Intestinal amoebiasis in a patient with acute graft-versus-host disease after allogeneic bone marrow transplantation successfully treated by metronidazole.

Amoebiasis has rarely been reported in patients undergoing hematopoietic stem cell transplantation, although it is a world-wide infection and extremely common. We present a case of intestinal amoebiasis unexpectedly revealed by colonoscopy after allogeneic bone marrow transplantation from a human leukocyte antigen-mismatched unrelated donor for acute myeloid leukemia arising from chronic myelomonocytic leukemia and successfully treated by metronidazole.

The antiretroviral lectin cyanovirin-N targets well-known and novel targets on the surface of Entamoeba histolytica trophozoites.

Entamoeba histolytica, the protist that causes amebic dysentery and liver abscess, has a truncated Asn-linked glycan (N-glycan) precursor composed of seven sugars (Man(5)GlcNAc(2)). Here, we show that glycoproteins with unmodified N-glycans are aggregated and capped on the surface of E. histolytica trophozoites by the antiretroviral lectin cyanovirin-N and then replenished from large intracellular pools. Cyanovirin-N cocaps the Gal/GalNAc adherence lectin, as well as glycoproteins containing O-phosphodiester-linked glycans recognized by an anti-proteophosphoglycan monoclonal antibody. Cyanovirin-N inhibits phagocytosis by E. histolytica trophozoites of mucin-coated beads, a surrogate assay for amebic virulence. For technical reasons, we used the plant lectin concanavalin A rather than cyanovirin-N to enrich secreted and membrane proteins for mass spectrometric identification. E. histolytica glycoproteins with occupied N-glycan sites include Gal/GalNAc lectins, proteases, and 17 previously hypothetical proteins. The latter glycoproteins, as well as 50 previously hypothetical proteins enriched by concanavalin A, may be vaccine targets as they are abundant and unique. In summary, the antiretroviral lectin cyanovirin-N binds to well-known and novel targets on the surface of E. histolytica that are rapidly replenished from large intracellular pools.

Anterior necrotizing scleritis after strabismus surgery in a child.

Anterior necrotizing scleritis is a rare but potentially devastating complication of ocular surgery that most often occurs after cataract surgery in elderly patients who may have an underlying systemic autoimmune condition(1) or, less likely, an infectious cause.(2) We describe the management and outcome of a case of bilateral anterior necrotizing scleritis after postoperative infection in a 19-month-old girl who had recently undergone strabismus surgery.

Fulminant Amebic Colitis after Corticosteroid Therapy: A Systematic Review.

BACKGROUND: Amebic colitis, caused by intestinal infection with the parasite, Entamoeba histolytica, is a common cause of diarrhea worldwide. Fulminant amebic colitis is the most devastating complication of this infection, associated with both high mortality and morbidity. We conducted a review of the English literature to describe cases of fulminant amebic colitis associated with exposure to corticosteroid medications in order to identify the risk factors for poor outcome and determine difficulties in diagnosis and treatment. METHODOLOGY AND PRINCIPAL FINDINGS: Articles reporting severe and fulminant forms of amebic colitis between 1991 and 2016 were collected. 525 records were screened to identify 24 cases for qualitative analysis associated with corticosteroid use. Cases arose from areas of high endemicity or travel to such areas. Most cases (14 of 24, 58%) were given corticosteroids for initially misdiagnosed colitis, mainly inflammatory bowel, resulting in rapid progression of disease. Nearly half of all cases underwent surgical intervention, and 25% of cases died, despite all patients eventually receiving treatment with metronidazole. The odds of death did not differ significantly by prior misdiagnosis, co-morbidities, bowel perforation or need for surgery. CONCLUSIONS AND SIGNIFICANCE: Infection with E. histolytica should be considered prior to the administration of corticosteroids, in particular for patients residing in endemic areas or those with appropriate travel history, especially prior to the diagnosis of inflammatory bowel disease. The development of preventative and treatment interventions are needed to improve outcomes of fulminant disease.

First report of invasive amebiasis in an organ transplant recipient.

T-cell mediated immunity is an important defense mechanism against amebiasis. However, organ transplant recipients with severe T-cell immunosuppression are not at increased risk of having Entamoeba histolytica invasive disease. The reasons are unclear and probably multifactorial, but it is likely that the absence of intestinal colonization with pathogenic strains in countries where transplants occur and the judicious intake of possible contaminated food and water are important contributing factors. We describe the first report of a liver transplant recipient with severe E. histolytica colitis who was successfully treated with metronidazole without modifying his immunosuppression therapy.

Amebiasis after bone marrow transplantation.

A patient undergoing BMT for acute non-lymphocytic leukemia (ANLL) developed bloody diarrhea due to amebiasis. The infection was successfully treated with intensive and prolonged antiparasitic therapy.

Extensive cutaneous burn complicated by severe necrotizing amebic enterocolitis. Pathogenic factors resulting in severe amebic disease.

A 59-yr-old Mexican-American man developed fatal necrotizing amebic enterocolitis following an extensive cutaneous thermal injury. Those factors in the severely burned patient which predispose to amebic disease are discussed.

Epidemiologic and clinical characteristics of acute diarrhea with emphasis on Entamoeba histolytica infections in preschool children in an urban slum of Dhaka, Bangladesh.

The epidemiology, clinical features, nutritional status, and causative agents of diarrhea were studied in 289 Bangladeshi children (147 boys and 142 girls) 2-5 years old. The use of improved diagnostic tests for amebiasis enabled for the first time analysis of the contribution of Entamoeba histolytica to total diarrheal illness in this community setting. The average incidence rate of diarrhea was 1.8/child-year, and the average number of diarrheal days was 3.7 days/child-year over an average observation period of 2.8 years/child. Seventy-five percent of the diarrheal episodes were < or = 2 days in duration. Persistent diarrhea was relatively uncommon (0.2% of the children) and chronic diarrhea was observed in only one episode. Compared with malnourished and/or stunted children, better-nourished children experienced significantly fewer diarrheal episodes. The diarrheal incidence rate for children with blood group A was significantly less that that of the children with blood groups O and AB. The most frequent bacterial enteropathogens isolated from diarrheal stool specimens were enterotoxigenic Escherichia coli (9%) and Aeromonas species (9%), followed by Plesimonas shigelloides (4%) and Shigella flexneri (3.8%). Rotavirus was the most common viral agent isolated from diarrheal stool samples (5%). Giardia lamblia, Cryptosporidium parvum, and E. histolytica were identified in 11%, 8.4%, and 8%, respectively, of the diarrheal stool specimens. Dysentery was observed in 7.7% of all diarrheal episodes. The most common pathogens isolated from dysenteric stool were S. flexneri (11.6%), Aeromonas sp. (10%), E. histolytica (8.7%), Campylobacter jejunii (5.8%), P. shigelloides (4.3%), and A. caviae (4.3%). The overall incidence rate of E. histolytica-associated diarrhea was 0.08/child-year. Visible blood and hemoccult test-detected blood loss was found in 7% and 25%, respectively, of cases of E. histolytica-associated diarrhea. Children who had recovered from a diarrheal episode with E. histolytica, but not E. dispar, had half the chance of developing subsequent E. histolytica-associated diarrhea, consistent with the development of species-specific acquired immunity. In conclusion, the use of modern diagnostic tests demonstrated that E. histolytica contributed to overall morbidity from diarrheal illness. Understanding the etiology, frequency, and consequences of acute diarrhea in children from a developing country should aid in the design of interventions to improve child health.

Treatment of infectious diarrhea in children.

Diarrheal diseases remain an important cause of childhood morbidity and death in developing countries, although diarrheal deaths have significantly declined in recent years, mostly due to successes in the implementation of oral rehydration therapy (ORT), which is the principal treatment modality. Diarrhea may occur for varied reasons; however, most episodes of diarrhea in developing countries are infectious in origin. Three clinical forms of diarrhea (acute watery diarrhea, invasive diarrhea, and persistent diarrhea) have been identified to formulate a management plan. Acute diarrhea may be watery (where features of dehydration are prominent) or dysenteric (where stools contain blood and mucus). Rehydration therapy is the key to management of acute watery diarrhea, whereas antimicrobial agents play a vital role in the management of acute invasive diarrhea, particularly shigellosis and amebiasis. In persistent diarrhea, nutritional therapy, including dietary manipulations, is a very important aspect in its management, in addition to rehydration therapy. Rehydration may be carried out either by the oral or intravenous route, depending upon the degree of dehydration. Oral rehydration salts (ORS) solution (World Health Organization formula) is recommended for ORT. Intravenous fluid is recommended for initial management of severe dehydration due to diarrhea, followed by ORT with ORS solution for correction of ongoing fluid losses. Antimicrobial therapy is beneficial for cholera and shigellosis. Antiparasitic agents are indicated only if amebiasis and giardiasis are present. Appropriate feeding during diarrhea is recommended for nutritional recovery and to prevent bodyweight loss. Antidiarrheal agents do not provide additional benefit in the management of infectious diarrhea. Although some probiotics have been shown to be beneficial in the treatment of acute diarrhea due to rotavirus, their use in the treatment of diarrhea is yet to be recommended, even in developed countries. The children of developing countries might benefit from zinc supplementation during the diarrheal illness, but its mode of delivery and cost effectiveness are yet to be decided.

Amebiasis at an evacuation site on the Thai-Cambodian border.

Symptomatic intestinal amebiasis was highly endemic among the Cambodians living at Green Hill, an evacuation site on the Thai-Cambodian border between June 1987 through May 1989. Monthly incidence rates of intestinal amebiasis were determined to be inversely proportional to cumulative monthly rainfall. The highest incidence of amebic dysentery was 63/1000 in children 12-23 months old. Behavioral risk factors were investigated by conducting a case-control study. A questionnaire was administered to 73 families, each having at least one member with confirmed intestinal amebiasis within the past 3 months, and to 95 randomly selected control families having no individual with diarrhea for at least 3 months. Individuals from families with greater than 4 members were at higher risk for acquiring intestinal amebiasis. No significant differences in behavioral risk factors were identified between case and control families. Eighty-six percent of 51 water samples drawn from wells where amebiasis patients obtained their drinking water had greater than 10 coliforms/100 ml. The main route of transmission of E. histolytica was not identified, but was most likely via the fecal-oral route.

[Amoebic dysentery: a relapsing case by cancer chemotherapy].

A 71-year-old man was admitted with a diagnosis of amoebic dysentery. He received a tonsillectomy 2 years prior to admission because of squamous cell carcinoma and had been treated with 5-FU. Laboratory examination showed T-lymphocytopenia and the T4/T8 ratio was markedly reduced. He experienced amoebic dysentery during World War II some 40 years ago, thus, this case report suggested that amoebiasis relapsed by depressed cellular immunity and was calculated as one of the opportunistic infections.

[Amoebiasis--a problem in patients with ulcerative colitis]. / Pelzakowica (amoebosis)--problem dotyczacy chorych z colitis ulcerosa.

The increasing problem is presented of Entamoeba histolytica invasion in patients with ulcerative colitis. The diagnostic-therapeutic management in five patients with amoebiasis is discussed in detail. This parasitic invasion occurred in five out of 103 patients with ulcerative colitis which accounts for 4.85%. This data is important for the treatment of chronically ill patients with ulcerative colitis.

Raw wastewater agricultural re-use and risk of protozoal infection in Beni-Mellal, Morocco.

This study was carried out to determine the potential risk of protozoal infection associated with raw wastewater use for agricultural purposes, among children of Beni-Mellal, Morocco. In a randomly-selected sample of 1343 children 740 from 5 regions which use raw wastewater for agriculture (exposed), while 603 were from 4 control regions that do not practice wastewater irrigation (unexposed). A questionnaire-interview with children and parents was used to collect data on demographic, hygienic, and risky water contact risk factors One or more protozoal infection was identified among 276(37.2%) of children living in the wastewater re-use regions, versus only among 22 (3.6%) living in control regions. The overall prevalence of 40.1% was observed among boys, and 33.3% among girls residing in exposed areas. The two identified protozoa were Entaemoeba histolytica and Giardia intestinalis, which infected 34.3% and 5.1% in the exposed population compared to only 3.3% and 0.3% in the control population, respectively. We also noted that the G. intestinalis prevalence was more than 40% among the children under 9 years, but less than 17% for those who were more than 12 years. Also, a significant excess of protozoal infection was observed among children who had risky contact with agricultural lands (p<0.001). In conclusion, raw wastewater use in Beni-Mellal can lead to a high risk of protozoal infections. Adequate treatment of wastewater prior to re-use, as well as public health education are highly recommended.