Nematodes 2

• Trichinella spiralis is also known as the Trichina Worm
• Trichinella spiralis was first described by Tiedemann in 1822
• Trichinella spiralis was demonstrated in human cadavers in London by James Paget and Richard Owen in 1835
• Raw or insufficiently cooked meat like pork causes human trichinellosis
• Trichinella spiralis is the most important cause of trichinellosis in humans
• Trichinella britovi is the second most common species affecting humans
• Trichinella nativa infects primarily wild carnivores in the frigid zones
• Trichinella spiralis is a zoonotic infection
• Trichinella spiralis is viviparous (larviparous)
• Trichinella spiralis is transmitted by ingestion of raw or undercooked meat of pig and other animals with encysted larvae
• Trichinella spiralis is a cosmopolitan infection with 10,000 cases/year and 0.2% resulting in mortality
• Trichinella spiralis is the smallest parasitic nematode to humans, thread-like, and ivory white in color
• Adult male Trichinella spiralis has a single testis near the posterior end of the body, joined by a genital tube in the mid-body, extends back to the cloaca, and no spicule
• Adult female Trichinella spiralis has a single ovary, oviduct, seminal receptacle, coiled uterus, vagina, and vulva with the vulva for copulation located at the anterior fifth, ventral side
• Larvae of Trichinella spiralis are spear-like for burrowing, have a digestive tract similar to adults, and the reproductive organs are not fully developed but it is possible to identify the sex
• Trichinella spiralis has a life cycle involving humans as the definitive host, intermediate host, and final host
• Trichinella spiralis larvae are released in the small intestine mucosa, develop into adults, copulate, and the female gives birth to larvae
• Transmission of encysted larvae in humans can occur through cannibalism or being eaten by an animal
• Trichinella spiralis infection can lead to different phases of infection including the enteric phase, invasion phase, and convalescent phase
• Symptoms of Trichinella spiralis infection depend on the intensity of infection, with light infections being asymptomatic, moderate infections being symptomatic, and severe infections causing severe disease
• Phases of infection include the enteric phase with symptoms like diarrhea and the invasion phase with symptoms like severe myalgia and periorbital edema
• Trichinella spiralis infection can lead to cardiac manifestations like pericardial pain and neurological manifestations like meningitis
• Prognosis of Trichinella spiralis infection is good in mild infections but death may occur in severe cases like heart failure or encephalitis
• Diagnosis of Trichinella spiralis involves demonstrating encysted larvae through muscle biopsy and other laboratory tests like ELISA and Western Blot
• Treatment of Trichinella spiralis includes Albendazole or Mebendazole for 10-15 days, with supportive treatment including analgesics and steroids
• Prevention and control measures for Trichinella spiralis include health education, proper cooking of food, freezing of meat, and regular animal monitoring