Rob writes:

Dear Vincent et al.

I wanted to follow-up on last week’s last week’s letter from Katreya on viruses that induce epigenetic changes in the host genome. There is now quite a body of work that suggests virus genes can directly manipulate the epigenetic landscape of the host genome. In the case of Epstein-Barr virus, the EBNA2 protein can drive histone acetylation to activate genes, while the EBNA3 proteins can induce repressive histone methylation. This is done to promote cellular proliferation and avoid cell death (amongst many other things). In addition, work from the West lab at the University of Sussex, UK, has shown that these proteins can both disrupt and induce the formation of long range enhancer-promoter interactions, thereby altering the 3D structure of genes (McClellan et al 2013 PLoS Pathogens 9 e1003636).  Also, work from the Allday lab here at Imperial suggests that EBNA3-induced epigenetic repression can be fixed as heritable DNA methylation in EBV-positive Burkitt lymphomas, despite the fact that the EBNA3 proteins are no longer produced in this lymphoma – a process of hit-and-run oncogenesis if you will (Paschos et al 2009 PLoS Pathogens 5; e1000492).

For more detail you can check out our review on the EBNA3 proteins (White, Bazot and Allday; 2015 – normally paywalled but downloadable free from our website, and for some examples from other viruses, see Paschos and Allday 2010 Trends Microbiol 18 p439.



PS FWIW, I would definitely attend a virologically themed board games session at ASV, if I make it across the pond next year.

Dr Rob White

Lecturer In Virology

Imperial College London

Dave writes:

Vincent and the gang—-

While your knowledge of viruses is impressive, your knowledge on North American Birds needs some literacy.

Far from being a introduced species, there are over 35 native sparrow species in North America:

As an avid bird watcher (and [like] Dixon, an avid Fly Fisherman), they are some of my favorite birds.

But Allen, while being wrong about sparrows, you are right about starlings.

They are a introduced species.

I enjoy your podcast immensely, although my thesis was on anarchism and the Russian Revolution.

TWiEVO is also a favorite, being eclectic in its mixing of disciplines.

Run with the hunted

Steve writes:

Hi Vincent et al.

Just a quick follow up note following your discussion of sparrows in response to your correspondent.

Dickson talking about the Chinese catching all their sparrows as pests, might have missed part of the motive. He reminded me that I had heard about China and massive numbers of sparrows before. Usually we hear of the World’s vanishing wildlife disappearing *into* China, but, this was a rare example of a reversal of the flow, of staggering proportions.

The wonders of Google instantly took me to the New Scientist of December 1993, where European ornithologists were shocked when a shipment of over 2 million frozen Tree Sparrows was discovered in Rotterdam en route from China [to Italy]!

This number is particularly astonishing to us in the UK, because our Tree Sparrows are on the way to becoming extinct, so two million in one shipment was unimaginable.

I would think that, if flu virus was recovered from bodies in permafrost, a shipment of an entire population of sparrows, frozen and transported around the globe, would spread avian viruses quite effectively–though actually getting to breathe them in would, of course, be difficult.

I never did hear anything more about the sparrow trade with China, again, until your podcast reminded me. I hope it was stopped. 🙁

Another fascinating programme. Keep them coming.

All the best.




Typically dull, grey, December, weather; and my new vitamin D calculating app tells me it will be impossible to get any from the sunlight here, until the end of February!

Anthony writes:

Perhaps Dr. Condit might wish to check out this Austin pizzeria.  It’ll be interesting to hear how it compares to Satchel’s.

With a pigeon as a logo, Hoboken Pie ought to be good.  If indeed it does make the grade  — a short walk from the Congress St. bridge — maybe a TWiV on the road could be recorded there.  And Emo’s music club is in the neighborhood, too.  With a little luck you might catch the Black Angels — the I-35 incarnation of the Velvet Underground.


Juan writes:

Hi, I was listening to your discussion of the relation between the overlap in DNA sensing by CGAS and the cell division mechanisms. It just occurs to me that the overlap makes sense because at some point during division the nucleus comes apart and then the cellular DNA is practically in the cytoplasm, so it would make sense to have a coordinated mechanism to turn off any sensing of DNA in the cytoplasm, so that when division is complete the cells are not left with a marker of “DNA invasion in the cytoplasm” and turn on some “antiviral” response where there shouldn’t be.


Bob writes:

This Stat/PBS Newshour article:

makes the problem seem eminently doable.

What does the panel think?

Regards, Bob


Johnye writes:

TWiV – Gurus

Belated Diwali Greetings from Delhi!

Chikungunya… young female hen by any other name

This came in the newspaper today: walk-in testing for “chicken gunia [sic]” and only 500₹ or ~ $7.50! A real bargain

The double humor, I am told, is that gunia, in Uttar Pradesh, means young girl, so a young hen, i.e. chick or pullet?  Hard to know. Or is there a reference to the life cycle of the virus or mosquito or what???

In the newspapers there is easy to find information about mosquito borne illnesses. The link is about Delhi’s 10K + cases, 8K+ confirmed cases of chikungunya, ( Reports are up outside Delhi as well with a headline about 20 year old student dying 9 days after becoming ill on October 8th  in Mumbai. The Hindu ( has an impressive science section on chikungunya with current information and updates.

The good news is there’s great public information and education available; the bad news: if you survive mosquito borne infections (I’m taking atovaquone-proguanil, 250 mg daily and using 100% DEET, with 30% DEET wipes to augment.), you are automatically advanced to the worst air quality survival challenge round. Out of the proverbial frying pan and into the mad, mad traffic, should you survive. Not liking the options, but challenging ones for sure.

One last viral public health awareness point, there was a large public poster in Gurugram,  formerly Guragon in Haryana State, warning parents to protect their children from the risk of Zika virus infection. Wish I had be able to get a picture, it was striking.

Back to ‘Baa-stun’ tonight. Dickson, and  Daniel, Delhi is quite a place as you know. Happy to have visited.


Johnye Ballenger, your primary care pediatrician in Cambrige, reporting live and (knock on wood) still well, from Delhi.

  1.  The 450₹ special, is the Fever Profile, usually  $13.50 but for a limited time only, $6.75! Get yours before prices go back up!!!  JB

Ben writes:

Dear Vincent,

I’m writing to you from Sydney Australia where it is currently perfectly sunny and 23 degrees C.

I’d like to thank you for your discussion of the Chikungunya virus with Michael Diamond in episode 414. I contracted this virus in Tuxtla Gutiérrez in southern Mexico in July 2015. There was a major epidemic of Chikungunya in southern Mexico at the time which I suspect was significantly under-reported by public health officials. Michael Diamond mentioned a figure of between one and two million cases in south and central America. Tuxtla Gutiérrez has a population of around 600 000 people and from conversations that my wife and I had with people around the city it would seem likely that at least half of the population was infected during the epidemic.

I realise this is purely anecdotal but I just wanted to raise the potential under-reporting of cases in Mexico when estimating the disease burden of this virus.

On the subject of that burden I am unfortunately among those who have gone on to develop chronic arthritic symptoms. I still have swelling in the joints of my hands and elbows. Obviously I’m not alone in this. Even if we go with the lower estimates of numbers of infections and rates of chronic arthritis we are still talking about tens to hundreds of thousands of people affected.

I realise that the other subject of episode 414 – the Zika virus – presents a pretty compelling case for research but I also hope that this doesn’t stop labs like Michael Diamond’s continuing to do their important work on the Chikungunya virus and that TWIV can provide us with Chikungunya updates as this story unfolds.

Kind regards

Samuel writes:

Hello Twivers!

    I have been a listener for close to two years but have never written in before. I just listened to TWiV 414, I was so excited to hear about the Chikungunya research done by Michael Diamond. I spent two years from January 2013 – December 2014 in El Salvador. later on in my time there we were warned about the Chikungunya virus, I have many friends were infected, especially those who lived by the coast. I loved learning more about this interesting virus and look forward to more in the future! Thank you all for spreading microbiology knowledge in such a consistent and clear way.



PS: here in Provo, Utah it is currently 14 degrees Celsius with a wind speed of 6km/h, a pretty warm fall day.  

Steve writes:

Hi Vincent et al,

I know you aren’t all into trees, but, when someone showed me this excellent city treescape appreciation idea from New York, I immediately thought of you and your listeners’ picks.

What a brilliant way to draw attention to the services that city trees render us, and to, literally educate the man in the street, in the street!

NYC Parks are to be congratulated on this beautiful resource. I only wish we treated our trees with such respect here. In my town a map like this would be kept secret by the council to help them plan the best way to cut them all down!

All the best,




Sharon writes:

Dear twiv,

I have been listening to your podcasts about viruses from around the world and I would like to bring your attention to a viral outbreak of mumps at SUNY New Paltz, which is 90 miles from New York City in the beautiful Shawangunk ridge. Many families travel here from the city to see the foliage, pick apples and get pumpkins in the fall. There are year round outdoors activities as well.

SUNY New Paltz is in the center of the town and the home of many activities. I am an alumni but also a current part time student studying Spanish. In October, we received an email explaining that one or two cases of possible mumps had been identified, and this was later confirmed by testing.  Then that number went up to 8. As of now, there are 12 confirmed cases, many of whom were connected with the swim team, though obviously the patients have not been identified. The swim team has been forbidden to compete in any away meets for the rest of the season, the ill have been isolated and 20 students who were not vaccinated have been removed from campus. I am attaching below the official statements from the school website below so you can see the current status.

My question and concern comes from the fact that all of the ill students have been properly immunized and became ill anyway. What is your expert opinion on this – is this a case of a modified virus or immunizations wearing off? Why weren’t they protected? Should people who are immunized feel safe? What do you think is happening here? How serious is the risk of contagion when mumps has a long incubation period?

Thanks for taking the time to address a virus outbreak happening in my backyard!


Ian writes:

Hello to the Twiv clade.

I’m working through (and greatly enjoying) the twiv backlog, and got to 254, which was on an approach to HIV vaccination (well, SIV) In Rhesus monkeys, using CMV.

It came to me that there have been a number of attempted vaccines using viruses to express various antigens into the host, with the aim of these viruses continuing to express some protein over time.

This has a number of problems, from the safety of the vector, to the presence of a non-naive population to the vector in the cohort.

Has anyone considered a rather dumber engineering approach?

Namely some form of implantable slow-release device.

Stabilisation of the antigen is of course an obvious issue, as is making a device that would continue to release antigen for decades.

Are there other issues I’m overlooking?

It seems it might also help in some cases with vaccines that require a booster dose months or years later to be most effective.

Ian, from Scotland, where the temperature is starting to bounce off freezing at night, and the trees are dropping their coat of gravel-glue.

Frank writes:

Dear Vincent,

Note that Dr. Rich Kessin foresaw the unintended viral sterilization of men in his 2014 fiction novel “The Famine of Men” as well as the ultimate consequences.

Best Regards,


Scott writes:

Hello TWIV Team,

I would like to start by saying I’m a huge fan of your podcast. I began listening around episode 350 and have been attempting to tackle the archives from both ends.

To tell a little about myself, I reside in Columbus Georgia  where the temperature is normally miserable, but today is fairly nice with a high of 21C with few clouds. I recently graduated with a MS in Biology, but my focus was nowhere near viruses, I actually did my thesis work on genetic fingerprinting in plants, and building fingerprint (we call it barcode) libraries for a local flora as well as building one for the flora of Bermuda.

I won’t say it was entirely thanks to your podcast that I am now employed as a Microbiologist, but at least 70% is fair. I know you get lots of emails with people telling you how much they appreciate what “yall” do for the virus loving community, but I can confidently say that you caused me to completely change the course of my academic career. I’m currently looking for PhD programs in virology, my interests are strongly pulled towards vaccinology, and even more specifically towards emerging diseases.

On a similar note, I do have a question for the team. Seeing as I’m going through a transitionary period, my first round of PhD applications was totally unsuccessful. Since then, I have taken this post as a microbiologist to gain experience, but is there anything else you would recommend to make up for my lack of true virology education? With the exception of a microbial diversity course and immunology course I was able to squeeze in at the end of my MS, I have only my work experience to teach me about microbes, and only Vincent’s online virology course (and TWIV!) to teach me about viruses.

Thank you again for the wonderful podcast, and for the guidance you didn’t even know you were giving.


PS: I picked up a copy of Marilyn Roossinck’s Virus a few days ago and haven’t been able to put it down yet! It’s amazing!

Robert writes:

Minor note: in this episode at about 41:40 minutes in the TWIV crew begins discussing a paper and starts kicking around the term “zoochlorellae,” and the pronunciation of its stem “zoo.”  In the joking “zoo” gets pronounced “Zoe” and “who is she married to,” Vincent says “Franny and Zooey,” and Dixon (?) states instead at 43:25, “F. Scott Fitzgerald… was married to Zooey.”  Fitzgerald was married to Zelda [nee Sayre.]

Also in this episode Vincent digs in on what level of proof is required for scientific deductions.  I’m with him.  I became a scientist because of an attraction to the certainty that comes with the scientific method.  Science evolves a view of the universe based on a current understanding, grounded in experiment.  That viewpoint is subject to a moment’s revision when new evidence overturns current thought.

“If it looks like a duck and walks like a duck…” deductions do not rise to the needed level of certainty required by rigorous science.  As the panel notes, this may be OK in informal discussion, with modifiers, as in: “It is looking increasingly certain that….,” etc.


Justin writes:

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