TWiP v3 275

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About Vincent



Vincent Racaniello

Vincent Racaniello

Vincent Racaniello is a virologist at Columbia University and science communicator. He is using Zika Diaries to communicate the personal and behind the scenes experiences of his laboratory as it moves from working on poliovirus (for 35 years) to Zika virus.

TWiV reveals the puppet master: an RNA virus injected with wasp eggs that paralyzes the ladybug so that she protects the cocoon until the adult emerges.

Thursday, 25 May 2017 10:01

TWiP 134 Letters

Case guesses:

Nita writes:


   Hello to the TWIP-tastic peeps! I missed Dr. Despommier on the last episode, but I had a great time listening in! For our last case 132, I did have a fun memory to share! Growing up in Taiwan during my grade school years, we would receive packets of slippets that had a target bulls-eye pattern that was sticky on one side to bring home. Every family member would stick it on their butts to essentially perform their own Scotch-tape exam, cover the sticky side with the clear plastic to keep whatever you stuck on your butt on the adhesive end, and bring them to school. Picture of what this looked like is in the link here:

   I have no idea who looks at all these packets, but I would guess someone in the health office (maybe the nurses or local doctor assigned to the school) would be the sad fellow appointed to this wriggling mess.

   Onto my guess for case 133, the young Haitian child suffering from failure to thrive with observed motile worms in feces opens the can of worms to a few possible differentials, notably, ascaris lumbricoides, hookworm, or whipworm. From this list, I think ascaris lumbricoides is probably the most likely answer. This is an intestinal parasite that clogs up the lymphatic system, which can explain our patient’s edema. It can also result in intestinal obstruction, which can manifest in the protuberant belly as this worm can multiply and grow quite large (as seen in the photographed preserved jar from the Meguro parasitological museum via my sneaky photo skills). Nutritional deficiency can result from the obstruction and the energy siphoning from the worms. The patient likely was infected through the fecal route with poor sanitary conditions. With earth floors, it is easy to track in infected dirt or with unsanitized water source, the worms may also be ingested. Usually, the worms are also found in the pulmonary system (as is the hookworm).

Diagnosis is done by stool microscopy, and I think the standard treatment can be albendazole 400mg PO or mebendazole 500mg for those older than 2 years old. Also, “everting uterus” from the pinworm made me giggle. What a great way to describe this! Thanks again for continuing the awesome podcast.

David writes:

Dear Hosts,

Judging from Daniel’s hints regarding a certain image in a book as well as adding up the factors described in the current case (abdominal discomfort, distended belly, lack of nutrition compared to her sister, long motile worm in the feces), I will venture a guess that this young girl has been infected with Ascaris lumbricoides. She most likely contracted the parasite eggs after coming into contact with soil or water contaminated with feces from her impoverished environment. I came across a link that states Ascaris is one of the most common worm infections in Haiti (, and I hope this little girl received the treatment she needed (treatment for this parasite [ascaricides] are albendazole, mebendazole, levamisole, pyrantel pamoate).

Thank you once again for the informative and entertaining podcasts

Sincerely, David P.

Molecular Helminthology Lab

Tufts Cummings School of Veterinary Medicine

Wink writes:

Dear TWIP Team,

I found the picture in your fantastic text, so I must say ascariasis with a heavy worm burden. But I was wondering if strongyloidiasis would also fit this case. I was thinking about the latter because of the edema on the abdomen and wondering if the immune-deficiency of malnutrition is sufficient to lead to hyper-infection.

Wink Weinberg (Atlanta)

Trudy writes:

Dear TWiPpers,

I think the girl is infected with Strongyloides stercoralis.  She probably contracted the parasite from the dirt floor in her home, as Strongyloides is one of the few parasites which can penetrate unbroken skin.  It could also be Strongyloides fuelleborni, but I’m going to stick to stercoralis.  

As an aside, other parasites which are capable of penetrating unbroken skin include schistosomes, cercariae, and hookworm.  I learned this from Dickson.  Thanks, Dickson!



Iosif writes:

Dear Twip Team,

My differential for this case would be that our young patient has an Ascaris infection. These large worms can live in our GI tracts and have a life cycle similar to Strongyloides, but without a reinfection. Our patient probably had food contaminated with ascaris eggs; from there the eggs would hatch within her GI system and the larvae would then spread via the blood vessels or lymphatics to her lungs where they would climb up the bronchi and then trachea and be swallowed so that they could live their adult lives in the GI system. Judging from her lack of lung symptoms and her short stature as compared to her sister, this infection is most likely a chronic one and she has thus lost a lot of nutrients over time. Thankfully it does not appear that full blown kwashiorkor or marasmus has developed, and without a painful belly I assume that there is no current GI or biliary obstruction. A stool sample could be used to look for eggs. A single dose of albendazole could be used for treatment.

I hope that she had enough catch up growth that she could at least match her sister in height.


Iosif Davidov

PS I had forgotten that you guys asked for audio clips for our differentials so I tried to do one for this case. I was pretty nervous making this so I do apologize for any awkward pauses. If this goes well then I will try to continue using audio files.

Elise writes:

Dear TWIP Trifecta,

I hope this finds all of you well.

Look at me, back in the swing of things (I hope) writing with a diagnosis (although the last one I submitted was late).

I suspect that the little girl Dr. Griffin met in the Dominican Republic is the victim of a substantial infestation of Ascaris lumbricoides. Initially, I thought that she suffered from something a little less dramatic but when I heard the detail of the mother actually seeing a large motile worm in her daughter’s stool, I revised my thinking.

The patient and her family live in conditions that are ideal for contracting this nematode. They are in constant contact with dirt and there is poor sanitation where they live. In addition, children are more likely to become more symptomatic and more adversely impacted by a roundworm infestation because their intestines are so much smaller than those of adults. It is not uncommon for people infected with ascaris lumbricoides to experience very few symptoms unless they are hosting a lot of worms. Younger children are more likely to have symptoms and be negatively impacted by an infestation, most notably by failing to grow properly due to not being able to absorb enough nutrients (as is the case with this child).

There is another possible parasitic suspecting this case: Trichuris trichina, or whipworm. Like ascaris, this is a soil-transmitted parasite, but the symptoms of a Trichuris infection (and since this case has appeared in such a rural area and there is little access to sophisticated testing, the little girl’s symptoms seem to provide the best guide for a diagnosis) involve much more obvious stomach upset: abdominal pain, nausea, bloody diarrhea, sudden weight loss. The patient in this case seems to have much more chronic symptoms most crucially failing to grow and her distended belly, which points more towards ascaris.  

In both cases, the most common treatment appears to be with mebendazole or albendazole, however this patient’s case seems so pronounced that I wonder if she needs some surgical intervention too, to remove the worms that have proliferated so much in her body.  

Thank you so much for your work. I hope all is well.

Elise in lower Manhattan.


Elise writes:

Dear TWIP Trifecta

How are you? I hope to be reporting that I am back from beyond and that I can be a responsible TWIP contributor. It has been a pretty chilly spring in lower Manhattan and all kinds of rain is predicted for the future.

I suspect that the young mother and her son described the case from TWIP 132 have pinworm infections. The symptoms are consistent with the basic pinworm signifiers: itchy anal areas, itch gets worse at night (while the pinworms are laying their eggs). While the woman would like to suggest that her sister’s children are the vector for this infestation, and she may be right because children often share pinworms with one another, her volunteer work with lots of children also provides other opportunities for infection. (Still, her sister’s kids, since they stayed in the home for a while are the most likely suspects. What was the verdict when she asked her sister if her kids had any symptoms?)

Diagnosis can be done in a variety of ways: looking for live worms around the anus and in bedclothes, or using tape around the anus first thing in the morning to collect eggs.

If pinworms are present, the entire house will need to be cleaned and all clothing and bedclothes washed with hot water. Everyone should be treated. Some people have no symptoms even when they have a pinworm infestation and unless everyone is treated, pinworms can come back and run rampant again. Everyone in the household will need to follow the medication protocol at the same time to ensure that the pinworms have been eradicated from all hosts. Getting rid of pinworms is tricky because everyone needs to take the medication and take great care with hygiene.

Thank you so much for all of your work. I have missed being a regular contributor.

Many best wishes,

Elise in lower Manhattan

Scott writes:


There was a bit of confusion expressed in the current TWIP about the candirú, a parasitic catfish of the family Trichomycteridae and native to the Amazon basin, that was discussed at some length.  As a serious freshwater aquarist, I have been aware of this fish since first reading the account of it in Gunther Sterba’s 1966 classic, “Freshwater Fishes of the World,” which includes a drawing of it.

I would recommend a fairly complete and informative article in Wikipedia about the species, Vandellia cirrhosa, the species in the genus most commonly blamed for being a human parasite. It is interesting to say the least, and worth the time it takes to read.  Seems that it’s not as scary as one might believe, considering the Internet legends and general misinformation circulating about it.  But it is an interesting species, with an interesting lifestyle, nevertheless.



Cartago, Costa Rica

TWiP solves the case of the Haitian Girl Who Failed To Thrive, and visit two studies that address the question of whether infection with Toxoplasma gondii alters human behavior.

Monday, 22 May 2017 08:32

TWiV 442 Letters

Anthony writes:

The Royal Society added 2 new photos.

12 mins ·

British physician Edward Jenner FRS, the pioneer of smallpox vaccine, the world’s first vaccine, was born #onthisday in 1749. (this was 17 May)

Often referred to as “the father of immunology”, his work is said to have “saved more lives than the work of any other human.”

Also: The Royal Society

It was #onthisday that British physician & scientist, Edward Jenner FRS, administered the first smallpox vaccination in 1796. (this was 14 May)

Often referred to as “the father of immunology”, his work is said to have “saved more lives than the work of any other human.”

Marion writes:

from twiv 441, at 1:31:

“A virologist by inheritance. Is that on the Y chromosome? I guess so.”


Paul writes:

Dear Vincent and fellow twivers

Greetings from Oz! Another great podcast this week with your focus on a paper describing the role of the Y chromosome on influenza susceptibility. As always, it made my trip to and from work at the University of Queensland both pleasurable and informed.

I wanted to pick up on a comment from another listener of a father and son virology connection and Vincent’s throw-away comment that this genotype/phenotype must be Y chromosome linked. Attached is irrefutable proof that the link must be anything other than the Y chromosome – perhaps epigenetic? The attached picture (  is of my daughter and I in front of our respective posters at the Boston Positive Strand RNA virus meeting a few years ago. We were thrilled to be presenting side-by-side at the meeting. Lucy is currently a post-doc working in viral immunology in Seattle with Ed Clarke. Her partner, Justin is in Mike Gayle’s lab next door. If the phenotype is hereditary, it will be strong in our family! Both are also big fans of TWiV.

Keep up the great work – lots of fans in Australia and I recommend the podcast to all my virology students.

Weather in Brisbane is currently sunny and 23degC, heading into what is our winter – or what we locally refer to as our not-so-hot season.



Professor Paul R Young | Head of School |

School of Chemistry and Molecular Biosciences (SCMB) | The University of Queensland | Brisbane | Queensland | Australia |

Australian Infectious Diseases Research Centre (AID) | The University of Queensland | Brisbane | Queensland | Australia |

PS Vincent, I meant to mention – I now have my first ever polio paper!! Trivalent IPV delivery to follow soon.



Raihan writes:

Dear TWiV hosts,

On TWiV 441 you guys went on a short tangent talking about the potential laptop ban on flights coming from Europe. You guys were mentioning how this is a problem as you can’t get work done on flights and may have to resort to reading a ‘paper book’ on the flight. Well the problem is more than that. I am a Singaporean working in the Middle East and the laptop ban had hit us several months earlier. The ban here includes both laptops and tablets. The regulations state that these devices need to be checked into the baggage and won’t be allowed on as hand carry. That’s where the problem lies. We are scientists and our electronic devices hold our extremely precious data (insert gollum meme here). We can’t run the risk of checking in our laptops when the airline can lose our bags or if our bags get handled roughly resulting in damage to the device. I know this is a perfect ad placement opportunity for Drobo to sell their products but still, a lost or broken laptop can put a researcher back several days if not weeks.

The laptop ban and the horror stories of people traveling to the US from the middle east has scared us pretty bad over here. I have been accepted to present a poster for ASM at New Orleans next month, but the fears of losing my laptop or getting manhandled on flight or at border security has led me to decide against going to ASM. I have asked our American collaborators to present our data on my behalf. The saddest part of all, I only found you that you guys will be recording a show at ASM after I had decided not to go.  I guess it’s a little too late to change my mind, especially since my collaborators have accepted to present.

On a side note, the IT store on campus now sells bubble wrap to wrap your laptops in if you’re travelling to the US. I know I sound a little paranoid, but I’ve been hearing too many horror stories from the news or fellow colleagues traveling to and from the US that I just won’t want to risk it, even if it means not getting a chance to meet you guys (*sad face).

Best Regards,


Trudy writes:

Hi TWiVers,

In follow-up to your discussion about mouse work on TWiV 441, I would like to add that when I was working on RSV we did all of our work in female mice, primarily because they are less aggressive than male mice.  

Also, when I was at the CDC I recall hearing a very interesting talk by a staff scientist from Jackson laboratories.  Most notably, she discussed breeding methods and the rules for mouse genetic nomenclature, which can be very confusing!  Unfortunately I don’t remember her name, but might I suggest finding such a person as a guest for TWiV?  I found her talk very interesting, and it might answer some of your questions.



Bob writes:

On TWiV441 the panel discusses “consomic strains,” details of genes on chromosome Y, etc. etc. I get at least the drift of the discussion, thanks to having taken Dr. Rosalind Redfield’s wonderful online Useful Genetics 1 & 2 courses.

Every time I hear such a discussion I again in frustration wonder whether there is a resource to learn more detail about the genome. Is there an “Encyclopedia Genomica,” as it were?

For example, when panelist Kathy Spindler talks about some details of multi-copy genes on the Y-chromosome, is she acquainted with such details as the result of her own research, papers she has read, or from such a resource

I know that this is not really a question specific to virology, but do any of the panelists know the answer?

Thanks in advance for any help you can offer.


Robert writes:

Hi Drs TWiV,

My name is Robert Huff, I am a Cell and Molecular Biology Masters student finishing up my first year at San Diego State University. I work in Dr. Roland Wolkowicz virology lab where I am in the process of developing a cell based assay to monitor the proteolytic cleavage of the Zika Virus proteome. The weather here is sunny and 23 degrees Celsius. I began listening to TWiV about a year ago and have been working my way through the archives in both directions.

My pick is for a science communication project that I just completed as an end of term presentation in one of my graduate classes where we were tasked with the project of explaining our research in a way that the general public could understand. We used a really cool presentation technology called Learning Glass where the speaker faces the audience and writes on a large transparent glass “white board”. There is a camera in the audience that films the speaker as they write and uses a computer program to flip the image and displays it on a multitude of TV screens in the room, so the presenter and write while facing the audience. Its a really awesome technology that I wasn’t aware of and helps to easily convey a message.

Anyways I think this is a great idea to use to help portray the important work that academic labs perform in a way that is easy to get across to an audience that aren’t necessarily experts in the science field.

I’ve attached a dropbox file of my presentation of my own work, although the presentation might not be the best out of my class I am very proud of the work. Hope you enjoy it!

Thank you all for such a great podcast! It keeps me sane when doing home made site mutagenesis, cloning, and countless hours of tissue culture experiments!

The best to all of you,


zika presentation.mp4

Monday, 22 May 2017 08:23

The New York Tim - TWiV 442

Freelance science journalist Tim Requarth joins TWiV to explain why scientists should stop thinking that explaining science will fix information illiteracy.

Thursday, 18 May 2017 21:26

TWiM 152 Letters

James writes:


Episode 150 was the best episode I've heard so far (Having listened for a couple of years now I guess).  I absolutely loved hearing about science jobs and the intersection of pure science, medicine and patients.  I will add, that is my fav part of TWIP too.  Just awesome.

I have written before, but this episode really hit me.  As a displaced and more or less retired Pharma rep with a double major in Biology and Chemistry I am actually going to look in to the possibility of a career change to medical laboratory technologist. It might be too late for me at 52 and being in a wheelchair but it is SO VERY interesting to me that I feel like I need to do my do-diligence to see if it might be a fit for me in some way...

Wednesday, 17 May 2017 20:02

Wooden steps - TWiM 152

The bacteria that allow a giant shipworm to oxidize sulfur, and algae that live within salamander cells.

Monday, 15 May 2017 09:15

TWiP 133 Letters

Case guesses:

Iosif writes:

Dear Twip Team,

My guess for this case is Entorobius vermicularis aka pinworm. This parasite is extremely common with greater than 10% of the US population likely being infected. Infections travel via the fecal-oral route with eggs being ingested leading to larvae growth within the small intestine, from there the larvae matures to an adult and sets up a home within the cecum and appendix of the large intestine. The adult females migrate to the rectum and out onto the perianal folds (usually at night) and lay their eggs in that area. The adult worm and eggs can be irritating which leads to the itchy anus plaguing our patient. Scratching the skin allows the eggs to spread to the fingers and other areas and thus the cycle can begin again. Treatment would consist of either albendazole or pyrantel pamoate, with pyrantel pamoate being preferred due to the fact that it is available OTC and is cheaper. The difficulty comes in the likelihood of reinfection. By the time treatment is administered, the whole family is likely infected and the household is swarming in eggs. Adults also appear to often be asymptomatic with infection. Treatment should consist of the entire family taking medication at one time (a single dose of either drug is effective), and then a second dose of treatment roughly 2 weeks later to remove any reinfection caused by remaining eggs. Furthermore, as much of the linen, underwear, curtains and other areas of the house should be washed within this period as possible. Lastly, the children should be taught the importance of washing their hands and having short nails.


Iosif Davidov

P.S. As for the pronunciation of certain medical words; I too find myself unsure of how to pronounce certain things. For example:

  1. Gilbert’s syndrome – I was told that Dr. Gilbert was French and it is actually pronounced as Zhil-Bear rather than with a hard G and t.
  2. Kaposi’s sarcoma – In the hospital everyone pronounces it as Kuh-po-si, but in the NEJM podcast I heard it pronounced as cap-o-shi. Which one is more accurate?
  3. Pneumocystis jirovecci – I’ve heard most people pronounce jirovecci with a hard juh , but I’ve also heard it pronounced with a yi sound instead of juh and a -tsi instead of a -chi.

I’m sorry if what I have above is confusing especially since I am doing this with an e-mail and cannot pronounce these things in person.

David writes:

Dear Hosts,

The case of the young boy and mother with an itchiness in the anal area which becomes more intense at night sounds like a classic case of pinworm infection by Enterobius vermicularis. This parasite is the most common roundworm infection in the developed world, and ~20% of people (particularly children) in the U.S. may develop this disease at some point in their lives. The itching is caused by the pinworms migrating to the anal region at night in order to lay their eggs in the perianal space.

The child likely caught the pinworms from one or more of his 3 cousins who came to visit – the boy showed no symptoms until after this visit (unless the infectious eggs were transferred from a sushi chef, but the three children visiting seems much more likely). Pinworm eggs are hardy and have an adhesive surface, which can allow eggs laid near the anal region to be easily transferred to an itching fingernail and subsequently onto any other items the infected child may touch (bedsheets, toys, clothing, furniture, etc.) which can explain how the mother caught the infection.

To confirm this diagnosis, doctors should employ the “scotch tape test” – applying a piece of clear adhesive tape to the anal region in order to pick up residual eggs to be viewed under a microscope. Treatment includes medication in the benzimidazole family, including albendazole and mebendazole, which inhibit the microtubule function in adult worms.

Thank you once again for the entertaining and informative podcasts


David P.

Trudy writes:

Dear TWiPpers,

In follow-up to Vincent’s question on TWiP 132 about whether or not one can acquire Paragonimiasis in the U.S., I happened to find the following abstract via Mark Crislip’s puscast:

Although I can’t read the actual paper because it’s behind a paywall, if I correctly recall Crislip’s comments, one has a pretty good chance of acquiring Paragonimiasis (from P. kellicotti) by consuming raw crawfish right here in the U.S.  However, to my recollection, there was no mention of crabs.

While I am writing, I might as well take a guess at this week’s case study.  I am pretty sure that the NYC lady from episode 132 is infected with Enterobius vermicularis, also colloquially known as pinworm.  

The life cycle of this parasite begins with the ingestion of the pinworm eggs, which can be found ALL OVER THE PLACE in houses with small children.  The eggs hatch in the duodenum, where the emerging worms grow and then migrate through the small intestine towards the colon.  Somewhere along the way, the female and male worms mate, the males subsequently die, and are passed with the stool.  The gravid females, however, migrate through the colon towards the rectum, and usually emerge from the anus at night to deposit their eggs around the perianal area.  This is usually what causes the itching sensation.  The reason they need to emerge is because the eggs require oxygen to mature, however, this emergence also causes the mother’s death.  

The itching usually causes small children to scratch themselves, trapping the eggs underneath their fingernails, and propagating the cycle when they put their hands in their mouths.  Yuck!!! Adults are less likely to scratch themselves (especially if they know what is causing the itching!), and even if they do scratch themselves, they are MUCH less likely to stick their hands in their mouths afterwards!!! However, the presence of the eggs all over the house, and the likelihood of the children sticking their hands in the parents’ mouths at times, increases the parents’ chance of becoming infected.  

The pinworm life cycle usually occurs over the course of about a month. Treatment with over-the-counter medications such as pyrantel pamoate, or prescription medications such as mebendazole and albendazole is very effective.  However, since these drugs only kill the actual worms and not the eggs, an effective treatment regimen usually requires a second (or third, or FOURTH) dose at two week intervals to prevent reinfection by adult worms that hatch from any eggs not killed by the first treatment.  

According to “a friend” who recently suffered from this affliction, the movement of the worms is probably THE MOST disgusting sensation that “this friend” has ever sensed! One can diagnose this infection by doing the “scotch tape test”, although why one might want to do that is beyond me.  I would think that the itching on its own would be indicative enough to immediately seek treatment.

Lastly, I think that giving an episode summary at the end of each of the TWiX podcasts is a great idea, because even though I am a loyal fan, my mind does tend to wander sometimes when I listen.    

Thank you for your continued diligence!


Bill writes:

Dear Doctors:

Thank you for the entertaining and educational podcast. I have enjoyed listening to them on my commute in the DC region, where it is an Endor-esque 68 degrees Fahrenheit today.

My guess for the diagnosis is pinworms! As far as my thought process goes, upon hearing the words ‘iching’ and ‘perianal region’. I immediately thought of TWIP #19. Relistening to the episode seems to confirm my diagnosis.

To test this, do a sticky-tape test on the perianal region of all suspected hosts at night. NB: Can use dolls as props, but in that case if the patient speaks Spanish and not English, also add this addendum: “Hazlo a la persona, no a la muñeca”.

As far as advice to give to the patient:

1) Don’t panic! Everybody gets this worm at some point. You can quote Dr. D. on this from TWIP 19: “Nobody is dying from this thing, nobody ever did, and nobody ever will.”

toxacara risk

2) Some people go overboard and become hyper-clean. Avoid this if possible as it can add a lot of stress and may be counterproductive, as unknowingly spreading the eggs all over the room can continue spreading the infection.

3) Do: bathe after waking up, wash your bedclothes regularly, wash your hands regularly, especially after using the bathroom or changing diapers, change your underwear every day, avoid nail biting, and avoid scratching the anal area

4) Treat with mebendazol until itching goes away. Itching may come back. If it does, come get some more mebendazol. At some point, the infection should clear with this strategy.

As an aside, listening to the TWIP on toxacara canis reminded me of this picture I have attached which my little brother (who is an award-winning photographer) took at one point from a beach in Brazil. Enjoy!


Nita writes:


   Hello again TWIP-tastic peeps! This is Nita again, the silly hopeful neurologist-to-be. I am glad to hear that the castrating barnacle was amusing! For this week, our young NYC woman experiencing anal itching for a few weeks puts pinworm on the top of my differential list. Often contracted by children through fecal-oral contamination, female pinworm crawl out of the anus at night and causes itching with egg-laying. The child then scratches and often ingests the eggs at a later timepoint, thus reinfecting the poor victim. The itch-scratch-itch cycle is perpetuated, and the child can easily pass this on to the rest of the family. In our patient, because of frequent contact with children and a son with similar symptoms, pinworm seems to be the most likely cause. Treatment is usually mebendazole.  Another parasitic culprit includes scabies, though it’s kind of unusual.

   Other causes of anal itching include dryness or irritation to the perianal skin. This can result from eczema or rashes (in which different textures like new underwear types or new soaps should be investigated). Allergic reactions could also cause irritation/itchiness, so maybe the sushi can cause this? Dry skin can be a result of using harsh soaps. Increased liquidy bowel movements, diarrhea, or incontinence can also result in itching/irritation.

   There are also other sources of infection, such as candidiasis, yeast infection, or HIV that should be investigated.

   Thanks again for the amazing podcasts!

Caleb writes:

Hello, doctors of TWIP!

I’m a relatively new listener, (a grand total of two episodes) and this is the first time that I’ve e-mailed the show.  I work in law enforcement, and listen to your show while I’m on patrol.  I really enjoy the case studies and as a total layperson, am glad to be able to understand about 40% at best of the science you talk about in the papers you review. Please, keep up the good and entertaining work.

I’ve noticed that the responses to case studies that I’ve heard in the past generally come from people who seem to have reference works to check for parasites, or some kind of expertise in the subject matter.  I have nothing of the sort.  Despite this handicap, I was able to muster up the courage to search Google for “anal itch parasite,” and I think I may have found an answer.  My guess is that your patient has an infection from Enterobius vermicularis, otherwise known more commonly as the pinworm.  The information that I found online says that a pinworm infection causes itching in the anal area as its main symptom, which matches the complaint by the patient.  In addition, pinworm infections are common among young children, especially when there are many in a confined area.  The patient could have been exposed when she hosted the three young relatives 3 months prior, OR in their frequent volunteer work with children. In addition, this seems to be the direction that Dr. Depommier was leaning, when he asks if the patient observed any white things in their feces.  The worms are small and white and can sometimes be observed in the feces of the host.  The pinworm settles and lays eggs in the anal area of the human host, which causes the itching.  The worms can be easily spread, and symptoms can be relatively mild, so it could well be that her son is also infected, since she believes she sees him scratching himself more often than normal, even if he isn’t openly complaining.

Pinworm infection can be diagnosed by what seems to be rather obviously called the “tape test.” Upon waking, the host can place the adhesive side of transparent tape to the anal area, and should be able to collect pinworm eggs, which can be viewed under a microscope. The information I’ve found says that the most common treatments for pinworm infections are the following three prescriptions: mebendazole, albendazole, and pyrantel pamoate, as well as good hand hygiene, as the eggs are often spread by hosts scratching the itchy area, and collecting eggs under their fingernails.  I’m at the mercy of the internet for all of this, so I hope this information is correct.

It’s a  beautiful day in eastern Nebraska, 70 degrees with a light north breeze, low humidity, and barometric pressure at 30.11.  Thanks again for putting so much time into entertaining and educating me and others.  Between TWIP and TWIV, you’ve inspired me to become interested in science in a way that I haven’t been since college.  Have a great day, and keep up the good work,
Caleb (pronounced Kay-lub)


Anthony writes:

Perhaps a Believe It or Not feature might be of interest on TWiP.  A candidate might be the Candiru:

The article is sceptical and that’s good.  That being said — if memory serves me correctly -in a tropical fish publication on Piranhas Candiru attacks are mentioned.  The story was that the indigenous people living on the Amazon only feared the Candiru and the sting ray — not piranhas, electric eels, big cats, or reptiles.

Burroughs mentions the Candiru, too:

On a separate note, Bradbury seems to have Delusional Parasitosis in mind in the Illustrated Man.  In that book, Ray Bradbury has his protagonist say this about his tattoos:

“Sometimes at night I can feel them, the pictures, like ants, crawling on my skin.”

Anthony writes:

Beware of ticks bearing young?

A search in Google books using the keywords tick, viviparous yields

Melophagus ovinus


Johan writes:

Here is a bit of additional information on the mosquitoes/mosquitos “controversy”.

I came across the diversity in spelling in a tweet by Darren Naish.

As I had Parasitic Diseases 6e open on my computer, I searched for both spellings and was slightly surprised to see both variants, so I went to Google Books Ngram Viewer

It appears the usage drifted towards ‘mosquitoes’ starting in the early 1820’s but ‘mosquitos’ has never completely disappeared from usage.

Screen Shot 2017 04 30 at 19.45.11 1140x403———

As to the pronunciation of my name, there are two answers as I have lived 30 years in California and I gave up a long time ago to make Americans people use the Swedish pronunciation. People just don’t hear what they are not expecting.

So, here is the American version followed by the Swedish version.

Anthony writes:

Deterioration of basic components of the anti-predator behavior in fish harboring eye fluke larvae

Monday, 15 May 2017 09:08

Tape test - TWiP 133

TWiP solves the case of the Woman With Anal Area Discomfort, and discuss the multiple functions of a clathrin adapter protein in formation of rhoptry and microneme secretory organelles of Toxoplasma gondii.

Monday, 15 May 2017 09:02

TWiV 441 Letters

Jean-Michel Claverie writes:

Dear Vincent:

Roaming on the net, we discovered yesterday that you dedicated a whole episode of TWiV (440) to Noumeavirus. Thanks for contributing to our fame ! 

Even though you made fun of me and Chantal about our style (“strict” embargo, circumvolution, etc …) we were impressed by the details in which you went through the paper. Good job. I wish our students/postdocs would go into such details too.

However, some of the questions you asked were actually answered in the …. supplementary materials (such as messenger polyadenylation). As for tracking the viral DNA inside the host cell, we tried (using EdU) but had no success yet. Same in expressing other GFP-tagged proteins. This is unfortunately tricky in the Acanthamoeba system.

As mentioned by Richard Condit, such experiments have been attempted with Poxviruses for dozens of years without success …. so give us more time.

As for the recent paper on the new “super giant”  Klosneuviruses authored by Schulz et al (with Koonin), I (and others) have huge reservations about it, and I will probably post my comments about it on PubPeer and/or pubmed in the near future. Basically, I don’t believe in viruses until I have is isolated in a tube. I believe ICTV does agree with me in not taking for granted metagenomic assemblies as good enough evidence for “new” viruses, especially “revolutionary” ones.

Thanks again for your interest in our research,

Bien amicalement and meilleurs souvenirs,

Jean-Michel & Chantal

Nir writes:

Hi all,

I just finished listening to TWIV 440 where you discussed the transient disruption of the nuclear integrity by the giant Noumeavirus. Rich mentioned that he thought the evidence was not conclusive as to rule out the possibility of the viral DNA first entering the nucleus to initiate transcription. This reminded me of the entry process of two small DNA viruses, SV40 – a member of polyomaviridae (with a capsid of 50nm) and MMV (minute virus of the mouse, a member of parvoviridae with a capsid of ~26nm). Both of these viruses transiently disrupt the nuclear envelope integrity during their entry into the nucleus. Similarly to what was described for Noumeavirus, these disruptions consist of transient morphological changes in the nucleus and increased “leakiness”. I’ve attached the relevant papers.

Keep on the good work,

Nir, a postdoc in gloomy Chicago, where the weather is currently 7 C, cloudy and nowhere near as nice as back home in Israel…

Trudy writes:

Dear TWiVers,

I am writing this letter in response to Allison’s letter on TWiV 440 regarding adverse effects of vaccination. Since Alan seems to think that anecdotes are more likely to attract the attention of people who are opposed to vaccination, I would like to offer a few of my very own personal anecdotes.

Anecdote Number 1: I had severe cases of the flu two years in a row, in 1998 and 1999. I remember those years exactly, because the illness was so debilitating that I remember wishing for nothing more than good health. Both times the illness lasted a total of two months, mostly due to the bronchitis that developed as a secondary infection. I will never forget the misery, the pain, and the feelings of hopelessness and uselessness because I just wanted to feel healthy and productive again. Since 1999 I have been getting a flu shot every single year and since then, I have not had the flu. I have been around plenty of people who had the flu, especially family members and co-workers who refuse to be vaccinated. This year in particular was a very difficult flu season, with lots of co-workers missing work repeatedly for extended periods of time. I however, still did not get sick. If I did get infected with influenza virus in the past 18 years, the illness manifested itself with minor aches and pains which maybe lasted a total of 1-2 days, and after which I felt completely healthy again. This is consistent with reports indicating that even if the flu vaccine fails, in most cases, the severity and duration of symptoms are significantly reduced. (Sorry, I used a statistical term… I just can’t shake the scientific approach…)   

Anecdote Number 2: My children, who have also received the flu vaccine every year of their lives, including during their in utero season, have never had a full blown case of the flu. If they did get sick, the illness lasted a total of 1-2 days, and they NEVER developed any respiratory complications. In addition, they are, at their respective ages of 1 and 3, completely up to date on their vaccines, and they have never had any adverse effects from their vaccinations, besides the slight elevation in body temperature that sometimes occurs the night following vaccination. They have also never had any other serious infections. They have never had the measles, mumps, or rubella. They have never had polio, diphtheria, rotavirus infection, hepatitis B, pertussis, tetanus, bronchitis, pneumonia, or chickenpox. And because they haven’t had any of these diseases they haven’t passed them on to other children. You know what else they haven’t had?  Smallpox. And you know why? Because Smallpox was eradicated with a very effective vaccine more than 35 years ago.

Anecdote number 3:  I did NOT receive the MMR vaccine as a child, and consequently I had a full blown case of the mumps at the age of 7. I remember the illness distinctly, as I was bedridden for at least two weeks with extreme pain in my salivary glands. I specifically remember the pain as I tried to lift my head off the pillow, which you have to do every time you turn in bed, or get up to eat, or go to the bathroom. Even though I obviously eventually got better, this disease left me deaf in my left ear… 85% deaf to be exact. While it is not the end of the world, and I am perfectly healthy otherwise, 85% deaf on one ear means you can’t hear sound in stereo, so you often don’t know which direction sounds come from (e.g. elevator dings, people calling your name in crowded places, car horns, etc.). You’re also a nuisance to the people around you, as you’re constantly asking them to repeat themselves. You listen to music and audio really loudly, once again annoying those around you. You always watch movies with subtitles on, in order to keep the volume at a reasonable level, so as to not annoy those around you. You may not hear people when they’re talking to you from the affected side, especially in environments with the slightest background noise. If people don’t know you or about your disability, this can create some social awkwardness. Whispering anything into that ear is completely out of the question, as is telephone use on that side. Long story short, it is a major, MAJOR nuisance. It may even be a hazard at times.

What I have noticed with this entire anti-vaccine sentiment is a very unfortunate glorification of the old days, because life was allegedly so much simpler and “less toxic” back then. But that is not so. People routinely lost children to simple bacterial infections. Women routinely died in childbirth. Surgery of any sort was always very risky. My own distant family history is rampant with infant, child, and adult deaths from pneumonia and complications from various other bacterial infections. Why do we forget that?  Maybe we need to remind people about science history.

Anyway, keep TWiVing, dear TWiVoners.

Kind Regards,


Jeffrey writes:

I guess one could say that the AHCA bill is the kind that makes you sick.

Jessica writes:

Good afternoon Beacons of Viral Education,

Episode 424 was a contemporary favorite. I’m writing to win but also in regards to the discussion of prion diseases. In episode 424 it was said that vCJD prevalence was rare in the population but I wanted to ask– is it? The fact is, given the potential long duration of the pathogenesis of this disease AND the fact that we do not routinely test the expired for presence of vCJD unless they were symptomatic, I think it’s a pretty big assumption that it’s rare! I think the newly developed assays are going to be extremely valuable in contributing to the prevalence numbers in given populations. Perhaps the rate is low but we will hopefully find out once the non-invasive assay is refined and approved. Even then the sample size may remain small because without a cure or therapy people may not elect to be tested.

In regards to the containment question–thank you Alan for asking!!!! As a Biosafety professional it makes me heart sing to hear such important researcher-safety questions raised.

In my job we discussed this very issue of appropriate handling practices involving human brain tissues with microtomes or cryostats. Considering the paper (Haybaek et al

I thought you’d covered this last year or before?) that demonstrated transmission of prion disease through the aerosol route, it seemed unnerving not to play it safe and recommend containment for this activity. Especially knowing that the true prevalence of vCJD in the population is unknown!

In any event, I loved the discussion and as a previous field research technician responsible for removing deer brain stems with an apple corer to test for CWD, prions have been an interest of mine since the days of my undergraduate career.

I hope I’m #17 because I love the topic of infectious diseases as much as I love traveling to far flung places and eating weird things. The way I look at it is, the cultural, social and potentially medical adventure I may go on will add to my varied and interesting life story either way and worst case maybe make for a interesting epitaph!

In any event, I love the show and wish there were more time in a day, week etc. so I could consume all episodes of the whole suite. I especially love listening to such provocative content when even NPR nauseates me for reporting on (and I realize they have to) the flagrant stupidity of the newly appointed administration (you don’t have to repeat that aloud!).

Thanks again,


PS In RI, it’s 42F and 59% humidity with a gale warning in effect

PPS I wish Blue Apron had a holiday giving program where you could order meals for families in need (food deserts!)

Ted writes:

To the wonderful faculty of TWIV,

Recent mention of Dr. Richard Kessin’s book, The Famine of Men, whose main premise is that a virus has made all males sterile, while not affecting women, brought to mind the late crime novelist P.D. James’   uncharacteristic foray into science fiction, the dystopian novel, The Children of Men.

The James story is set in England in 2021 and its premise is that due to universal infertility of unidentifiable etiology, no babies have been born since 1995. One female who is a member of a dissident political group finds herself pregnant and the plot revolves about the small band’s flight for survival.

 The early pages of the novel contain the author’s well crafted take on Western’s science’s achievements which I think you will enjoy:

“We are outraged and demoralized less by the impending end of our species, less even by our inability to prevent it, than by our failure to discover the cause. Western science and Western Medicine haven’t prepared us for the magnitude and humiliation of this ultimate failure. There have been many diseases which have been difficult to diagnose or cure and one which almost depopulated two continents before it spent itself. But we have always in the end been able to explain why. We have given names to the viruses and germs, which, even today take possession of us, much to our chagrin since it seems a personal affront that they should still assail us, like old enemies who keep up the skirmish and bring down the occasional victim when their victory is assured. Western science has been our god. In the variety of its power it has preserved , comforted, healed, warmed, fed and entertained us and we have felt free to criticize and occasionally reject it as men have always rejected their gods, but in the knowledge that despite our apostasy, our creature and our slave, would still provide for us; the anesthetic for the pain, the spare heart, the new lung, the antibiotic, the moving wheels, and the moving pictures. The light will always come on when we press the switch and if it doesn’t we can find out why.”

Thank you all for the wonderful podcasts. May you keep the lights on in good health for many years to come.

Ted Splaver DMD

Adjunct Faculty, Department of Oral & Maxillofacial Surgery, College of Dental Medicine, NOVA SE University, Davie/Ft. Lauderdale, Florida

Cait writes:

Hi TWiV folks,

First time writing in after listening for about a year and a half, and hoping I’m the lucky winner for the book contest! I fell behind a few weeks so I was pleasantly surprised while listening to this past sunday’s episode to hear you still hadn’t reached #27. Hope I’m it!

While catching up, I was excited to find the previous episode (#429) was taped with a group from the University of Wisconsin. I am from Madison originally and graduated from UW in May of 2014. During my last two years I was lucky enough to be an undergrad in Andy Mehle’s lab (influenza transmission) and it’s great to hear about all the cool work going on in virology back home.

I also just wanted to say thanks for all you do. Your podcasts help me get through my long days as a lab technician while I patiently wait for my boyfriend to finish up his PhD in microbio. Soon it will be my turn to go to school (applying to virology PhD programs this fall!) and TWiV keeps me up to date with the ever-evolving field of virology. Thank you for the intelligent discussions and laughter!



PS: In case you are still polling, I do listen all the way to the end of the episode!

David writes:

Hi, Twivniks,

It seems like every week I have an idea to write you about but never get around to it (do you have a round tuit, to spare?).

Anyway, this topic really strikes home so I am extra-motivated to contribute.

With respect to your discussion of potential protein folding disorders that have non-neurological consequences (twiv 431), there is at least one class that I am personally aware of. Desminopathies are caused by mutations in the gene that encodes the scaffold protein desmin, a component of the muscle contractile apparatus. At least in its autosomal dominant forms, desminopathy results in the accumulation of mis-folded aggregates in muscle cells that eventually produce what is called myofibrillar myopathy.

People with desmin mutations can present with muscular dystrophies that have varying ages of onset and rates of progression. The one in my family has a fourth to sixth decade-of-life onset, usually appearing as a limb-girdle-type dystrophy, affecting use of the legs and, more slowly, the arms. Loss of ambulatory function sometimes may not occur until the eighth decade. Perhaps the slow progression arises because “garbage disposals” in cells can deal with the mis-folded aggregates until they become too abundant, or the cells get “too old”.   

Desmin is particularly abundant in cardiac muscle, and desminopathy can manifest as both cardiomyopathy and conduction disease. Sometimes the consequences of the latter, before any skeletal muscle issues surface, are the first sign: sudden cardiac death can result.

Other organ systems in the body that depend on muscle function also can be affected.

I wonder if the cellular turnover (or lack of same) in a tissue is critical for whether it’s likely to be affected by a protein folding disorder. Cells that turn over rapidly might not allow accumulation of the aggregates. On the other hand, cells like neurons, and maybe muscle when there isn’t a lot of turnover, might be more susceptible. If the hypothesis is correct, one might expect exercise to slow the progression. I don’t think the relationship between desminopathy progression and exercise has been examined. This is counter-intuitive, don’t you think?  Because you might predict that constantly breaking down muscle and trying to rebuild it in a person with a muscle disease would be deleterious, not favorable.

So much for this diversion.

It’s currently 63° (17°C) with cloudless skies in Hershey, Pennsylvania. We’re expecting 1-3” of snow after midnight. Don’t you just love March in the temperate zones!

Virology Rules and you folks are the Court Royale!

Best regards,


David J. Spector, Ph. D

Professor Emeritus of Microbiology and Immunology

Penn State Hershey

Jon Yewdell writes:


  1. Many thanks to you and the TWIV crew for another fantastic year of podcasts.
  2. Now for the pedantic comment. In TWIV 422, there seemed to be a consensus (@ 43 min) that the CNS is a dead end for viruses (in this case Zika). Rabies provides a clear example where CNS infection plays a critical, albeit indirect role in virus transmission, since the increased physical aggression driven by the virus (which can even be seen in humans, though not in this gruesome video ), fosters transmission through biting, as viral replication peaks in the salivary glands. It is plausible that CNS infection can foster transmission of mosquito borne viruses through numerous mechanisms. These include changing host behavior (making the patient less likely to avoid/prevent mosquito bites, thus favoring transmission), modulating the immune response (the CNS plays an underappreciated role in systemic antiviral immunity; see attached papers for participation of sympathetic nervous system in flu immune response), and like herpes viruses, infecting nerves that deliver the virus to barrier tissues (e.g. skin, mouth). The TWIV panel can probably come up with other potential mechanisms in a blue-sky discussion.
  3. A proposal. How about a father son TWIV episode?  Would be a first?  My son Teddy is a post-doc at Sloane Kettering. Though a virologist only by inheritance, he is working on B cell responses, and using flu as a model antigen (we just published our first co-authored paper). This could be really fun, and provide a new perspective on scientific careers.
  4. Very best wishes for the new year!


Karin writes:

Long time listener, first time caller!

I have read about extracellular morphological changes in archaeal viruses but can’t find such a technique in any other domain. I thought I would ask the experts.

Spreading the TWiX world here at Stony Brook,


Anthony writes:

I’ve been thinking of this in the letters to TWiV 425:

“My question for you and your many guests is what are the anomalous and unexplained phenomena in virology today – the facts and circumstances that defy explanation by the standard model?”

# # #

Before giving an answer, I’ll have to be very confident of knowing “the standard model.”

A few things did come to mind. If memory serves me correctly here

Sam Walton notes that in the early days of computer generated sales reports, He’d go into the office at a quiet time. (2 am Saturday morning?)  He’d place the stacks of big fanfold printout paper on the conference room table and then walk up and down looking for outliers. When he found a store doing better with some item, Sam Walton would call the manager to ask what they were doing.

Somewhere I read that the SEC “trolls” for insider trading by casting out an algorithm for every stock quote to swim through.. The software nets behavior that does not mirror the market,  If there’s later on some public announcement that explains the previous up or down movement, the SEC considers investigating.

Clearly, insight and intuition will be self-seeding in the garden of the prepared mind. Even so, might there be devised automated nets for fishing in the growing waters of metadata?

And, before anomalies can be caught, the trend needs to be known.

“’Information overload equals pattern recognition.’ At instant speed the hidden becomes plain to see.”

Marshall McLuhan


Brandon writes:

Dear TWiV consortium,

            First, please forgive my formatting, for I am not much of a letter writer. Second, my name is Brandon from Denver Colorado, a long-time listener who has only emailed once. Even that was a halfhearted attempt to win one of your contests. As for the weather right now I look out from my desk to a somewhat overcast 18 C day, expecting snow over the next two days. We are long overdue for our March snow storm but I enjoyed the ~22C weather while it lasted.  

            I write for no particular reason; a large part of it is the admiration I have for you all, part of it is that I have eked out just enough time to put together an email for you all, something I’ve wanted to do for a long time. My favorite episodes are TWiV 373 with Dr. Younger and TWiV 395, The Cancer Thief, I have listened to those episodes many times over and have stopped me from remaining current. As much as I love the usual gang, your interviews with other distinguished virologists tend to be especially riveting.

            Now a little about myself (the least interesting part, I assure you). I am a high school dropout from a family of high school dropouts that eventually realized school is cool. I went back and finished my high school diploma and I am now in my final semester as an undergrad, earning a degree in Biology with a minor in chemistry. I am proud to say I will be going to the University of Florida to pursue a master’s degree in microbiology this upcoming fall, something that has never felt real or possible. I often have felt like quitting everything, but the Good Doctors of TWiV help keep me motivated. Through your constant humor (or “humor” from Dickson), stimulating discussions and continued desire to learn. Thank you all for the work that you do.

Tiredly yours, Brandon


P.S. I do find Dickson quite funny and appreciated his attempt at the OVER 9000 meme. I often find myself rolling my eyes with a smile on my face after one of his puns.

P.P.S There is a Regional Conference for ASM on April 15th that I am excited to attend and I thought others might be interested.

P.P.P.S I miss Rich.

Steve writes:

Hi Vincent et al,

I just read this brilliant editorial view from Richard Horton, and I think it would make a great listener pick, and deserves wide circulation for pinpointing one of the most insidious and damaging trends of our time.

Who knows: it might even help him see we don’t just like harassing him over PACE! 

“Difficult truths about a post-truth world.”  Lancet 170401

This is a great piece from Richard Horton, editor of The Lancet. It should remind us all that, while Brussels may seem to have more of a ‘green’, ‘socially responsible’ face than our own rabid government, the EU exists for the explicit purpose of promoting business, and is run by the business lobby, for the business lobby.

Especially note how the principle of truth of scientific objectivity, is being encouraged to be thought of as just another biased view from vested interests. This lobbying angle literally is capable of destroying worlds.

All the best,





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