Case guesses:

Daniel writes:

Dear Tripartite

I enjoy your podcasts, especially TWIP.  I am very familiar with Dr. Despommier’s background, that of a medical laboratorian. I have been teaching diagnostic microbiology/parasitology/mycology/virology to medical laboratory science (MLS) and medical laboratory technician (MLT) students for over 25 years.  He and Dr. Griffin often give a shout out to all of the hard-working people behind the scene who help clinicians.  Next week, 4/23 – 4/29, we celebrate National Medical Laboratory Professionals Week.  The general public hardly knows we exist, but we supply critical information that a physician can use to make life-saving medical decisions.  And right now, there is a nation-wide shortage of qualified MLS and MLT.  Your listeners can find lots of great information at the American Society for Clinical Laboratory Science website.

Thanks again for the great podcasts. I’m still waiting for TWIF!

BTW: I’ll guess Paragonimus westermani for this week’s case. I introduce this one in my medical parasitology course, so if I get it wrong I will not hear the end of it from my students!

Daniel P deRegnier, MS, MT(ASCP) | Associate Professor | CLS Program Coordinator

Ferris State University | College of Health Professions

Clinical Laboratory Sciences | Big Rapids, MI

David writes:

Dear TWIPanelists,

This case with hemoptysis appears to be straightforward.  It’s hard to imagine that the subject of this case was not worried right away when he coughed up blood.  He must have abstained from visiting a doctor right away out of anxiety for the results, until eventually the duration of the symptoms and his family members’ constant nagging to get professional help won him over.

The culprit is seemingly a lung fluke of the Paragonimus species. Parasitic Diseases 6th edition describes Paragonimus Westermani, but I am quietly considering whether it could have been P Siamensis given the geographical location.  The symptoms match and the eating of crab has likely played a role in becoming infected.

Treatment would be praziquantel or albendazole. I wonder if his postponing his visit has seriously worsened the outcomes, but it cannot have helped.

It is real hot in Nicaragua right now, with temperatures getting near to 100 F – lately I try to “feel” what temperatures in Fahrenheit are like as Vincent recommended in TWIV, as I spent my whole life feeling in Celsius instead.

Thank you so much for your show, it is so much more than just a podcast.

Iosif writes:

Dear Twip Team,

My guess for this case would be paragonimiasis which he most likely obtained from his diet of Som tum. Diagnosis could be made from the findings of eggs within the sputum. While, you could do a BAL in this patient, I think that a sputum would probably be a better choice. Praziquantel for three days would be curative.

In this case, once I had the results from the sputum I probably would not test for TB, but would it be a good idea to get a PPD or a quantiferon gold along with the sputum initially?


Iosif Davidov

Hofstra Northwell SoM

Class of 2018

Nita writes:


    Hello, TWIP-tastic peeps! This is Nita the hopeful neurology MS4. I did a happy little dance when I listened to the last podcast and got brown recluse correct. Didn’t get the correct species, though.

    For this new case with our Thai man who is obsessed with crab som tum, my primary differential is the lung fluke paragonimiasis. P. westermani is common in asia-pacific, and can infect those who consume undercooked crab or crayfish. The larva penetrates the intestines and matures, eventually returning back into the abdominal cavity to penetrate into the diaphragm. Initial signs can include diarrhea, abdominal pain, chest pain, and fatigue. Eventually, when the fluke enters the pleural space, dry cough that can become blood-tinged can occur. The signs can mimic TB, so ruling this out for our patient would be important. Paragonimiasis can enter the cns and eventually cause meningitis. Diagnosis is made though sputum or through feces. Treatment is triclabendazole I believe.

   Other crab-related parasites include angiostronglyus that causes bacterial eosinophilic meningitis. This resolves spontaneously usually, and I don’t think dry cough is usually a classic sign.

    Of course, the sexy guess for this case would be sacculina, the castrating barnacle parasite. It causes behavioral changes in the crab and arrests its reproductive development. It even tunnels its growth into the sexual sac of the crab!! Talk about some parasitic manipulation! I really enjoyed the book This is Your Brain on Parasites, which talked about it. Highly recommended!

Included are my happy face at the meguro museum and a sacculina manifesto! Thanks again for the awesome podcasts!

Brian writes:

Good day ViroMediSite docs! (That’s is my own portmanteau for my favorite podcast hosts!)  I’m back, it’s been a while since my last email for the case study guess and I have been playing catch up on past episodes. In case you have forgotten, I am the guy that likes to listen at work and also tries to type while working. Though I think I am too old for this as I usually make many mistakes, the millennial generation is much better at this. Nonetheless, I am on my smart trying to multitask.

My guess for case 131 is Paragonimiasis caused by P. westermani.  I love this parasite and i have been interested in since reading a case study in my undergraduate parasitology class. I think you even covered the same case from St. Louis involving P. kellicotti from the surrounding areas, some of which I have visited during summer getaways. This parasite is acquired by consuming raw or undercooked crustaceans harboring the infective metacercariae that excyst in the duodenum and then it burrows through the intestine, peritoneal cavity and diaphragm into the lungs where it encapsulates and develops into an adult. I think it takes about 2-3 months to begin egg production.

However, there is usually more symptoms such as, abdominal pain, fever, and weight loss and eosinophilia.

So, that’s my guess, and even though I don’t always write in (if you can call my barely coherent rambling, writing) I do listen to all the TWiX series with this being my favorite. Keep them coming! And just because it can’t be said enough… be nice to Dickson!

Thank you,


Suellen writes:

First, an important note: My name is pronounced SUE ELLEN. I can’t help that my mom decided to shove it together and make it one word. I’m used to it being mispronounced, and I adore you guys and your show, so I am not taking offense, just correcting.

Loved the last episode, even though I once again failed to provide the correct diagnosis. At least I’m consistent! But I’m not happy with my performance thus far, so I’m going to try to get it right this time.

There is not much to go on with our Thai guy, the main symptom is that he’s vomiting blood. Based on the location (Thailand) and the patient’s eating habits, I’m going with Paragonimiasis, or lung flukes. To quote my primary source, the Southern Nevada Health District’s web site:

Humans most commonly become infected by eating raw, undercooked, salted or pickled freshwater crabs or crayfish that contain the parasite inside a cyst. One study found that approximately 17 percent of harvested crabs contained the infectious cysts.

I’m not going to add much to this, since if I got it wrong again, I don’t want to go on and on like I did last week with the wrong diagnosis. My guess could be confirmed by checking for eggs in the patient’s sputum. If it does prove to be Paragonimiasis, then praziquantel seems to be the drug of choice. (An aside, I use praziquantel to help control large and small strongyles in my horses.)

Keep giving us these great podcasts. I listen to all of them, and I really enjoy learning all the cool stuff in them.



David writes:

Dear Hosts,

After being stumped for the last few case studies, I have returned to once again partake in the parasitic puzzler! I believe the man in Thailand suffering from hemoptysis is suffering from a lung fluke in the Paragonimus genus contracted by the consumption of raw crab.

  1. westermani occurs primarily in Asian countries such as Thailand, China, Vietnam, and the Philippines. The CDC website notes that “specialty dishes in which shellfish are consumed raw or prepared only in vinegar, brine, or wine without cooking play a key role in the transmission of paragonimiasis”, and salted crab som tum seems to fit into this category nicely. Treatment for paragonimiasis includes praziquantel given at 75 mg/kg per day with 3 doses taken over 3 days.

The weather has finally been looking up: it is a very pleasant 21 degrees Celsius and mostly cloudy in North Grafton, MA. Once again, thank you for the informative podcasts.


David P.


Anthony writes:

In TWiP #131, there was a brief discussion of arthropod illusions and delusions — the perception / imagination of being bitten by spiders and of things crawling on or in the body.  I’d not thought of it in over thirty years, but I ran across something perhaps similar.  One of the many things that I did in the hope — generally futile — of generating income was to run a residential exterminating business.  I answered one call in nearby North Hudson and was let into a well kept apartment.  The tenant — a non-immigrant in his early 40s — explained that the place was filled with very small flies that he was unable to get rid of.  There were no flies.

With these papers in mind:

A Case of Delusional Parasitosis Associated with Multiple Lesions at the Root of Trigeminal Nerve


Apotemnophilia: a neurological disorder

Might Delusional Parasitosis be a form of Apotemnophilia?

“Self-mutilation can occur in severe cases. The wounds appear in areas accessible to the patient, where they have attempted to excavate the parasites.”

Is Delusional Parasitosis one of “such curious conditions that stand in the hinterland between neurology and psychiatry”?  Curiouser and curiouser indeed!

With an organic basis, alleviation may result from suggestion while the affliction does not.


Thank you.

BTW, here:

they appear not to be updating the TWiP Page.  At a quick glance, the other Pages for your podcasts at Microbeworld look OK.

Anson writes:

Hello TWIP podcasters,

I’ve been studying Haycocknema perplexum for the last two years.   A friend recently shared with me your podcast and I thought I would write in.   

Haycocknema was originally thought to be Trichinella pseudospiralis but subsequent cases showed it to be something completely different (Several papers were published on the initial case calling it T. pseudospiralis). Dave Spratt and Ian Beveridge named it Haycocknema (after Peter Haycock who was the first to dissect out an intact specimen) and perplexum (due to the amorphous cell supporting a gourd-shaped reservoir in the rectal region containing one or more refractile, thick-rimmed globules).

Dave then placed it within the Muspiceoid nematodes due to morphological similarities with other strange nematodes, some which are found in Australian marsupials.  The Muspiceoids were grouped in the Dorylaima nematodes.  There are two families:  Muspiceidae which are found in mice and bats and the Robertdollfusidae found in humans, birds, marsupials and reindeer. Only one muspiceoid sample (cox1 from a bat) was on GenBank. I was able to sequence cox1 and 18s for Haycocknema and it does not group together with the bat sample.  The closest match on genBank has ~90% similarity which can be a problem when you are trying to pinpoint where it fits in on the nematode tree.   More sequences from the different “Muspiceoid” genera are needed to help place them with higher confidence.  Right now Haycocknema falls near the Oxyurids and Rhigonematids (millipede nematodes).   Interestingly these historically have direct or insect-related life cycles. Larval Robertdollfusidae stages have been “identified” in midguts of black flies in Cameroon and in midges of Australia.  

When you look at the known cases from an epidemiological perspective the bush meat hypothesis doesn’t really hold up.   The first patient (a vegetarian botanist in Tasmania) claims to have strayed by eating wallaby once or twice. Two other patients claim to have never eaten native animals. Perhaps the initial diagnosis of T. pseudospiralis helped to fuel the bushmeat hypothesis in subsequent cases?  More genetic evidence from a variety of muspiceoids is needed to help clear it all up.  

Incidentally, the Haycocknema-like nematode found in the Swiss horse is most likely Halicephalobus gingivalis.  Perhaps another interesting candidate for a future podcast?   We just had the first case of Halicephalobus here in Australia a few years ago. The case in the UK with the kidney transplants is quite terrifying.

I created a powerpoint last year for a talk at the ICTMM conference in Brisbane that features both H. perplexum and Halicephalobus if you are interested. I would include it but it is over 10MB.  

Looking forward to hearing more of your future podcasts.


-Anson Koehler

Dr Anson Koehler | Molecular Parasitologist | The University of Melbourne

Johan writes:

Dear parasite fanciers,

Why are there two spellings of mosquito[e]s in Parasitic Diseases 6th Edition?

  • mosquitoes 84 times
  • mosquitos 4 + 1*

Sincerely Yours,



Sollentuna Sweden

*) There is one occurrence of “mosquitos” in the title of “Mosquitos, Malaria, and Man.” by G. Harrison, 1978, but I don’t think that counts.

Deborah writes:

Hello gentlemen,

I am neither a student, doctor, scientist or anyone else related to your world.  I am someone who has recently been diagnosed with Rheumatoid Arthritis.  I’m 47, and was under incredible amounts of stress when my symptoms began.  

Now that I’ve been diagnosed, I’ve found everyone has a treatment for me, and of course, coming to you, I’ve been told about helminth therapy–taking hookworm pills.  I’ve listened to a few podcasts and you seem like you would be the exact people to debate the implications of autoimmune sufferers to begin introducing hookworms into polite society.

What do you think of this?  Have you discussed this before and I’m not seeing the podcast?

Thank you,


p.s.–I found you through pinterest!

Dave the sheep shearer writes:

Good day good Doctors.

Thank you for the interest in my tickology. Further to the babies coming out of the cut in half “tick”. This happened about 15 years ago so pre digital camera (for me) and smart phone so no pics except the ones burned into my memory chips. So here goes. The “tick” was in the area clear of wool on beside the ewe’s udder (yes we have to shear right up to the udder so that the new born labs don’t suck on the wool). It was clearly a tick, fully engorged with tiny legs sticking out on the sides. It was still attached to the ewe. This was not a spider (very short legs sticking straight out from the body) It was in a clear area so when I cut through it I could see that the “babies” came out of the black blood coming from the cut tick.

My wife just reminded me that we took a tick from our dog here at home in southern AB that had live babies in it. This was about 12 years ago

A further note I am currently down with what appears to be Lyme. Likely contacted 3 years ago (when the symptoms started) shearing alpacas in the Okanagan area of BC. This year from one alpaca we took 20 ticks off. 5 black legged deer ticks, 8 what were referred to as Rocky Mountain Spotted( brown tick with a white spot/spots and the rest I couldn’t ID. Wanted to take the zip lock that the owner put the pulled ticks in so I could study the but got vetoed. The pics I took didn’t turn out so I’m sorry but don’t have photo proof .

Dave the shearer in rainy southern AB. Thank you for the wonderful podcast. If I had science teachers like this in school I would have been hooked on science

ps the owner of the alpacas was from Switzerland and had the handiest tick remover that he brought from that country. It looks like a credit card with a slit in one corner. You just put the card against the skin, lining the slit up with the tick. You then slide the card forward until the slit engages the tick. Then you can roll the card over, this action pulls the tick and you can examine the bottom side of the card to make sure you have all the parts of the tick. I’ve tried the “TICK KEY” and it doesn’t work near as well. Can’t remember the name but will try to get the name if you are interested.

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