Lance writes:

I’m still a week behind on TWiV at the moment, but I heard Dixon suggest that someone from the UK who was interested in helping should contact the London School of Hygiene & Tropical Medicine.

In fact the UK register of volunteers is being held at the Liverpool School of Tropical Medicine and can be accessed here:

This is also accessible through the UK International Emergency Medical Register here:—page-under.html

Note there is also a specific request for NON healthcare workers – people with skills in logistics, sanitation, management, communications, etc.

Keep up the good work


Dr Lance Turtle
NIHR clinical lecturer in infectious diseases
Institute of Infection and Global Health
University of Liverpool

Jacki writes:

Dear Vincent and the TWiV team,

I should start by thanking you so much for all that you do to make TWiV possible. The world is a better place for having your podcast in it and I have been a longtime fan. I was really pleased to see…well, “hear” that you had Jeff Shaman on to talk about the epidemiological dimensions of the outbreak! This was a great episode!

I am a medical anthropologist at the American Museum of Natural History, although I concentrated on virology in my undergraduate and postbacc and originally planned to become a virologist focusing on VHF, particularly Ebola, a disease I became interested in while living in East Africa in the mid 2000s. However, my time there also underscored that viral outbreaks like this are indeed, sociological problems as much as they are microbial and epidemiological, and I transitioned into medical anthropology.

I was struck by the quote from an episode several weeks ago when either you or Alan indicated that for a VHF epidemic to get to the point that this many people are becoming infected, we have to acknowledge that are social dimensions rather than some remarkable pathogenicity that makes this possible. “This is a sociological problem.” I have this quote on my wall now, with a #twiv hashtag next to it.

I am writing to let you know about a webinar organized by the American Anthropological Association that I am participating in on tomorrow afternoon about the role of anthropology in the current Ebola epidemic. The information on the webinar can be found here:
It is live streaming at 1 PM and people can post their questions to the feed and on Twitter, but it will be archived on Youtube after this. One of the questions that the panelists are discussing ahead of tomorrow are the ethical implications of Liberia as a “living lab” for virologists and epidemiologists if Ebola does indeed become (or is perceived as becoming) endemic in the region. I would love to hear your perspective on this.

I thought you or your listeners might find this web-event interesting. I would also be keen to talk to you more about how social, biological and medical scientists can better work together on viral epidemics— in terms of coordinating more accurate media coverage, working to assist affected communities with more comprehensive and contexually-appropriate responses, and to advocate for greater and more multidisciplinary research funding from NSF and other funding bodies. My current work is a media tone analysis of how proximity of perceived threat translates into coverage that veers toward ‘alarmist’ or ‘comforting’/‘othering’ media messages. I am interested in making this work more accessible to virologists (who I still consider ‘my people’ too!) because much of this work looks at how the lab work is translated to the public and impacts political capital downstream, which I think is the other half of the “sociological” cycle you identify in an early episode. There is a poor grasp across all sectors of the role of structural violence and colonial and war histories in these places and this understanding is crucial for understanding why there is much resistance to public health interventions from the West. The findings that are generated from the lab and collected in the field are being disseminated into media that are context-poor when it comes to West Africans and their lives both before and during this epidemic. A deeper understanding of the in situ can only help the folks in the lab and a demystification of the lab can only help social scientists in their efforts.

I am also noting a strong de-emphasis on the ‘hemorrhagic’ aspect of how Ebola is discussed in public spheres with this outbreak, in contrast to the wave of outbreaks in the mid 1990s or the mid 2000s and I am beginning to assess how and why this is happening. My hypothesis is that this outbreak has been perceived as having “pandemic potential” in a way that other VHF outbreaks have not had beyond the “worst case scenario” speculation and so the more extreme/extraordinary symptoms are being de-emphasized to reduce the potential for generating a grassroots panic, which would be epidemiologically detrimental. It is hard to assess all of this in the midst of an outbreak, of course, but I am setting the methodologies in place to study these phenomena over the coming months.

Vincent, I know you are just over at Columbia— I am not sure if you already know anyone over here at AMNH, but if you haven’t gotten the behind the scenes tour here, I’d be thrilled to welcome you here sometime or head up your way, if you had some time to talk about some of this further!

Thanks again for all that you do to make virology more accessible to the public!

Kind regards,

Jacklyn Lacey
Curatorial Associate, African and Pacific Ethnology
Division of Anthropology
American Museum of Natural History
New York, New York 10024

Daniel writes:

Dear Dr Racaniello, Dr Despommier, Dr Dove, and Dr Spindler,

After listening to a number of those parasitism podcasts I thought I might try introducing a bit of TWIV, ‘A netcast about viruses – the kind that make you sick’ into my commute. I am a clinician and researcher splitting my time between clinical care of patients with infectious diseases and medical research. I jumped right into your podcasts that discussed EBOLA and have found them very edutaining. Last Fall I delivered a lecture on Chikungunya and one on Ebola to an audience of clinicians and we all discussed this week how my lectures on topics considered esoteric for clinicians here in the states have now become relevant.

As I may head to West Africa, likely Sierra Leone, next month for a period of time to assist with the current outbreak I have been listening to your recent discussions more than just academic interest. You are all doing an excellent job and I hoped just to make a comment in this email.

-Listening to the beginning of the Borna podcast I had a bit of an emotional reaction to your discussion about how airborne is defined in the literature. Now perhaps it was just the caffeine from my double Latte hitting the blood stream but in case it was not, I did want to comment. When one refers to ‘The Literature’ I usually need to ask myself who the speaker is and to what literature they are referring. If it be my wife this might be to those things written by Jane Austen and the like. For my kids it might be the Percy Jackson genre or something featuring Harry Potter. Being one trying to converse in the parlance of clinicians and of basic scientists, I find that ‘the literature of the clinician’ and ‘the literature of the researcher’ may use the same term differently.

As a routine part of the infection control responsibility of an Infectious Disease Physician I am asked to write or make recommendations regarding the ‘isolation’ orders for patient care. Here I will put in a link to the ‘CDC

2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings’

I believe this needs to be updated as this was composed in 2007 and is outdated in certain minor areas but I do keep this as a shortcut on my smart phone. When admitting a patient or rooming them in the clinic for evaluation and care we classify potentially infectious patients as capable of transmitting through ‘contact’, ‘droplets’, or ‘airborne’. Some infectious agents may require isolation covering multiple possible types of transmission.

When dealing with an potentially infectious patient we use the term ‘airborne’ to refer to transmission that requires a patient to be placed in a negative pressure room and staff need wear respirators in this environment for which we undergo yearly fit testing. Airborne precautions are used routinely for the TB cases we see, the disseminated zoster cases, and the measles cases that are now back in circulation.

Droplet precautions are used for many respiratory pathogens as a good cough, or a sneeze might propel infectious material up to six feet before the effects of gravity drive them to the ground. For such situations when we perform a procedure such as bronchoscopy where we might generate an aerosol we introduce airborne precautions.

Contact is rather straight forward. In general I initially stand a good 6 feet from my patients until I have a better sense of the potential pathogen and request they be placed in a negative pressure room and arrive in my N95 respirator if the story is more concerning.

Remember that we are simple clinicians and are happy discussing particle size in terms of qualitative terms mostly but get uncomfortable when people start talking about microns much as the Starbucks Barista might if you ordered your coffee drink and requested your beverage size in millilters rather than tall, grande or venti. We, like patients, want to know if someone has to touch us (contact), cough on us (droplet), or can we catch something floating around the room 30 minutes after the patient headed off to get some expensive test done (airborne).

I do think it is reasonable to recognize and discuss the term ‘airborne’ as it is used by clinicians and defined by the CDC while recognizing that ‘airborne’ might be used differently by those publishing in the basic science literature and even by concerned non-clinicians and non-scientists. In my discussions with concerned patients, I find they are not actually really asking about airborne transmission as defined by scientists or clinicians. What patients are asking me usually is whether Ebola can spread like influenza through respiratory droplets. They want to know if they can catch Ebola in the subway, in the ER, or from a coworker coughing across the table at lunch. Patients are asking me if they can get Ebola from a hearty sneeze or whether they actually need to touch an infected person. They want to know: do they have to touch a sick person (contact), get coughed on us (droplet) or can they catch something floating around the room when they are more than 6 feet away (airborne).

Unfortunately cough is a clinical feature reported with Ebola (Clin Lab Med 30 (2010) 161–177) although the cough is described as dry and it would seem that there is no evidence to suggest that one can catch Ebola as easily as influenza and a near 0 probability of that becoming the case.

Continue with the good work!


Daniel Griffin, MD PhD
Associate Research Scientist
Department of Biochemisty and Molecular BioPhysics
Columbia University
College of Physicians and Surgeons

Attending Physician
Division of Infectious Diseases
Hofstra NorthShore-LIJ School of Medicine
Manhasset, NY

Darrin writes:

Lasers have been used to treat virus without damaging blood

Here using 776 nm pulsed laser

Here using 425 nm pulsed laser

Ebola is usually 974 nm to 1,086 nm long and 80 nm wide making its resonant frequency similar to its length if it behaves in the same way as an antenna would.

It seems to me you can get the fluence of 970 nm light high enough to kill Ebola without killing cells.

Red 700 nm and near infrared 700 nm-1200 nm penetrates well through blood and you can see red through your finger for example.

The resonance effect should make Ebola both more receptive to receiving energy at 980 nm or 1064 nm. Both these frequencies are commercial laser frequencies available in laser pointers for as low as $10 on ebay for 980nm.

It appears that the common 5 mW laser pointer with a 2-3 mm^2 spot is providing 0.167 Watts/cm^2

I understand that herpes has been killed via laser at 4J/cm so a common laser pointer could likely kill Ebola at a surface spot if applied for 30-40 seconds.

Wouldn’t the introduction of non functional Ebola allow the body to make antibodies?

Seems to me a full body scanner could be made that would “cure” Ebola to a depth of 2 cm.

Thanks for your time,

Fox writes:

Hi TWiV,

I am a new listener over here in Corvallis, OR, where it is strangely 26 C and 39% humidity… normally at this point in the season it would be much cooler and much wetter. I started listening after I heard an interview with Vincent and Dixon on “Omega Tau”.

I am a data scientist working for the USFS PNW Research Station on the Oregon State Campus on the analysis of long-term climate data. I was so pleased to hear Jeff Shaman talking last week on the Ebola outbreak; having taken most of my Ph.D. coursework in geostatistics here, it was wonderful to see the robust techniques of geostatistics (which have their origin story in epidemiology with the John Snow cholera outbreak in the 1850’s, ironically) applied to the field. Also “go beavers”, our noble Oregon State mascot.

I don’t have a particularly thoughtful comment to contribute apart from that I was really taken aback by the listener email last week regarding the need for a scientist to “look something up.” I’ve been working on literally the same 10 square kilometer area for the past five years, and even now I still have to look up the geographic coordinates of study locations or measurement numbers of certain instruments. But I’d certainly rather do that than say “oh, well, I guess we’re like at about 45 N or something like that, I mean, a few degrees this way or that, who really cares…”

As a data scientist, I have the utmost respect for PI’s and scientists who would rather go out of their way to look up the right information (as you all very respectively do) and to tell the truth (as you also do) rather than try to act in a dramatic way or to coddle a pet theory (which you all don’t). Keep up the great and thoughtful work, I’ve still got about 280 TWiV’s to catch up on, but thankfully our rainy season is coming up soon, so there will be plenty of time!

PS. Relative humidity is (roughly) the amount of moisture in the air relative to the maximum amount that could be stored at a given temperature of the air. This is an exponential relationship starting at “the origin”; i.e. more water can be held in the air at higher temperatures. So if you say the relative humidity is 40% at 25 C, then you are saying, of the XXX units of choice water that could be stored in the air per unit volume at 25C, only 40% are currently there. When you cross that threshold of maximum storage– condensation! (rain, snow, etc.)! The easiest way to explain this is in the context of two derived measurements, dewpoint and vapor pressure deficit. If you’re still curious, if you look up Clausius Clapeyron curve, it’s a really great way to understand the relationship between temperature, relative humidity, vapor pressure, and dewpoint. (And yes, I still look it up when I’m looking at data from any of these measurements!)

Jessie and Carmen write:

Dear Grand Masters of the TWIV,

First, let us say we love your show, and it provides us expats working in Europe hours of nerdy entertainment in English.

So, we have a question. In a couple of the Ebola segments on your podcast (ie. TWIV #302, ca. min 39), you have mentioned that there has been no evidence of replicating (active) virus found in seminal/vaginal fluid after clearance of virus from the blood, and no evidence for sexual transmission. We have been looking into this question, and have even submitted a grant to work on it (unsuccessfully), as it’s true that the data are extremely sparse. However, we are curious as to your interpretation of those data that do exist: have we mistaken (in reading the evidence from, for example Rodriguez et al. 1999 and Bausch et al. 2007) that there IS in fact a small [!!] amount of evidence for replicating virus in seminal fluid after recovery from the acute phase?

We have attached the papers we cite. As we are infectious disease biologists, but not virologists per se, we do not want to be misinterpreting these kinds of results. Also, maybe you could offer us your advice on what would be needed to conclusively show sexual transmission (both in an ideal setting vs. under the current social limitations which are not conducive to the ideal set of “Koch’s postulates”)?

Our specific questions are below:
1. How could a non-replicating virus manage to avoid being degraded in mucosal tissue or fluids (that are, to our understanding, constantly being replaced/expelled) for many months?
2. Given the comparatively strong evidence for sexual transmission of Marburg and Lassa, two closely-related viruses, what might be different about EBOV that would prevent it from being transmitted in this manner?
3. Rodriguez et al. (1999) state that one sample of EBOV-positive semen collected 82 days after onset of symptoms “yielded an EBO virus isolate on E6 Vero cells”. And Bausch et al. (2007) also “isolate virus” from E6 Vero cells 40 days post-onset. Is this not a valid demonstration of infectivity? and if not, why? Actually, we just heard Kathy Spindler mention this paper in your latest cast: you sounded convinced. Is this the case? If so, why was the same 1999 evidence dismissed?
4. In LeRoy et al. (2000), they use an RT-PCR technique with primers designed to amplify the POSITIVE sense sequence (ie, the stage only present during replication) to identify infectious virus. They identified several asymptomatic patients with transient positive detection before seroconversion. Would this be an adequate method in your opinion(s)? If so, why do you think others have not used this method since it was described?

Thank you very much, from our sunny perch here in Montpellier, France.
Jessie and Carmen

Robin writes:

When someone shovels aside the male bovine faecal material:

Curt writes:

Hello TWiV doctors, I hope this letter finds you all in good spirits.

I’ll start with something I’ve been meaning to get off my chest since the Ebola arc started. How do you KNOW won’t go airborne, or worse, telepathic? How can you know that it won’t hitch a ride on a mosquito and establish itself in America’s Bigfoot population? Can you show me some proof Ebola isn’t a conspiracy by mercola to push colloidal silver? How dare you speak with some confidence, albeit appropriately cautious, when you’re asked to prove a negative!

Second, a listener wanted to know (rhetorically, I recognize) why the ambulance and crew were taken out of service for EBOV exposure in Dallas when no such measure would be employed for, say, Carbapenem Resistant Enterococci Pneumonia or hep C. I feel that since I work in this field, I may be able to help clarify the rationale. I would propose multiple reasons working in concert, first and foremost being fear, since this is, after all, a BSL-4 pathogen that’s known to the public for turning people into soup. Secondly, ambulance designs have to fulfill multiple roles beyond providing healthcare, such as providing safe transport, and packing away a trauma room worth of equipment into the back of a van. Unfortunately, this can lead to many tight, poorly accessible surfaces that can ultimately prove much more difficult to clean effectively than your typical hospital room, especially if your patient is busily unleashing four liters of Ebola in the form of diarrhea. Third, providers who are with the patient during transport are in much closer quarters with poorer air circulation, sometimes for longer periods of time than your typical hospital personnel, making the likelihood of inspiration of sneezed droplets or accidental shmearing of contaminated sweat on one’s person or equipment much more likely. It’s clear that the Dallas patient was quite ill (read: messy) when he was transported, and I don’t entirely disagree with them downing the rig and crew until they could be certain that they weren’t creating a giant community-wide fomite in the form of a 911 ambulance and crew. As the threat of Ebola importation becomes more of a reality, EMS agencies are forming plans to pre-empt a recurrence of the Dallas situation. See links from both of these organizations, of which I am a part.
(Go to the bottom and look for a list of links, click on ‘policies and procedures/memos’, then click on ‘special memos’, and the memo on screening for and handling suspected EBOV cases will be at the top of the list under ‘Ebola’)

Regarding closure of borders to prevent spread to other third world nations across the globe, I can say that there doesn’t seem to be much direct travel among non-adjacent third world countries such as via airlines. Rather, it seems more to be the case that travel regarding affected countries would be a) among adjacent countries regardless of economic status; b) from the third to the first world; c) from the first world to the third world and back. As such, it doesn’t seem like travel blackouts would be worth the damage they’d cause. Instead of spending money locking down borders and travel and developing expensive DOD projects, we could be saving a lot of lives right now with relatively inexpensive IV fluids. The only problem is that we’re actually in an IV saline shortage. Go figure, an American company actually having trouble delivering a salt-laden product to the masses.

Also, I’ve recently seen an uptick of respiratory cases. EVD68, maybe? It’s hard to say when our air is so polluted that I’m certain it could be successfully shoveled, but it’s good to keep in mind.

Thanks for all the hard work you all put in, and congratulations on the sponsorship.

PS: If I was going to bet on the next non-seasonal outbreak, I’d say a corona, or maybe something introduced from the domestic animal population such as parvovirus or canine distemper.

Mauricio writes:

Dear viral gurus,

I am slowly catching up with the last three weeks of TWIV; since I have not been commuting from Frederick to Bethesda in the past weeks, I have not listened to the latest episodes, but now I am short by one episode to be up to date. I would like to have an input on some of the follow ups on the Ebola virus epidemic. Although it has been mentioned before there are some “pseudo-doctors” who go around saying that at some point Ebola virus will mutate to become airborne. I think that Hollywood is the main factor in producing such idea, however I think that CDC, WHO and Doctors without borders should all get together to give a press conference showing a unifying front in which they explain not only the route of infection but on how unlikely it is that a mutation could confer a complete change in the way this virus propagates. In fact they should say the number of negative and positive RNA viruses that have changed their route of infection in a natural scenario (not in a gain of function experiment under well controlled laboratory conditions). In fact will not be surprised if somewhere someone has made a mathematical model in which they have calculated the probability for a RNA virus to have a mutation that would change is route of infection.

Anyway initial reason to send this e-mail was to send propose a pick of the week from the latest Journal of Virology issue;

Investigating a Mystery Disease: Tales from a Viral Detective
W. Ian Lipkin
J. Virol. November 2014 88:12176-12179

It is very interesting piece of work and I greatly enjoyed it.

Cheers from cloudy Frederick, MD. Now it is 79F (26C) with 50% chance of rain, 54% humidity and 26 km/h winds.


HIV Drug Resistance Program
National Cancer Institute

Heather writes:

Hello Dr.s TWIV,

First I would like to say how much I appreciate the public service you are providing with your ongoing discussion of the Ebola outbreak. I would also like to convey my dismay at the constant vitriol that you are having to rebut. I think you are doing so admirably. Secondly, I would like to suggest a new segment for your podcast: This Week in Ebola, updates and follow ups of no more than 25 minutes per show. Third, I heartily endorse the suggestion a show about lassa fever. If you would like more ideas about (non-ebola) viruses that might be interesting here are my suggestions: PaV1 in spiny lobsters (scroll down for links to publications, if you wanted to try to recruit a guest for this topic I suggest Dr. Behringer or Dr. Shields) methods for detection and surveillance of VHS virus (scroll down for link to paper.), citrus tristeza virus or other important agricultural viruses that could have an effect on the economy and food supply, or a discussion of HPV. HPV is a very “important” virus that does not get nearly enough attention or discussion in my opinion. Any (non-ebola) virology topic you choose will be very interesting I’m sure. I have been enjoying the inclusion of plant, ecology, and insect virus topics as of late and I really enjoyed your discussion with Jeff the bioinformatician. If you could recruit a veterinary virologist as a TWiV guest I think that would be fascinating. I’m looking forward to the next TWiV, keep up the good work.


P.S. Here is my humble pick if you are so inclined: Diversity Journal Club

Robin writes:

The plot thickens…

Todd writes:

Just saw the famous virology blog header on MSNBC! They referred to a microbiologist from Columbia University, and I turned to see your name emblazoned on my TV screen during the program called “The Cycle”.

Perhaps they didn’t know the ‘black and yellow” trick for pronouncing your name. 🙂

I have listened carefully all the times I’ve seen Tony Fauci, after getting to know him through TWIV, and have had to shake my head at the media trying to force words into his mouth. He holds to his role as a sensible informer and never allows that to happen.

Thanks for all your work.

Todd from Northern Colorado.

Charles writes:

Dear Meteorologists, er Ebola Pundits, or was it Virologists?

With our 24hr news cycle and sensationalist headlines, I thought you could appreciate this not-so-subtle critique of the coverage of Ebola in the news:

Thanks as always for your wonderful podcast; I’ve just finished applying to vet schools, and you all have inspired me to pursue veterinary virology and the study of emerging infectious disease.


P.S. Here in Minneapolis, it snowed this weekend, on October 4th.

Jerry writes:

Wow! As a long term listener of TWIV I can empathize with your current situation.

My own interest in virology sprang from personal interests, as mentioned in my previous letter where I explained how Tom bought in to the persuasive misinformation about HIV that had such terrible consequences.

When I juxtapose his situation to the current one with Ebola, I find similarities. The problem here is that the belief that Ebola is a lie, affected all of us. I cringed when I heard about the Liberians who stormed the treatment center to “save” the patients from MSF volunteers, who they believed made up Ebola as an elaborate ruse as a cover for their nefarious ulterior motives.

I personally believe we lost control when that misguided mob took infectious people, virally saturated mattresses and bloody blankets in to the most densely populated and poorest region of Liberia – West Point.

It’s kind of sad because because most people actually have good intentions. Trust is a very important, perhaps the most important key to reducing the transmission rate down below 1 to 1 so this outbreak abates.

You guys have an important role in disseminating information. Everyone is going to look to TWIV for answers, reassurances and knowledge that will help save their lives.

Vince, I am glad to hear that you expressed some concerns about the current policies related to air travel. I don’t prescribe to the belief that quarantines or outright flight restrictions are a viable option, but I do feel the current mode of operation is fraught with problems.

With all due respect, we are dealing with human beings. The previously mentioned mob situation in Liberia is a perfect example. We are not dealing with virologists in a BSL4 research lab, and I am concerned that unpredictable behavior can precipitate unforeseen results. I can’t allow myself to put so much faith in the American medical system, much less other countries. I feel like many of the opining authorities are a bit too cocky about our abilities. Maybe it is just a means to reduce panic.

This virus is nothing like any HVC, it kills in a month. In that time it manages to infect 2 others – this takes HCV 10 years to accomplish the same. It affects the people we most need to help us, the doctors. In a perfect world, we can contain it, but statistics are hinting that it is exploiting our weaknesses.

I find myself researching various studies of adenosine analogs and small molecules that I
think may help to treat this nasty virus. d dideoxy adenosine, CAdo, adenosine aldehyde and some flouro heterocyclic molecules work with impressive efficay in murine, and hamster subjects when treated early. I wonder though, do you think these methyl transferase inhibitors, – I believe that is what they are – would be of use in humans? Do you think the reduction in viral load prior to the viral burden becoming insurmountable would allow the person to develop a natural immunity?

My concern would be that a person may recover, only to relapse. It appears to me that people can recover, so that tells me that our bodies can fight it off. Perhaps all we need is a little help. If we can prevent the virus from overwhelming us quickly, and save some of our strength to allow the immune system to do its thing, we might be able to attain a high level of survival.

I also found an interesting story about Liberian doc that gave his patients 3TC, the NRTI used for HIV and HBV. He claims only 2 of 17 patients died. I don’t think this drug exhibited efficacy in vitro but, those are significant results albeit small.

Of course a vaccine would be ideal, much cheaper and timing would not be critical, but maybe these could buy us some time to prepare the vaccines.

As far as preventing infections in hospitals and homes, I hope all the hospitals and institutions invest in those UV systems, ozone generators. and even gamma radiation chambers to disinfect irregular surfaces, clothes and equipment. I’m sure the people running this know what they are doing, at least I hope so.

Thanks again to all Vince, Kathy, Alan, and Dixon for all you do.


Sidd writes:

Hi TWIV Crew!

I am a graduate student in Immunology at Washington University in St. Louis and have been listening to TWIV since 2009. It’s a great podcast and has help foster my interest in Virology and Host-Virus interactions.

The increased questions about airborne transmission of Ebola has made me identify a gap in my knowledge about the molecular basis of viral transmissibility. Specifically, I found that I was unable to describe a molecular argument for Ebola is unlikely to become airborne (other than invoking Vincent’s argument that a virus has never evolved over this short of a time period to change its transmission pattern). In fact, I couldn’t find any papers describing the general biophysical/molecular requirements a virion must fulfill to be potentially airborne transmissible. While I know there are specific virion properties that tend to correlate with other transmission modes, such as fecal-oral transmitted viruses generally lacking envelopes, I am unaware of any similar correlation with airborne transmitted viruses.

My questions to you are these:

1. Given a virus, are there any molecular/biophysical properties that can be measured in vitro that can indicate, or at least highly suggest that a virus can be transmitted via the airborne route?

2. Given a known airborne virus, are there any molecular/biophysical properties can be inferred about this virus, without having to culture/sequence it?

Thanks for your time and I greatly appreciate the work you guys put in the Podcast. I can only imagine the amount of panicked Ebola e-mail you must receive.


PS. The temperature in St. Louis is 13 C and clear skies. Perfect to see the Total Lunar Eclipse tonight.

Fernando writes:

Hi TWiV team,

I just read two articles that deepened my understanding of what you all and especially Alan have been saying about the social causes of EVD, and what (not to) fear:

Atul Gawande in the New Yorker:
Rebekah Schulz:

Your listeners might appreciate the personal, social, and organizational perspectives in these stories.

Thank you for the great work!

Sandra writes:

Today here in Dallas an Ebola patient died at a local hospital. There has been a bit of discussion at my office about Ebola, so I have “come out of the closet” as a “nerd” by telling people I listen to TWiV each week and sharing Ebola info from TWiV (particularly about the chances of a mutation making the virus transmissable by air.)

This question from a co-worker I could not answer: If someone touches an object, say a used tissue, which object has body fluid from someone with Ebola (such as nasal discharge), can the person who touched it get Ebola? In general, how long can the virus live on inorganic surfaces? I am assuming here that nasal discharge contains transmissable virus and realize that may be incorrect.

Re the man who died of Ebola here in a hospital yesterday: The body (or “carcass” as Dickson would call it……) was cremated. Radio news this morning was that no decision has been made about how his ASHES will be handled. Now that is some powerful fear. I hope they will be given to his fiance/mother of his child if she wants them.

We still don’t seem to have all the facts about what happened at the hospital. The hospital has given conflicting accounts. All we know for sure is that he went to the ER feeling ill and was examined and sent home. Reportedly he told a nurse he had been in West Africa, but lied when he was asked about contact with any sick people there. Supposedly the doctor who saw him was not aware he had just been to West Africa. It was 2 days later when he worsened and returned to that same ER that he was admitted.

On a more upbeat note, when his fiance and her kids were quarantined in their small apartment, someone with the City or County found a person to loan a house for them to live in for a while, as the City and County supposedly have no budget to house people in a situation like this. Keeping the young kids inside all the time was making them all miserable and the other residents in the very low income complex were frightened.

One of our county judges PERSONALLY went to the apartment and drove the woman and her kids to the home that was loaned in an effort to calm fears about transmission. The judge did NOT wear ANY protective gear. I bet that Fox “News” hasn’t carried that story. story here:

At 3:45 pm here it is 88 degrees F with 44% humidity, thus it “feels like” 89. Yesterday our high temp was 98. But no, most people in Texas don’t believe in climate change.

Hayley writes:
Greetings Twiv!

Here in Portland, Oregon, the weather — at a balmy 75 degrees Fahrenheit (24 Celsius) with clear blue skies — is unseasonably warm enough for me to make an anecdotal observation about climate change!

Thanks so much for your delightful podcasts! I just recently took the advice of a professor who recommended them, and what a timely decision it was to start tuning in!

I have been fascinated researching the experimental treatments for Ebola that have recently been implemented to save patients ailing in the U.S., and I was particularly puzzled at why Brincidofovir was chosen (after the exhaustion of Z-Mapp clonal antibody treatment). From what I understand (which is admittedly little) Brincidofovir is used to treat viruses with DNA genomes like herpes, adenovirus and cytomegalovirus. Can one assume that just because a drug is successful at inhibiting a DNA polymerase, that it must also be effective at inhibiting an RNA polymerase? Is there an assumption that RNA polymerases are in general more error prone than DNA polymerases, and thus if cytomegalovirus and adenovirus were tricked, then Zaire Ebola virus must be tricked as well? I also wondered whether the bulky conjugated lipid part of brincidofovir, even though it aids penetration of cell membranes, might lead to a narrowing of the range of polymerases that might accept it. Lastly, I wonder if it could even be a potentially harmful treatment for a patient suffering from a disease that affects blood vessels, because its close cousin cidofovir (the analog without the attached conjugated lipid) is known to apparently suppress basic fibroblast growth factor.

Thanks for possibly entertaining my speculation, and keep up the wonderful podcasts!


Mollie writes:
Dear Twiv,

Absolutely love twiv. It is the most interesting and inspiring podcast! Quick question on Ebola, (I know you’re sick of it-sorry): was it necessary for officials to kill the Spanish nurse’s dog? Maybe you mention this already and I missed it, but are dogs a very likely carrier? Can they be infected? Or is this just another example of scare tactics? Thank you.

P.s. It is a chilling 38 degrees at 5:30 am in Wyoming, USA . Just prepping for the coming winter with some snow and lots of wind.


Jim writes:
Dear TWIVers:

Thanks for spending so much time on answering Ebola questions. I have two more.

1) I was recently reading an article about when Ebola first appeared in Africa in the mid 1970s and the article indicated that there were two unrelated outbreaks of the virus (different strains) at the same time. This has happened again in the current outbreak – ie. West Africa and DRC. Is this just a coincidence or is there some environmental factor involved?

2) with the new infection(s) in Spain, they quickly euthanized one of the quarantined nurse’s pet dog. This seems like a missed opportunity to see if the dog became a victim of the virus.

My bigger question is; once the West African outbreak is finally brought under control is it likely that there will be new animal reservoirs for the virus? Dogs come to mind because there must be a lot of them whose masters have died going hungry and many of the human victims are buried in shallow graves or sometimes not at all. In addition to dogs, there are many wild animals that will eat carrion and the recently dead humans can still harbour the virus.

Thanks again for your contributions in answering questions about this deadly outbreak.


Jim in Vancouver
14 C with partial clouds

Gail writes:
Dear Twiv stars,
Another Ebola question! You discussed a paper recently about antibodies to ebola being found in dogs in the field, and discussed positive results in France with regard to potential for false positives. In light of the news that the Spanish nurse’s dog has been euthanased as a potential risk to humans without being shown to be viraemic, it seems. I did a very quick literature search and couldn’t find a great deal of information on pets and the likelihood of them being infectious to humans.

This brought several questions to mind. If there is likely to be increasing risk of people carrying ebola coming into developed countries, is there a (‘political’) need to investigate the potential for pets to transmit ebola. Telling a potential ebola sufferer that you are going to euthanase their beloved pet seems to open up the risk of these animals being moved or hidden rather than kept in isolation with the family for example, much in the same way as banning travel would just make people travel in secret.

As a vet I would take a pragmatic approach in that euthanasia is not a welfare issue in itself (vegetarians may have other views) but surely the threat of having one’s beloved pet euthanased unnecessarily is not conducive to people following protocol. Also how far does this go? Do you euthanase the pets of in-contacts or, pets the sufferer has had any contact with but does not live with? I’m not sure how I would feel if I were in this situation, and perhaps other concerns would be more pressing.

But this brought up more questions –

1 : If for example I had Ebola and my husband and dog had been exposed, and my husband is isolated at home ( I think that is the usual scenario in the developed world too) why can my dog not be isolated with him if that is what he chooses and as long as he remains well enough to look after the dog, and the dog tested – presumably this could increase necessary isolation time and potentially risk to my husband (but we do not know), but if both tested negative at the appropriate time-points then would this not be a possibility?

2: what happens to the bodily waste of people exposed to ebola who are in isolation? Is it collected in bags rather than flushed, or is flushing safer re low survival time of infectious virus in the environment, or is there a disinfection method in situ- in which case could my husband not do the same with the dog’s waste assuming the dog was made to do its business in a disinfectable environment inside?

3: If there is no more information on transmission by pet species at this stage, would this be likely to be something that might now be seen as worth studying in a BSL4 lab? How long would it take to carry out this study if someone had the idea today, in light of the increased risk of ‘introduction’ of ebola into developed countries? Presumably this would be a much quicker study than producing a safe vaccine, but presumably that is the priority for BSL4 labs dealing with Ebola. I’m not sure how many BSL4 labs in the world would have facilities for dogs?

I am not saying in any way that I believe that putting people at further risk is outweighed by animal or pet owner rights, but if this outbreak is predicted to carry on for a long time, perhaps it would be safer to investigate the risks, rather than risking people moving their dog before reporting their suspected ebola.

Sorry is a long e-mail. Thankyou for Twix, keep up the good work, and I am totally in support of the fact checking thing, as long as you know a good source, there’s nothing wrong with checking your facts!

Thomas writes:

I’m listening to your latest podcast [#305] on Ebola and you just said no patient with Ebola has died if treated in the USA, while I’m at the same time reading of the first death of an Ebola patient being cared for in the USA.

This goes back to my previous email where I warn about drawing ANY conclusions from too small a data sample. As a scientist, you should know this to be true more than most people.

I continue to say that Ebola still is being seen by the “professionals” through “rose colored glasses” because they are driven the desire to stop people from overreacting.

I also just read of a “recovered” Ebola victim that infected his sexual partner, apparently through semen.

Sorry but from what I know of Africa and its myriad of cultures and unbound ignorance about things medical, I would be very cautious about thinking “recovered” victims would cease having sex for any extended period of time. The spread of HIV through behavior which is based on ignorance in Africa is commonplace.

Wouldn’t a photograph of some of our thousand [or is it more] volunteers at “work” be interesting? I often have my photographs of the high school rodeo rejected because it shows the rider falling off the bull/horse. The local newspaper actually prefers photos where the rider hasn’t yet fallen off, albeit the body of the rider being hurled through the air is more sensational and photographically more appealing [at least to me]. I think it is a bit cynical on your part to dismiss the recent NYT photo coverage series on Ebola I referenced as being merely sensationalism.

Several European and African countries have instituted quarantines and as far as I know they haven’t had any cases of Ebola. Hardly news. Better we send 2000, vice 1000, volunteers to Africa than deal with the risk of treating these patients in the USA. How many Ebola patients have we treated in the USA?

Ebola is so frightening to most people because of the horrid symptoms accompanying this disease. Bleeding from every orifice [sic?] doesn’t sound like anything most people want to deal with. Yes, it does appeal to sensationalism. Just the fact that you are spending so much time covering this disease speaks for itself.

I am listening to what you say. I’m not totally convinced with your responses yet but getting there, re Ebola being so thoroughly researched.

Your reply re the mosquito and HIV transmission question I raised was absolutely convincing. Thank you. This is exactly why I raise these questions or email you my “suspicions”.

Anyway, I do appreciate that you provide a platform for listeners like myself. I will continue to avail myself of your repository of knowledge.

I suggest you look at the following URL. I don’t want to be on any plane that recently visited any African country where Ebola is rampant. The following is just why I suggest a quarantine be put in effect until Ebola is under control in Africa:

My respect for your podcast keeps me listening and asking questions and making “insinuations” which you, in almost all cases answer/resolve to my satisfaction.

Truth, like virginity, isn’t readily reparable once violated. No wonder people don’t trust most government sources. Academic institutions of the sort you and your team work for are far more likely to be believed than any government source, including the CDC. I appreciate your keeping it that way.

Johnye writes:
Prof. Racaniello and Friends,

Thank you for the continued presentation and defense of reason and knowledge in the face of fear and headlined misinformation about EVD.

If not already a recent “pick”, public school educators, in particular, may appreciate, Flu Attack! How A Virus Invades Your Body | The Kid Should See This.
The site, The Kid Should See This, was a previous pick that continues to amaze, delight and inform.

Also, I’d like to bring to Alan Dove’s attention especially, the fact that Robert Krulwich’s blog, Krulwich Wonders, on NPR’s website, ended at the end of September. A loss.

A video in a last post, Everything Dies, Right? was interesting:

May cool, informed heads and minds prevail.

Johnye Ballenger

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