Trichinosis' in man is caused by

Question

Accepted Answer

The correct option is 1:

Trichinosis, clinically known as trichinellosis, is a parasitic disease in humans caused by ingesting the raw or undercooked meat of an animal that is infected with the larvae of the *Trichinella* roundworm. The primary domestic animal historically and epidemiologically linked to human infection is the *Pig* (swine). Pigs are omnivores, and in their natural feeding habits or through unsafe farming practices (such as being fed uncooked garbage or infected meat scraps), they ingest the encysted larvae from other infected animals, often rodents or other pigs. Once the larvae are consumed, they mature in the pig's intestines and produce new larvae that migrate to and encyst in the pig's muscle tissue, forming the infectious cysts. When humans eat this infected pork without cooking it to a high enough internal temperature to kill the cysts, they complete the life cycle of the parasite, causing the infection. While infection from commercially raised pigs is now rare in many developed countries due to strict regulations, non-commercial pork and wild game remain significant sources, making *Pigs* the correct and original answer to this question.

The incorrect option is 2:

Cattles (cows or beef) are not considered a natural or major source of human trichinosis infection. This is due to their biological classification as herbivores; their natural diet is composed of plant matter, which prevents them from acquiring the *Trichinella* parasite, which is transmitted through the consumption of infected meat tissue. Therefore, cattle do not serve as a biological reservoir for the parasite in the same way that omnivores like pigs do. Any documented cases of trichinosis linked to beef consumption are extremely rare and are virtually always the result of gross cross-contamination. This typically occurs when ground beef is mixed with infected pork or wild game meat during processing, or when processing equipment, like a meat grinder, is used for infected meat and not thoroughly cleaned before processing the beef. Consequently, the cattle themselves are not the causative host.

The incorrect option is 3:

Goat meat is not a recognized or common cause of trichinosis in humans. Like cattle, goats are grazing herbivores, and their digestive system and diet do not allow for the natural entry and establishment of the *Trichinella* parasite in their muscle tissue. The established hosts for the parasite are carnivores and omnivores that actively prey on or scavenge the meat of other animals. Since the goat does not engage in these behaviors, the chance of a goat becoming infected and transmitting the disease is negligible under normal circumstances. Thus, the epidemiological data and biological facts clearly exclude goats as a primary or secondary source of trichinosis, rendering this option incorrect.

The incorrect option is 4:

The option "All options are right" is incorrect because it falsely includes both *Cattles* and *Goat* as causes of trichinosis. As established, trichinosis is primarily a risk associated with omnivorous and carnivorous animals, chiefly pigs and certain wild game animals. Since cattle and goats are herbivores and are not primary or even common reservoir hosts for the *Trichinella* parasite, claiming that all three options are right is factually inaccurate. Only *Pigs* is the correct primary source from the given choices.