Trichinosis

Trichinosis
Other namesTrichinellosis, trichiniasis
Trichinella larvae in pressed bear meat, partially digested with pepsin. The classic coil shape is visible.
SpecialtyInfectious disease
SymptomsInitially: diarrhea, abdominal pain, vomiting[1]
Later: swelling of the face, inflammation of the whites of the eyes, fever, muscle pains, rash[1]
ComplicationsInflammation of heart muscle, inflammation of the lungs[1]
CausesTrichinella from eating undercooked meat[1]
Diagnostic methodAntibodies in the blood, larvae on tissue biopsy[1]
Differential diagnosisMeasles, dermatomyositis, gastroenteritis[2]
PreventionFully cooking meat[3]
MedicationAlbendazole, mebendazole[4]
PrognosisLow risk of death[5]
Frequency~10,000 cases a year[6]

Trichinosis, also known as trichinellosis, is a parasitic disease caused by roundworms of the Trichinella genus.[1] During the initial infection, invasion of the intestines can result in diarrhea, abdominal pain, and vomiting.[1] Migration of larvae to muscle, which occurs about a week after being infected, can cause swelling of the face, inflammation of the whites of the eyes, fever, muscle pains, and a rash.[1] Minor infection may be without symptoms.[1] Complications may include inflammation of heart muscle, central nervous system involvement, and inflammation of the lungs.[1]

Trichinosis is mainly spread when undercooked meat containing Trichinella cysts is eaten.[1] In North America this is most often bear, but infection can also occur from pork, boar, and dog meat.[7] Several species of Trichinella can cause disease, with T. spiralis being the most common.[1] After the infected meat has been eaten, the larvae are released from their cysts in the stomach.[1] They then invade the wall of the small intestine, where they develop into adult worms.[1] After one week, the females release new larvae that migrate to voluntarily controlled muscles, where they form cysts.[1] The diagnosis is usually based on symptoms and confirmed by finding specific antibodies in the blood, or larvae on tissue biopsy.[1]

The best way to prevent trichinosis is to fully cook meat.[3] A food thermometer can verify that the temperature inside the meat is high enough.[3] Infection is typically treated with antiparasitic medication such as albendazole or mebendazole.[4] Rapid treatment may kill adult worms and thereby stop further worsening of symptoms.[4] Both medications are considered safe, but have been associated with side effects such as bone marrow suppression.[4] Their use during pregnancy or in children under the age of 2 years is poorly studied, but appears to be safe.[4] Treatment with steroids is sometimes also required in severe cases.[4] Without treatment, symptoms typically resolve within three months.[5]

Worldwide, about 10,000 infections occur a year.[6] At least 55 countries including the United States, China, Argentina, and Russia have had recently documented cases.[5] While the disease occurs in the tropics, it is less common there.[5] Rates of trichinosis in the United States have decreased from about 400 cases per year in the 1940s to 20 or fewer per year in the 2000s.[6][8] The risk of death from infection is low.[5]

  1. ^ a b c d e f g h i j k l m n o p "CDC – DPDx – Trichinellosis – index". www.cdc.gov. Archived from the original on 2015-07-04. Retrieved 2015-07-19.
  2. ^ Ferri FF (2010). "Chapter T". Ferri's differential diagnosis : a practical guide to the differential diagnosis of symptoms, signs, and clinical disorders (2nd ed.). Philadelphia, PA: Elsevier/Mosby. ISBN 978-0323076999.
  3. ^ a b c "CDC – Trichinellosis – Prevention & Control". www.cdc.gov. Archived from the original on 2015-09-24. Retrieved 2015-07-25.
  4. ^ a b c d e f "CDC – DPDx – Trichinellosis – Treatment Information". www.cdc.gov. Archived from the original on 2015-08-22. Retrieved 2015-07-25.
  5. ^ a b c d e Farrar J (2013). Manson's tropical diseases (23 ed.). Philadelphia: Saunders [Imprint]. pp. 791–94. ISBN 978-0-7020-5101-2.
  6. ^ a b c "Trichinellosis Fact Sheet – Division of Parasitic Diseases". Centre for Disease Control, US Government. August 2012. Archived from the original on 2016-05-22. Retrieved 2016-06-05. During 2008–2010, 20 cases were reported to CDC each year on average.
  7. ^ Cook GC, Zumla A (2009). Manson's Tropical Diseases. Elsevier Health Sciences. p. 325. ISBN 978-1416044703.
  8. ^ "Trichinellosis Epidemiology & Risk Factor". Archived from the original on 2010-12-20. Retrieved 2020-03-06. During 2002–2007, 11 cases were reported to CDC each year on average.