El Salvador Atlas of Gastrointestinal VideoEndoscopy. A Large Database of Images and Video Clips with Cases Reported.
El Salvador Atlas of Gastrointestinal VideoEndoscopy
Amebiasis Colitis. Inflammatory bowel disease. At the beginning the macroscopic images were not specific. Crohn´s Disease or Amebiasis colitis.? This sequence displays multiple ulcers at the rectum, but at the ascending colon and others segments it seems to be a Crohn´s disease. The rectum nodules are ulcerated and look flask shaped consistently with amebic colitis. A 33 year-old male patient, who for work reasons had to live in Mexico for 5 months. 3 months earlier, he suffered an unspecified abdominal pain and diarrhea. He was hospitalized for a series of exams, to look at the endoscopic findings showed in this endoscopic sequence. In the majority of the cases, endoscopic findings of inflammatory bowel disease are unspecific and the diagnosis is established based on the patient's evolution and clinical picture. The biopsies are mostly unspecified and a therapeutic trial is needed. As in this case, if colitis is caused by amebas, it should show a clinical improvement soon and a colonoscopy repeated 6 weeks later.

Video Endoscopic Sequence 1 of 7.

Amebiasis Colitis.

 Inflammatory bowel disease. At the beginning the
 macroscopic images were not specific.
       Crohn´s Disease or Amebiasis colitis.?
 This sequence displays multiple ulcers at the rectum,
 but at the ascending colon and others segments it seems
 to be a Crohn´s disease.
 The rectum nodules are ulcerated and look “flask shaped”
 consistently with amebic colitis.

 A 33 year-old male patient, who for work reasons had to
 live in Mexico for 5 months. 3 months earlier, he suffered
 an unspecified abdominal pain and diarrhea. He was
 hospitalized for a series of exams, to look at
 the endoscopic findings showed in this endoscopic sequence. 

 In the majority of the cases, endoscopic findings of
 inflammatory bowel disease are unspecific and the
 diagnosis is established based on the patient’s evolution
 and clinical picture. The biopsies are mostly unspecified
 and a therapeutic trial is needed. As in this case, if colitis is
 caused by amebas, it should show a clinical improvement
 soon and a colonoscopy repeated 6 weeks later.

 In countries where there is a high prevalence of
 Entamoeba Hystolitica, as in the case of Mexico and El
 Salvador, it is reasonable such therapeutic trial, where
 infection from this parasites is suspected.
 Our patient had been under treatment with metronidazole
 250 mg,tid, for 10 days, and ciprofloxacin 250 mg tid. After
 six weeks a full after six week a full colonoscopy was
 performed and all lesions displayed in this endoscopic
 sequence, disappeared. 

 Download the video clips by clicking on the endoscopic
 images, if you wish to observe in full screen, wait to be
 downloaded complete then press Alt and Enter for
 Windows media, Real Player Ctrl and 3. 
 Configure the windows media in repeat is optimal.
 All endoscopic images shown in this Atlas contain
 video clips. We recommend seeing the video clips in full
 screen mode.    
The image displays the rectum with a ulcerated polypoid like "flask shaped" and several tiny ulcers (aphtas). Entamoeba histolytic Mature cysts are ingested via contaminated water or food. After excitation in the small intestine, trophozoites inhabit the large intestine and can either invade the tissue (pathogenic amoebas) or are eliminated in the stools. Trophozoites do not survive outside the body. This parasite was named for its remarkable ability to lyse human tissues. A prerequisite to amebic invasion is the parasite's ability to colonize and penetrate colonic mucins overlying the intestinal epithelium.

Video Endoscopic Sequence 2 of 7.


 The image displays the rectum with a ulcerated polypoide
 like “flask shaped” and several tiny ulcers (aphtas).

 Entamoeba histolytica

 Mature cysts are ingested via contaminated water or food.
 After excystation in the small intestine, trophozoites
 inhabit the large intestine and can either invade the tissue
 (pathogenic amebas) or are eliminated in the stools.
 Trophozoites do not survive outside the body. This parasite
 was named for its remarkable ability to lyse human tissues.
 A prerequisite to amebic invasion is the parasite's ability
 to colonize and penetrate colonic mucins overlying the
 intestinal epithelium.
Flask shaped ulcers. The image and the video display multiple rectal nodular ulcers (retroflexed image).

Video Endoscopic Sequence 3 of 7.

“Flask shaped ulcers”.

 The image and the video display multiple rectal nodular
 ulcers (retroflexed image).
The image and the video shows an ulcer of the sigmoid colon.

Video Endoscopic Sequence 4 of 7.

 The image and the video shows an ulcer of the sigmoid
 colon.
The lumen of apendix. There are some ulcers; we introduced the colonoscope to the proximal first third of the appendiceal lumen, using a thin colonoscope (pediatric).

Video Endoscopic Sequence 5 of 7.

 The lumen of apendix. There are some ulcers; we
 introduced the colonoscope to the proximal first third of the
 appendiceal lumen, using a thin colonoscope (pediatric).

Ascending colon; multiple ulcers are displayed here; these findings are consistent with Crohn´s disease.

Video Endoscopic Sequence 6 of 7.

 Ascending colon; multiple ulcers are displayed here; these
 findings are consistent with Crohn´s disease.
Another view of the ascending colon. Multiple ulcers are appreciated.

Video Endoscopic Sequence 7 of 7.

 Another view of the ascending colon. Multiple ulcers are
 appreciated.
Multiple ?flask shaped? ulcers.

 Amebic Colitis.

Multiple “flask shaped” ulcers.

 Amebiasis is the infection of the human gastrointestinal
 tract by Entamoeba histolytica, a protozoan parasite that is
 capable of invading the intestinal mucosa and may spread
 to other organs, mainly the liver. Entamoeba dispar, an
 ameba morphologically similar to E. histolytica that also
 colonizes the human gut, has been recognized recently as a
 separate species with no invasive potential. The
 acceptance of E. dispar as a distinct but closely related
 protozoan species has had profound implications for the
 epidemiology of amebiasis, since most asymptomatic
 infections found worldwide are now attributed to this
 noninvasive ameba.   
Amebic Colitis. The typical ulcers and redness are seen.

Amebic Colitis.

       The typical ulcers and redness are seen.

 Invasive amebiasis due to E. histolytica is more common
 in developing countries. In areas of endemic infection, a
 variety of conditions including ignorance, poverty,
 overcrowding, inadequate and contaminated water supplies,
 and poor sanitation favor direct fecal-oral transmission of
 amebas from one person to another. Being responsible for
 approximately 70 thousand deaths annually, amebiasis is
 the fourth leading cause of death due to a protozoan
 infection after malaria, Chagas' disease, and leishmaniasis
 and the third cause of morbidity in this organism group
 after malaria and trichomoniasis, according to recent
 World Health Organization estimates
Amebic Colitis. Ulcers with slightly undermined edges are seen in this image of colonic amebiasis.

 Amebic Colitis.

 Ulcers with slightly undermined edges are seen in this
 image of colonic amebiasis.

 The motile form of E. histolytica, the trophozoite, lives in
 the lumen of the large intestine, where it multiplies and
 differentiates into the cyst, the resistant form responsible
 for the transmission of the infection. Cysts are excreted in
 stools and may be ingested by a new host via contaminated
 food or water. The parasite excysts in the terminal ileum,
 with each emerging quadrinucleate trophozoite giving rise
 to eight uninucleated trophozoites. Trophozoites may
 invade the colonic mucosa and cause dysentery and,
 through spreading via the bloodstream, may give rise to
 extraintestinal lesions, mainly liver abscesses.
The classic "flask shaped" ulcer in a patient with amebic colitis. See the next image and video clip to appreciate another lesion in the same person.

Video Endoscopic Sequence 1 of 2.

 The classic “flask shaped” ulcer in a patient with amebic
 colitis. See the next image and video clip to appreciate
 another lesion in the same person.

 
Ameboma. The formation of a mass lesion at sigmoid colon. It is essential that these could not be misdiagnossed as inflamatory bowel disease or tumor. An ameboma is a mass of tissue in the bowel that is formed by entamoeba hytolitica organisms. It can result from either chronic intestinal infection or acute amebic dysentery. Amebomas may produce symptoms that mimic cancer or other intestinal diseases.

Video Endoscopic Sequence 2 of 2.

Ameboma.

 The formation of a mass lesion at sigmoid colon.
 It is essential that these could not be misdiagnossed as
 inflamatory bowel disease or tumor.
 An ameboma is a mass of tissue in the bowel that is formed
 by entamoeba hytolitica organisms. It can result from
 either chronic intestinal infection or acute amebic
 dysentery.
 Amebomas may produce symptoms that mimic cancer or
 other intestinal diseases.

Amebic Colitis.

Amebic Colitis.

 Depending on the affected organ, the clinical
 manifestations of amebiasis are intestinal or
 extraintestinal. There are four clinical forms of invasive
 intestinal amebiasis, all of which are generally acute:
 dysentery or bloody diarrhea, fulminating colitis, amebic
 appendicitis, and ameboma of the colon. Dysenteric and
 diarrheic syndromes account for 90% of cases of invasive
 intestinal amebiasis. Patients with dysentery have an
 average of three to five mucosanguineous evacuations per
 day, with moderate colic pain preceding discharge, and they
 have rectal tenesmus. In patients with bloody diarrhea,
 evacuations are also few but the stools are composed of
 liquid fecal material stained with blood. While there is
 moderate colic pain, there is no rectal tenesmus. Fever and
 systemic manifestations are generally absent. These
 syndromes constitute the classic ambulatory dysentery and
 can easily be distinguished from that of bacterial origin,
 where the patient frequently complains of systemic signs
 and symptoms such as fever, chills, headache, malaise,
 anorexia, nausea, vomiting, cramping abdominal pain, and
 tenesmus.
Rectal Amebiasis. A 45 year-old female, with rectal bleeding with dark red color, two ulcers are observed "flask shaped" ulcer.

Video Endoscopic Sequence 1 of 2.

Rectal Amebiasis.

 A 45 year-old female, with rectal bleeding with dark red
 color, two ulcers are observed “flask shaped” ulcer.

 Download the video clip.
Same case as above, retroflexed maneuver.

Video Endoscopic Sequence 2 of 2.

 Same case as above, retroflexed maneuver.
 
Amebic Colitis. Infection of the large intestine by Entamoeba histolytica may result in an illness of variable severity.

Amebic Colitis.

 Infection of the large intestine by Entamoeba histolytica may
 result in an illness of variable severity, ranging from mild,
 chronic diarrhea to fulminant dysentery. Infection also may
 be asymptomatic.

 Extraintestinal infection also can occur
 (e.g., hepatic abscess).

 
Histopathology of Amebiasis. Rectal mucosa with surface erosion and Entamoeba histolytica trophozoites.

Histopathology of Amebiasis

 Rectal mucosa with surface erosion and Entamoeba
 histolytica trophozoites.
 Phagocytosis as a Virulence Factor

 

 
A Close up. E ntamoeba histolytica trophozoites are able to degrade human erythrocytes, Traditionally, erythrophagocytosis has been the main laboratory criterion to identify pathogenic amebas. One of the fundamental questions of the biology of Entamoeba histolytica directly related to the understanding of human amebiasis concerns the nature of the factors that determine the virulence of the parasite. The initiation of invasive amebiasis may result from the rupture of a host-parasite equilibrium that is maintained while E. histolytica is restricted to a commensal phase.

A Close up.

 Entamoeba histolytica trophozoites are able to degrade
 human erythrocytes, Traditionally, erythrophagocytosis
 has been the main laboratory criterion to identify
 pathogenic amebas.

 One of the fundamental questions of the biology of
 Entamoeba histolytica directly related to the
 understanding of human amebiasis concerns the nature of
 the factors that determine the virulence of the parasite.
 The initiation of invasive amebiasis may result from the
 rupture of a host-parasite equilibrium that is maintained
 while E. histolytica is restricted to a commensal phase.
High power detail of E. histolytica trophozoites with eritrocytes inside. The degree of virulence of cultured E. histolytica varies according to the strain and culture condition The factors responsible for these variations remain obscure. Despite a large amount of information on the subject, ultrastructural and biochemical studies have not been able to demonstrate differences that could explain the variable degree of virulence. Certain cell surface properties appear to characterize pathogenic strains: adhesion to epithelial cells), susceptibility to agglutinate with concanavalin A, ability to produce lytic effect on cultured cells and phagocytosis oferythrocytes. Recently, a correlation between collagenase production and virulence has been found.

 High power detail of E. histolytica trophozoites with
 eritrocytes inside.

 The degree of virulence of cultured E. histolytica varies
 according to the strain and culture condition The factors
 responsible for these variations remain obscure. Despite a
 large amount of information on the subject, ultrastructural
 and biochemical studies have not been able to demonstrate
 differences that could explain the variable degree of
 virulence. Certain cell surface properties appear to
 characterize pathogenic strains: adhesion to epithelial cells)
, susceptibility to agglutinate with concanavalin A, ability to
 produce lytic effect on cultured cells and phagocytosis
 oferythrocytes. Recently, a correlation between
 collagenase production and virulence has been found.
Close up of trophozoites of E. histolytica showing the nuclear appearance and erythrophagocytosis.

 

 Close up of trophozoites of E. histolytica showing the
 nuclear appearance and erythrophagocytosis.