Amoebic toxic colitis: analysis of factors related to mortality

Necrotizing amebic colitis in an elder patient: an unexpected autopsy finding

Necrotizing amebic colitis is an uncommon amebiasis complication associated with high mortality. We present a case of necrotizing amebic colitis in an old patient whose diagnosis was revealed at postmortem examination. An 81-year-old man died at home without medical attention. The postmortem examination revealed ulcers involving the entire colon and intestinal perforation. The ulcers were large, geographic, and necrotizing, extending from the cecum to the rectum. The histological examination disclosed the infectious etiology by showing amebic trophozoites at the base of the ulcers. No extra-intestinal lesions were found. No information about previous episodes of dysentery or travel could be obtained. The potential role of aging or drug-causing immunosuppression and the evolution of chronic and latent intestinal infection to a severe and invasive form of amebiasis is discussed. This case reinforces the value of postmortem examination for diagnosing diseases not clinically identified.

A Case of Intestinal Amoebiasis Mimicking Intestinal Behçet's Disease

Intestinal amoebiasis is caused by Entamoeba histolytica (E. histolytica) and is characterized by cecal lesions, multiple lesions, aphthae, and multiple exudative erosions. Intestinal Behçet's disease (BD) is a chronic inflammatory disorder that is characterized by multiple ulcers. Although the etiologies of these two bowel diseases are unrelated, they are difficult to distinguish because they present similarly with inflammation and ulcers, especially if evidence of specific pathogens is not detected. Herein, we report a case of intestinal amoebiasis in a patient with BD. The patient underwent colonoscopy four times before intestinal amoebiasis was diagnosed. As intestinal BD was initially suspected, she received high-dose glucocorticoid therapy, which exacerbated her condition. Following exacerbation, she underwent colonoscopy, and E. histolytica was revealed. Deliberate care should be taken to distinguish between intestinal amoebiasis and intestinal BD, as the appropriate treatments for these diseases are entirely different.

Amebiasis and Amebic Liver Abscess in Children

Although rare in the developed world, amebiasis continues to be a leading cause of diarrhea and illness in developing nations with crowding, poor sanitation, and lack of clean water supply. Recent immigrants or travelers returning from endemic regions after a prolonged stay are at high risk of developing amebiasis. A high index of suspicion for amebiasis should be maintained for other high-risk groups like men having sex with men, people with AIDS/HIV, immunocompromised hosts, residents of mental health facility or group homes. Clinical presentation of intestinal amebiasis varies from diarrhea to colitis and dysentery. Amebic liver abscess (ALA) is the most common form of extraintestinal amebiasis. Various diagnostic tools are available and when amebiasis is suspected, a combination of stool tests and serology should be sent to maximize the yield of testing. Treatment with an amebicidal drug such as metronidazole/tinidazole and a luminal cysticidal agent such as paromomycin for clinical disease is indicated. However, for asymptomatic disease treatment with a luminal cysticidal agent to decrease chances of invasive disease and transmission is recommended.

Percutaneous catheter drainage of uncomplicated amoebic liver abscess: prospective evaluation of a clinical protocol for catheter removal and the significance of residual collections

INTRODUCTION

Patients with amoebic liver abscess (ALA) may require percutaneous catheter drainage (PCD). Once the PCD output is substantially reduced or has ceased along with clinical recovery, residual collections on radiological evaluation may concern the treating physicians. The prevalence and significance of such collections is unknown, and the subsequent approach how to tackle them is unclear.

METHODS

Consecutive patients with one or more uncomplicated ALAs requiring drainage were prospectively enrolled from 3 hospitals and managed based on a standard approach. Catheter removal was attempted after the patients fulfilled all 4 of the following criteria: disappearance of abdominal pain, absence of fever for at least 48 h, an improving trend of TLC (documented on 2 consecutive reports), and catheter drain output of < 10 ml/day for at least 2 consecutive days.

RESULTS

A total of 110 patients (mean age 46.6 ± 10.5 years, 93.6% males, 89.1% alcoholics) underwent PCD placement; 69 patients (69/110; 62.7%) met all 4 criteria within 5 days of PCD placement (optimal response) and had an uncomplicated course. Patients with suboptimal responses (41/110; 37.3%) were evaluated for local and systemic complications; the appearance of fresh collections (5/110; 4.5%), abscess rupture (2/110; 1.8%), bile leakage (3/110; 2.7%), cholangitis (2/110; 1.8%), thrombophlebitis (2/110; 1.8%) and hospital-acquired infections (2/110; 1.8%) were diagnosed and treated accordingly. Ultimately, PCD removal (based on the fulfilment of all 4 criteria) was universally successful after a median of 5 days (IQR, 4-9 days). None of the patients had symptom recurrence after PCD removal, although residual collections were still seen in 97.3% of patients at the time of PCD removal and in 92.1% and 84.9% of patients available for follow-up at 1 and 3 months, respectively.

CONCLUSION

Based on our clinical protocol, PCD removal in ALA can be successfully expedited even in the presence of residual collections. An inability to fulfill all 4 criteria within 5 days of PCD placement warrants further evaluations for local and systemic complications that require additional therapeutic measures.

Fulminant amebic colitis: An unusual postoperative complication of intraabdominal malignancy

Amebiasis caused by protozoa Entamoeba histolytica (EH) is the third leading parasitic cause of human mortality. Although amebiasis is endemic in India, only about 10% of the infected individuals manifest disease. Clinical spectrum of amebiasis ranges from asymptomatic colonization to amebic colitis to hemorrhagic and fulminant colitis. Factors causing an invasive infection are not completely understood. Pathogen virulence, host immunity, and ability of the pathogen to evade host immune response play vital role in determining the disease course. Host factors such as immunocompromised states may make an individual susceptible to develop symptomatic infection. Malignancies usually result in chronic debilitation which may make the individual prone to develop invasive amebiasis with rapid progression. We report two cases of invasive amebiasis which developed a fulminant course in the immediate postoperative period after abdominal surgeries for visceral malignancies.

Nitazoxanide in the Treatment of Intestinal Parasitic Infections in Children: A Systematic Review and Meta-Analysis

OBJECTIVES

To evaluate the efficacy and safety of nitazoxanide in intestinal parasitic infections in children.

METHODS

Four databases, PubMed, EMBASE, Web of Science and Cochrane Library, have been systematically searched from the inception of each database up to March 1st, 2019. The enrolled studies were limited to randomized clinical trials in children, comparing nitazoxanide with placebo or other antiparasitic drugs. The data extraction and quality assessment of pooled studies were conducted by two reviewers independently. For meta-analysis, Stata12.0 was used and a randomized effect model or a fixed effect model was selected according to the outcomes of heterogeneity test.

RESULTS

A total of 1645 subjects in 13 randomized controlled trials (RCTs) were enrolled, including 768 cases in the trial group and 877 cases in the control group. The effect of nitazoxanide vs. placebo and other antiparasitic drugs on the excretion rate of pathogens was uncertain (OR = 2.06, 95%CI [1.01,4.20], P = 0.047; I² = 84.7%; very low quality evidence). Compared with placebo, subgroup analysis suggested that nitazoxanide could significantly improve the excretion rate of pathogens (OR = 7.01, 95%CI [1.82,26.94], P = 0.005; I² = 79.1%; moderate quality evidence), while it made little or no difference compared with antiparasitic drugs (OR = 0.72, 95%CI [0.47,1.09], P = 0.124; I² = 33.1%; low quality evidence). Meanwhile, nitazoxanide might increase the remission rate of diarrhea with OR = 5.12, 95%CI [2.00,13.08], P = 0.001; I² = 72.3%; low quality evidence). However, it might also increase the rate of adverse events (OR = 1.47, 95%CI [1.05,2.07], P = 0.026; I² = 44.7%; low quality evidence).

CONCLUSIONS

The authors are uncertain whether or not nitazoxanide could improve the excretion rate of pathogens. Based on low-certainty evidence, nitazoxanide may improve the remission rate of diarrhea in children with intestinal parasite infections, but it may be associated with an increased risk of adverse reactions. Hence, more RCTs with a low risk of bias are still needed to assess the efficacy and safety of nitazoxanide.

Multiple colonic and ileal perforations due to unsuspected intestinal amoebiasis-Case report and review

Amoebiasis, caused by the intestinal protozoan Entamoeba histolytica, though a relatively common parasitic disease in the tropical and subtropical regions, is uncommon in the developed countries. In these countries, as amoebic colitis shares similar clinical symptoms and endoscopic features with inflammatory bowel disease (IBD), these cases can be easily unrecognized and misdiagnosed. In this case report, we discuss the case of an adult patient with invasive intestinal amoebiasis, who was initially managed as Crohn's disease on corticosteroid treatment and subsequently rapidly deteriorated and developed multiple perforations in the colon and ileum. Despite total colectomy followed by resection of the small bowel, he died of multiple organ failure and sepsis within two months of his initial clinical presentation of diarrhea with abdominal pain. The learning point of this case is that invasive intestinal amoebiasis should be considered as a differential diagnosis at the first clinical adult presentation of IBD-like symptoms despite suggestive endoscopic findings of Crohn's like ulcers. Regardless of negative endoscopic biopsies, due to the low sensitivity of microscopic examination, serology test for antibody and molecular test for Entamoeba DNA are recommended for accurate detection and identification of Entamoeba species, especially in the high risk populations with recent travel to endemic zones and for patients with immunosuppression and comorbidities such as diabetes mellitus, tuberculosis, alcoholism, HIV/AIDS and in pregnant women. Amoebiasis should be completely ruled out prior to corticosteroid administration, to avoid severe complications such as fulminant intestinal amoebiasis which is associated with an inherently high mortality.

Entamoeba Histolytica: Updates in Clinical Manifestation, Pathogenesis, and Vaccine Development

Entamoeba histolytica is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. With increased travel and emigration to developed countries, infection is becoming more common in nonendemic areas. Although the majority of individuals infected with E. histolytica remain asymptomatic, some present with amoebic colitis and disseminated disease. As more is learned about its pathogenesis and the host's immune response, the potential for developing a vaccine holds promise. This narrative review outlines the current knowledge regarding E. histolytica and E. dispar and insight in the development of a vaccine.

Colonic perforation due to amebiasis, a rare and lethal complication

Amebiasis is still a major healthcare concern, especially in developing countries like Ecuador. The lack of sanitary control and hygiene measures make parasites infections still a burden for patients and physicians. Despite infections due to this parasites are usually mild, severe infections and fatal outcomes although rare still occur. Bowel perforation is a rare complication of amebiasis, and unfortunately, it continues to be almost fatal. We present a case of an Ecuadorian patient who presented to the emergency room with an acute abdomen, despite adequate surgery and critical care, the patient regrettably died. Bowel perforation due to Entamoeba histolytica was the final diagnosis.

A case of amebiasis with negative serologic markers that caused intra-abdominal abscess

A 23-year-old Japanese woman presented with abdominal distention following fever, diarrhea, and abdominal pain during a stay in Taiwan. Serology for the detection of amebic-antibodies and stool microscopic examination were both negative. A computed tomography scan showed a 13 cm diameter abscess spreading from the lower abdominal wall to the pelvic retroperitoneal space. Needle aspiration of the abscess was done under computed tomography guidance, and microscopy of the aspirated fluid revealed trophozoites of Entamoeba. The patient was diagnosed as amebiasis with negative serologic markers that caused intra-abdominal abscess. Intravenous metronidazole treatment for two weeks did not result in any improvement of the abscess. After irrigation and drainage of the abscess, her symptoms resolved. This case report highlights that amebiasis should be considered when indicated by patient history, including travelers returning from endemic areas, and that further evaluation is necessary for diagnosis, even if the serology and stool test are negative.