Amoebiasis

Amoebiasis
Other namesAmoebic dysentery, amebiasis, entamoebiasis[1]
The life-cycle of various intestinal Entamoeba species
SpecialtyInfectious disease
SymptomsBloody diarrhea, abdominal pain[2]
ComplicationsSevere colitis, colonic perforation, anemia[2]
CausesEntamoeba histolytica [2]
Diagnostic methodStool examination, antibodies in the blood[2]
Differential diagnosisBacterial colitis[2]
PreventionImproved sanitation[2]
TreatmentTissue disease: metronidazole, tinidazole, nitazoxanide, dehydroemetine, chloroquine,
Intestinal infection: diloxanide furoate, iodoquinoline[2]
Frequency~480 million[2]

Amoebiasis, or amoebic dysentery, is an infection of the intestines caused by a parasitic amoeba Entamoeba histolytica.[3][4] Amoebiasis can be present with no, mild, or severe symptoms.[2] Symptoms may include lethargy, loss of weight, colonic ulcerations, abdominal pain, diarrhea, or bloody diarrhea.[5][2] Complications can include inflammation and ulceration of the colon with tissue death or perforation, which may result in peritonitis.[2] Anemia may develop due to prolonged gastric bleeding.[2]

Cysts of Entamoeba can survive for up to a month in soil or for up to 45 minutes under fingernails.[2] Invasion of the intestinal lining results in bloody diarrhea.[2] If the parasite reaches the bloodstream it can spread through the body, most frequently ending up in the liver where it can cause amoebic liver abscesses.[2] Liver abscesses can occur without previous diarrhea.[2] Diagnosis is made by stool examination using microscopy, but it can be difficult to distinguish E. hystolitica from other harmless entamoeba species.[3] An increased white blood cell count may be present in severe cases.[2] The most accurate test is finding specific antibodies in the blood, but it may remain positive following treatment.[2] Bacterial colitis can result in similar symptoms.[2]

Prevention of amoebiasis is by improved sanitation, including separating food and water from faeces.[2] There is no vaccine.[2] There are two treatment options depending on the location of the infection.[2] Amoebiasis in tissues is treated with either metronidazole, tinidazole, nitazoxanide, dehydroemetine or chloroquine. Luminal infection is treated with diloxanide furoate or iodoquinoline.[2] Effective treatment against all stages of the disease may require a combination of medications.[2] Infections without symptoms may be treated with just one antibiotic, and infections with symptoms are treated with two antibiotics.[3]

Amoebiasis is present all over the world,[6] though most cases occur in the developing world.[7] About 480 million people are currently infected with about 40 million new cases per year with significant symptoms.[2][8] This results in the death of between 40,000–100,000 people a year.[4] The first case of amoebiasis was documented in 1875. In 1891, the disease was described in detail, resulting in the terms amoebic dysentery and amoebic liver abscess.[2] Further evidence from the Philippines in 1913 found that upon swallowing cysts of E. histolytica volunteers developed the disease.[2]

  1. ^ "Entamoebiasis". Medical Subject Headings. National Library of Medicine. Retrieved 24 November 2024.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa Kelly P (2014). "Intestinal Protozoa". Manson's Tropical Infectious Diseases. pp. 664–682.e2. doi:10.1016/B978-0-7020-5101-2.00050-9. ISBN 978-0-7020-5101-2.
  3. ^ a b c "General Information | Amebiasis | Parasites | CDC". www.cdc.gov. 29 December 2021. Retrieved 13 September 2022.
  4. ^ a b Carrero JC, Reyes-López M, Serrano-Luna J, Shibayama M, Unzueta J, León-Sicairos N, de la Garza M (January 2020). "Intestinal amoebiasis: 160 years of its first detection and still remains as a health problem in developing countries". Int J Med Microbiol. 310 (1): 151358. doi:10.1016/j.ijmm.2019.151358. PMID 31587966. S2CID 203849436.
  5. ^ Roy M, Rawat A, Kaushik S, Jyoti A, Srivastava VK (August 2022). "Endogenous cysteine protease inhibitors in upmost pathogenic parasitic protozoa". Microbiological Research. 261: 127061. doi:10.1016/j.micres.2022.127061. PMID 35605309. S2CID 248741177.
  6. ^ Beeching N, Gill G (17 April 2014). "Amoebiasis". Tropical Medicine. John Wiley & Sons. pp. 177–182. ISBN 978-1-118-73456-8.
  7. ^ Shirley DT, Farr L, Watanabe K, Moonah S (July 2018). "A Review of the Global Burden, New Diagnostics, and Current Therapeutics for Amebiasis". Open Forum Infectious Diseases. 5 (7): ofy161. doi:10.1093/ofid/ofy161. PMC 6055529. PMID 30046644.
  8. ^ Beiting DP, John AR (2022). "Parasitic diseases: Protozoa". Yamada's Textbook of Gastroenterology. pp. 3022–3038. doi:10.1002/9781119600206.ch146. ISBN 978-1-119-60016-9.