Parasitology club of Central Lancashire writes:
Dear TWIP professors,
Greetings from Parasitology Club at the University of Central Lancashire in the beautiful northwest of England, currently the weather has started to bring us autumn it is 6c in the evening and 15c in the day the UK weather is not so cold for this time of year.
We would like to add our considered opinion for the elderly Guatemalan gentleman with multiple co-morbidities who was admitted to the ‘Acronym City Hospital’ with right bundle branch blockage, and diarrhoea for an unspecified period.
The most probable cause of the condition is flagellate protozoan parasite, Trypanosoma cruzi which causes Chaga’s disease. The infection is spread through vector borne transmission when parasite trypomastogotes are introduced through broken skin or mucous membranes from the excreta of triatomine insects in areas of endemicity (CDC, 2022). However, Fujita et al (2019) in Brazil reported an association between Chagas disease and the consumption of contaminated Açaí fruit products.
Infected triatomines release trypomastigotes which gain entry through a wound or mucosal membranes. Trypomastigotes differentiate into intracellular amastigotes which replicate by binary fission. Amastigotes differentiate into trypomastigotes which are released into blood stream and infect wide variety of tissue and may be ingested in a blood meal of the triatomine bug. The trypomastigotes transform into epimastigotes in parasite’s midgut and differentiate into infective metacyclic trypomastigotes in the hindgut and are excreted in faeces (CDC, 2019).
A minority of patients develop an acute syndrome for 4-8 weeks. These symptoms include prolonged fever, subcutaneous oedema, myocarditis, and meningoencephalitis. The acute syndrome resolves even if it is not treated with antibiotics. In 30-40% of cases, cardiac or digestive disorders similar to those experienced by the case develop (Marcolido et al., 2015).
Trypanosomiasis is endemic in South and Central America and parts of North America and eight million people are affected (CDC,2022). In a study by Bochi et al., (2017) of Latin Americans living in Los Angeles suffering from right bundle branch block right bundle branch block and left anterior fascicular block, 17.9% had Chagas disease.
During the acute phase, treatment is focused on managing symptoms and eliminating the parasite, benznidazole and nifurtimox are drugs of choice (Mayo Clinic, 2022). The chronic phase cannot be cured by medication but sudden cardiac death may be mitigated by heart transplant or implanted defibrillator- cardioverter devices (Bochi et al., 2017).
Thank you once again for a wonderful and challenging parasitology case.
Jaskirat and the University of Central Lancashire Parasitology Club.
Bocchi EA, Bestetti RB, Scanavacca MI, Cunha Neto E, Issa VS. Chronic Chagas Heart Disease Management: From Etiology to Cardiomyopathy Treatment. J Am Coll Cardiol. 2017;70(12):1510-1524. doi:10.1016/j.jacc.2017.08.004
CDC.gov (2022) American Trypanosomiasis also knowns a Chagas disease [online]. Available at https://www.cdc.gov/dpdx/trypanosomiasisamerican/index.html. [Accessed 17th October 2022].
Fujita DM, Nascimento MS, de Andrade Júnior HF. The oral transmission of chagas disease in Brazil: New food supplies and travel experience. Acta Trop. 2019;197:105038. doi:10.1016/j.actatropica.2019.05.029
Marcolino MS, Palhares DM, Ferreira LR, Ribeiro AL. Electrocardiogram and Chagas disease: a large population database of primary care patients. Glob Heart. 2015;10(3):167-172. doi:10.1016/j.gheart.2015.07.001
Mayoclinic. (2020). Chagas Disease [online]. Available at
https://www.mayoclinic.org/diseases-conditions/chagas-disease/symptoms-causes/syc-20356212 [Accessed 17th October 2022].
Greetings from a sunny day in Quebec, in Canada.
I am working in my archaeoparasitology lab with views to the St. Lawrence river listening to TWIP.
I am going to go straight to my diagnosis, I believe the patient shows signs of Chagas disease caused by Trypanosoma cruzi.
Although referred to as vector-borne disease, oral transmission of Chagas has increased in the past few years and the consumption of juices made with fresh fruit is identified as one of the main causes of this increase. The pathogenesis described aligns with the chronic symptoms of the disease. Orthostatic stress and slow heart rate have been observed in patients, and arterial hypertension has also been correlated to Chagas. Diarrhea is common in the acute phase, and since the patient has noted it for a longer period of time than the symptoms that took him to the doctor it may indicate persistence and a quick evolution to a chronic phase which has been noted in many orally-transmitted cases.
I found myself interpelled by this week’s case as I am working with archaeological remains that also show signs of the same infection. Looking at a disease with more than 9,000 years of infection to humans!
Thank you for all your work,
ps: consider me for the book please 🙏🤗
Greetings TWIP team,
I’m back from Bat Cave, NC, on this beautiful, sunny, 48 degree morning. My guess for the case in Episode 210 is Chagas Disease based on the man’s residence in Guatemala, where Chagas is endemic, as well as his EKG results and dizziness upon standing. Living in rural Guatemala in a thatched roof home is a risk factor for exposure to the Triatomine Bug vector. Chagas Disease is spread primarily via the feces of triatomine bugs infected with the parasite Trypanosoma cruzi. The parasite, present in the feces of the infected bug then enters the host through the bite wound. Additionally, vertical transmission and infection via blood transfusion are possible, and less commonly, Chagas Disease can be spread orally. The patient’s mention of enjoying fruit juice sparked my curiosity here.
High temperatures and lack of moisture can kill the T. cruzi parasite, as well as freezing. Ideal conditions for T. cruzi survival and growth include ambient temperature and liquid or high moisture content. As such, according to an article by Michael Miles in the Journal of Infectious Diseases, “palm, sugar cane, and fruit juices are therefore ideal contaminated sources for oral outbreaks, because they are often grown, harvested, and pressed locally, with the aid of artificial light, in rural or periurban areas where sylvatic triatomines may be abundant.”1
Specific to Guatemala, another study reported an outbreak of Chagas related to home-made guava juice. An outbreak was traced to in-home production of the juice, which included a period of time in which the juice was left out overnight, allowing triatomines and vegetation to fall into the juice, leading to contamination.2
Lastly, related to the EKG results, a slow heart rate and Right bundle branch block are common in patients with chronic Chagas Disease.3-4 Cardiovascular complications can also result in dizziness upon standing.
That’s my guess and I’m sticking to it. Looking forward to hearing your diagnosis,
Barreto de Albuquerque J, Silva Dos Santos D, Stein JV, de Meis J. Oral Versus Intragastric Inoculation: Similar Pathways of Trypanosoma cruzi Experimental Infection? From Target Tissues, Parasite Evasion, and Immune Response. Front Immunol. 2018;9:1734. Published 2018 Jul 27. doi:10.3389/fimmu.2018.01734
Diaz-Bello Z, Zavala-Jaspe R, Reyes-Lugo M, Colmenares C, Noya-Alarcon O, et al. (2016) Urban Trypanosoma cruzi Oral Transmission: from a Zoonotic Founder Focus to the Largest Microepidemic of Chagas Disease. SOJ Microbiol Infect Dis 4(1): 1-9. DOI: http://dx.doi.org/10.15226/sojmid/4/1/00147
Palmero HA, Caeiro TF, Iosa D. Prevalence of slow heart rates in chronic Chagas’ disease. Am J Trop Med Hyg. 1981;30(6):1179-1182. doi:10.4269/ajtmh.1981.30.1179
4. Rojas LZ, Glisic M, Pletsch-Borba L, et al. Electrocardiographic abnormalities in Chagas disease in the general population: A systematic review and meta-analysis. PLoS Negl Trop Dis. 2018;12(6):e0006567. Published 2018 Jun 13. doi:10.1371/journal.pntd.0006567
Dear TWiP Team,
So thankful for your monthly therapeutic rants! And the case studies are truly “parasitic” – they won’t leave my mind until I make an attempt at solving.
I believe the old man is suffering from chronic Chagas disease, caused by a Trypanosoma cruzi infection. He likely encountered an infected triatomine, reduviid bug, one night while sleeping in his thatched hut as a child in rural Guatemala. Or perhaps he drank some fresh fruit juice containing a squished bug or two. He may even recall having had a swollen eyelid, Romana’s sign, or a Chagoma, at some point in childhood.
At this time, his infection is in a chronic/latent phase and parasite persistence in tissues is the main mechanism of pathogenesis. In his heart, cell damage has caused myocardial fibrosis and disrupted the conduction system, causing the classic early finding of RBBB seen on his EKG.
I imagine that a serum IgG test, ordered by an astute ID doctor (and clearly NOT the cardiologist!), was positive. Two positive serology tests are needed to confirm the diagnosis.
Treatment options for this gentleman are limited. Both nifurtimox and benznidazole are limited by toxicity and poor cure rates, especially in ages over 50. They are indicated mostly for acute, congenital, or reactivated infection.
I read a 2019 PLoS Neglected Tropical Disease paper that discussed the use of prospective vaccines for both preventative and therapeutic purposes. Vaccines in mouse models have been shown to reduce parasite burden by redirecting the immune response. In this fashion, they might be capable of reducing both congenital transmission in pregnant seropositive women, as well as halting the progression of cardiac complications in chronic Chagas disease. Imagine that!
But, alas, science is not there yet……….so, I fear this gentleman’s fate rests in the hands of a narrow-minded cardiologist. A pacemaker will surely be implanted for his bradycardia and if he has signs of dilated cardiomyopathy and heart failure, other management such as diuretics, may help prevent even further progression.
Grateful as always! Kimona
Ps – Vincent, I guess I shouldn’t be surprised that you’d recognize my name (Kimona) – which was brought back by my grandparents who spent 40+ years in the DRC (old Zaire). My grandfather remains buried over there, having succumbed in the late 60s to the bite of a Tsetse fly and African trypanosomiasis (sleeping sickness). I don’t believe we had treatments back then.
Greetings from Washington DC, where ID week is about to begin and the US capital will be overtaken by infectious disease curiosos.
In regards to the gentleman from Guatemala, I suspect he has chronic trypanosomiasis from T. Cruzi infection leading to heart block. His endemic origin gives concern for this. If this gentleman would have been from midwest and enjoyed outdoor tick heavy activities, I might also suggest lyme borreliosis, however this is a parasite podcast. In chronic trypanosomiasis the diagnosis is confirmed with two serologic testing based on different antigens should be used in parallel to confirm accuracy of diagnosis.
Thank you for this excellent podcast and all the microbe TV content.
Alice Lehman MD, CTropMed® (she/her)
Adult and Pediatrics Infectious Diseases Fellow
University of Minnesota
My best guess is Chagas disease, caused by the parasite Trypanosoma cruzi . The insect vector is informally called the “ kissing bug, “ which often lives in thatched roofs in the Americas. It is known to cause heart problems if not treated early. It also has a history of transmission through blood transfusions.
I look forward to hearing the right answer! Tell Dickson I liked his sign off, and all of your podcasts worm their way into our waiting memories! I also listen to his Urban Agriculture podcast even though my memory is waning, or is the proper term, “contracting”?
Thank you to you all,
First Vienna Parasitology Passion Club writes:
A Guatemalan gentleman visiting the US presents with orthostatic symptoms, bradycardia and conduction abnormality.
When considering the combination of right bundle branch block and hemodynamically relevant bradyarrhythmia, we can divide our differential in two important categories: non-structural causes like electrolyte abnormalities, intoxications, etc. and structural causes. The most common etiology to consider would be ischemic heart disease and resulting cardiomyopathy. Other important causes are toxic cardiomyopathy (alcohol), genetic causes, valvular pathology, infiltrative disease and myocarditis.
The history of this patient is suggestive of two of these etiologies: His age and comorbidity put him at an increased risk for ischemic heart disease, while his country of origin, residing in rural areas and possibly the partiality to fresh fruit juices point towards Chagas disease as a cause for cardiomyopathy with conduction delays.
We recommend a repeat EKG, an echocardiogram, lab examinations with lipid profile, HbA1c and possibly hs-troponin to rule out myocarditis or an acute ischemic event. Furthermore, a serology for Chagas disease with both ELISA and IFA is strongly recommended. Imaging and/or endoscopy may follow in order to evaluate for other manifestations of the disease, including colonic disease (as a possible explanation for the diarrhea) and esophageal dilation and achalasia. Microscopic evaluation of the diseased tissue is not very sensitive and should not be routinely performed.
Chagas disease is caused by Trypanosoma cruzii, a distant cousin of the African trypanosomes that cause sleeping sickness. T. cruzii is transmitted by the “kiss” of the Triatomos bug, lovingly termed “Reduviido” by Prof. Racaniello. The bugs are commonly found in thatched roofs and clay walls in rural areas of central and south america. At night, the bugs transmit the trypanosomes via their stool during feeding. Another vector for the infection is fruit or sugarcane juice, as some triatomos bugs may be crushed during preparation of the beverage (which is why I recommend forgoing the sugarcane juice in favor
of the more invigorating Cachaça).
Therapy options for Chagas depend on whether the diagnosis is made during the acute or the chronic stage of the disease. During acute illness, medications such as benznidazole and nifurtimox can be used. These drugs may also be beneficial for congenital infection in infants and immunosuppressed individuals. For chronic Chagas disease, there is currently no curative medication available, but Benznidazole and nifurtimox may reduce disease progression. Another important factor when treating chronic Chagas disease is the management of Chagas-related heart conditions and gastrointestinal symptoms.
Millions of people in the endemic regions of Central and South America are affected by Chagas disease, 300.000 of which currently live in the US. The most important risk factor for contracting Chagas disease is poverty, as the buildings harboring the vector are usually clay constructions with thatched roofs, found in rural, underdeveloped areas. Due to this association, the diagnosis is associated with a great deal of stigma in endemic countries, which hinders attempts to improve surveillance and diagnosis.
Thank you for this great case. All the best,
Michelle and Alexander from the First Vienna Parasitology Passion Club
Hello all from beautiful Providence, where fall is in full swing. I have been meaning to write for a while now, and happy to do it now. I have been listening to this podcast during my Trop Med Diploma course and have recommended it to my other colleagues as well. This was a fantastic adjunct to the course, especially the first episodes of the show. I am now preparing for the ctrop med exam which is coming up in a few weeks.
This man from Guatemala likely has cardiomyopathy from chronic Chagas disease caused by American Trypanosome. Though primarily transmitted by triatomine insects, this patient could have gotten it orally since he loves fruit juice so much. This is a disease with a large public health impact and is now found outside of South America as well.
Thank you for the knowledge you are disseminating.
Fan of the show,
Ramu Kharel, MD, MPH, DTM&H
Assistant Professor | Department of Emergency Medicine
Student Internship and Communications Coordinator | Division of Global Emergency Medicine
Alpert Medical School of Brown University
Nepal Cluster Coordinator | Center of Contemporary South Asia
Raquel and Leon write:
Dear TWIP Team,
We are two ongoing scientists from Buenos Aires (Argentina) and Grenoble (France) who met each other one week ago in Brazil at a Trypasomosatids Summer School and now decided to solve TWIP cases together.
The cardiac involvement and the difficulty of detection, together with the conditions the patient grew up in let our bells ring: for us it sounded like Chronic Chagas Disease. EKG results showing RBBB is one of the hallmarks of Chronic Chagas Disease. The unspecified chronic diarrhea could also be a sign of intestinal involvement, therefore they should run some more tests to confirm it, though it could not be related at all. The diagnosis fits perfectly with the geographic and social situations where the patient grew up, since Trypanosoma cruzi is endemic in Guatemala. You can get infected with T. cruzi through the consumption of food (fruit juice!!!) contaminated with feces of kissing bugs.
Because of the patient’s pre-medical history and the nature of Chronic Chagas disease, is not surprising that the Cardiologist couldn’t find any evidence for an infection process. The blood sample taken at the first medical facility could have been tested for IgG, which is the standard diagnosis for Chagas disease, and this test had to be confirmed with a second IgG test, because one is not reliable enough.
PCR test at Chronic stage of Chagas is not routinely performed, but it could be worth to perform. The alternative would be heart tissue biopsy but might not be advisable for an old patient, especially with his previous medical history.
Treatment for patients over 70 with Chronic Chagas disease must be individualized based on risk/benefits of the treatment options.
Best greetings from two passionate Trypanosomes Scientists!
Raquel and Leon
Dear TWiP hosts,
It is a cool 13 degrees C here in Seattle, Washington. I am a long-time fan of TWiP and felt the time was long overdue to try my hand at the case diagnosis and a shot at the Parasitic Diseases text.
In The Case of the Heartsick Guatemalan Septuagenarian, the patient presents with an aberrant ECG, exhibiting both a right bundle branch block and a junctional heart rhythm with a rate in the 40s range. Both the bundle branch block and apparent absence of a functioning sinoatrial node is suggestive of at least two structural defects within the heart. These ECG findings, coupled with the history of rural living in Central America in decades past, raises the diagnosis of chronic infection with Trypanosoma cruzi to the fore of the differential diagnosis. T. cruzi is the protozoan parasite responsible for the disease known as American trypanosomiasis, also known as Chagas disease. T. cruzi is a vector-borne disease transmitted by nocturnal blood-feeding triatomine bugs, but sometimes is acquired via organ transplant, transplacentally, or via contaminated food and drink.
If the acute phase of Chagas disease goes untreated, the individual may enter a chronic phase in which the disease is latent, with symptomology appearing years or decades later. This symptomology typically manifests as structural gastrointestinal disturbances and/or cardiomyopathy. So-called Chagas cardiomyopathy can present with right bundle branch block and with various levels of atrioventricular junction blocks.
Until a diagnosis of Chagas cardiomyopathy can be confirmed via serologic testing for IgG antibodies to T. cruzi, prudent diagnosticians should consider other etiologies as well. According to the 9th edition of the Hunter’s Tropical Medicine text, these include ischemic heart disease, cytomegalovirus, HIV, post-streptococcal rheumatic fever, Lyme disease, histoplasmosis, systemic lupus erythematosus, and sarcoidosis, to name a few.
Management options of Chagas cardiomyopathy for this patient ranges from antiarrhythmic drugs to heart transplant. In this case, the progression of the disease is likely too far gone to consider the antiparasitic drugs benznidazole and nifurtimox, which are best administered during the early acute stage of American trypanosomiasis.
I am a former Army Special Forces Medic with years of service in low- and middle-income countries, and am now a full time medical educator specializing in trauma care, Tropical Medicine, Advanced Cardiac Life Support, and minor surgical procedures. I have just begun my final year at the London School of Hygiene and Tropical Medicine’s master’s in Infectious Diseases program.
I think the patient has Chagas disease (American trypanosomiasis), caused by the parasite Trypanosoma cruzi.
I looked up parasites that can affect the heart and found a page listing five. Of those, three were described as causing heart arrhythmia: Trichinella spiralis, Echinococcus granulosus and Trypanosoma cruzi. I looked those up on Wikipedia.
Of those, T cruzi seemed to be the most likely because it is common in Central America in rural areas (which is where the patient grew up), and because one route of acquisition is drinking contaminated fruit juice (and Dr Griffin specifically mentioned that the patient enjoys drinking fruit juice). The fact that the patient no longer lives in a rural area is consistent because heart disease is a long-term manifestation of Chagas disease.
Happy Sunday from a rainy Washington, DC. I believe that this week’s case is a man with Chagas disease (caused by Trypanosoma cruzi), a protozoan parasite that is endemic to rural Guatemala. It is typically transmitted through the feces of the triatomine vector (aka kissing big) however can also be transmitted through organ/blood donation and through vertical transmission. Some patients may recall some of the acute symptoms such as romanas sign or an acute flu-like illness, however many are asymptomatic. Al large percentage of infected patients go on to develop chronic infection and may develop GI or cardiac symptoms (like our patient) years or decades later. This patient’s EKG findings are classic for chagas cardiomyopathy. These patients are also at high risk of embolic stroke due to parasite-induced cardiac aneurysms.
It’s sad and frustrating to hear the cardiologist’s dismissal of a potential infectious cause. I hope that the patient’s family and son are screened for T. cruzi (ELISA and IFA) to potentially receive treatment prior to symptom onset. Treatment would include either nifurtimox or benznidazole depending on age of the patient.
Thanks for the case and to you all for your continued efforts in this podcast and beyond!
Dear Doctors TWiP,
When I first listened to the TWiP episode, I drew a blank on parasites that cause heart complications in humans, but then later that week I was listening to TWiV and when Dr. Despommier mentioned myocarditis caused by Chagas Disease it clicked! Suddenly the thatched roof home fit into place as well. Thus I submit Trypanosoma cruzi as my case guess. I hope the family can acquire bed nets to protect the patient’s wife and children from the present kissing bugs.
Keep on cruzin’,
I’m on the road without the red book. So googled: Parasite Heart Block Guatemala. My answer is Chagas’ disease caused by Trypanosoma cruzi, named after Dr.Carlos Chagas and Dr. Oswaldo Cruz respectively. Ahh, the good old days when people were honored to have diseases and disease causing organisms named after them.
Best wishes to all
Greetings from a cold and rainy Braunschweig, 10°C.
My guess is trypanosoma cruzi, which causes chagas disease. In its chronic state the symptoms correspond with those described.
Looking forward to listen to all those well written letters each month.
Thanks for all twivs
In Washington DC it is: -7.765° W.
Parasite: Trypanosoma cruzi
(ineligible as a prior winner)
Does anyone still use Gentian violet to treat transfusion blood?
I’m that small town New England cop who wrote to you with some questions at the beginning of the pandemic.
We fared well with not much interesting to report. The constant information you provided helped a lot of us stay safe.
For the case study I’ll pile in (with I’m sure a bunch of folks) and say our gentleman likely has Chagas cardiomyopathy, caused by the protozoan Trypanosoma cruzi. He probably drank squished triatomines or triatomine poop (eeew)
As for treatment, I would radio dispatch to send rescue and let the EMTs get him to the proper doctors. I’ll worry about the bad guys.
Thanks for enriching us science nerds wherever we are!
Writing this case guess for Episode 209 from David Geffen School of Medicine, where I am preparing for my first clinical rotation. I cannot wait to diagnose all of the parasitic infections!
For the case of the 70-year-old male who visited Guatemala, my guess is Trypanosoma cruzi, the etiologic agent of Chagas disease. This parasite is a significant cause of cardiomyopathy and can lead to the EKG findings described. This parasite is usually transmitted by the bite of the hemipteran kissing bug. However, one of the many mind-blowing facts I learned from Professor Eva Harris’ molecular parasitology class at UC Berkeley was that drinking blended bugs has become quite a problem.
To get a healthy dose of antioxidants and vitamins, one might want to enjoy a nice Acai berry or Guava smoothie. The problem is, a kissing bug might be hitching a ride on the fruit, and if it’s blended, one might also be getting an unhealthy dose of bug guts and trypanosomes along with it. Should I be concerned about the prepackaged Acai smoothies they sell at the store or does freezing kill off the trypanosomes?
P.S. As I go back in time listening to old TWIPs, I was delighted to come across Trout and Parasites, and I honestly wish I was part of that conversation. As someone who was once dead set on becoming a freshwater ecologist, even working on the ecology of Oncorhynchus Mykiss and the invertebrates that share its home streams, hearing Professor Despommier talk about fish so excitedly brought back memories of me trying to tell people how cool fish and bugs are, usually only to be met with bemused glances. I still get those glances nowadays, but it’s mostly when I go on long tangents about viruses and parasites.
Thank you for all you do!
(Have not won a book yet 🙂
Infectious Diseases and Vaccinology
University of California, Berkeley
Dear Drs. Racaniello, Despommier, Griffin, and Naula,
Instead of the weather, I will describe the tea I am sipping. It brought joyful tears to my eyes the first time I tasted it. It is an oolong tea from Taiwan, called “Dongfang meiren”. The first sip I had of this tea (courtesy of my co-intern) surprised me with the sweet aroma of muscato wine, followed by the scent of peonies and ripe golden figs. At the end of a sip, the tea glimmers like sunlight hitting honeycomb. I assumed the tea leaves were flavored with something (dried grapes, maybe? or peony petals?)… but no! I was wrong.
The tea leaves somehow expressed all these flavors on their own. I had to find out how. The answer? The tiny tea jassid (Jacobiasca formosana). This critter bites into a tea leaf triggering a chemical reaction whereby a terpene and an aromatic compound called hotrienol are released. These compounds, in turn, attract a spider who comes to eat the tea jassid (unless the jassid jumps away). The result of this fascinating relationship is that when the tea leaves are picked and oxidized, the flavors released could bring a person (or at least this person) to tears. It can be steeped at ~195 F or ~95 C for 1-2 minutes.
Now on to the case:
This is Trypanosma cruzi, the cause of Chagas disease. It is transmitted via the kissing bug (triatomine) that burrows into mud huts (and crevices in other homes) and emerges to bite people and suck their blood at night. The protazoa appears like a scarf waving in the wind under H+E stain. It is introduced when the kissing bug defecates in its own bite (less common) or defecates near a bite or mucus membrane and the person rubs the bug feces into an open wound or the eye or the mouth. (Unilateral periorbital edema with the right exposure history equals Chagas disease in my mind, I forget what this is called but there is a name for it.)
Unfortunately, for this individual I believe his isolated arrhythmia is from chronic trypanosomiasis and the main treatments to offer him at this stage are a permanent pacemaker and routine treatment for any heart failure he has developed. He could qualify for a heart transplant however I think reinfections are also possible so it would be important to provide some kind of prophylaxis or suppressive therapy. Given the high rates of vertical transmission, if the patient were a person capable of bearing children, it would be especially important to eradicate any parasites present prior to pregnancy. The treatment is benznidazole and providing people with bug-free housing.
Other considerations, in order of likelihood:
With the right exposures, I would have suspected lyme carditis secondary to early disseminated Borellia burgdorferi infection via tick bite (would expect to see first degree heart block rather than left bundle branch block).
Toxoplasma gondii in an immunocompromised host with exposure to raw meat and/or cat feces.
Viral myocarditis can also present with a new arrythmia, here I would implicate Coxsackie viridae, acute HIV infection, adenoviridae, vaccinia (though not described in MPX yet, I don’t think?), chikungunya, covid and influenza
Run-of-the-mill bacterial endocarditis can affect the conduction of electric signals through the myocardium, particularly when a perivalvular abscess is involved.
The unfortunate hubris of the cardiologist involved in the case recalls something my grandmother used to tell me when she was still living: “Don’t distract yourself with what you already know. It’s what you have yet to learn that should concern you.” To me, each of you four professors exemplify this maxim and it’s absolutely inspiring as a young trainee to see people as experienced as you continue to approach science with humility and wonder. I hope I will always be able to follow your example.
Thank you so much for teaching me,
p.s. I still haven’t won a book, but I’m still keeping my hopes up!