Diagnosis Of Amebic Liver Abscess Research Articles

364. Diagnosis of Amebic Liver Abscess by a Commercial Multiplex Stool Amplification Assay. A Potentially Useful Alternative in Limited-Resources Settings.

Abstract Background Amoebic liver abscess (ALA) is caused by the protozoan parasite Entamoeba histolytica. Clinical and radiological features of ALA often mimic those of pyogenic liver abscess (PLA). Currently, differential diagnosis between ALA and PLA relys on microscopic examination, anti-amoebic IgG serology, and culture of aspirate for pyogenic organisms. Therefore, there is a need for new, rapid and more accurate microbiological methods for diagnosing ALA. Unfortunately, with few exceptions, available reports involved the use of inhouse or laboratory-tailored polymerase chain reaction (PCR) assays. We herein report our recent experience with the successful use of a commercial multiplex, nested PCR assay designed for stool, in the diagnosis of two cases of ALA. Methods Two severely ill adult Latin American migrants presented with fever, malaise, non-bloody diarrhea, abdominal pain and leukocytosis. CT scans revealed single large hypodense, inflammatory, liver cystic lesions. Results Necrotic material obtained by needle aspiration under guidance and stool samples were processed by FilmArray Gastrointestinal Panel (BioFire Diagnostics, Salt Lake City), designed to detect 13 bacterial, 5 viral and 4 parasitic pathogens, both amplified only for E. hystolitica DNA. ELISA serology for amoeba was also positive. Bacterial cultures were sterile. Treatment with Metronidazole and paromomycin resulted in complete recovery. Conclusion Analysis of liver abscess content using a commercially available, multiplex, nested PCR assay designed for stool, may represent a convenient alternative to currently available diagnostic methods, providing rapid results and allowing for immediate choosing of specific therapy targeting single pathogens on more rational basis. Since there are several commercially available multiplex PCR panels containing primers for E. histolytica, their use for evaluation of liver abscess samples has some theoretical advantages for the diagnosis of ALA, such as simplicity, ample availability, rapid processing time and capacity to exclude simultaneously several potential pathogens. Nevertheless, further testing is necessary to validate their use in liver abscess diagnosis and define their false positivity and negativity rates. Disclosures All Authors: No reported disclosures.

Metronidazole-related neurotoxicity in a referral hospital

Objectives: Metronidazole is commonly used drug in almost all the fields of medicine. Commonly patients use medication for a shorter time than was prescribed, but in this report, the patients have used medication for long time based on ultrasound images. This study aims to assess metronidazole-related neurotoxicity at this hospital. Material and Methods: All the patients with diagnosis of amebic liver abscess, who developed neurotoxicity with metronidazole, were evaluated retrospectively. Results: Ten patients with metronidazole neurotoxicity were seen from April 2017 to March 2019. All ten had peripheral neuropathy; one each had in addition cerebellar ataxia and new onset seizures. Conclusion: A preventable toxic effect with metronidazole has to be recognized early during drug therapy for hepatic amebic abscesses. A dose adjustment during therapy helps in preventing this neurotoxicity. The patients have to be educated that metronidazole should not be continued on ultrasound images.

The Role of Serology Test in Diagnosis of Amebic Liver Abscess

The Role of Serology Test in Diagnosis of Amebic Liver Abscess

Progress in the research on diagnosis and vaccines in amebiasis.

Entameba histolytica causes amebiasis, which includes both intestinal and extraintestinal amebiasis. E. histolytica causes 34 million to 50 million symptomatic cases of amebiasis worldwide every year, causing 40 thousand to 100 thousand deaths annually. E. histolytica, the pathogenic species of amebae is indistinguishable in its cyst and trophozoite stages from those of E. moshkovskii, a free-living ameba, and E. dispar, a non-invasive ameba, by microscopy, except in cases of invasive disease, where E. histolytica trophozoite may contain ingested red blood cells, but such a finding is rarely seen. This leads to a confusing scenario for the definite identification and differentiation of E. histolytica from E. moshkovskii and E. dispar by conventional microscopy, in the diagnosis of intestinal amebiasis. The advent of molecular methods such as multiplex PCR and real time PCR have facilitated a better and accurate diagnosis of E. histolytica, E. moshkovskii, and E. dispar in stool, urine, saliva, and other specimens. Multiplex PCR for the diagnosis of amebic liver abscess, using urine and saliva as clinical specimens, has been used, and the results have been encouraging. Real-time PCR is a new and a very attractive methodology for laboratory diagnosis of amebiasis, because of its characteristics that eliminate post-PCR analysis, leading to a shorter turnaround time. Microarray-based approaches represent an attractive diagnostic tool for the detection and identification of amebae in clinical and epidemiological investigations. Development of vaccines against amebiasis is still in its infancy. However, in recent years, progress has been made in the identification of possible vaccine candidates, the route of application, and the understanding of the immune response, which is required for protection against amebiasis. Thus, it is just a matter of time, and hopefully, amebiasis vaccine for human trials will be available in the next few years.

Low sensitivity of ultrasonography for the early diagnosis of amebic liver abscess

Amebic liver abscess, the most common extraintestinal manifestation of Entamoeba histolytica infection, occurs in 3% to 9% of patients with intestinal amebiasis (1). Worldwide, 40,000 to 100,000 people are estimated to die each year from amebic colitis and amebic liver abscess (2). Early diagnosis and prompt initiation of therapy, which is essential to reduce mortality from amebic liver abscess (3), relies primarily on the identification of a space-occupying lesion of the liver (4). Abdominal ultrasonography is considered to be the method of choice for the diagnosis of amebic liver abscess (4,5), with a reported sensitivity of 90% or greater (6–9).

Enfoque clínico y diagnóstico del absceso hepático

The non invasive diagnosis of amebic liver abscess allows the use of empirical therapy without the requirement of invasive diagnostic procedures. To determine the discriminatory capacity of clinical, laboratory and ultrasound studies for the etiological diagnosis of liver abscess. Sixty one patients were initially included in this prospective study, but 12 did not comply with the inclusion criteria. Of the rest, 29 (59%) had an amebic liver abscess, 16 (33%) had a pyogenic liver abscess and four (8%) had an abscess of mixed etiology. Blood cultures were done in 42 patients. Ultrasound guided needle aspiration was done in 7 patients with amebic liver abscess and 13 patients with non amebic liver abscess. The clinical picture and ultrasound findings were similar in all types of amebic abscess. ELISA test for IgG anti-Entamoeba histolytica antibodies were positive in 100% of patients with amebic liver abscess. Antibodies measured by gel diffusion were positive in 93%. All patients with mixed liver abscess had positive antibodies and some of them positive culture. Blood cultures were positive for anaerobic bacteria in five patients. Cultures of aspirated material were positive in 7 patients (obligate anaerobic bacteria in 3 and facultative anaerobic bacteria in the rest). The most common complications, whatever the etiology, were right pleural effusion and systemic inflammatory response. A final model of binomial regression analysis revealed that age under 40 years, an hematocrit greater than 35% and an elevation in prothrombin time of less than 1.5 seconds had enough discriminatory capacity for the diagnosis of amoebic liver abscess.

Common Presentations of Amebic Liver Abscess

Study objective: The most common extraintestinal manifestation of Entamoeba histolytica , the agent of amebiasis, is a hepatic abscess. This infection is common throughout the world and can be associated with life-threatening consequences. Given the often nonspecific nature of the complaints related to an amebic abscess, a retrospective review of patients with confirmed disease was done to recognize the most common patterns of presentation. Methods: A retrospective case series was conducted of all patients with confirmed amebic liver abscess over a 5-year period. All available emergency department and inpatient records were reviewed. Age, sex, country of origin, chief complaint (including duration), vital signs, and physical and laboratory findings were recorded. The use of ultrasonography, computed tomography scan, chest radiograph, and serum antibodies was noted, as well as the final ED diagnosis. Results: Seventy-five patients were reviewed; mean patient age was 35.5 years, 80% were male, and Mexico was the country of origin for 64%. The most common complaint was fever (77%), followed by abdominal pain (72%), which was most often located in the right upper quadrant. Cough (16%), chest pain (19%), and chest radiographic abnormalities (57%) were also common. The majority of patients (69%) had symptoms for less than 13 days. The WBC count was the most consistent laboratory abnormality (83%), whereas the liver aminotransferase, alkaline phosphatase, and bilirubin levels were often normal. Most patients received their diagnoses on the basis of ultrasonography (85%), followed by a confirmatory serum antibody titer (88%). The diagnosis of amebic liver abscess was correctly made in the ED in 31.5% of the patients, with the most common misdiagnoses being cholecystitis (16.4%), hepatitis (12.3%), and pneumonia (9.6%). Conclusion: Patients with amebic liver abscess do present to EDs in the southwestern United States, especially in areas with a high immigrant population from endemic areas. Patients with complaints of fever and right upper quadrant abdominal pain, especially men of Hispanic origin, warrant a high degree of vigilance. Whereas most laboratory studies are unhelpful, the diagnosis can often be made in the ED by means of a bedside ultrasonographic test. Treatment should be initiated with metronidazole with disposition to an inpatient medical service. [Hoffner RJ, Kilaghbian T, Esekogwu VI, Henderson SO: Common presentations of amebic liver abscess. Ann Emerg Med September 1999;34:351-355.]

Co-agglutination test for the detection of circulating antigen in amebic liver abscess.

We report here a simple and economical slide agglutination test, the co-agglutination (Co-A) test, for the detection of circulating amebic antigen in sera for the diagnosis of amebic liver abscess. Fifty serum specimens from cases of amebic liver abscess, 25 from other individuals with parasitic and miscellaneous infections, and 25 from healthy controls were tested for the presence of serum antigen by the Co-A test. Forty-five (90%) amebic liver abscess sera were found to be amebic-antigen positive by the Co-A test. None of 25 sera from healthy controls were positive for the antigen. However, false-positive results were seen with two sera from those with other parasitic and miscellaneous infection controls. These results show that the Co-A test can be used as a sensitive and specific rapid slide agglutination test for the detection of amebic antigen in the sera for diagnosis of cases of amebic liver abscess in a routine parasitology laboratory.

Longitudinal study of the antibody response to recombinant Entamoeba histolytica antigens in patients with amebic liver abscess.

Serology is a critical component in the diagnosis of amebic liver abscess. However, in areas endemic for amebiasis there is a high background level of seropositivity for amebiasis (owing to previous infection with Entamoeba histolytica), which may complicate the interpretation of a positive serologic test result. Recently, we reported that serologic tests based on recombinant E. histolytica antigens might offer improved diagnosis of current invasive amebiasis because they apparently differentiated active infection from past exposure to the parasite. To confirm this finding, we have performed a longitudinal study on 20 patients with amebic liver abscess by examining their seroreactivity over time with recombinant versions of two major E. histolytica proteins, the serine rich E. histolytica protein (SREHP), and the 170-kD subunit of the galactose-specific adhesin. We found that more than 50% of the patients examined had become seronegative by one or both recombinant tests within 180 days of their diagnosis of amebic liver abscess. In the case of the recombinant SREHP-based tests, 12 patients had become seronegative 90 days after presentation. In contrast, all patients remained seropositive by a standard conventional test, an indirect hemagglutination test, at more than six months after presentation. Our study shows that patients lose seroreactivity with the recombinant SREHP or 170-kD antigen-based tests more rapidly than with a conventional serologic test; this may make them useful for the serologic diagnosis of amebiasis in endemic areas.

FOCAL INFLAMMATORY DISEASE OF THE LIVER

Imaging and image-guided intervention have revolutionized management of hepatic inflammatory diseases. Pyogenic abscess is preferentially treated percutaneously. Radiologic techniques are crucial for the diagnosis of amebic liver abscess and infectious conditions of the liver in immunocompromised patients.

Amebic liver abscess: Spare the knife but save the child

Background/Purpose: Amebic liver abscess (ALA), the most common extraintestinal manifestation of infection with Entameba histolytica, carries significant morbidity and mortality in the pediatric age group. The efficacy of metronidazole in the treatment of ALA is well established, but the role of surgical intervention remains controversial. Many investigators still advocate aggressive surgical therapy for complicated and ruptured ALA. Reports regarding management of ALA in children are sparse and deal with small numbers of patients. The objective of this study was to assess the effectiveness of parenteral metronidazole combined with judicious aspiration of ALA in obviating the need for surgical intervention. Methods: The medical records of all children admitted with the diagnosis of ALA between 1986 and 1997 to the Aga Khan University Hospital were reviewed retrospectively. The diagnosis of ALA was confirmed in 48 patients by an ultrasound scan together with elevated indirect hemagglutination (IHA) titres (>250). Ages ranged from 3 weeks to 14.5 years. Results: Thirty-seven (75%) children were below the fifth percentile for height and weight, and 45 (93.7%) presented with a hemoglobin level of less than 10.0 g/dL. Comorbid factors included pulmonary tuberculosis (n = 2, chicken pox (n = 1), tetralogy of Fallot (n = 1), and thalassemia major (n = 2). There was a mean delay of 13 days before presentation to the hospital. All patients were treated with parenteral metronidazole and broad-spectrum antibiotics. The latter were discontinued on confirmation of the diagnosis. The duration of treatment with metronidazole ranged from 2 to 5 weeks. Percutaneous aspiration of the ALA was performed under ultrasound guidance using sedation in 28 patients for one or more of the following indications; ALA greater than 7.0 cms (n = 20), left lobe involvement (n = 8), and no response after 48 hours of medical therapy (n = 6). Nine patients required more than one aspiration. One patient with peritoneal rupture of the ALA additionally underwent percutaneous aspiration of the peritoneal cavity under ultrasound guidance. One patient required insertion of a chest tube after rupture of the ALA into the right pleural cavity, and another underwent urgent bronchoscopy after rupture of the abscess into the tracheobronchial tree. The hepatobronchial fistula closed spontaneously with medical therapy. No patient required open surgical drainage, and all recovered without relapse. The mean duration of hospitalization was 12 days. Conclusion: Our experience suggests that parenteral metronidazole combined with timely aspiration of the abscess can obviate the need for surgical intervention in large and complicated ALA even in malnourished children who present late for treatment.

Use of micro samples of finger prick blood dried on filter paper for a quick and simple dipstick dot‐EIA for diagnosis of amebic liver abscess (ALA)

Filter paper was used as a support to absorb micro samples of finger prick blood for detection of antibodies to Entamoeba histolytica (causative organism of amebiasis) by a rapid dipstick dot-EIA technique; 8 microliters of blood was sufficient to saturate discs (diameter 6 mm) of Whatman paper No. 3. Conditions of elution of blood from the discs were optimized and the best results were obtained when 0.4 ml of buffer was used for elution for 30 minutes at room temperature. The filter paper technique is extremely useful for field use and for diagnosis of amebic liver abscess on a large scale since it does not involve centrifugation of blood and use of sterile vials because blood dried on paper can be stored in polythene bags at room temperature for up to 3 months and for a week at 42 degrees C without significant loss of antibody activity, thereby eliminating the need of refrigeration of samples for storage or transportation to a reference laboratory. Elution of blood from different discs of the same patient was found to be highly reproducible without appreciable loss of sensitivity or specificity. Twenty-four confirmed ALA, 29 non-ALA, and 25 apparently normal healthy controls, with no previous history of amebiasis, were tested. Sensitivity and specificity of the test was found to be 96% and 92%, respectively.

Detection of pathogenic entamoeba histolytica DNA in liver abscess fluid by polymerase chain reaction

Tachibana H., Kobayashi S., Okuzawa E. and Masuda G. 1992. Detection of pathogenic Entamoeba histolytica DNA in liver abscess fluid by polymerase chain reaction. International Journal for Parasitology 22: 1193–1196. A sensitive method for detection of pathogenic Entamoeba histolytica DNA in drained fluids from liver abscess patients, using the polymerase chain reaction (PCR), has been developed. The PCR employs oligonucleotide primers specific for the gene encoding the 30 kDa molecule of pathogenic E. histolytica. Liver abscess fluids (19 samples), from 14 patients with a presumptive amebic liver abscess, were examined microscopically and by the PCR method. Only two of the 19 samples were positive microscopically, whereas all 19 samples tested positive by PCR. This technique can be used to confirm the diagnosis of amebic liver abscess.

A CASE OF AMEBIC ABSCES OF THE LIVER WITH DIFFICULTIES IN DIAGNOSING AND TREATING

A 58-year-old man visited another hospital because of general fatigue and fever. He has never been abroad. CT revealed an area of hypoabsorption in the right lobe of the liver. Under a diagnosis of liver abscess antibiotic regimen was started, but no remission could be attained. The patient was referred to the department. On admission an increased leucocytes and impairment of the liver function were noted. CT revealed a huge hypoabsorbent area in the right lobe of the liver. Drainaging of the abscess and administration of antibiotics were started, however, no remission was obtained. As strong positive response to serum amebic antibody was observed, a diagnosis of amebic liver abscess was made. Antiamebic agents were administered. Unfortunately, severe jaundice and ARDS developed and the patient died of liver and respiratory failure on the 39th hospital day. These findings indicated that the patient had fluminating amebic liver abscess who might infected through some route in Japan. From this experience, we would emphasize the importance of early diagnosis and efficient prevention of complications. Some notes on relevant literature are also presented.

Hepatic abscess

Hepatic abscess--amebic or pyogenic--can be diagnosed with great accuracy by either ultrasonography or computed tomographic (CT) scanning. Ultrasound is the modality of choice and will detect almost 100% of abscesses. Confirmation of a diagnosis of amebic liver abscess is made by the indirect hemagglutination test that should be positive in almost 100% of cases. Cultures of pus from the abscess and from the blood must be obtained in cases of pyogenic liver abscess. A positive culture of pus from the abscess has been achieved in 90% of cases. Ultrasound or CT guidance is utilized in aspiration of a hepatic abscess. In the treatment of an amebic liver abscess, metronidazole is the amebicide of choice. Open drainage is contraindicated. For cases that fail to respond to therapy with amebicides, closed drainage guided by CT or ultrasound is performed. Secondary bacterial infection of an amebic liver abscess is an extremely rare event. The identification and determination of the antibiotic sensitivity of organisms responsible for pyogenic liver abscess is a crucially important step. Unless a celiotomy is necessary to correct an intraabdominal process or the abscess is extremely large, the initial treatment of pyogenic liver abscess is a 2 week course of appropriate antibiotics followed by a 1 month course of oral antibiotics. The majority of pyogenic liver abscesses will respond to such treatment. If drainage of a pyogenic abscess is required, the preferable technique is with a percutaneous CT- or ultrasound-directed catheter.(ABSTRACT TRUNCATED AT 250 WORDS)

A CASE OF RUPTURED AMEBIC LIVER ABSCESS WITH PANPERITONITIS

A case of ruptured amebic liver abscess during conservative treatment is reported.A 39-year-old man underwent percutaneous transhepatic abscess drainage and antibiotic regimen for suspected liver abscess, however, no symptomatic remission could be attained and the liver function was impaired, leading to panperitonitis. Surgical drainage of the abscess and peritoneal cavity was performed. The diagnosis of amebic liver abscess was confirmed, because Entamoeba histolytica was detected from pus in the abscess. After anti-amebic agents of metronidazole and chloroquine were administered, no ameba was detected, and the symptoms and signs disappeared. The patient was discharged with normalized liver function. In this case the pathway of amebic infection was unknown, because he had not been abroad and no ameba was detected from stool of his wife. The serum reaction of syphilis and ATLV-III antibody were negative.In the diagnosis of amebic abscess the detection of ameba is essential, but recently, it can be diagnosed serologically. This case was also strongly positive for E. histolytica antibody.

Diagnosis and treatment of hepatic amebic abscess in children

From 1 January 1976 to 31 December 1985, 11 children under the age of 12 years (range 11 months to 11 years) were treated for hepatic amebic abscess at the UCLA-affiliated hospitals with no mortality. There were 7 girls and 4 boys, and all were of Mexican or Mexican-American descent. In only 3 instances (27%) was the correct diagnosis considered on admission. In 3 patients the diagnosis was made when symptoms persisted following a negative laparotomy for appendicitis, but all 3 made a complete recovery on medical therapy. A delay in diagnosis in 2 other patients contributed to intrahospital rupture of the abscess and resultant urgent surgical drainage. In the remaining 6 patients, amebicidal therapy alone proved effective and no surgery was required. The complex of fever, abdominal pain, anemia, leukocytosis, and elevated erythrocyte sedimentation rate in a child without a definite diagnosis should prompt the clinician to entertain an early diagnosis of amebic liver abscess and to begin immediate therapy with a safe and efficacious drug.

Amebic liver abscess: a therapeutic approach.

The clinical presentation of 48 patients with amebic liver abscess was no different than that reported in earlier studies. However, most patients were from countries endemic for parasitic disease. Failure to consider this diagnosis resulted in potentially avoidable surgery for six patients. Although metronidazole was successful primary therapy in 85% of 41 patients so treated, four of seven ruptured abscesses occurred in cases where metronidazole treatment failed. For assessment of factors that might predict metronidazole treatment failures, multiple parameters were analyzed. Of the factors evaluated, only timing of clinical response correlated with successful therapy. Ninety-four percent of metronidazole responders showed dramatic clinical improvement within 72 hours of initiation of therapy, whereas only 33% nonresponders had improved modestly during this time (P = .0014). Therefore, early diagnosis of amebic liver abscess in patients from endemic areas and treatment with metronidazole will result in successful therapy in 85% of cases. Surgical intervention or alternative medical therapy is indicated for those patients who do not respond after 72 hours of metronidazole therapy.

Amebic liver abscess: Differential diagnosis of cholecystitis

Among patients presenting with pain and tenderness in the right upper quadrant were 75 with cholelithiasis (13 male, 2 under age 50) and 9 with amebic hepatic abscess (6 male, all under age 45). The differential diagnosis of cholelithiasis versus liver abscess was accurately made by prompt sonography and hepatobiliary scintigraphy. Amebic abscess was confirmed by positive serum ameba titers. Presenting symptoms and results of laboratory studies of patients with amebic abscess were indistinguishable from those of patients with cholecystitis. It is concluded that an accurate diagnosis of amebic liver abscess in the differential diagnosis of cholecystitis can be made by sonography and hepatobiliary imaging. Also, in endemic areas of the southwestern United States, amebic ascess should be strongly considered in the differential diagnosis of patients presenting with pain and tenderness in the right upper quadrant and is more common than cholecystitis in young men.

Amebiasis. A persistent problem.

The case report in this issue, by Kovaleski and his colleagues (see p 132), raises a number of important questions about the diagnosis and treatment of amebiasis. The critical clinical problems were (1) the known difficulties in diagnosing invasive amebic disease, and (2) a false-negative ultrasonogram of the liver. It is well established that most patients with amebic liver abscess have negative stool examinations for Entamoeba histolytica . 1 In addition, the diagnosis of amebiasis, based on morphologic criteria, is one of the most demanding tests in the clinical laboratory 2 and, like other morphologic tests, is inherently insensitive. Thus, this case report both reinforces the value of serologic studies in the diagnosis of amebic liver abscess 2 and illustrates problems in the detection of amebic infection that are by no means unique to one institution. The false-negative ultrasonogram in the patient described by Kovaleski et al raises the question