- Author: Vinod K Dhawan, MD, FACP, FRCPC, FIDSA; Chief Editor: Michael Stuart Bronze, MD more...
Asymptomatic amebiasis in nonendemic areas should be treated with a luminal agent (iodoquinol, paromomycin, or diloxanide furoate) to eradicate infection. Asymptomatic Entamoeba dispar infections should not be treated, but education should be pursued.
Amebic colitis is treated first with a nitroimidazole derivative and then with a luminal agent to eradicate colonization. Paromomycin is safe, well tolerated, and effective in the treatment of intestinal amebiasis, including in patients with HIV infection. Diloxanide is a dichloroacetamide derivative that is amebicidal against trophozoite and cyst forms of E histolytica. It is not available in the United States.
Amebic liver abscess can be cured without drainage by using metronidazole. Treatment with a luminal agent should also follow. Disseminated amebiasis should be treated with metronidazole, which can cross the brain-blood barrier. Empirical antibacterial therapy should be used concomitantly if perforated bowel is a concern.
Several agents are active against anaerobic bacteria and protozoa. Metronidazole is the drug of choice for symptomatic, invasive disease; paromomycin is the drug of choice for noninvasive disease. Because parasites persist in the intestines of 40-60% of patients treated with metronidazole, this drug should be followed with paromomycin to cure luminal infection. Do not give the 2 medications at the same time; the diarrhea that often results from paromomycin might be confused with continuing active intestinal disease from the parasite.
Metronidazole kills trophozoites of Entamoeba histolytica in intestines and tissue but does not eradicate cysts from intestines. It appears to be absorbed into cells. Intermediate metabolized compounds are formed and bind DNA and inhibit protein synthesis, causing cell death. Antimicrobial effect may be due to production of free radicals. Metronidazole is indicated for invasive amebiasis.
Tinidazole is a 5-nitroimidazole derivative used to treat susceptible protozoal infections. The mechanism by which it acts against Giardia and Entamoeba species is not known. Tinidazole is indicated for treatment of intestinal amebiasis and amebic liver abscess caused by E histolytica in adults and children aged 3 years and older.
Paromomycin is an amebicidal and antibacterial aminoglycoside obtained from a strain of Streptomyces rimosus; it is poorly absorbed and is active only against the intraluminal form of amebiasis. Used to eradicate cysts of E histolytica after treatment with metronidazole or tinidazole for invasive disease.
Parasite biochemical pathways are sufficiently different from those of the human host to allow selective interference by chemotherapeutic agents in relatively small doses.
Iodoquinol is a halogenated hydroxyquinoline that is a luminal amebicide; it acts primarily in the bowel lumen because it is poorly absorbed. It is best tolerated when given with meals. Because iodoquinol is active only against intraluminal form of amebiasis, it is used to eradicate cysts of E histolytica after treatment of invasive disease.
Chloroquine phosphate inhibits growth by concentrating within acid vesicles of the parasite, thereby increasing the organism's internal pH. It also inhibits the organism's hemoglobin utilization and metabolism.
In vitro studies involving trophozoites of E histolytica demonstrate that chloroquine possesses amebicidal activity comparable to that of emetine. It is highly effective in treating amebic liver abscess when administered with emetine or dehydroemetine; however, like emetine and dehydroemetine, it is not effective against luminal forms. Irreversible retinal damage does not occur with the dosage and treatment duration used for treatment of hepatic amebiasis.
Dehydroemetine is preferred to emetine because it is less toxic. It eradicates amebic tissue infections, including liver abscess, but does not act on luminal forms. To eradicate a bowel luminal infection, a luminal amebicide must be used as well. Dehydroemetine is effective only against trophozoites, not against cysts. In the United States, it is available only from the Parasitic Disease Drug Service of the Centers for Disease Control and Prevention (CDC).
Pritt BS, Clark CG. Amebiasis. Mayo Clin Proc. 2008 Oct. 83(10):1154-9; quiz 1159-60. [Medline].
Grecu F, Bulgariu T, Blanaru O, Dragomir C, Lunca C, Stratan I, et al. Invasive amebiasis. Chirurgia (Bucur). 2006 Sep-Oct. 101(5):539-42. [Medline].
Haque R, Huston CD, Hughes M, Houpt E, Petri WA Jr. Amebiasis. N Engl J Med. 2003 Apr 17. 348(16):1565-73. [Medline].
Stanley SL Jr. Amoebiasis. Lancet. 2003 Mar 22. 361(9362):1025-34. [Medline].
Ravdin JI, Stanley P, Murphy CF, Petri WA Jr. Characterization of cell surface carbohydrate receptors for Entamoeba histolytica adherence lectin. Infect Immun. 1989 Jul. 57(7):2179-86. [Medline]. [Full Text].
Haque R, Mondal D, Duggal P, Kabir M, Roy S, Farr BM, et al. Entamoeba histolytica infection in children and protection from subsequent amebiasis. Infect Immun. 2006 Feb. 74(2):904-9. [Medline]. [Full Text].
Seydel KB, Stanley SL Jr. Entamoeba histolytica induces host cell death in amebic liver abscess by a non-Fas-dependent, non-tumor necrosis factor alpha-dependent pathway of apoptosis. Infect Immun. 1998 Jun. 66(6):2980-3. [Medline]. [Full Text].
Kelsall BL, Ravdin JI. Degradation of human IgA by Entamoeba histolytica. J Infect Dis. 1993 Nov. 168(5):1319-22. [Medline].
Reed SL, Keene WE, McKerrow JH, Gigli I. Cleavage of C3 by a neutral cysteine proteinase of Entamoeba histolytica. J Immunol. 1989 Jul 1. 143(1):189-95. [Medline].
Abhyankar MM, Shrimal S, Gilchrist CA, Bhattacharya A, Petri WA Jr. The Entamoeba histolytica serum-inducible transmembrane kinase EhTMKB1-9 is involved in intestinal amebiasis. Int J Parasitol Drugs Drug Resist. 2012 Dec. 2:243-248. [Medline]. [Full Text].
Seydel KB, Li E, Swanson PE, Stanley SL Jr. Human intestinal epithelial cells produce proinflammatory cytokines in response to infection in a SCID mouse-human intestinal xenograft model of amebiasis. Infect Immun. 1997 May. 65(5):1631-9. [Medline]. [Full Text].
Braga LL, Ninomiya H, McCoy JJ, Eacker S, Wiedmer T, Pham C, et al. Inhibition of the complement membrane attack complex by the galactose-specific adhesion of Entamoeba histolytica. J Clin Invest. 1992 Sep. 90(3):1131-7. [Medline]. [Full Text].
Fotedar R, Stark D, Beebe N, Marriott D, Ellis J, Harkness J. Laboratory diagnostic techniques for Entamoeba species. Clin Microbiol Rev. 2007 Jul. 20(3):511-32, table of contents. [Medline]. [Full Text].
Freedman DO, Weld LH, Kozarsky PE, Fisk T, Robins R, von Sonnenburg F, et al. Spectrum of disease and relation to place of exposure among ill returned travelers. N Engl J Med. 2006 Jan 12. 354(2):119-30. [Medline].
Valenzuela O, Morán P, Gómez A, Cordova K, Corrales N, Cardoza J, et al. Epidemiology of amoebic liver abscess in Mexico: the case of Sonora. Ann Trop Med Parasitol. 2007 Sep. 101(6):533-8. [Medline].
van Hal SJ, Stark DJ, Fotedar R, Marriott D, Ellis JT, Harkness JL. Amoebiasis: current status in Australia. Med J Aust. 2007 Apr 16. 186(8):412-6. [Medline].
Ximénez C, Morán P, Rojas L, Valadez A, Gómez A. Reassessment of the epidemiology of amebiasis: state of the art. Infect Genet Evol. 2009 Dec. 9(6):1023-32. [Medline].
Stauffer W, Abd-Alla M, Ravdin JI. Prevalence and incidence of Entamoeba histolytica infection in South Africa and Egypt. Arch Med Res. 2006 Feb. 37(2):266-9. [Medline].
Tengku SA, Norhayati M. Public health and clinical importance of amoebiasis in Malaysia: a review. Trop Biomed. 2011 Aug. 28(2):194-222. [Medline].
Caballero-Salcedo A, Viveros-Rogel M, Salvatierra B, Tapia-Conyer R, Sepulveda-Amor J, Gutierrez G, et al. Seroepidemiology of amebiasis in Mexico. Am J Trop Med Hyg. 1994 Apr. 50(4):412-9. [Medline].
Blessmann J, Van Linh P, Nu PA, Thi HD, Muller-Myhsok B, Buss H, et al. Epidemiology of amebiasis in a region of high incidence of amebic liver abscess in central Vietnam. Am J Trop Med Hyg. 2002 May. 66(5):578-83. [Medline].
Bowley DM, Loveland J, Omar T, Pitcher GJ. Human immunodeficiency virus infection and amebiasis. Pediatr Infect Dis J. 2006 Dec. 25(12):1192-3. [Medline].
Brindicci G, Picciarelli C, Fumarola L, Carbonara S, Stano F, Ciracì E, et al. Amoebic hepatic abscesses in an HIV-positive patient. AIDS Patient Care STDS. 2006 Sep. 20(9):606-11. [Medline].
Chen Y, Zhang Y, Yang B, Qi T, Lu H, Cheng X, et al. Seroprevalence of Entamoeba histolytica infection in HIV-infected patients in China. Am J Trop Med Hyg. 2007 Nov. 77(5):825-8. [Medline]. [Full Text].
Hsu MS, Hsieh SM, Chen MY, Hung CC, Chang SC. Association between amebic liver abscess and human immunodeficiency virus infection in Taiwanese subjects. BMC Infect Dis. 2008 Apr 16. 8:48. [Medline]. [Full Text].
Karp CL, Auwaerter PG. Coinfection with HIV and tropical infectious diseases. I. Protozoal pathogens. Clin Infect Dis. 2007 Nov 1. 45(9):1208-13. [Medline].
Infection by human immunodeficiency virus-1 is not a risk factor for amebiasis. Am J Trop Med Hyg. 2006 Nov. 75(5):1023. [Medline].
Hung CC, Ji DD, Sun HY, Lee YT, Hsu SY, Chang SY, et al. Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan. PLoS Negl Trop Dis. 2008 Feb 27. 2(2):e175. [Medline]. [Full Text].
Muzaffar J, Madan K, Sharma MP, Kar P. Randomized, single-blind, placebo-controlled multicenter trial to compare the efficacy and safety of metronidazole and satranidazole in patients with amebic liver abscess. Dig Dis Sci. 2006 Dec. 51(12):2270-3. [Medline].
Hung CC, Wu PY, Chang SY, Ji DD, Sun HY, Liu WC, et al. Amebiasis among persons who sought voluntary counseling and testing for human immunodeficiency virus infection: a case-control study. Am J Trop Med Hyg. 2011 Jan. 84(1):65-9. [Medline]. [Full Text].
Acuna-Soto R, Maguire JH, Wirth DF. Gender distribution in asymptomatic and invasive amebiasis. Am J Gastroenterol. 2000 May. 95(5):1277-83. [Medline].
Nagata N, Shimbo T, Akiyama J, Nakashima R, Nishimura S, Yada T. Risk factors for intestinal invasive amebiasis in Japan, 2003-2009. Emerg Infect Dis. 2012 May. 18(5):717-24. [Medline].
Aristizábal H, Acevedo J, Botero M. Fulminant amebic colitis. World J Surg. 1991 Mar-Apr. 15(2):216-21. [Medline].
Andrade JE, Mederos R, Rivero H, Sendzischew MA, Soaita M, Robinson MJ, et al. Amebiasis presenting as acute appendicitis. South Med J. 2007 Nov. 100(11):1140-2. [Medline].
Hardin RE, Ferzli GS, Zenilman ME, Gadangi PK, Bowne WB. Invasive amebiasis and ameboma formation presenting as a rectal mass: An uncommon case of malignant masquerade at a western medical center. World J Gastroenterol. 2007 Nov 14. 13(42):5659-61. [Medline].
Loulergue P, Mir O. Pleural empyema secondary to amebic liver abscess. Int J Infect Dis. 2009 May. 13(3):e135-6. [Medline].
Otan E, Akbulut S, Kayaalp C. Amebic acute appendicitis: systematic review of 174 cases. World J Surg. 2013 Sep. 37(9):2061-73. [Medline].
Sodhi KS, Ojili V, Sakhuja V, Khandelwal N. Hepatic and inferior vena caval thrombosis: vascular complication of amebic liver abscess. J Emerg Med. 2008 Feb. 34(2):155-7. [Medline].
Abd-Alla MD, Jackson TF, Gathiram V, el-Hawey AM, Ravdin JI. Differentiation of pathogenic Entamoeba histolytica infections from nonpathogenic infections by detection of galactose-inhibitable adherence protein antigen in sera and feces. J Clin Microbiol. 1993 Nov. 31(11):2845-50. [Medline]. [Full Text].
Haque R, Mollah NU, Ali IK, Alam K, Eubanks A, Lyerly D, et al. Diagnosis of amebic liver abscess and intestinal infection with the TechLab Entamoeba histolytica II antigen detection and antibody tests. J Clin Microbiol. 2000 Sep. 38(9):3235-9. [Medline]. [Full Text].
Helmy MM, Rashed LA, Abdel-Fattah HS. Detection and differentiation of Entamoeba histolytica and Entamoeba dispar isolates in clinical samples by PCR. J Egypt Soc Parasitol. 2007 Apr. 37(1):257-74. [Medline].
Shamsuzzaman SM, Haque R, Hasin SK, Hashiguchi Y. Evaluation of indirect fluorescent antibody test and enzyme-linked immunosorbent assay for diagnosis of hepatic amebiasis in Bangladesh. J Parasitol. 2000 Jun. 86(3):611-5. [Medline].
Ahmad N, Khan M, Hoque MI, Haque R, Mondol D. Detection of Entamoeba histolytica DNA from liver abscess aspirate using polymerase chain reaction (PCR): a diagnostic tool for amoebic liver abscess. Bangladesh Med Res Counc Bull. 2007 Apr. 33(1):13-20. [Medline].
Fotedar R, Stark D, Beebe N, Marriott D, Ellis J, Harkness J. PCR detection of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii in stool samples from Sydney, Australia. J Clin Microbiol. 2007 Mar. 45(3):1035-7. [Medline]. [Full Text].
Khairnar K, Parija SC. A novel nested multiplex polymerase chain reaction (PCR) assay for differential detection of Entamoeba histolytica, E. moshkovskii and E. dispar DNA in stool samples. BMC Microbiol. 2007 May 24. 7:47. [Medline]. [Full Text].
Stark D, van Hal S, Fotedar R, Butcher A, Marriott D, Ellis J, et al. Comparison of stool antigen detection kits to PCR for diagnosis of amebiasis. J Clin Microbiol. 2008 May. 46(5):1678-81. [Medline]. [Full Text].
Singh P, Mirdha BR, Ahuja V, Singh S. Loop-mediated isothermal amplification (LAMP) assay for rapid detection of Entamoeba histolytica in amoebic liver abscess. World J Microbiol Biotechnol. 2013 Jan. 29(1):27-32. [Medline].
Misra SP, Misra V, Dwivedi M. Ileocecal masses in patients with amebic liver abscess: etiology and management. World J Gastroenterol. 2006 Mar 28. 12(12):1933-6. [Medline].
Nagata N, Shimbo T, Akiyama J, Nakashima R, Niikura R, Nishimura S, et al. Predictive value of endoscopic findings in the diagnosis of active intestinal amebiasis. Endoscopy. 2012 Apr. 44(4):425-8. [Medline].
Gonzales ML, Dans LF, Martinez EG. Antiamoebic drugs for treating amoebic colitis. Cochrane Database Syst Rev. 2009 Apr 15. CD006085. [Medline].
Petri WA Jr, Singh U. Diagnosis and management of amebiasis. Clin Infect Dis. 1999 Nov. 29(5):1117-25. [Medline].
Salles JM, Salles MJ, Moraes LA, Silva MC. Invasive amebiasis: an update on diagnosis and management. Expert Rev Anti Infect Ther. 2007 Oct. 5(5):893-901. [Medline].
Kimura M, Nakamura T, Nawa Y. Experience with intravenous metronidazole to treat moderate-to-severe amebiasis in Japan. Am J Trop Med Hyg. 2007 Aug. 77(2):381-5. [Medline].
Moon TD, Oberhelman RA. Antiparasitic therapy in children. Pediatr Clin North Am. 2005 Jun. 52(3):917-48, viii. [Medline].
Bammigatti C, Ramasubramanian NS, Kadhiravan T, Das AK. Percutaneous needle aspiration in uncomplicated amebic liver abscess: a randomized trial. Trop Doct. 2013 Jan. 43(1):19-22. [Medline].
Athié-Gutiérrez C, Rodea-Rosas H, Guízar-Bermúdez C, Alcántara A, Montalvo-Javé EE. Evolution of surgical treatment of amebiasis-associated colon perforation. J Gastrointest Surg. 2010 Jan. 14(1):82-7. [Medline].
Jha AK, Das G, Maitra S, Sengupta TK, Sen S. Management of large amoebic liver abscess--a comparative study of needle aspiration and catheter drainage. J Indian Med Assoc. 2012 Jan. 110(1):13-5. [Medline].
Chaudhry OA, Petri WA Jr. Vaccine prospects for amebiasis. Expert Rev Vaccines. 2005 Oct. 4(5):657-68. [Medline].
Snow MJ, Stanley SL Jr. Recent progress in vaccines for amebiasis. Arch Med Res. 2006 Feb. 37(2):280-7. [Medline].
Stanley SL Jr. Vaccines for amoebiasis: barriers and opportunities. Parasitology. 2006. 133 Suppl:S81-6. [Medline].
Quach J, St-Pierre J, Chadee K. The future for vaccine development against Entamoeba histolytica. Hum Vaccin Immunother. 2014 Feb 6. 10(6):[Medline].
Kikuchi T, Koga M, Shimizu S, Miura T, Maruyama H, Kimura M. Efficacy and safety of paromomycin for treating amebiasis in Japan. Parasitol Int. 2013 Dec. 62(6):497-501. [Medline].