Disclaimer: all information in this post is from the CDC’s information and the author’s professional knowledge. If you have any questions please contact me and I can ask her!
My little sister, who is an epidemiology student, wrote this post about T. spiralis for me. I’m so excited to share it with you all!
Have you ever wondered why restaurants will ask how you’d like your beef cooked, but never your pork? Surely eating any meat too raw could pose a potential hazard, but what is it about pork specifically that makes it so important to cook your meal thoroughly? Well, if you’re looking for a reason to ensure that your pork is cooked well, look no further than Trichinella spiralis.
T. spiralis is a species of nematode, also referred to as roundworms, and is known to cause the disease trichinosis. Before we get into the nitty gritty of what this disease does and why it’s so crucial to avoid exposure, let’s talk about the lifecycle of this parasite and how it relates to pork consumption in humans. This parasite, like many others, exists in both a domestic and sylvatic cycle. Sylvatic cycles generally refer to the cycle that the parasite exists in in the “wild”. In the case of T. spiralis, this cycle primarily involves two players- rodents and carnivores. A rodent picks up the parasite and is subsequently consumed by a carnivore. The parasite then passes on to the carnivore. Once the carnivore dies, it is picked at by rodents and the parasite once again begins a new cycle in the rodent. Sylvatic cycles are extremely important in parasite ecologybecause they can very much complicate control measures. Even if a parasite is briefly controlled in the human population, it may very well still exist in the sylvatic cycle and can consequently re-enter the human population at a later point in time.
The domestic cycle begins when a pig ingests meat scrapsor animals that are infected with the parasite. When the parasite enters the pig, the larva, or immature form, of the parasite is released in the intestines. While remaining in the intestines, the larva grows into adult worms, which then mate to produce more larva. The new larva circulates throughout the body and become encysted in muscle. When a parasitic worm becomes encysted, it means that the larva has formed a protective capsule in which it is resting until the next stage in the life cycle. It’s at this pointthat the larva is in the infective stage and subsequently, if a human consumes undercooked pork meat that contains encysted larva, they will become infected.
But what does it mean to be infected with T. spiralis? Is it dangerous? What does the disease actually look like? Well, like many diseases, the answers to these questions are actually quite complicated. Some people won’t experience any symptoms and could be completely oblivious to the fact that they’re hosting these worms. On the other extreme, some people can face severe symptoms or complications that ultimately result in death. However, for the vast majority of those who do exhibit symptoms, the disease acts somewhat similarly to other common illnesses and fades away with time.
The disease exists in two sort of phases. In the first phase, symptoms might include nausea and gastrointestinal problems. In the second phase, symptoms might include fever, muscle pain, or generic weakness. Due to the fact that symptoms are vague and interchangeable from other diseases, such as the flu, it’s likely that many people with trichinosis are misdiagnosed or simply go undiagnosed. Furthermore, like other parasitic diseases, the severity of the disease is partially dependent on the “weight of infection”. If a person is infected many times, which is a possibility in places that lack access to good sanitation techniques, the infection is called “heavy” and symptoms may be worse.
In the United States, cases of trichinosis are rare. Control programs by the pork industry have shown great success and while, trichinosis is not considered much of a threat these days, it’s still very important to cook all your meat properly! Stay healthy, stay safe, and stay curious!
Disclaimer 2: I know the author still says my name, I’m trying to have it fixed. I submitted a ticket with Wix!
Cover Art: Encyclopedia Britannica