Once Upon A Parasite

Looking at this X-ray of the thigh … What do you see?

Figure 1 - X-ray of legs [1]

You may notice…

✅ Clear visibility of bone density

✅ Soft tissue/ Muscles “transparent” 

✅ No broken bones

How about now?

Figure 2 - X-ray of woman’s legs [2]

What if I told you this x-ray is of a parasite-filled woman from China, who ate raw pork for over 10 YEARS?

A typical non-vegetarian loves to devour meat occasionally in their meals, but what happens when the meat starts to devour you?

Trichinosis

Trichinosis aka Trichinellosis, is a parasitic food-borne disease that arises from eating uncooked or raw meat, infected with trichinella larvae. The woman’s picture above is an extreme case of trichinosis...

As we all know from Biology GCSE, our stomach’s hydrochloric acid and enzymes digest what we eat into smaller more soluble molecules, which are then absorbed into the bloodstream. 3 However, when you eat raw meat infested with larvae, rather than breaking it down, the hard outside shell surrounding the trichinella larvae breaks, freeing the adult worms into your body. 

Like most animals, trichinella mate and reproduce, bringing forth more larvae. With this reproduction, more larvae take up space in your tissue and muscles, causing an infestation. Not a pretty sight. These parasitic phenomena can live for months or even years in your body! 

Larvae →  The active immune form of an insect (e.g. a tadpole is the larvae of a frog)

Trichinella → A parasitic tapeworm (4 helminths)

Figure 3 - Trichinella [5]

How do trichinella thrive?

Survival. Arguably the prime purpose for all organisms, including the tiniest species, like a worm. To thrive in mammals, Trichinella has adapted to survive the extreme conditions of a human body - differing temperatures, variation in acidity, and its ruthless defence system. 

Trichinella can mature at human temperature (37°C) hence why it's recommended to 6 thoroughly cook your meat around 71°C or freeze it at sub-zero temperatures to kill the larvae and halt its development. Once the stomach’s acidity breaks the shell of the larvae, the newborn larvae will start to feast on host nutrients for growth and maturation and head towards the muscle cells for housing. Without any protection, the body’s immune system is usually active and present in getting rid of foreign guests, however trichinella has found a loophole in this system. After Trichinella absorbs nutrients in the small intestine, the larvae migrate to neighbouring muscle cells, where they infect and transform them into nurse cells. 7 This ingenious technique enables the larvae to evade the immune system, as the nurse cells create a capsule around the larvae, shielding it from the host's immune system. 7 Additionally, the nurse cells provide a steady supply of nutrients, eliminating the need for the larvae to "go out" and retrieve them, adding another layer of protection. 

Nurse cell → An infected cell that provides food and nutrients FOR the trichinella

Identification and symptoms...

Symptoms of Trichinosis can vary depending on the severity of the infestation and where you are in the trichinella’s life cycle. Those who are fortunate to have a mild case of trichinosis, often experience 8 little to no symptoms. However, symptoms for people who have moderate to severe cases, can worsen. Between days 1 and 2 after infection, people are reported to have: diarrhoea, stomach pain, severe tiredness/weakness, nausea and vomiting. Between 2–8 weeks of infection, symptoms worsen to high fevers, muscle tenderness, pink eye, sensitivity to light, itchy irritated skin and swollen eyelids/face. As with all diseases, you know your body best and if you notice anything abnormal it's imperative to seek professional help.

A doctor can run a series of tests to verify if someone has trichinosis and aid in their diagnosis. 9 Blood tests can be done to identify if there is an increase in white blood cells, depending on the number we can infer if there is a foreign object stimulating the production of antibodies. If not a blood test, a 9 Muscle Biopsy, an operation where a small piece of muscle is removed and examined under a microscope, can be done to look for the trichinella larvae. 

Treating the worm...

Treatment for Trichinosis includes Antiparasitic drugs such as:

• [9] Mebendazole can remove the worms from the muscles but not the larvae.

• [10]  Albendazole, prevents the worm from absorbing glucose, so it eventually dies

• [9] Steroid Medicine such as [11] prednisolone can be used to treat the pain and swelling of tissue

Any treatment plan is a case of ethics and equitability depending on the patient’s symptoms and circumstances, i.e. Pregnancy. The 4 pillars of medicine; Beneficence, Nonmaleficence, justice and autonomy {read more here: https://www.themedicportal.com/application-guide/medical-school-interview/medical-ethics/} can be applied. 

For instance, a patient comes in complaining of nausea and abdominal pain. You successfully diagnose the disease as trichinosis. However, they have an autoimmune disease and their case of trichinosis is not severe. Would you then administer Prednisolone, knowing that the side effects can cause significant harm and outweigh the benefits? 

No, that would be violating the non-maleficence pillar. 

Alternatively, since some trichinosis cases can resolve on their own, withholding aggressive treatment for anyone could be more beneficial, due to their harsh side effects, reinforcing the beneficence pillar.

As you can see, doctors constantly need to evaluate the root needs and causes of a patient, which takes time and can be tedious, hence many promote “Preventative medicine” to foster a healthier society.

Preventative medicine (PM) can take many forms, as long as it works to prevent a disease. Here are some specific PM examples:

• Buying from legitimate and clean meat vendors.

• Thoroughly cooking your meat.

• Stricter regulations on meat inspections and hygiene in slaughterhouses.

Preventative medicine →  The idea that prevention is better than a cure

Equitability → Treating all patients in a way that meets their individual needs

References

1 - Chanpen, P. (2019, June 18). X-ray of whole leg, lower extremity. Scanogram of lower extremity. IStock. https://www.istockphoto.com/photo/x-ray-of-total-lower-extremity-gm1156212421-315032924

2 - This X-Ray Of A Woman Who Ate Raw Pork Will Convince You To Become A Vegetarian - Buzzing Lives. (2015, August 19). Buzzing Lives. https://buzzinglives.com/this-x-ray-of-a-woman-who-ate-raw-pork-will-convince-you-to-become-a-vegetarian/

3 - Trichinosis: Causes, Symptoms, Treatment & Prevention. (2022, May 24). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/7142-trichinosis

4 - Caporuscio, J. (2022, February 16). Parasites: Types, in humans, worms, and ectoparasites. Www.medicalnewstoday.com. https://www.medicalnewstoday.com/articles/220302#treatments

5 - Jade, H. (2018, March 2). Trichinosis - Causes, Prevention, Signs, Symptoms, Diagnosis, Treatment. Health Jade. https://healthjade.com/trichinosis/

6 - Pozio, E. (2021, March). Trichinellosis in Animals - Generalized Conditions. MSD Veterinary Manual. https://www.msdvetmanual.com/generalized-conditions/trichinellosis/trichinellosis-in-animals

7 - Nurse cell. (2020, May 29). Wikipedia. https://en.wikipedia.org/wiki/Nurse_cell

8 - Mayo Clinic. (2018). Trichinosis - Symptoms and causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/trichinosis/symptoms-causes/syc-20378583

9 - Mayo Clinic. (2022, May 25). Trichinosis - Diagnosis and treatment - Mayo Clinic. Mayoclinic.org. https://www.mayoclinic.org/diseases-conditions/trichinosis/diagnosis-treatment/drc-20378587

10 - Albendazole (Oral Route) Description and Brand Names - Mayo Clinic. (n.d.). Www.mayoclinic.org. https://www.mayoclinic.org/drugs-supplements/albendazole-oral-route/description/drg-20061505

 11 - Shimoni, Z., Klein, Z., Weiner, P., Assous, M. V., & Froom, P. (2007). The use of prednisone in the treatment of trichinellosis. The Israel Medical Association Journal: IMAJ, 9(7), 537–539. https://pubmed.ncbi.nlm.nih.gov/17710786/

StoryMD. (2024). What Causes Trichinellosis? StoryMD.com. https://storymd.com/journal/jo2dd6ohnm-trichinellosis/page/7a3ootk554p-what-causes-trichinellosis

StoryMD. (2024). What Are the Signs and Symptoms of Trichinellosis? StoryMD.com. https://storymd.com/journal/jo2dd6ohnm-trichinellosis/page/b7n58u699q2-what-are-the-signs-and-symptoms-of-trichinellosis