Which of the following parasites abundants in muscles
**Core Concept**
Trichinella spiralis is a parasitic nematode that causes trichinosis, a zoonotic infection characterized by the invasion of skeletal muscles by the parasite. This phenomenon is known as encystation, where the parasite forms a cyst-like structure within the muscle fibers.
**Why the Correct Answer is Right**
During encystation, Trichinella spiralis larvae penetrate the muscle fibers and become embedded within the muscle tissue, where they form a protective cyst-like structure. This process is mediated by the parasite's ability to secrete enzymes that break down the muscle fibers and create a safe environment for the larvae to develop. The larvae then undergo a series of developmental stages, eventually becoming adult worms that reproduce and produce offspring, which can then infect other hosts. The parasitic infection can lead to muscle pain, weakness, and other systemic symptoms.
**Why Each Wrong Option is Incorrect**
* **Option A:** Toxoplasma gondii, a different parasite, primarily infects the brain, liver, and lungs, rather than muscles.
* **Option B:** Taenia solium, another type of tapeworm, infects the gastrointestinal tract, not muscles.
* **Option C:** Echinococcus granulosus, a tapeworm that causes hydatid disease, primarily infects the liver and lungs, not muscles.
**Clinical Pearl / High-Yield Fact**
Trichinosis is often acquired through the consumption of undercooked or raw meat, particularly pork, that contains Trichinella spiralis larvae. It's essential to cook meat to an internal temperature of at least 160°F (71°C) to kill the parasites and prevent infection.
**Correct Answer:** C.