Amebiasis Clinical Presentation
- Author: Vinod K Dhawan, MD, FACP, FRCPC, FIDSA; Chief Editor: Michael Stuart Bronze, MD more...
The incubation period for E histolytica infection is commonly 2-4 weeks but may range from a few days to years. The clinical spectrum of amebiasis ranges from asymptomatic infection to fulminant colitis and peritonitis to extraintestinal amebiasis, the most common form of which is amebic liver abscess.
Amebiasis is more severe in very young patients, in elderly patients, and in patients receiving corticosteroids. The clinical expression of amebiasis may be related to geography. For instance, amebic colitis is the predominant presentation in Egypt, whereas amebic liver abscesses predominate in South Africa.
Asymptomatic infections are common after ingestion of the parasite. E dispar does not cause invasive disease or antibody production. As many as 90% of E histolytica infections are also asymptomatic. The infection is self-limited but may be recurrent. It is not possible to distinguish between E histolytica and E dispar on clinical grounds; only antigen detection tests can make this distinction.
Amebic colitis is gradual in onset, with symptoms presenting over 1-2 weeks; this pattern distinguishes this condition from bacterial dysentery. Diarrhea is the most common symptom. Patients with amebic colitis typically present with cramping abdominal pain, watery or bloody diarrhea, and weight loss or anorexia. Fever is noted in 10-30% of patients. Intestinal amebiasis may mimic acute appendicitis. Rectal bleeding without diarrhea can occur, especially in children.
Fulminant amebic colitis is a rare complication of amebic dysentery (< 0.5% of cases). It presents with the rapid onset of severe bloody diarrhea, severe abdominal pain, and evidence of peritonitis and fever. Predisposing factors for fulminant colitis include poor nutrition, pregnancy, corticosteroid use, and very young age (< 2 years). Intestinal perforation is common. Patients may develop toxic megacolon, which is typically associated with the use of corticosteroids. Mortality from fulminant amebic colitis may exceed 40%.
Chronic amebic colitis is clinically similar to inflammatory bowel disease (IBD). Recurrent episodes of bloody diarrhea and vague abdominal discomfort develop in 90% of patients with chronic amebic colitis who have antibodies to E histolytica. Amebic colitis should be ruled out before treatment of suspected IBD because corticosteroid therapy worsens amebiasis.
Amebic liver abscess
Amebic liver abscess is the most common form of extraintestinal amebiasis. It occurs in as many as 5% of patients with symptomatic intestinal amebiasis and is 10 times as frequent in men as in women. Approximately 80% of patients with amebic liver abscess present within 2-4 weeks of infection. An estimated 95% of amebic liver abscesses related to travel develop within 5 months, though some may not manifest until years after travel to or residency in an endemic area.
The most typical presentation of amebic liver abscess is fever (in 85-90% of cases, in contrast to amebic colitis), right upper quadrant pain, and tenderness of less than 10 days’ duration. Involvement of the diaphragmatic surface of the liver may lead to right-side pleuritic pain or referred shoulder pain. Acute abdominal symptoms and signs should prompt rapid investigation for intraperitoneal rupture.
Associated gastrointestinal (GI) symptoms occur in 10-35% of patients and include nausea, vomiting, abdominal distention, diarrhea, and constipation. Approximately 40% of patients who have amebic liver abscess do not have a history of prior bowel symptoms. Although 60-70% of patients with amebic liver abscess do not have concomitant colitis, a history of dysentery within the previous year may be obtained.In a recent study of routine colonoscopy in patients with amebic liver abscess, colonic involvement was noted in two thirds of cases. When colon was involved, right colonic lesion was universally present.
A small subset of patients with amebic liver abscess have a subacute presentation with vague abdominal discomfort, weight loss or anorexia, and anemia. Jaundice is unusual. Cough can occur. A history of alcohol abuse is common, but whether a causal relation exists is unclear.
Other manifestations of amebiasis
Ameboma, a less common form of intestinal disease, arises from the formation of annular colonic granulation in response to the infecting organisms, which results in a large local lesion of the bowel. It presents as a right lower quadrant abdominal mass, which may be mistaken for carcinoma, tuberculosis, Crohn disease, actinomycosis, or lymphoma. Biopsy findings assist in establishing the correct diagnosis. Rectal masses that resemble carcinoma on colonoscopy have also been noted.
Pleuropulmonary amebiasis is most commonly the result of contiguous spread from a liver abscess rupturing through the right hemidiaphragm. However, a case of amebic lung abscess acquired through hematogenous spread has been reported. The typical age group is 20-40 years. The male-to-female ratio is 10:1.
Approximately 10% of patients with amebic liver abscess develop pleuropulmonary amebiasis, which presents with cough, pleuritic pain, and dyspnea. A hepatobronchial fistula is an unusual problem characterized by the expectoration of sputum resembling anchovy paste. The trophozoites of E histolytica may be found in the sputum sample. Primary amebic pneumonia as a result of hematogenous spread has been reported, though rarely.
Amebic abscesses resulting from hematogenous spread have occasionally been described in the brain. Cerebral amebiasis occurs in 0.6% of amebic liver abscess cases. Patients commonly present with the abrupt onset of nausea, vomiting, headache, and mental status changes. Computed tomography (CT) reveals irregular lesions without a surrounding capsule or enhancement. A tissue biopsy sample reveals the trophozoites. Progression can be very rapid, sometimes leading to death within 12-72 hours.
Amebic peritonitis is generally secondary to a ruptured liver abscess. Left-lobe liver abscesses are more likely to rupture. Patients present with fever and a rigid distended abdomen. Roughly 2-7% of liver abscesses rupture into the peritoneum.
Amebic pericarditis is rare but is the most serious complication of hepatic amebiasis. It is usually caused by a rupture of a left-liver lobe abscess and occurs in 3% of patients with hepatic amebiasis. It presents with chest pain and the features of congestive heart failure.
Genitourinary involvement may cause painful genital ulcers or fallopian tube amebiasis.
Patients with acute amebic colitis may have lower quadrant abdominal tenderness (12-85% of cases). Fever is noted in only a minority of patients (10-30%). Weight loss occurs in 40%. Dehydration is uncommon. Occult blood is nearly always present in stools (70-100%). Fulminant amebic colitis is commonly characterized by abdominal pain, distention, and rebound tenderness.
Amebic liver abscess may present with fever (85-90% of cases) and tender hepatomegaly (30-50%). Right lower intercostal tenderness may be elicited, particularly posteriorly (84-90%). Weight loss is noted in 33-50%. Breath sounds may be diminished at the right lung base, and rales may be heard. A small subset of patients has a subacute presentation with hepatomegaly, weight loss, and anemia. Jaundice is unusual (6-10%).
Other physical findings in amebiasis include the following:
Pleuropulmonary amebiasis may produce right-side pleural effusions, empyema, basilar atelectasis, pneumonia, and lung abscess
Patients with amebic peritonitis have fever and a tender, rigid, and distended abdomen
Amebic pericarditis presents with features of congestive heart failure; a pericardial friction rub may be audible
Cerebral amebiasis presents with altered consciousness and focal neurologic signs
Genital ulcers due to amebiasis have a punched-out appearance and profuse discharge
Complications of amebic colitis include the following:
Fulminant or necrotizing colitis
Complications of amebic liver abscess include the following:
Intraperitoneal, intrathoracic, or intrapericardial rupture, with or without secondary bacterial infection
Direct extension to pleura or pericardium
Dissemination and formation of brain abscess
Other complications due to amebiasis include the following[41, 47] :
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].