Trichinellosis: A zoonosis that still requires vigilance

Trichinellosis is a parasitic disease in humans caused by nematodes of the genus Trichinella, usually acquired through the consumption of raw or undercooked meat, mainly from pigs or wild animals, containing infective larvae. Although often overlooked, this disease has affected humans for centuries and continues to be a public health concern in many parts of the world, especially where food safety measures are inadequate. In this millennium, significant progress has been made in understanding the disease pathophysiology and host immune response, mainly through experimental studies in rodents, while human pathophysiology and immune response still await elucidation. This review integrates current knowledge on the biology, transmission, and manifestations of trichinellosis, as well as challenges in diagnosis, treatment, and prevention. The parasite's life cycle involves an initial intestinal phase followed by systemic migration of larvae into striated muscles, where long-lasting cysts are established. The clinical presentation varies from mild gastrointestinal discomfort to severe systemic manifestations such as fever, periorbital edema, and muscle pain. In some cases, chronic symptoms, including fatigue and reduced muscle strength, may persist for years. The immune response is characterized by a Th2-skewed profile and prominent eosinophilia. Diagnosis relies on clinical signs and symptoms, epidemiological evidence of a common infection source, serological testing, and parasitological confirmation through detection of larvae in infected meat and identification of the Trichinella species. Preventive strategies include public education, controlled animal farming, and meat inspection. A deeper understanding of host-parasite interactions, chronic disease mechanisms, and species-specific differences remains essential for improving clinical management and guiding public health interventions.

A comprehensive literature search was performed in PubMed, Scopus, Google Scholar, and Web of Science to identify publications on Trichinella and trichinellosis from 1990 through August 2025. The search strategy employed keywords such as "trichinellosis," "Trichinella," "Trichinella life cycle," "trichinellosis pathophysiology," "diagnosis," "epidemiology," "treatment," and "control." Only articles published in English were considered. Titles and abstracts were screened for relevance, and full-text articles were assessed to extract information on life cycle, epidemiology, pathophysiology, clinical manifestations, diagnostic approaches, therapeutic options, and prevention strategies. Additional references were identified by cross-checking the bibliographies of the included articles.