Trichinellosis is a term for a parasitic infection caused by Trichinella species, most notably Trichinella spiralis. This condition occurs in humans by ingestion of various meat products (mainly pork) that are contaminated with this parasite. The clinical presentation correlates with the amount of parasite ingested, ranging from asymptomatic and mild constitutional complaints to severe myalgia, urticaria, conjunctival hemorrhage, fever, hypoalbuminemia, and the development of life-threatening complications. The diagnosis is made through serological testing and a thorough patient history that identifies recent consumption of "suspicious" meat products.
Trichinellosis denotes an infection by the tissue nematode Trichinella, with many discovered species   . The vast majority of human cases, however, are caused by Trichinella spiralis, which is found in many parts of the world    . The pathogenesis of this zoonotic disease starts by the consumption of the parasite through contaminated or undercooked meat products and animals that have been confirmed as the source of T. spiralis - pigs, horses, wild boars, and even dogs in certain geographic areas    . The clinical course strongly depends on the quantity of parasite introduced into the organism, with an average incubation period around 1-3 weeks  . In milder cases, the presentation may be asymptomatic or consist of few constitutional symptoms - myalgia, low-grade fever, and gastrointestinal discomfort. When a substantial parasitic load has occurred, symptoms in the form of diarrhea, nausea, vomiting, headache, and severe myalgia characterize trichinellosis and appear within days   . As the parasite attempts to migrate from the gastrointestinal tract into other tissues several weeks after the initial infection, a prominent immunological reaction develops, inducing a more prominent clinical response - high-grade fever accompanied by chills, swelling, periorbital edema, urticarial rash, conjunctival hemorrhage, and myalgia as a constitutive feature  . Furthermore, various complications have been reported, including myocarditis, encephalitis, and thromboembolic disease, which may be life-threatening in the absence of proper therapy     .
Due to the nonspecific clinical presentation of trichinellosis, the diagnosis might be difficult to attain     . For this reason, a thorough patient history is often the crucial component of the workup. Physicians must ask the patients if they consumed undercooked or "suspicious" game meat, pork, or other meat products and determine if the timetable matches the clinical course . A detailed physical examination should not be overlooked, as it may provide further clues toward trichinellosis as the cause of symptoms. But in order to make a definite diagnosis, both laboratory and specific microbiological studies need to be performed. A complete blood count (CBC) will almost always show marked eosinophilia, which is typical for a parasitic infection, whereas very high levels of serum creatine phosphokinase (CBK or CK) are highly indicative of trichinellosis in the presence of myalgia and eosinophilia   . Conversely, specific serology testing for the detection of T. spiralis antigens and respective antibodies through enzyme-linked immunosorbent assay (ELISA) is a reliable method that can confirm the presence of this parasite . However, the test may be false-negative in the initial stages of the ailment, as antibodies are not yet formed against the pathogen  . Although being highly invasive is not always recommended, a muscle biopsy can sometimes be carried out in order to obtain a viable sample of parasitological testing  .