  A single strong nasal expiration results in a few hundreds droplets with a few in the 1-2 µm in diameter.  Counting loudly creates a few hundred droplets in the 1-2 µm range.  A single cough produces a few thousand and a single sneeze produces a few hundred thousands to a few million 1-2 µm droplets that can contain viral particles.  There is a a video of what happens to those millions of sneeze generated particle in an airplane.  It might be a good place to wear a mask but that assumes that you have it on before the sneeze.  Atomization can also occur from vomit (10⁷ viral particles per ml) and feces (10¹² viral particles per gram).   Those routes of transmission have been important for SARS and Norwalk Like Viruses.

The most recent estimate of costs due to building influenced communicable respiratory infections was about $10 billion in direct treatment costs and indirect costs of $19 billion in lost productivity and $3 billion in performance losses.  Asthma is significantly affected and possibly caused by airborne respiratory viruses and that is another $18 billion in costs ($10 billion direct and $8 billion indirect).  My interest has been in trying to promote more attention to the problem especially at the environmental levels.  Just altering airflow characteristics or making other changes in the humidity and air temperature can reduce the infectivity rates by as much as 50%.  Apart from the cost, it has an immeasurable effect on employee morale.  It is difficult for anyone to work knowing that at least one month out of the year they will have significant symptoms of a respiratory syndrome.

Why did I post this and in particular on a psychiatry blog?  In my 23 years of inpatient experience, respiratory viruses plagued the staff and the patients we were treating.  Any attempt I made to change that from a non-medical environmental perspective was met with no response.  I think that is the standard response of our culture and most employers.  Mental health settings tend to be located in older buildings and older parts of health care campuses and respiratory viruses is likely a bigger problem.  Health care settings should be leaders in developing environments and infrastructure that is hardened for the airborne respiratory virus problem.  It is imperative as a healthy environment for workers and patients and it provides reserve capacity in the event of a more widespread pandemic.  I have also made some observations about the impact of FLI on psychiatric symptomatology - both improvements and worsening.  There is a increasing literature on the effect of cytokine signaling on brain function and I suspect that is what I was seeing, but more research is needed.    

In the meantime, keep washing your hands.  Keep in mind that this post is only about airborne infections.  Any physician with direct contact with patients needs to wash their hands after seeing a patient and before seeing the next patient.  Most hospitals have a rule that hand washing needs to occur every time a physician enters or leaves a room.   For airborne respiratory viruses, it is not enough but it decreases the risk of respiratory infections to a slight degree.  My guess is that the more highly infectious airborne viruses are much less containable with hand washing and that environmental measures involving airflow, relative humidity, and possibly filtration and UV sterilization is what is required.  Anyone planning new construction should focus on these measures and obtain appropriate heating and air conditioning consultation with an emphasis on reducing respiratory infections.


George Dawson, MD, DFAPA

References:


1:  Aiello AE, Murray GF, Perez V, Coulborn RM, Davis BM, Uddin M, Shay DK,Waterman SH, Monto AS. Mask use, hand hygiene, and seasonal influenza-like illness among young adults: a randomized intervention trial. J Infect Dis. 2010 Feb 15;201(4):491-8. doi: 10.1086/650396. PubMed PMID: 20088690.

2: Verreault D, Moineau S, Duchaine C. Methods for sampling of airborne viruses. Microbiol Mol Biol Rev. 2008 Sep;72(3):413-44. doi: 10.1128/MMBR.00002-08. Review. PubMed PMID: 18772283; PubMed Central PMCID: PMC2546863.

3: Morawska L. Droplet fate in indoor environments, or can we prevent the spread of infection? Indoor Air. 2006 Oct;16(5):335-47. Review. PubMed PMID: 16948710.

4: Noti JD, Lindsley WG, Blachere FM, Cao G, Kashon ML, Thewlis RE, McMillen CM, King WP, Szalajda JV, Beezhold DH. Detection of infectious influenza virus in cough aerosols generated in a simulated patient examination room. Clin Infect Dis. 2012 Jun;54(11):1569-77. doi: 10.1093/cid/cis237. Epub 2012 Mar 29. PubMed PMID: 22460981.

5. ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) ASHRAE Position Document on Airborne Infectious Diseases Approved by ASHRAE Board of Directors January 19, 2014 Expires January 19, 2017.  - This is an interesting approach that looks at how to look at engineering approaches to airborne infectious particles and come up with a better approach.

Supplementary 1:  Various inhalers used over the past year following a probable rhinovirus exacerbation of asthma in January of 2013.  This is a rapid way to meet your annual deductible.

Supplementary 2:  Graphic of pathogens detected per week is from the Minnesota Department of Health web site.