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Dr. Thomas Herzinger

Non-Oscar Winning Parasites

Sophia Linton, MSc Candidate, Translational Medicine

At the March 5, Medical Grand Rounds, the Department of Medicine was fortunate to host Dr. Thomas Herzinger, a Professor and world-renowned Dermatologist here at Queen's University. Dr. Herzinger opened our eyes to the colorful and clinically relevant world of dermatology, specifically parasitic infections.
 

A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. Parasitic infections cause a tremendous burden of disease in both the tropics and subtropics as well as in more temperate climates. Dr. Herzinger prefaced his talk by stating that many parasitic diseases suffer from a lack of attention by the public health community, yet they affect over 1 billion people—one-sixth of the world’s population—particularly in rural areas of developing countries. 
 

Dr. Herzinger hosted his very own award ceremony for "non-Oscar winning parasites," with seven nominees up for “Best Parasite”. Honorable mentions were given to Trombiculidae (chiggers), Pediculus humanus corporis (body louse) and Pthirus pubis (pubic louse), which can all be treated easily with pediculicides. Fleas, specifically Yersinia pestis, were not forgotten for their role as the causative agent in the Plague. Today, modern antibiotics are effective in treating the plague. However, without immediate treatment, the disease can cause serious illness or death.
 

Three parasites were left in the running for the "bug statuette": head lice, scabies and bed bugs.
 

Head lice are roughly 2–3 mm long and infest the head and neck by attaching their eggs to the base of the hair shaft. Head lice infestation, or pediculosis, is typically spread by close person-to-person contact. In Canada, pediculosis is most common among preschool- and elementary school-age children and their household members and caretakers. Dr. Herzinger emphasized that getting head lice is not related to the cleanliness of the person or their environment and can be easily treated with over the counter and prescription medications. The head louse's popularity among the younger generation was awarded a third-place finish at the "Academy Awards."
 

Scabies is an infestation of the skin by the human itch mite. The scabies mite is typically spread by direct, prolonged; skin-to-skin contact with a person who has scabies. There are two basic diagnostic methods to identify scabies infection: skin scrapings and scabioscopy. Dr. Herzinger explained that both methods require special equipment and expertise that may not be readily available to every physician faced with the challenge of diagnosing scabies. In response, he adapted the technique of Superficial Cyanoacrylate Biopsy (SCAB) as an alternative method for mite identification in scabies. Here, a small drop of cyanoacrylate glue is applied to a glass slide, which is immediately pressed on the skin lesion. After 30 seconds, the slide is swiftly detached, and examined with a conventional microscope. Under the microscope, the mites are discernable as tiny dark oval dots. Perhaps, the "Academy's" vested interest in scabies had a hand in its second-place finish. However, the global impact of scabies in institutions such as nursing homes, extended-care facilities, and prisons is undeniable.
 

And the non-Oscar goes to … bed bugs! These parasites are found across the globe and feed solely on the blood of people and animals while they sleep. Although the presence of bed bugs has traditionally been seen as a problem in developing countries, it has become rampant in parts of the United States, Canada, the United Kingdom, and other parts of Europe. Bed bugs have been found in five-star hotels and resorts, and their presence is not determined by the cleanliness of the living conditions where they are located. The good news is that bed bugs do not transmit disease. The “Academy” recognizing its resurgence, effect on property loss, expense, and inconvenience awarded it “Best Parasite.”

Dr. Herzinger emphasized that it isn't easy to disentangle the relative importance of economic, environmental, and behavioral factors since they frequently co-exist in these cases. He urges dermatologists to take this into account when diagnosing and treating cutaneous parasitic infections in the clinic and to be considerate of the lifestyle changes required to treat these patients. Dr. Herzinger believes it is especially important to recognize the role of primary care physicians in diagnosing parasitic infections, as most cases can be diagnosed and treated without a dermatologist.
 

It was a pleasure to hear from Dr. Herzinger at the Medical Grand Rounds. On behalf of the TMED graduate students, we thank him for his time and invaluable introduction to the world of parasites.

Comments

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Sarah G

Mon, 03/09/2020 - 11:57

Very interesting blog! Just a question. If we saw a patient with scabies in the clinic, would it be prudent to disinfect the whole home? Is there benefit to vacuuming? Or pesticide sprays? Thank you!!

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Sarah G

Hi Sarah,

Thanks for your question!

While I am no expert, I can relay what Dr. Herzinger discussed in his talk. Concerning seeing a patient in the clinic with scabies, there is no need to disinfect the entire home. This is true because typically only 5-15 mites are found on the body at one time.

This is not the case for patients who have crusted scabies, which is very contagious.

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Sophia

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Austin

Mon, 03/09/2020 - 15:12

Great summary Sophia!

In case anyone is interested, I found a paper published by Short et al., discussing the impact that climate change may have on the spread and distribution of parasitic diseases and their associated vectors. In short, this paper suggests that as the climate continues to change, parasites will likely appear in areas not previously habitable, which may ultimately cause increased infection rates.
The article is titled "Climate Change Contribution to the Emergence or Re-Emergence of Parasitic Diseases"

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Austin

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Madison MacKinnon

Mon, 03/09/2020 - 15:16

Great post, Sophia! I wanted to note there is a lot of room for improvement for the discussion of head lice in our society. There is a lot of stigma associated with head lice, particularly the embarrassment kids can feel when they have it. As well, some prevention policies put in schools could be considered out-of-date. For example, the "no-nit" policy, which prevents students from returning to school if they still have nits (the empty eggs of the louse) in their hair, despite the fact that just having nits in one's hair is not a good predictor of one actually having a lice infection.

I would be curious if anyone has any suggestions on how this stigma could be reduced? Or how to better inform the public?

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Madison MacKinnon

You raise an excellent question Maddie! The distribution of letters associated with a "head lice outbreak" from schools definitely can be detrimental to the mental health of children affected. The National Association of School Nurses (NASN) has suggested that schools implement intervention strategies that are student-centered that actively encourage these children to maintain social relationships to minimize social isolation throughout the duration of their treatment.

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Thalia Hua

What a great suggestion Thalia.

Speaking from experience, I found that having lice checks amidst your peers to be a super anxious process.

Perhaps private/personal lice checks (while more inconvenient), would be a better solution.

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Sophia

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Jay Kataria

Mon, 03/09/2020 - 21:51

Thanks for leading the discussion, Sophia and thank you for the great talk, Dr. Herzinger. Sophia, as bed bugs are pests that cause psychological, social, and economic problems, do you think more funding should be allocated to healthcare policy to develop better programs to avoid bed bugs or do you think our primary care team is sufficient enough to solve the ongoing problem of bed bugs?

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Jay Kataria

Thanks again for the wonderful discussion that you facilitated Sophia. Jay, you pose a very interesting question as you expand the outlook of parasites to the sociocultural and socioeconomic determinants of health. I think it is imperative that better policy is developed that will help lower the rates of bedbugs in lower SES populations, as an infestation of bedbugs in this population will likely spread quickly and little resources to deal with the infestation. Furthermore, I think that programs that teach individuals and families to routinely search for parasites and be aware of their adverse effects will also be a beneficial health policy to lay out. Let me know what you think! I always believe in educating and empowering the masses to improve the overall health of our society!

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Quentin Tsang

Hi Jay and Quentin!

Thanks for your compliments, and great questions.

I think Quentin is on the right track. It's imperative to recognize that many parasites are categorized as neglected tropical diseases, and so funding (and even data) for these diseases is sparse.

Policies that have proved the most effective are school-based programs. De-worming campaigns in schools are very effective in decreasing the worm burden in rural communities in developing countries.

I think a similar approach could be taken here with bed bugs. As Quentin suggested, education is vital! An in-class workshop and a brochure to take home to parents would probably be beneficial.

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Sophia

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Joe Nashed

Wed, 03/11/2020 - 07:50

Thanks for the great summary Sophia. One of the things that struck me a little bit in our discussion was the BIG differences in Dr. Herzinger's practices between Europe and Canada. I though it was interesting how a physician could be exposed to such different diseases simply based on the geography and medical bodies that oversee those regions.

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Joe Nashed

Great summary Sophia. Joe, this is something that I find interesting as well. Although medicine is essentially "the same" perhaps in terms of disease entities, universally accepted methods of making diagnoses and the management of diseases, there are multiple factors that affect the actual practice of medicine including culture, geographic location, regulatory authorities, health insurance and many many more. It is quite interesting that even within a single country, the practice may be significantly different from one province to another or even one hospital to another within the same area.

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Edwin Ocran

Thanks for bringing this up, Joe.

Indeed - Dr. Herzinger also mentioned that the disease demographics are so different here. He mentioned that in Germany, Hidradenitis suppurativa was common in older, overweight males, but in Canada, it is more common in young, otherwise healthy females.

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Sophia

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Reem Alzafiri

Wed, 03/11/2020 - 09:32

Excellent summary Sophia! What intrigued me the most during Dr. Herzinger's talk was how the environment plays a key role in the infestation of these parasites. I do wonder though, how do bed bugs begin to infest one's home, where do they come from and how is it that they can live for weeks without feeding. It's quite interesting how tiny insects can cause so much havoc in one's life.

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Reem Alzafiri

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Spencer Finn

Wed, 03/11/2020 - 21:17

Hi Sophia,

Great summary, I like how you followed his awards, it gave me a great laugh! I thought I'd bring up a point we discussed slightly during our discussion with Dr. Herzinger. We discussed how many of these parasites are beginning to show some resistance to traditional treatments, such as scabies. This demonstrates that there may be a need for the development of new treatments for these parasites. I was wondering if you have seen if there has been any research into any new treatments, or even any research why there is this resistance that is developing?

Name
Spencer Finn

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