Common presentations of amebic liver abscess

Updates on the worldwide burden of amoebiasis: A case series and literature review

BACKGROUND

Amoebiasis is an intestinal and tissue parasitic infection caused by the protozoan Entamoeba histolytica. Despite significant medical importance and worldwide dispersion, little is known about the epidemiology and distinct geographical distribution of various clinical forms of amoebiasis in the world. In this study, we present an amoebiasis case series referred to Avicenne Hospital (Bobigny, France) from 2010 to 2022 followed by an overview of the released literature to explore diverse clinico-pathology of amoebiasis and to update the actual epidemiological situation of this parasitosis worldwide.

METHODS

The referred patients underwent a combination of clinical and parasitological examinations and imaging. The study was followed by an overview of released literature performed based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline.

RESULTS

A total of 15 patients with amoebiasis were diagnosed with an average age of 48.5 years old at the occurrence time of infection. Men (78%) were the most affected patients. Most of the cases were reported following a trip to endemic regions, such as Mali, India, Nepal, Algeria, Cameroon or Congo. All of the processed patients exhibited a hepatic amoebiasis. Amoebic abscess was observed in all cases with an average size of 6.3 cm. Of these patients, seven cases (46.7%) benefited from drainage following a risk of rupture or superinfection of the abscess. A compilation of findings extracted from 390 scientific publications via seven major medical databases, allowed us to update the main epidemiological and clinical events that has led to the current worldwide expansion of amoebiasis. We presented a clinical and epidemiological overview of the amoebiasis accompanied with a worldwide illustrative map displaying the current distribution of known amoebiasis foci in each geographical ecozone of Asia, Europe, Africa, Americas, and Australia.

CONCLUSIONS

Although Metropolitan France is not known as an endemic region of amoebiasis, amoebic liver abscess was the most frequent clinical form observed among our 15 patients processed. Most of infected patients had a history of travel to or lived-in endemic areas before arriving in France.

Study of ultrasound-guided needle aspiration and catheter drainage in the management of liver abscesses

PURPOSE

To evaluate and compare the efficacy of intermittent needle aspiration and continuous catheter drainage in ultrasound-guided management of liver abscesses.

METHODS

This was a prospective, randomised study conducted on 100 patients (88 males and 12 females; age range 22-74 years) with liver abscess(es) and having abscess size more than 5 cm, divided into two groups: Percutaneous needle aspiration (PNA) (n = 50) and percutaneous catheter drainage (PCD) (n = 50). Criteria of exclusion were: rupture of abscess before intervention; prior intervention; uncorrectable coagulopathy; concomitant biliary tract malignancy. In the PNA group, pus was aspirated by an 18-gauge needle using freehand technique and the number of aspirations was limited to two. Failure of abscess size to decline below 50% of the original diameter or of clinical improvement after second aspiration was considered as failure of aspiration. In the PCD group, drainage was done by 12-French catheters using Seldinger technique. Drainage was considered as failure if abscess cavity did not resolve and laparotomy was needed to evacuate the pus cavity.

RESULT

The success rate in the PNA group was 88% and 92% in the PCD group; however, this difference was statistically not significant, suggesting that both are equally efficacious. The total duration of hospital stay (mean 6.8 days [PNA] vs 10.5 days [PCD]; p value: 0.011) and the average duration between intervention and discharge (5.9 days [PNA] vs 10.2 days [PCD]; p value:0.026) were significantly less in the PNA group. One major complication was seen in our study: peritonitis due to peri-catheter leak in PCD group.

CONCLUSION

Both procedures are equally efficacious in the management of liver abscesses; however in view of less duration of hospital stay, patient safety and comfort, procedure simplicity, and the reduced cost, needle aspiration should be used as the first-line procedure in the treatment of liver abscess (even in abscesses more than 5 cm). Catheter drainage should be reserved for cases that do not respond to a second attempt of aspiration.

Amoebic Liver Abscesses in Fiji: Epidemiology, Clinical Presentation and Comparison of Percutaneous Aspiration and Percutaneous Catheter Drainage

BACKGROUND

Amoebic liver abscess (ALA) is a common clinical problem in tropical countries related to poor sanitation. The epidemiology and clinical presentation of ALA in Fiji has not been previously described. It is unclear whether percutaneous aspiration (PA) or percutaneous catheter drainage (PCD) has better outcomes.

PURPOSE

The aims were to describe the epidemiology and clinical presentation of ALA in Fiji and to compare the outcomes of PA and PCD for treatment of ALA.

METHODS

A retrospective case note review of patients treated with either PA or PCD between 2010 and 2015 was performed. Indications for intervention were ALA > 5 cm, ALA in the left lateral lobe, risk of imminent rupture and failure to respond to medical treatment.

RESULTS

There were 262 patients, 90% were male, 92.9% I-Taukei ethnicity and 86.2% regular recreational kava drinkers. Most presented with upper abdominal pain and fevers. The majority (90.3%) had a single abscess with 87.8% being in the right lobe. 174 (66.4%) had LA and 88 (33.6%) had PCD. There was an unintended selection bias for PA in abscess with a volume of <1 litre. PA was associated with a more rapid resolution of fever and shorter hospital stay, more rapid resolution of the cavity and no morbidity. PCD had five complications, one bleed and four bile leaks. There was no mortality in either group.

CONCLUSIONS

ALA in Fiji occurs in I-Taukei males who drink kava. PA appears to offer equivalent if not better outcomes for treatment of ALA.

Outcomes of a conservative approach to management in amoebic liver abscess

Context:

Unfortunately, there is confusion among the medical community regarding the management of amoebic liver abscess (ALA). Therapeutic options range from simple pharmacotherapy to use of interventions like a needle or catheter aspiration under ultrasound guidance to surgical intervention. There is a plethora of thresholds for parameters such as the maximum diameter of the abscess and volume on ultrasound examination suggested by various authors to serve as a criterion to help to decide when to use which modality in these cases.

Aims:

To assess the outcome of patients with uncomplicated ALA treated using a conservative approach. Moreover, to identify factors associated with its failure.

Settings and Design:

A prospective, observational study was carried out at a large municipal urban health care center over a period of 3-year (2011–2014) in India.

Materials and Methods:

Patients with uncomplicated ALA were recruited. All patients were managed with pharmacotherapy initially for a period of 72 h. Response to treatment was assessed by resolution of symptoms within the given time frame. Failure to respond was considered an indication for intervention. Needle aspiration was offered to these patients and response assessed within 72 h. Failure to respond to aspiration was considered an indication for catheter drainage. Statistical Analysis Used: Data recorded were entered in a Microsoft Office Excel Sheet and analyzed using the SPSS version 16.0 (IBM).

Results:

Sixty patients with ALA were included in the study over its duration. Forty-nine (81.67%) patients were managed conservatively, while 11 (18.33%) patients needed an intervention for relief. Patients who required intervention had deranged liver function at presentation, a larger abscess diameter (10.09 ± 2.23 vs. 6.33 ± 1.69 cm P < 0.001) and volume (399.73 ± 244.46 vs. 138.34 ± 117.85 ml, P < 0.001) compared to those who did not need it. Patients that required intervention had a longer length of hospital stay (7.1 ± 2.4 vs. 4.8 ± 0.9 days, P < 0.001). On post hoc analysis, a maximum diameter of >7.7 cm was found to be the optimal criterion to predict the need of intervention in cases of ALA.

Conclusions:

A conservative approach is effective in the management of ALA for a majority of patients. Failure of conservative management was predicted by the size of the abscess (maximum diameter >7.7 cm). Even in the cases of failure, a gradual step-up with interventions was found to be safe and effective.

Biliary Peritonitis due to a Ruptured Amebic Liver Abscess Mimicking a Periampullary Tumor and Liver Metastases with the Elevation of CA 19-9 and CA 125: A Case Report

Introduction

An amebic liver abscess is the most common presentation of extraintestinal amebiasis. This condition is the result of a parasite infection caused by Entamoeba histolytica.

Materials and Methods

We report a case of a 53-year-old male who presented with abdominal pain in the right upper quadrant, jaundice, and a 10-kg weight loss within a 1-month span.

Results and Conclusion

A wide range of symptoms and findings in the imaging tests suggestive of neoplasia, elevated levels of CA 19-9 and CA 125, and the presentation of biliary peritonitis as a complication makes this case a challenge for its approach and management.

Cloning, Characterization and Anion Inhibition Studies of a β-Carbonic Anhydrase from the Pathogenic Protozoan Entamoeba histolytica

We report the cloning and catalytic activity of a β-carbonic anhydrase (CA, EC 4.2.1.1), isolated from the pathogenic protozoan Entamoeba histolytica, EhiCA. This enzyme has a high catalytic activity for the physiologic CO₂ hydration reaction, with a k_cat of 6.7 × 10⁵ s⁻¹ and a k_cat/K_m of 8.9 × 10⁷ M⁻¹ × s⁻¹. An anion inhibition study of EhiCA with inorganic/organic anions and small molecules revealed that fluoride, chloride, cyanide, azide, pyrodiphosphate, perchlorate, tetrafluoroborate and sulfamic acid did not inhibit the enzyme activity, whereas pseudohalides (cyanate and thiocyanate), bicarbonate, nitrate, nitrite, diethyldithiocarbamate, and many complex inorganic anions showed inhibition in the millimolar range (K_Is of 0.51–8.4 mM). The best EhiCA inhibitors were fluorosulfonate, sulfamide, phenylboronic acid and phenylarsonic acid (K_Is in the range of 28–86 μM). Since β-CAs are not present in vertebrates, the present study may be useful for detecting lead compounds for the design of effective enzyme inhibitors, with potential to develop anti-infectives with alternative mechanisms of action.

Amoeboma in a Saudi resident: a case report

Introduction:

Amoebiasis is the third most frequent cause of mortality after malaria and schistosomiasis. In developed countries, amebiasis is also seen in migrants who have travelled to endemic areas. The factors responsible for its progression from intestinal amebiasis to an amebic liver abscess are not fully understood.

Case presentation:

A 54-year-old man presented with abdominal pain, fever and diarrhoea. Laparotomy confirmed an inflammatory mass involving the right colon, and he underwent a right hemicolectomy. He later developed abdominal distenstion due to an amoebic liver abscess and died from secondary nosocomial bacterial infection and surgical complications.

Conclusion:

Amoeboma is an uncommon manifestation of amoebiasis, and can mimic both carcinoma and inflammatory bowel disease; so, distinguishing between these two conditions is the key to providing appropriate therapy. Hepatic amoebiasis is the most common extraintestinal disease of invasive amoebiasis. This clinical report presents a case of an uncommon parasitic disease in Saudi Arabia and discusses the difficulties encountered while attempting to establish the correct diagnosis. Hence, a high index of suspicion is crucial for diagnosing Entamoeba histolytica to avoid unnecessary surgery and further complications.

Amebic liver abscess in northern region of Bangladesh: sociodemographic determinants and clinical outcomes

Background

Amebic liver abscess (ALA) is endemic in Bangladesh since historical age but its epidemiology and sociodemographic determinants are not well described in the literatures. This paper focuses on the endemicity, sociodemographic determinants and clinical outcomes of ALA patients from certain northern districts in Bangladesh. Ninety hospitalized ALA patients enrolled from 6 northern districts of Bangladesh during July 2008 to June 2010 were analyzed.

Findings

Clinical presentations of ALA was initially substantiated by ultrasound imaging and later confirmed by detection of small subunit rRNA gene of E. histolytica using a Real Time PCR. Structured questionnaire and data sheet were used to record sociodemographic characteristics, clinical presentations and outcomes. Patients were followed for immediate and late treatment outcomes up to 2 years since diagnosis. Northern districts those situated on the Ganges basin were noted as endemic areas. Male significantly outnumbered the female with a male to female ratio of 21:1 and majority of patients (58%) were in their 3rd and 4th decades. A significant (21%) number of patients were aborigines despite their ethnic minority as population under investigation and overall 68% belonged to low socioeconomic group. Habit of indigenous alcohol consumption was very high (78%) among ALA patients with overwhelming majority was illiterate (74.44%) and from rural population (70%). Fever with right hypochondriac pain of variable duration was the principal presenting complains. Gross fluid derangements including pleural effusion, edema and ascities were observed in 39% cases and 6% had rupture of abscess. All patients were treated with standard antimicrobial regimen and discharged with initial recovery. Recurrent attack was observed in 6% cases and 3 (3.33%) patients died during 2 years follow-up period. Complicated (37.78%) ALA patients showed significant Odds ratio (P < 0.05) for major sociodemographic determinants in comparison to non-complicated patients.

Conclusions

Amebic liver abscess is endemic in certain northern districts of Bangladesh especially on the Ganges basin with relatively high prevalence among aborigines. Rural habitat, ethnicity (Aborigine) and habit of indigenous alcohol consumption were found to be strong determinants, especially for complicated ALA, which were associated with different grades of morbidity and a few mortalities.

Unusual multiple large abscesses of the liver: interest of the radiological features and the real-time PCR to distinguish between bacterial and amebic etiologies

We report a rare case of amebiasis generating 19 large liver abscesses. Such a quantity of abscesses is rare, especially when occurring in a young casual traveler without any immunodeficiency disorders. A possible co-infection was excluded. By contrast, the amebic etiology was confirmed by means of serology and real-time PCR.

Clinical manifestations and risk factors of amebic liver abscess in Southeast Taiwan compared with other regions of Taiwan

Amebic liver abscess (ALA) had previously been endemic in Taiwan, particularly in the southern region, although its occurrence in the southeastern area was unknown. Thus, we conducted a retrospective study for southeastern Taiwan. We identified 14 patients who were diagnosed with ALA between July of 1995 and July of 2008. These patients were predominantly male and older in age. Most patients lived in rural areas (85.7%). Alcoholism (78.6%) and diabetes (35.7%) were risk factors for ALA. No human immunodeficiency virus (HIV) infections were detected. The most common clinical symptoms were fever (100%) and abdominal pain (100%). Short mean durations of symptoms, high bilirubin levels, and low albumin levels were also noted. Most patients (92.86%) had a single lesion, particularly in the right liver lobe (71.4%). Six patients also had secondary Klebsiella pneumoniae bacterial infections. Clinicians should be aware of the different risk factors in different regions when diagnosing amebic liver abscess in Taiwan.

Prognostic indications of the failure to treat amoebic liver abscesses

OBJECTIVES

To identify the variables that predict the failure to treat amoebic liver abscesses.

METHODS

We prospectively carried out a case-control study on a cohort of patients who had been diagnosed with amoebic liver abscesses using clinical, ultrasonic, and serologic methods. Patients with pyogenic abscesses, negative ELISA tests for amoebiasis, immunosuppression status, or previous abdominal surgery were excluded. All patients received metronidazole, and those who demonstrated 4 days of unfavorable clinical responses received percutaneous or surgical draining of the abscess. Demographic, laboratory, and ultrasonographic characteristics were assessed as prognostic indications of failure.

RESULTS

Of 40 patients with amoebic liver abscess, 24 (mean age: 36·7±11·2 years) responded to medical treatment and 16 (41·8±11·6 years) required drainage, including 14 patients who underwent percutaneous drainage and two patients who required surgery. The albumin level, abscess volume, abscess diameter, and alkaline phosphatase level were all statistically significant (P<0·05) on the bivariate analysis. The highest (>99%) sensitivity and negative predictive value were observed for an abscess volume >500 ml and diameter >10 cm, while the best specificity and positive predictive value were achieved with the combination of low serum albumin level, high alkaline phosphatase level, and large abscess volume or diameter.

CONCLUSIONS

The prognostic indications of the failure to treat amoebic liver abscesses include low albumin, high alkaline phosphatase, and large abscess volume or diameter. The combination of these variables is a useful and easy tool for determining appropriate therapy.

An unusual cause of haemoptysis: a diagnostic challenge for clinicians

A 32-year-old male patient presented with haemoptysis in the background of high-grade fever for 3 weeks. Chest examination and x-ray were suggestive of right-sided moderate pleural effusion. On finding tender hepatomegaly in abdominal examination, an ultrasonography of abdomen was performed which was suggestive of ruptured hepatic abscess. Cytological examination of both sputum and aspirate from hepatic abscess showed neutrophilic debris mixed with red blood cells. The serological test for antibody to Entamoeba histolytica was positive. Computerised tomography-guided trans-tracheal fistulogram demonstrated presence of hepato-bronchial fistula. Our case responded to conservative management. Follow-up ultrasonography after 6 months showed total abolition of abscess cavity and sealing of bronchial connection. Amoebic liver abscess complicating into hepato-bronchial fistula is thought to be an obsolete entity in contemporary world. But possibility of amoebic liver abscess should be kept in mind while managing a patient of haemoptysis in appropriate clinical setting in endemic areas.

Parasitic infestations requiring surgical interventions

Parasitic infestation is common in developing countries especially in Africa. Children are often more vulnerable to these infections. Many health problems result from these infestations, including malnutrition, iron-deficiency anemia, surgical morbidities, and even impaired cognitive function and educational achievement. Surgical intervention may be needed to treat serious complications caused by some of these parasites. Amoebic colitis and liver abscess caused by protozoan infections; intestinal obstruction, biliary infestation with cholangitis and liver abscess, and pancreatitis caused by Ascaris lumbricoides; biliary obstruction caused by Faschiola; hepatic and pulmonary hydatid cysts caused by Echinococcus granulosus and multilocularis are examples. Expenditure of medical care of affected children may cause a great burden on many African governments, which are already suffering from economic instability. The clinical presentation, investigation, and management of some parasitic infestations of surgical relevance in African children are discussed in this article.

Amoebic liver abscess in the medical emergency of a North Indian hospital

BACKGROUND

Amoebic Liver abscess although fairly common in developing countries, yet, there is limited data on the clinical presentation to the emergency department. A retrospective analysis of 86 indoor cases of Amoebic Liver Abscess presenting to the emergency department over a 5-year period was carried out.

FINDINGS

The mean age of patients was 40.5 +/- 2.1 years (male-female ratio = 7:1). Fever, pain abdomen and diarrhea were seen in 94%, 90% and 10.5% respectively. Duration of symptoms less than 2 weeks was seen in 48% cases. Hepatomegaly was present in 16% cases only, a right sided pleural effusion in 14% cases and ascites in 5.7%. On ultrasound, a right lobe abscess was seen in 65%, a left lobe abscess in 13% and multiple abscesses in both the lobes in 22% cases. Seventy one cases underwent per-cutaneous pigtail catheter drainage for a mean period of 13.4 +/- 0.8 days. The mortality rate was 5.8%. On multivariate regression and correlation analysis, a higher number of inserted pigtail catheters correlated to mortality.

CONCLUSIONS

Amoebic liver abscess presents commonly to the emergency department and should be suspected in persons with prolonged fever and pain abdomen. Conservative management for uncomplicated amoebic liver abscess and insertion of single per-cutaneous pigtail catheter drainage for complicated amoebic liver abscess are efficacious as treatment modalities.

Fever in returned travellers presenting in the United Kingdom: recommendations for investigation and initial management

International travel is increasing. Most physicians and general practitioners will encounter returned travellers with fever and the majority of travel-related infection is associated with travel to the tropics. In those returning from the tropics malaria must always be excluded, and HIV considered, from all settings. Common causes of non-malarial fever include from Africa rickettsial diseases, amoebic liver abscess and Katayama syndrome; from South and South East Asia, enteric fever and arboviral infection; from the Middle East, brucellosis and from the Horn of Africa visceral leishmaniasis. Other rare but important diseases from particular geographical areas include leptospirosis, trypanosomiasis and viral haemorrhagic fever. North and South America, Europe and Australia also have infections which are geographically concentrated. Empirical treatment may have to be started based on epidemiological probability of infection whilst waiting for results to return. The evidence base for much of the management of tropical infections is limited. These recommendations provide a pragmatic approach to the initial diagnosis and management of fever in returned travellers, based on evidence where it is available and on consensus of expert opinion where it is not. With early diagnosis and treatment the majority of patients with a potentially fatal infection related to travel will make a rapid and full recovery.

[Analysis of factors associated to failure of medical treatment of amoebic liver abscess]

INTRODUCTION

To identify the laboratory and ultrasound factors that could predict the response to medical treatment of amoebic liver abscess.

MATERIAL AND METHOD

Retrospective study of patients diagnosis with amoebic liver abscess in Hospital Central in San Luis Potosí, Mexico. We included patients greater than 15 years of both sexes. We excluded those with probable pyogenic abscess, immunosupression, history of abdominal or biliary surgery, abdominal neoplasm abdominal or sepsis. We identified patients with good response to medical treatment and patients who needed the abscess drained. We studied the ultrasound findings, plasma levels of albumin, alkaline phosphatase and bilirubin.

RESULTS

We analysed 45 patients, 31 had a good response (controls) and 14 needed drainage (cases). The medians of the variables with statistical significance in bivariate analysis were: albumin 2.65 g/dl and 1.7 g/dl (p < 0.001); alkaline phosphatase 133 U and 259 U (p = 0.02) and diameter of absences 5.9 cm and 9.95 cm (p < 0.001), controls and cases respectively. By logistic regression the diameter of the abscess showed a determination coefficient of 0.447 (p < 0.05) and OR = 14.85 (95% CI, 2.11-104.9) for drain if it was > or = 8 cm.

CONCLUSIONS

A diameter bigger than 8 cm in hepatic amoebic abscess is associated with failure of medical treatment. Low albumin could be related to malnutrition and increased alkaline phosphatase with extrinsic compression of extrahepatic conducts due to big abscesses.

Gigantic hepatic amebic abscess presenting as acute abdomen: a case report

Introduction

Amebiasis is a parasitic disease caused by Entamoeba histolytica. It most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients develop intestinal invasive or extra-intestinal diseases. Liver abscess is the most common extra-intestinal manifestation. The large number of clinical presentations of amebic liver abscess makes the diagnosis very challenging in non-endemic countries. Late diagnosis of the amebic abscess may lead to perforation and amebic peritonitis, resulting in high mortality rates.

Case presentation

This report describes a 37-year-old white man, suffering from hepatitis B, with a gigantic amebic liver abscess presenting as an acute abdomen due to its rupture. Rapid deterioration of the patient's condition and acute abdomen led to an emergency operation. A large volume of free fluid together with debris was found at the moment of entry into the peritoneal cavity because of a rupture of the hepatic abscess at the position of the segment VIII. Surgical drainage of the hepatic abscess was performed; two wide drains were placed in the remaining hepatic cavities and one on the right hemithorax. The patient was hospitalized in the ICU for 14 days and for another 14 days in our department. The diagnosis of amebic abscess was made by the pathologists who identified E. histolytica in the debris.

Conclusion

Acute abdomen due to a ruptured amebic liver abscess is extremely rare in western countries where the parasite is not endemic. Prompt diagnosis and treatment are fundamental to preserving the patient's life since the mortality rates remain extremely high when untreated, even nowadays.

Amebic liver abscess

Amebic liver abscess is the most common extraintestinal manifestation of infection with Entamoeba histolytica, and it is associated with significant morbidity and mortality. In this article the most recent available information is reviewed relating to epidemiology, pathogenesis, presentation, diagnosis, and treatment. We reviewed thousands of cases of amebic liver abscess in the medical literature and present that information as it pertains to mortality, gender, anatomic location of abscesses, and clinical signs and symptoms.

Amoebiasis

Amoebiasis is the second leading cause of death from parasitic disease worldwide. The causative protozoan parasite, Entamoeba histolytica, is a potent pathogen. Secreting proteinases that dissolve host tissues, killing host cells on contact, and engulfing red blood cells, E histolytica trophozoites invade the intestinal mucosa, causing amoebic colitis. In some cases amoebas breach the mucosal barrier and travel through the portal circulation to the liver, where they cause abscesses consisting of a few E histolytica trophozoites surrounding dead and dying hepatocytes and liquefied cellular debris. Amoebic liver abscesses grow inexorably and, at one time, were almost always fatal, but now even large abscesses can be cured by one dose of antibiotic. Evidence that what we thought was a single species based on morphology is, in fact, two genetically distinct species--now termed Entamoeba histolytica (the pathogen) and Entamoeba dispar (a commensal)--has turned conventional wisdom about the epidemiology and diagnosis of amoebiasis upside down. New models of disease have linked E histolytica induction of intestinal inflammation and hepatocyte programmed cell death to the pathogenesis of amoebic colitis and amoebic liver abscess.

Amebic Liver Abscess

Amebic liver abscess should be suspected in travelers returning from endemic areas or in immunocompromised patients who present with fever, right upper quadrant pain, hepatomegaly, and a liver lesion on an imaging study. Rapid initiation of therapy without serologic confirmation of infection, if necessary, is important to minimize complications. Metronidazole is given orally or intravenously for 14 days. The drug is generally well tolerated and leads to resolution of symptoms in most patients within 2 to 3 days. It is effective against luminal cysts in only 50% of patients and, therefore, must be followed by a course of treatment with paromomycin (Humatin; Parke-Davis, Morris Plains, NJ) or another luminal antiamebic agent to eradicate the parasite. Image-guided drainage of an amebic liver abscess is indicated in patients who do not respond to antimicrobial therapy or who are at risk of abscess rupture. Surgery is reserved for patients with a ruptured abscess. Although medical therapy is generally successful in the treatment of infection caused by Entamoeba histolytica, the development of potent vaccines will be needed for worldwide eradication of disease attributable to E. histolytica.

A note on clinical presentations of amebic liver abscess: an overview from 62 Thai patients

BACKGROUND

Amebic liver abscess is a tropical disease with a wide spectrum of clinical presentations. Given the often nonspecific nature of the complaints related to amebic abscess, a retrospective review of patients with confirmed disease to recognize the most common patterns of presentation is useful. Here, we study the clinical presentations of 62 Thai patients with amebic liver abscess. We also compare the clinical presentations of Anti HIV seronegative and Anti HIV seropositive patients.

METHODS

A retrospective case review was carried out for 62 Thai patients who had been diagnosed with amebic liver abscess. Clinical information was collected, including symptoms and signs, location and number of abscesses. The Anti HIV serology laboratory investigation was also reviewed.

RESULTS

According to our study, the common clinical symptoms and signs are abdominal pain (85.5 %), fever and chills (74.2 %), and abdominal tenderness (69.4 %). The location of the abscess was predominantly in the right lobe (74.2 %), and most of patients had a single abscess (77.4 %). Similar trends in clinical presentations were observed in both Anti HIV seropositive and Anti HIV seronegative subjects.

CONCLUSIONS

In conclusion, the clinical presentations of our amebic liver abscess patients were similar to those in previous reports. A similarity to those in the pyogenic liver abscess patients can be observed. Nevertheless, we could not detect important significant differences in the clinical presentations between Anti HIV seropositive and Anti HIV seronegative groups of patients.

Amebic liver abscesses masquerading as pyemic abscesses

We describe a 50-year-old man who presented with multiple liver abscesses that suggested biliary sepsis or portal pyemia. A wet preparation of a sample of aspirate showed the presence of amebic trophozoites, and subsequent serological testing for amebae was strongly reactive.

Specific detection of Entamoeba histolytica DNA by hemolysin gene targeted PCR

Diagnostic differentiation of pathogenic Entamoeba histolytica from non-pathogenic Entamoeba dispar is of great clinical importance. We have developed and evaluated a new polymerase chain reaction (PCR) assay (haemo-PCR) based on the novel E. histolytica hemolysin gene HLY6. The specificity of this assay was confirmed by analyzing different Entamoeba species, faeces samples, human and bacterial DNA, and digestion of amplification products with appropriate restriction enzymes. The sensitivity was confirmed by serial dilutions of E. histolytica HM-1:IMSS DNA in the excess of human DNA. Totally, 45 clinical samples were analyzed by the haemo-PCR assay including amoebic liver abscess (ALA) fluids from 23 patients suspected for amoebiasis, four faeces samples containing E. histolytica and E. dispar, and positive and negative controls. The results were compared with those obtained with PCRs for cystein-rich surface protein (P30) and small subunit ribosomal RNA (ssu rRNA) genes. The haemo-PCR gave a positive result in 18 (89%) ALA fluids compared with 14 (77%) and five (28%) by PCR for p30, and ssu rRNA, respectively. PCR products were obtained only from specimens containing E. histolytica DNA. The haemo-PCR assay was therefore found to be a valuable diagnostic tool for identification of E. histolytica infections both in faeces and ALA samples.

Amebic abscess of the liver presenting as acute cholecystitis

A case report is presented of a 37-year-old active duty Navy petty officer with amebic abscess of the liver presenting as acute cholecystitis. He was admitted with severe right upper quadrant pain and a positive Murphy's sign, but sonogram and computed tomography (CT) scan demonstrated an abscess in the right lobe of the liver. "Anchovy paste" material was obtained on percutaneous drainage, and he was placed on metronidazole administration with a tentative diagnosis of amebic abscess. This was confirmed on enzyme-linked immunosorbent assay. Symptoms resolved within a few days, and the abscess progressively decreased in size. Amebic abscess of the liver is discussed, with emphasis on pathogenesis, diagnosis, and treatment. Although uncommon, the condition is still seen in various population groups including the United States military. Difficulty in diagnosis is not unusual, and as in the herein-reported case, amebic abscesses of the liver may be confused with acute cholecystitis and other intra-abdominal infections. Abdominal sonogram and CT examination will identify a process in the liver, but the presence of amebiasis must be confirmed by laboratory studies on serum or contents of the abscess. Amebicidal agents are effective in many cases, but there remain roles for aspiration of the abscess, percutaneous drainage, and even open surgical drainage. Failure to establish an early diagnosis may result in rupture of the abscess, with catastrophic results.

Heptaobiliary infections

Although cholangitis is the most prevalent hepatobiliary infectious process, liver abscess represents the most serious and conspicuous hepatobiliary infection. Amebic liver abscess typically occurs in individuals from endemic areas or those traveling to endemic areas. It is associated with an excellent prognosis when managed expediently with antiamebic antibiotics. Recent reports emphasize a possible association between amebic liver abscess and HIV infection. Drainage or surgery for amebic liver abscess is rarely necessary. In contrast, pyogenic liver abscess is associated with significant morbidity and mortality, although the prognosis of patients with this hepatobiliary infection has improved in recent years. Pyogenic liver abscess occurs most often in patients without identifiable predisposing factors, but when identified, they are most often biliary tract-related. Management of pyogenic liver abscess has historically been surgical, but in recent years, there has been a dramatic shift toward noninvasive management, particularly involving strategies based on percutaneous drainage techniques.