Trichinellosis B75.x0

Trichinella spiralis; Trichinella britovi;

Widespread worldwide. Rare in Central Europe. Isolated in Eastern Europe (Bulgaria, Serbia) and Greece. Mostly sporadic or in small epidemics as in Bulgaria a few years ago (Vutova K et al. 2020).

Ingestion of the pathogens through consumption of pork containing larvae. Maturation of the worms in the small intestine. After 5 days: birth of new larvae; these penetrate the intestinal wall and enter the entire organism via the bloodstream, causing cytotoxic phenomena (see below Trichinella spiralis).

The clinical picture begins like food poisoning. Within 24 hours after ingestion, nausea, diarrhoea and colicky abdominal discomfort occur. Initially no fever. From day 7-11 after infection, larvae begin to seed into the tissues. This then leads to fever up to^410C, headache and fatigue, myalgias, arthralgias; furthermore difficulty in movements, oedema of the face (eyelid oedema - DD acute dermatomyositis), conjunctival hyperaemia, ocular haemorrhages. Macular exanthema, subungual splinter hemorrhages (Vutova K et al 2020) . A feared complications are myocarditis, encephalitis, meningitis and pneumonia. The acute phase of trichin(ell)ose lasts 4-6 weeks.

Laboratory abnormalities were manifested by marked eosinophilia (97.2%), leukocytosis (70.8%), elevated serum creatine phosphokinase levels (82%), and antibody-positive results by ELISA and indirect hemagglutination (Vutova K et al. 2020).

The following statements are recommendations to assist physicians in treatment and prophylaxis after relevant exposure (e.g. consumption of meat products that are highly likely to contain live Trichinella) (RKI information).

In the presence of relevant symptoms (see "Clinical picture)

Initiate clinical and laboratory diagnostics (incl. creatine kinase determination and determination of the eosinophil count, serology):

If laboratory results are unremarkable (no creatine kinase elevation, absent eosinophilia and absent antibodies): Repeat laboratory diagnostics after a few days. If still negative: search for other diseases.

Positive findings in initial or repeat tests: contact specialized center, initiation of therapy usually necessary. Mildly infected patients usually recover without complications under symptomatic therapy with bed rest, antipyretics and analgesics.

Patients with severe disease (e.g., severe myositis, myocarditis, fever) are treated with combination therapy of glucocorticoids and high-dose mebendazole (or albendazole). An effect of mebendazole or albendazole against encystosed larvae in muscle has not been clearly demonstrated.

Exposure within the past 7 days without symptoms

• Drug prophylaxis: Mebendazole 2 x 5 mg/kg body weight for 5 days.
• Contraindication: Children under 2 years and during pregnancy (consult centre for alternative treatment with pyrantel).

Exposure 8-30 days ago without symptoms

Initiate laboratory diagnostics (incl. creatine kinase determination and determination of the eosinophil count, serology):

• If creatine kinase elevation or eosinophilia (> 500/µl) or positive serology: Treatment may be required. Contact specialized center (serology may still be negative initially).
• Negative results in above tests: no further action (observation for development of symptoms).

Exposure > 30 days ago without symptoms

• No further diagnostics (observation regarding development of symptoms).

1. Cortes-Blanco M et al. (2002) Outbreak of trichinellosis in Caceres, Spain, December 2001-February 2002 Euro Surveill 7: 136-138.
2. Holstein A et al. (1999) Father and son with muscle pain and loss of muscle strength. Acute trichinosis. Internist 40: 673-677
3. Liu M et al (2002) Trichinellosis in China: epidemiology and control. Trends Parasitol 18: 553-556
4. Owen R (1835) Description of a microscopic entozoon infesting the muscles of the human body. London Med Gaz 16: 125-127
5. RKI (2021) Trichinellosis, guidebook
6. Roy SL (2003) Trichinellosis surveillance--United States, 1997-2001. MMWR Surveill Summ 52: 1-8.
7. Virchow R (1859) Recherches sur le developpement de la trichina spiralis (ce ver devient adulte dans l'intestin du chien). CR Seanc Acad Sci 49: 660-662

8. Vutova K et al. (2020) Clinical and epidemiological descriptions from trichinellosis outbreaks in Bulgaria. Exp Parasitol 212:107874.

9. Zenker FA (1860) Ueber die Trichinen-krankheit des Menschen. Arch Pathol Anat Physiol Klin Med 18: 561-572.