Colocolic Intussusception Associated with Octangium sp. (Digenea: Microscaphidiidae) in a Green Sea Turtle Chelonia mydas

Reports of intussusception in sea turtles are generally linked to marine debris ingestion; therefore, only a few cases of the disease are associated with parasitic infestations. The objective of this study was to describe the necropsy findings of the first reported case of colocolic intussusception in a green sea turtle Chelonia mydas, associated with the helminth Octangium sp. A juvenile female green sea turtle, which was registered and rescued by the team from the Cetaceans Project of Costa Branca, State University of Rio Grande do Norte, was examined. The animal died 1 d after being treated and was immediately submitted for necropsy. Our findings indicated that parasitic infestation by Octangium sp. in the green sea turtle caused intussusception and consequently led to the animal's death. Early diagnosis and surgical correction are fundamental for a good prognosis and, consequently, for successful rehabilitation of marine species.

[Colonic balantidiasis: report of a fatal case and review of the literature]

Balantidiasis is a zoonosis produced by Balantidium coli, which inhabits the large intestine of the pig and man. Infection is uncommon in humans and mainly affects the colon. It occurs more frequently in developing countries, tropical and subtropical regions. Colonic balantidiasis can occur in most cases asymptomatically and reach in the most severe cases such as dysenteric diarrhea that can be complicated by low digestive bleeding and even perforation. We present the case of a 72-year-old man, from the Peruvian highlands, who was a farmer and breeder of swine and sheep, who came for 3 months of illness, initially characterized by liquid stools with bloodless mucus, abdominal pain, nausea, vomiting and in the last month of illness he presents dysenteric diarrhea. Colonoscopy was performed due to suspicion of infectious colitis, Balantidium coli trophozoites were found in the fresh sample and colonic tissue biopsy. Patient receives treatment with amebicide and antibacterial without clinical improvement, presenting as a complication multiple perforation in the sigmoid colon, treated with resection and terminal colostomy. Finally, the patient died despite receiving medical and surgical treatment.

Intestinal spirochaetosis mimicking acute appendicitis with review of the literature

Human intestinal spirochaetosis is a well-established micro-organism existing in the colon. It is less commonly seen in the appendix, and rarely presents as acute appendicitis. We present a case of a man presenting with symptoms consistent with acute appendicitis. The literature on spirochaetosis presenting as acute appendicitis is also reviewed.

Endoscopic resection of sparganosis presenting as colon submucosal tumor: A case report

Human sparganosis is a rare parasitic disease caused by infection with the tapeworm Sparganum, the migrating plerocercoid (second stage) larva of Spirometra species. Sparganosis usually involves subcutaneous tissues and/or muscles of various parts of the body, but involvement of other sites such as the brain, eye, peritoneopleural cavity, urinary track, scrotum, and abdominal viscera has also been documented. Infections caused by sparganum have a worldwide distribution but are most common in Southeast Asia such as China, Japan, and South Korea. Rectal sparganosis is an uncommon disease but should be considered in the differential diagnosis of unusual and suspicious rectal submucosal tumors. We report a case of rectal sparganosis presenting as rectal submucosal tumor. We performed endoscopic submucosal dissection of the rectal submucosal tumor. The sparganosis was confirmed based on the presence of calcospherules in the submucosal layer on histological examination. Moreover, the result of the immunoglobulin G antibody test for sparganosis was positive but became negative after endoscopic submucosal dissection. Though rare, rectal sparganosis should be considered in the differential diagnosis of rectal submucosal tumor-like lesions. This case suggests that physicians should make effort to exclude sparganosis through careful diagnostic approaches, including detailed history taking and serological tests for parasites. In this report, we aimed to highlight the clinical presentation of Sparganum infection as a rectal submucosal tumor.

[Massive hookworm infection as a cause of intestinal bleeding and severe anemia]

Overt gastrointestinal bleeding caused by hookworm infection is rarely reported. We present a 34 year old male with lower gastrointestinal bleeding with evidence of massive hookworm infection on colonoscopy and discuss the need to consider hookworm infection as a possible etiology of gastrointestinal bleed in endemic areas.

Three successive cases of enteric anisakiasis

Enteric anisakiasis is relatively rare, and the preoperative diagnosis is difficult. We report 3 cases of enteric anisakiasis: 1 was confirmed by operation, and the other 2 cases were suspected by the patient history. The 1st patient was a 48-year-old female presenting with abdominal pain. An abdominal computed tomography scan showed a dilated small intestine and accumulation of ascites. We performed partial resection of the small intestine, and an Anisakis nematode was found on the wall of the resected bowel. After surgery, the detailed history revealed that the patient consumed a raw sardine with vinegar and miso, fermented soybean paste. Three days after her operation, 2 men presenting with abdominal pain visited the hospital, and computed tomography scans of the patients showed dilated small intestines and accumulation of ascites. By taking patient histories, we found that both of them consumed sardines with vinegar and miso, and both were given conservative treatment with fasting and transfusion. By the experience of the 1st case, we could diagnose the following 2 cases as having enteric anisakiasis. In conclusion, the possibility of anisakiasis should be considered in patients with abdominal pain after ingesting raw fish, especially when intestinal obstruction is suspected.

Radiology corner. Answer to last month's radiology case and images: Schistosomiasis japonicum involving the liver and colon

Abdominal radiography showed subtle curvilinear densities overlying the left lower quadrant and central within the pelvis (Fig. 1a). This was confirmed on intravenous contrast-enhanced abdominopelvic CT to be caused by thin mucosal surface calcifications within the descending and sigmoid colons (Fig. 1b, c). Incidental note is made of thin right hepatic lobe capsule calcifications (Fig. 1d). These colonic and hepatic calcifications are characteristic of Schistosomiasis infection of the gastrointestinal tract. Liver biopsy confirmed Schistosomiasis japonicum infection.

Colonic amoebiasis and spirochetosis: morphological, ultrastructural and microbiological evaluation

BACKGROUND

The present study reports on a prompt diagnosis of colonic amoebiasis with colonic spirochetosis by Brachyspira aalborgi and B. pilosicoli; such diagnosis allowed exclusion of other diseases and resolution of the case after specific treatment.

METHODS AND RESULTS

A 37-year-old Italian man with a history of several months' mucosal diarrhea travelled to Greece, Romania and Tunisia. After his last trip he presented with an increase of up to 3-5 discharges daily, associated with bloody diarrhea, supporting the clinical suspect of inflammatory bowel disease. Colonoscopy revealed erosions from the cecum to the rectum, and ulcers both in the descending and sigmoid colon. Structures resembling amoebic trophozoites and sinusoidal microorganisms were observed in the colonic biopsies at histopathology and electron microscopy. Entamoeba histolytica DNA was detected by small-subunit rDNA polymerase chain reaction (PCR) from feces, rectal biopsies and isolated trophozoites. Spirochetes were identified from feces, colonic biopsies and cultures using a 16S rDNA restriction fragment length polymorphism-PCR specific for the detection of B. aalborgi and B. pilosicoli. After therapy, the patient was restored to health.

CONCLUSIONS

The rapid identification of E. histolytica, B. aalborgi and B. pilosicoli using traditional and specific and sensitive molecular methods permitted an accurate diagnosis and a specific therapy. It is suggested that mixed infection by parasites and spirochetes might occur more frequently than expected: it would be of extreme interest and importance to intensify clinical findings, and one infection should not prompt the pathologist/clinician to stop looking.

Computed tomographic findings of trichuriasis

In this report, we present computed tomographic findings of colonic trichuriasis. The patient was a 75-year-old man who complained of abdominal pain, and weight loss. Diagnosis was achieved by colonoscopic biopsy. Abdominal computed tomography showed irregular and nodular thickening of the wall of the cecum and ascending colon. Although these findings are nonspecific, they may be one of the findings of trichuriasis. These findings, confirmed by pathologic analysis of the biopsied tissue and Kato-Katz parasitological stool flotation technique, revealed adult Trichuris. To our knowledge, this is the first report of colonic trichuriasis indicated by computed tomography.

A case of colonic lymphoid tissue invasion by Gymnophalloides seoi in a Korean man

A 65-year old Korean man, living in Mokpo-city, Jeollanam-do, Republic of Korea, visited a local clinic complaining of right upper quadrant pain and indigestion. At colonoscopy, he was diagnosed as having a carcinoma of the ascending colon, and thus, a palliative right hemicolectomy was performed. Subsequently, an adult fluke of Gymnophalloides seoi was incidentally found in a surgical pathology specimen of the lymph node around the colon. The worm was found to have invaded gut lymphoid tissue, with characteristic morphologies of a large oral sucker, a small ventral sucker, and a ventral pit surrounded by strong muscle fibers. This is the first reported case of mucosal tissue invasion by G. seoi in the human intestinal tract.

A rare cause of colonic stricture: amebiasis

A 41-year-old man presenting with lower abdominal pain, constipation, abdominal distention, fever (37.5 degrees C) and fatigue was evaluated, and a mass localized to the left lower abdomen was identified. Radiographic and colonoscopic examination revealed a stricture 10 cm in length localized to the sigmoid-descending colon junction. The diagnosis of amebiasis was confirmed by histological examination of a biopsy specimen taken from the stricture and stool examination. One month after the initiation of metronidazole treatment, complete clinical and laboratory improvement was observed. In the differential diagnosis of colonic stricture, amebiasis should also be considered.

Amebic perforation of the colon: rare and frequently fatal complication

Amebic colitis perforation is a rare clinical form of amebiasis characteristically associated with high morbidity and mortality. We here present our series of eight patients with amebic colitis perforation. These patients represent 5% of 150 patients hospitalized during the same period for chronic amebic colitis. Only 50% of our patients had a correct preoperative diagnosis, and signs of generalized peritonitis such as rebound tenderness or muscular rigidity were not as common as might have been expected. Our mortality rate was 50% despite aggressive surgical treatment. Every effort should be made to have an early diagnosis, which would lead to early treatment with antiamebic agents, earlier and more limited surgery, and improved survival of these patients.

Hypertensive portal colopathy in schistosomiasis mansoni: proposal for a classification

Portal hypertension is a frequent complication of chronic liver disease, detected not only in schistosomiasis, but also in cirrhosis of any etiology. Vascular alterations in the colonic mucosa are a potential source for acute or chronic bleeding and have been observed in patients with portal hypertension. The purpose of this prospective study was to describe and propose a classification for the vascular alterations of portal hypertension in the colonic mucosa among patients with hepatosplenic schistosomiasis mansoni. One or more alterations of portal colopathy were observed in all patients and they were classified according to their intensity, obeying the classification proposed by the authors. Portal colopathy is an important finding in hepatosplenic schistosomiasis and might be the cause of lower gastrointestinal bleeding in patients with severe portal hypertension.

Juvenile rhesus monkeys have more colonic granulomas than adults after primary infection with Schistosoma mansoni

Adults and children have differences in their susceptibility to schistosomiasis. Whether this age-dependent innate susceptibility influences parasite-caused granulomogenesis is difficult to assess in humans. Therefore, we exposed juvenile and adult female rhesus monkeys to primary infection with Schistosoma mansoni. Hepatic and intestinal granuloma formation was observed in both pre-pubescent and adult monkeys. Two distinct stages of granulomas were discerned, the exudative and the productive stage. In the intestine, more granulomas were generated in the colon than in the ileum. In contrast to the adult animals, the juvenile rhesus monkeys had higher numbers of colonic granulomas, these higher numbers being predominantly of the more advanced productive stage. Juvenile animals had a statistically non-significant increased worm burden. These results suggest that juvenile rhesus monkeys have a significantly more intense and advanced colonic response towards entrapped S. mansoni eggs after primary schistosome infections and, thereby, are more susceptible to parasite infection.

Factors influencing colonic involvement in patients with amebic liver abscess

BACKGROUND

The frequency of colonic involvement in patients with amebic liver abscess has not been studied in detail. The factors influencing colonic involvement also are unknown.

METHODS

Seventy-one patients with amebic liver abscess were studied. Colonoscopy was performed in all patients.

RESULTS

Abdominal pain and fever were the most common presenting manifestations. Ten patients (14%) had diarrhea at admission. Ten other patients had a history of diarrhea during the preceding 2 months. Thirty-nine (55%) patients had colonic ulcers. Colonic ulcers were present in 18 of the 20 (90%) patients with ongoing diarrhea or a history of recent diarrhea, and in 21 of 51 (41%) patients without diarrhea (p<0.001). Thirty (42%) patients had small, discrete ulcers in the cecum, the ascending colon, or the region of the hepatic flexure. Nine patients had large, multiple ulcers with surrounding inflammation. In these patients, the ulcers were present either in the left colon (n=7) or throughout the colon (n=2). The mean (standard deviation) age of patients with 5 or more ulcers was significantly greater than that of patients with fewer than 5 ulcers (49.8 [14.6] years vs. 37 [11.7] years; p<0.05). Multiple ulcers were noted in 7 of the 10 patients (70%) with diarrhea at admission and in two of the 61 patients (3%) in whom diarrhea was not a presenting symptom (p<0.001). No association was noted between the location of the abscess in the liver and the colonic lesions.

CONCLUSIONS

Colonic ulcers are a common finding, occurring in more than half of patients with amebic liver abscess. They are more likely to be present if the patient has diarrhea as a presenting symptom or has had diarrhea in the recent past. Multiple, large, and left-sided ulcers are more common in elderly patients and in those in whom diarrhea is the presenting symptom. However, there is no association between the location of the abscess in the liver and colonic lesions.

[Diagnostic problems associated with intestinal amoeboma: case report]

Amoeboma is an inflammatory mass of the colon. It is uncommon with most cases occurring in Latin America and South Africa. When amoeboma is the presenting symptom of amoebiasis, it poses the problem of differential diagnosis of colon cancer. This report describes the case of a 60-year-old patient who presented a painful mass in the left hypochondrium. Radiologic and endoscopic examinations depicted a ring-like stenosis of the transverse colon in association with a mesenteric reaction. The presumptive diagnosis was colon cancer and the patient was referred to the National Oncology Institute for surgical treatment. Histological examination of the surgical specimen after segmental colectomy confirmed diagnosis of intestinal amoeboma. The patient was treated medically using metronidazole. Since intestinal amoebiasis is common in our country, amoeboma must be considered as a rare but potential diagnosis in patients presenting masses of the colon. Differential diagnosis of carcinoma is necessary to avoid the risks associated with unnecessary surgery.

Anisakiasis of the colon presenting as bowel obstruction

Anisakiasis is a disease caused by human infection by the Anisakis larvae, a marine nematode found in raw or undercooked fish. With the increased popularity of eating sushi and raw fish (sashimi) in the United States infection with anisakis is expected to rise. We present the first reported case in the United States of intestinal anisakiasis presenting as a bowel obstruction. A 25-year-old healthy woman with no prior history of surgery presented to the emergency room with bowel obstruction by history and CT. CT also showed a mass in the right lower quadrant. She had eaten seviche, a raw fish appetizer, 2 days earlier and sashimi 3 weeks before admission. She was taken to the operating room for an exploratory laparotomy and was found to have an obstruction, the 2-cm mass in the mesentery, and diffuse mesenteric adenopathy. She had an ileocolectomy. Pathology showed a degenerating fish worm, anisakiasis. She also had a serologic test for immunoglobulin E specific to anisakiasis and it was highly positive. Human infections, as mentioned before, are principally the result of ingestion of the Anisakis larvae. These larvae are usually found in herring, mackerel, salmon, cod, halibut, rockfish, sardine, and squid. Most human infections have been reported from Japan and The Netherlands and involve the stomach. Invasion of the gastric or intestinal wall one to 5 days after eating raw fish may be characterized by the abrupt onset of abdominal pain, nausea and/or vomiting, diarrhea, or an ileus. For transient anisakiasis, supportive measures and reassurance are all that is needed. If the larvae have invaded the intestine or the stomach wall diagnosis and cure occur with endoscopic or surgical removal if evidence of obstruction or perforation is found. The incidence of anisakiasis in the United States is unknown but will likely continue to increase with the popularity of eating sashimi. This case is meant to demonstrate another possible cause for bowel obstruction in the patient who has just eaten raw or undercooked fish.

Enhancement of disease and pathology by synergy of Trichuris suis and Campylobacter jejuni in the colon of immunologically naive swine

Campylobacter jejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries, which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on the C jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections such as Trichuris, which drive type 2 cytokine responses and down-regulate type 1 immune responses. In this study, three-day-old germ-free pigs given dual infections with Trichuris suis and C jejuni had more frequent, more severe diarrhea and severe pathology than pigs given no pathogens, only T. suis, or only C jejuni. These pigs had significant hemorrhage and inflammatory cell infiltrates in the proximal colon where adult worms were found, and abscessed lymphoglandular complexes in the distal colon with intracellular C jejuni. Pigs given only C jejuni had mild clinical signs and pathology, and bacteria in feces or extracellular sites. Pigs given T. suis or no pathogens had no disease and minimal pathology. Thus, these agents synergized to produce significant disease and pathology, which was site specific.

[Colorectal spirochetosis, a possible but unusual cause of chronic diarrhea?]

INTRODUCTION

Human intestinal spirochetosis has been known since the end of the nineteenth century.

OBSERVATION

We report one case of intestinal spirochetosis revealed by chronic diarrhoea and diagnosed on colonic biopsies. The chronic diarrhoea disappeared with antibiotherapy.

COMMENTARIES

The prevalence of intestinal spirochetosis in rectal and colonic biopsies, among patients with digestive disorders, varies in occidental countries from 2% to 7%. Presently, the pathogenic role of intestinal spirochetosis is controversial.

Cyst production and transmission of Entamoeba and Endolimax

We studied the cyst production of 340 asymptomatic carriers with single or mixed infections of Entamoeba histolytica/Entamoeba dispar, Endolimax nana and Entamoeba coli. It was found that the main source of transmission was a small group of 37 (10.9%) carriers who produced 70.2% of all cysts. Gender was an important factor for cyst production of Ent. histolytica/Ent. dispar, since males produced 6-fold more cysts than females. Females produced 'large' (13-15 microns) Ent. histolytica/Ent. dispar cysts and males small (10-12 microns) cysts when concentration was > 2000 cysts/g. When concentration was < 2000 cysts/g, cysts were the same size for both sexes (11.6 +/- 0.3 microns). In Ent. coli infections, an inverse relationship between the number and size of cyst was found for both sexes. Cysts of End. nana were not affected by gender or cyst concentration. Following cyst production by a carrier infected with Ent. coli and Ent. histolytica for 28 days, we identified synchronized cycles of cyst production for both species. Altogether, these data suggest that cyst-mediated transmission is a highly regulated process in which synchronization among different species and gender of the host have an important role in transmission.

Isolated mesosigmoidal hydatid cyst as an unusual cause of colonic obstruction: report of a case

We report herein an unusual case of primary mesosigmoidal hydatid cyst that presented as acute left colonic obstruction mimicking sigmoid colon cancer. A 61-year-old man with a 3-day history of abdominal pain, distention, obstipation, vomiting, and fever was admitted to the emergency department of our hospital. Surgery was performed under a presumptive diagnosis of acute left colonic obstruction. The intraoperative findings were highly suggestive of sigmoid colonic carcinoma and Hartmann's procedure was performed. Histopathological examination of the pathological specimen revealed an isolated hydatid cyst embedded in mesosigmoid which had caused mechanical sigmoidal obstruction. Primary extrahepatic, intra-abdominal localization of a hydatid cyst is not unusual. Therefore, as a hydatid cyst may cause a wide variety of clinical syndromes, it should be kept in mind in the differential diagnosis of mechanical bowel obstruction, especially in endemic regions.

The histopathology of 103 consecutive colonoscopy biopsies from 82 symptomatic patients with acquired immunodeficiency syndrome: original and look-back diagnoses

OBJECTIVE

To compare the primary diagnoses assigned by general surgical pathologists on a series of 103 consecutive colon biopsies from individuals infected with human immunodeficiency virus (HIV) with diagnoses rendered by a pathologist with extensive experience in gastrointestinal pathology in HIV/acquired immunodeficiency syndrome.

DESIGN

New sections were cut from paraffin blocks of 103 consecutive colon biopsies taken during colonoscopies of 82 different HIV-infected patients; all new sections were stained with hematoxylin-eosin. These individuals either had negative stool studies or had failed to respond to therapy and had chronic large bowel symptoms, such as frequent small volume-type diarrhea, tenesmus, and/or bright red blood per rectum. Immunohistochemistry for cytomegalovirus (CMV) was performed on 18 of 22 specimens originally diagnosed with CMV colitis.

RESULTS

The initial study yielded 70 (68%) negative or nonspecific diagnoses, 22 (21%) cases of CMV colitis, 5 (5%) Cryptosporidium diagnoses, 2 cases each of adenomatous polyps and Kaposi sarcoma, and 1 case each of spirochetosis and squamous cell carcinoma of the anorectum. Review of the recuts yielded 64 (62%) negative or nonspecific diagnoses, 12 (12%) new adenovirus infections (3 combined with CMV), and 11 (11%) lone CMV infections. Three attaching and effacing bacterial infections were diagnosed, 1 with adenovirus coinfection. A total of 4 spirochetosis cases were found on review. Seven (7%) of the biopsies showed at least 1 coinfection. Nine biopsies had features suggestive of inflammatory bowel disease.

CONCLUSIONS

Colonoscopy with biopsy after negative stool studies or failure to respond to therapy yielded a high proportion of negative or nonspecific diagnoses. Adenovirus and enteropathogenic bacterial infections had been totally overlooked on initial examination. It takes particular experience to evaluate gastrointestinal biopsies from HIV-infected patients.

Human oesophagostomiasis: a histomorphometric study of 13 new cases in northern Ghana

Oesophagostomiasis is an infrequently described and recognised parasitic infection in humans, caused by Oesophagostomum bifurcum. Although the disease is most often found in the northern part of Togo and the neighbouring part of Ghana, sporadic cases have been described in other parts of Africa and in Asia and South America: Uganda, Ivory Coast, Sudan, Kenya, Ethiopia, Indonesia, Malaysia and Brazil. Infection probably occurs by way of the ingestion of L3 larvae. These larvae penetrate the intestinal wall, especially that of the colon. Some of these larvae develop into young adult worms and return to the bowel lumen. Other larvae, however, develop into immature worms, which fail to settle in the lumen, forming abscesses in the bowel wall and causing pathology. In the literature 105 human cases have been described, many originating in the northern regions of Ghana and Togo. The present study was performed to evaluate 13 new cases originating in the northern part of Ghana (7 female and 6 male patients, aged between 2 and 60 years). Histopathologically, the patients could be divided into two groups: the first group showed multinodular disease, while patients in the second group presented with a single, nodular mass. In the first group, abscesses were seen throughout the colonic wall. The mean size of the cavities was 4.3+/-0.7 mm. There was no relation between the size and the localisation in the colonic wall. Abscesses were significantly larger in male patients than in female patients. There was no correlation with age. In the second group, histopathological examination showed a cyst of variable wall thickness with very limited inflammation. These cysts represented older lesions, often encapsulated in the mesentery. In conclusion, in this study we present 13 new cases of human oesophagostomiasis. The abscess formation was found to be organ specific, independent of age, and gender-related, producing a more intense tissue reaction in male patients.

Study of the distribution pattern of Schistosoma haematobium egg antigens recognised by six different monoclonal antibodies in the parasite and the host

Recently a new panel of monoclonal antibodies was developed against soluble egg antigens in the hatching fluid of Schistosoma mansoni. These antibodies have been used to develop an improved ELISA for the detection of circulating soluble egg antigens in serum and urine that would have a higher sensitivity in the immunodiagnosis of S. mansoni infections. Although these antibodies showed no improvement in the immunodiagnosis of S. mansoni infections compared with egg antigen-based ELISAs already described (Nourel Din et al., 1994a), they may have a potential role in the identification of S. haematobium infections. This study has looked into the immunolocalisation of S. haematobium egg antigens in both the parasite and the host as recognised by four newly developed monoclonal antibodies (290-2D9-A, 290-2E6-A, 290-2H12-A and 290-4A8-A) and two already described antibodies (114-5B1-A and 114-4D12-A). The antibodies 114-5B1-A and 114-4D12-A appeared to have in S. haematobium eggs a similar staining pattern when compared to S. mansoni eggs. The antibodies prepared against the hatching fluid showed a characteristic signal, especially 290-2E6-A. These antibodies recognised a component originating from the lateral glands of the miracidium. In the host a similar immunohistochemical tissue localisation pattern (mainly phagocytising reticulo-endothelial cells) was seen as previously described for S. mansoni infected hamsters.

Ultrasound diagnosis of oesophagostomiasis

Human infection with Oesophagostomum bifurcum, a parasitic intestinal helminth, is endemic in parts of West Africa. Oesophagostomum bifurcum juveniles develop in the colonic wall, causing pus-filled granulomas. The pathology has two distinct forms. Multinodular oesophagostomiasis comprises hundreds of small nodules within a thickened, oedematous wall of the large intestine. Uninodular oesophagostomiasis, called the Dapaong tumour, presents as a painful 30-60 mm granulomatous mass in the abdominal wall or within the abdominal cavity. Diagnosis of oesophagostomiasis on clinical grounds alone is difficult. We describe cases illustrating the ultrasound appearance of these two presentations. Multinodular disease shows nodular "target" and "pseudokidney" colonic lesions. The Dapaong tumour is an echo-free ovoid lumen enveloped within a well defined poorly reflective wall.

[Colonic balantidiasis]

Balantidium coli is a Protozoa that is not usually pathogenic in man, although epidemics have been described in tropical areas. It mainly affects the colon and clinical presentation varies from asymptomatic forms to severe dysenteric syndromes. We present a case of endoscopically diagnosed colonic balantidiasis and review the most important characteristics of this parasite-induced disease.

[Massive trichuriasis in an adult diagnosed by colonoscopy]

A case of massive trichuriasis in a 37-year-old female from a rural locality of the Metropolitan Region of Chile, with antecedents of alcoholism, chronic hepatic damage and portal cavernomatosis, is presented. Since 12 year ago she has had geophagia. In the last six months she has frequently presented liquid diarrhea, colic abdominal pains, tenesmus and sensation of abdominal distention. Clinical and laboratory tests confirmed her hepatic affection associated with a celiac disease with anemia and hypereosinophilia. Within a week diarrhea became worse and dysentery appeared. A colonoscopy revealed an impressive and massive trichuriasis. The patient was successfully treated with two cures of 200 mg tablets of mebendazole twice daily for three days with a week interval. After the first cure she evacuated a big amount of Tricuris trichiura, fecal evacuations became normal, geophagia disappeared and recovered 4 kg of body weight.

[Anisakiasis, rare pseudotumor colonic involvement. Apropos of a case]

History taking should search for intake of raw or uncooked fish in patients with acute abdominal symptoms. The colon is an uncommon localization of anisakiasis. We describe the case of a 31-year-old man with acute abdominal pain whose abdominal CT scan showed a pseudotumoral formation of the colon. History taking and endoscopic ablation gave the diagnosis of anisakiasis. Whole worm extraction led to restituo ad integrum or the colonic wall.

Colonic obstruction and perforation related to heavy Trichuris trichiura infestation

Heavy Trichuris trichiura infestation is rare in developed countries, and complications requiring surgical intervention have been described rarely in human trichuriasis. A case of colonic obstruction and perforation related to heavy whip-worm infection is described in an 84 year old woman. The woman was admitted to hospital because of a chest infection. Two days after admission she suffered nausea and vomiting followed a day later by bowel stoppage. Laparotomy indicated intestinal obstruction by a tumour. A partial right sided ileocolectomy was performed. Pathological examination of the resected bowel revealed heavy infestation with T trichiura causing a pseudotumour following a proliferative inflammatory response.

Schistosoma mansoni: development and modulation of the granuloma after or multiple exposures in the baboon (Papio cynocephalus anubis)

The ability of the host to modulate the granulomatous response around ova trapped in tissues determines the severity of disease to schistosome infections. Multiple factors may affect this modulation such as age, prior sensitization, history of treatment, and exposure. The present study examines the effect of different patterns of exposure on the sequential development and modulation of granuloma in juvenile Kenyan baboons (Papio cynocephalus anubis) after receiving either a single infection (SI) of 1500 Schistosoma mansoni cercariae or multiple infections (MI) of 150 cercariae, once a week for 10 weeks. Prior to sacrifice at 17 weeks postinfection (p.i.), liver biopsies were obtained at Weeks 0, 6, 9, and 13. SI animals experienced more prolonged dysentery and greater weight loss compared to MI animals. Peak hepatic granuloma size (mean 355 +/- 65.5 microns diameter), the maximum percentage of eosinophils in the granuloma (61%), and severity of disease occurred at 6 weeks in SI animals. Peak granuloma size and pathology did not appear until Week 9 in the MI animals (mean 317.7 +/- 67.3 microns diameter). Granuloma size, tissue eosinophilia, and gross pathology diminished by Week 13 p.i. and were virtually absent in both groups by Week 17. The decrease in granuloma size, pathology, and clinical illness resolved more rapidly in the MI baboons. Singly infected baboons were more susceptible to infection (83 +/- 12% of cercariae developed into adult worms) compared to MI baboons (67 +/- 7%, P < 0.01). Eggs recovered from tissues at necropsy were primarily confined to the large intestine (85% of total egg recovered), followed by liver (10%) and small intestine (5%). Significantly more eggs were recovered from MI compared to SI animals, indicating a higher fecundity of female worms in the MI baboons. These date demonstrate that granulomatous responses develop more slowly and modulate more rapidly with repeated infection compared to a single heavy infection and suggest the type of exposure may affect the pathologic response to infection.

Colonic Strongyloides stercoralis infection masquerading as ulcerative colitis

Strongyloides stercoralis is a nematode infection which predominantly involves the small bowel. Spillover infection to the colon does occur, but is uncommon and is usually associated with an immunocompromised host. Accurate diagnosis is essential and, as this case demonstrates, a long history does not preclude an infective aetiology.

[Anisakidosis of the colon as a cause of acute abdomen]

We report a case of acute abdomen caused by the invasion of the ascending colon by larvae of Anisakis simplex in a 57 year-old-woman whose initial symptoms were colic abdominal pain, diarrhea and fever. The diagnosis was done by the histological study of the surgical specimen in which two parasites were morphologically identified in the submucosa. Although a causal relationship of the disease with the ingestion of crude fish could not be established initially, there were antecedents of ingestion of anchovy in vinegar (Engraulis encrasicholus) and dyspeptic symptoms for several months.