Analysis of 69 patients with amebic liver abscess

All 69 patients with amebic liver abscess that we treated in 1981–1992 were studied retrospectively. Men predominated by a 101 ratio. Of our 227 patients with amebiasis, some 30% yearly had liver involvement. The incidence peaked in 1988, decreasing later but increasing again in 1992. Most patients were 30–50 years old, the overall mean age being 45 years (range, 22–79), and decreasing with time. Patients with the related factors of travel abroad, positive results of a test forTreponema pallidum hemagglutination, and homosexuality have increased in number in recent years. Fever, abdominal pain, and hepatomegaly were the most frequent findings, and 39 patients had neither bloody stools nor diarrhea. Only 8 patients had had amebiasis previously. A solitary abscess in the right lobe of the liver was found in 40 patients.Eniamoeba histolytica was found in the stool of 31 patients and in the pus of 39 patients. Sixty-one patients had positive results for an amebic serological test(s). The abscesses ruptured into the peritoneal cavity in 4 patients. All patients received metronidazole. Percutaneous or surgical drainage (or both) was done in 62 patients. The outcome was good, with 1 exception, and only 2 patients had recurrences.     

实验性肝阿米巴病的病理组织学观察

应用肝内接种法建立实验性肝阿米巴病金黄仓鼠模型。观察肝阿米巴病的病理形态,其大体标本可分为孤立型、多结节型和破溃型3种脓肿类型。光镜观察变质性病变和增生性病变可分别显示早、晚期肝阿米巴病的病理组织学特性。本文探讨了肝阿米巴病的发展和溶组织内阿米巴的致病机制。     

A case of pulmonary amebiasis

A 57-year-old man was admitted to our hospital because of dyspnea and right abdominal pain. Chest X-ray radiogram showed right massive pleural effusion. Ultrasonic echogram of abdomen showed a unilocular liver cyst. He was treated with intravenous infusion of meropenem, and percutaneous pleural and liver drainage were performed. At the time of drainage, we injected contrast medium into the liver cyst and confirmed a fistula connecting to the right pleural space. Initially we made a diagnosis of bacterial empyema and liver abscess, yet there was no response to the initial treatment. Cultures of pleural effusion and liver abscess were confirmed to be negative. A few days after admission, the patient stated that he was a homosexual. Liver amebiasis and its perforation became the most likely diagnosis, and metronidazole was administered. On admission day 21, tests for anti-amebic antibody were positive. Finally he fully recovered. We must be aware of the rare pulmonary manifestation of amebiasis. We report this case and review the literature.     

Amebiasis in Japanese homosexual men with human immunodeficiency virus infection

We report cases of amebiasis in 6 human immunodeficiency virus (HIV)-positive male patients. Five were confirmed homosexuals while one was suspected. Three patients had liver abscess and 5 had colitis with duration of 10 days to months. The patients with liver abscess showed a lower incidence of abdominal pain but a higher incidence of concomitant diarrhea. Drainage therapy was effective for rapid afebrile results. Two invasive colitis cases died from perforation. This may have been due to delayed diagnosis. Invasive amebiasis is not common even in HIV-infected individuals. Among Japanese homosexual men, however, it may cause symptomatic diseases.     

A case of AIDS complicated with liver tuberculosis

We experienced a double infection of tuberculosis and amebiasis of the liver. A 28 year old male with AIDS was admitted to our hospital because of severe diarrhea and liver abscess by Entamoeba histolytica. In spite of improvement of the diarrhea and liver abscess by the therapy against E. historicica, serum levels of gamma-GTP and ALP remained high and hepatosplenomegaly gradually increased. A liver biopsy was performed. Pathology showed a granulomatous lesion with Langhans' giant cells. From this specimen, IS6110 gene, a specific DNA for Mycobacterium tuberculosis was detected by PCR method. After anti-tuberculosis treatment was given for 6 months the increased serum gamma-GTP, ALP decreased and hepatosplenomegaly diminished.     

The presence of liver auto-antibodies induced by Entamoeba histolytica in the sera from both naturally infected humans and immunized rabbits.

Auto-antibodies against normal human liver have been detected in the sera of humans with highly positive indirect hemagglutination (IHA) amebiasis titers and with clinically-proven amebic liver abscess. Sera of amebiasis patients and rabbits immunized with killed Entamoeba histolytica were tested for anti-amebic antibodies by the IHA test and for auto-antibodies by the complement fixation test, using the antigens prepared from extracts of human liver and rabbit liver. A direct correlation was found to exist between high anti-Entamoeba antibody titers and the presence of anti-liver antibody in the serum. It is proposed that, in addition to direct parasite damage to host tissue, immunological damage could result from the attachment of circulating antigen to the cell surfaces of host tissues such as the liver.     

Amebic liver abscess and human immunodeficiency virus infection: a report of three cases.

Invasive amebiasis rarely occurs in homosexual men and human immunodeficiency virus (HIV)-infected individuals and has not been regarded as a beacon for concomitant HIV infection. We encountered a bisexual man with a protracted course of amebic liver abscess and amebic colitis. In the presence of fever, generalized lymphadenopathy, and elevated serum aminotransferase levels, HIV infection was suspected and then confirmed by a de novo seroconversion of HIV antibody. Subsequently, we noted two consecutive patients with amebic liver abscess, also later found to be infected with HIV. The ameba obtained from these three cases was identified as Entamoeba histolytica by amplification of 16S ribosomal RNA by polymerase chain reaction and direct sequencing. This observation suggests that amebic liver abscess and colitis can be presentations for HIV infection in the Far East. Thus, the local patients with invasive amebiasis, especially those with a protracted course or with risk factors of HIV infection, should be tested for HIV.     

Hepatic abscess caused bySalmonella typhi

Summary Salmonella typhi is a rare cause of liver abscess. We describe a 47-year-old African male with multiple liver abscesses due toS. typhi in an area where hepatic amebiasis is endemic. The patient did not respond appropriately to amebicidal therapy and culture of the liver aspirate on two occasions yieldedS. typhi. The Widal test, initially negative, became positive on repeat testing 10 days later. Percutaneous aspiration combined with appropriate antibiotic therapy resulted in a complete recovery. No predisposing cause could be found. We report the clinical, radiological, and microbiological features of this case and review the literature on this rare but easily treatable condition.     

Amebic Liver Abscess

We present a patient with an acute amebic liver abscess with nonreactive serologic tests. Motile hematophagous trophozoites of Entamoeba histolytica were seen microscopically in scrapings from the wall of the abscess. Postoperative serologies revealed rapidly rising then falling titers by SAFA and IHA antibody assays. Serologic tests for amebiasis may be reative in greater than 95% of patients with invasive amebiasis. Nevertheless, a reactive serologic test should not be relied upon exclusively to establish the diagnosis. Sequential serologic testing and surgical intervention to obtain material for microscopic examination, gram stain and bacteriologic culture are warranted in patients with hepatic abscess and nonreactive serologic tests for antibodies to E. histolytica.     

Gender distribution in asymptomatic and invasive amebiasis

OBJECTIVE: The majority of individuals infected by the protozoan parasite Entamoeba histolytica experience subclinical infections. However, a small proportion of parasitized individuals develop severe invasive disease such as amebic dysentery or amebic liver abscess. Invasive amebiasis affects predominantly men; the usual explanation for this has been that men have a higher rate of asymptomatic infections and therefore experience a higher rate of invasive disease. To date, there is no convincing evidence of an increased rate of asymptomatic infection of men as compared with women. The purpose of this study was to evaluate the evidence supporting the hypothesis that men have higher rates of asymptomatic infection and thus an increased frequency of invasive amebiasis. METHODS: We reviewed published reports of invasive amebiasis and population-based parasitological studies from 1929-1997 to compare the gender ratio of asymptomatic and symptomatic E. histolytica infection. Infections with E. histolytica were differentiated from the nonpathogenic E. dispar whenever possible. RESULTS: The reports of invasive amebiasis (dysentery, liver abscess, colonic perforation, peritonitis, appendicitis, and ameboma) showed a higher proportion of men than women (ratio, male:female = 3.2:1, p < 0.05). This contrasts with the epidemiological surveys, where the rate of asymptomatic infection with E. histolytica was the same (1:1) for both genders (p > 0.05). CONCLUSIONS: Asymptomatic E. histolytica infection is equally distributed between the genders. The high proportion of men with invasive amebiasis may be due to a male-related susceptibility to invasive disease.     

Experience with intravenous metronidazole to treat moderate-to-severe amebiasis in Japan

Twenty-eight cases of either intestinal amebiasis, amebic liver abscess, or both, most of which were of moderate-to-severe intensity, were treated with intravenous metronidazole, pioneered by the Research Group on Chemotherapy of Tropical Diseases, Japan. This study was not conducted as a formal clinical trial, and all patients either underwent colectomy for intestinal amebiasis, received oral metronidazole, or both. Despite these limitations, intravenous metronidazole was shown to be well tolerated and seemed to be very effective. This agent should be more widely recommended than previously thought for treating moderate-to-severe amebiasis, especially its intestinal form.     

Hepato-pulmonary amebiasis: a case report

Infections with Entamoeba histolytica are seen worldwide and are more prevalent in the tropics. About 90% of infections are asymptomatic, and the remaining 10% produce a spectrum of clinical syndromes, ranging from dysentery to abscesses of the liver or other organs. Extra-intestinal infection by E. histolytica most often involves liver. Pleuro-pulmonary involvement, seen as the second most common extra-intestinal pattern of infection, is frequently associated with amebic liver abscess. Pulmonary amebiasis occurs in about 2-3% of patients with invasive amebiasis. We report herein the case of a 45-year-old male presenting with hepato-pulmonary amebiasis. The diagnosis was established from direct examination of sputum, in which trophozoites of E. histolytica were detected, and by serology. Following treatment with metronidazole and chloroquine, the clinical evolution improved significantly. On regular follow-up visits, the patient was asymptomatic. This case report reiterates the need for collaboration between clinicians and microbiologists for timely diagnosis of such infections.     

Association between amebic liver abscess and Human Immunodeficiency Virus infection in Taiwanese subjects

Purpose  

Invasive amebiasis is an emerging parasitic disorder in Taiwan, especially in patients diagnosed with human immunodeficiency virus (HIV) infection. Thirty-three Taiwanese subjects with amebic liver abscess (ALA) were examined and a possible correlation between ALA and HIV infection was investigated.     

Amebic liver abscess with bacterial superinfection in a patient with no epidemiologic risk factors.

The amebic liver abscess is uncommon in developed countries like Spain, but the incidence is increasing probably due to the migratory movements of the population. We report a case of an amebic abscess, initially unsuspected due to the absence of epidemiologic risk factors and the negative serology for amebiasis, in the early stages of the disease.     

Amebiasis: Clinical implications of the recognition of Entamoeba dispar

Entamoeba histolytica was recently reclassified to recognize the existence of two genetically distinct but morphologically indistinguishable species: E. histolytica, the protozoan parasite that causes amebic dysentery and liver abscess, and Entamoeba dispar, a nonpathogenic intestinal parasite. Acceptance of this redefinition has dramatically changed both our understanding of the true epidemiology of E. histolytica and the optimal methods for diagnosing amebiasis. Molecular-based diagnostic tests using polymerase chain reaction (PCR) to amplify amebic DNA or enzyme-linked immunosorbent assay (ELISA) to identify amebic antigens in stool samples have been developed to distinguish infection with E. histolytica from infection with E. dispar. Because of its ability to differentiate strains of E. histolytica, PCR is a very useful research tool. Only the ELISA-based test is simple to perform, making it clinically useful in the developing world. To avoid unnecessary treatment of individuals infected with E. dispar, the World Health Organization has stressed the importance of making a specific diagnosis of E. histolytica infection (not E. histolytica/E. dispar) before treating for amebiasis.     

Amebic pericarditis.

Amebic pericarditis in a 40-year-old man who presented with insidious onset of symptoms is reported. Pericarditis is an infrequent complication of liver abscess and accounts for 4 percent of all extraintestinal amebiasis. Communication between the left lobe of liver and pericardium has been demonstrated in this patient.     

Differences in complement-mediated killing of Entamoeba histolytica between men and women--an explanation for the increased susceptibility of men to invasive amebiasis?

Men are more than 7 times more likely to develop amebic liver abscess or amebic dysentery caused by Entamoeba histolytica than women. Because the complement system could play a key role in controlling amebiasis, we determined whether serum from men and women differ in the ability to kill amebic trophozoites. We found that serum from women was significantly more effective in killing E. histolytica trophozoites than serum from men, and this killing was complement dependent. Our results provide a possible explanation for the differential susceptibility of men and women to amebic liver abscess and amebic colitis.     

Thoracic amebiasis

Pleuropulmonary amebiasis is the common and pericardial amebiasis the rare form of thoracic amebiasis. Low socioeconomic conditions, malnutrition, chronic alcoholism, and ASD with left to right shunt are contributing factors to the development of pulmonary amebiasis. Although no age is exempt, it commonly occurs in patients aged 20 to 40 years, with an adult male to female ratio of 10:1. Children rarely develop thoracic amebiasis: when it does occur there is an equal sex distribution. The infection usually spreads to the lungs by extension of an amebic liver abscess. Infection may pass to the thorax directly from the primary intestinal lesion through hematogenous spread, however. Lymphatic spread is one possible route. Inhalation of dust containing cysts and aspiration of cysts or trophozoites of E histolytica in the lungs are some other hypothetical routes. The lung is the second most common extraintestinal site of amebic involvement after the liver. Usually the lower lobe, and sometimes the middle lobe of the right lung, are affected, but it may affect any lobe of the lungs. The patient develops fever and right upper quadrant pain that is referred to the tip of the right shoulder or in between the scapula. Hemophtysis is common. The diagnosis of thoracic amebiasis is suggested by the combination of an elevated hemidiaphragm (usually right), hepatomegaly, pleural effusion, and involvement of the right lung base in the form of haziness and obliteration of costophrenic and costodiaphragmatic angles. Infection is usually extended to the thorax by perforation of a hepatic abscess through the diaphragm and across an obliterated pleural space, producing pulmonary consolidation, abscesses, or broncho-hepatic fistula. Empyema develops when a liver abscess ruptures into the pleural space. Rarely, a posterior amebic liver abscess can burst into the inferior vena cava and develop an embolism of the inferior vena cava and thromboembolic disease of the lungs with congestive cardiac failure or corpulmonale. Diagnosis by finding E histolytica in stool specimens is of limited value. In a limited number of cases amebae might be found in aspirated pus or expectorated sputum. "Anchovy sauce-like" pus or sputum may be found. Presence of bile in sputum indicates that the pus is of liver origin. Serological tests are of immense value in diagnosis. Liver enzymes are usually normal and neutrophilic leucocytosis may or may not be found. ESR is invariably elevated. Anti-amebic antibodies can be detected by ELISA, IFAT, and IHA. Amebic antigen can be detected from serum and pus by ELISA. Detection of Entamoeba DNA in pus or sputum may be a sensitive and specific method. Pleuropulmonary amebiasis is easily confused with other illnesses and is treated as pulmonary TB, bacterial lung abscesses, and carcinoma of the lung. A single drug regimen with metronidazole with supportive therapy usually cures patients without residual anomalies. Aspiration of pus from empyema thoracis may be needed for confirmation and therapeutic purposes. The pericardium is usually involved by direct extension from the amebic abscess of the left lobe of the liver, sometimes from the right lobe of the liver, and rarely from the lungs or pleura. An initial accumulation of serous fluid due to reactive pericarditis followed by intrapericardial rupture may develop either (1) acute onset of severe symptoms with chest pain, dyspnea, and cardiac tamponade, shock, and death, or (2) progressive effusion with thoracic cage pain, progressive dyspnea, and fever. Chest radiograph, ultrasound examination, and CT scan usually confirm the presence of a liver abscess in continuity with the pericardium and fluid within the pericardial sac with or without the fistulous tract. Echocardiography may demonstrate fluid in the pericardial cavity. Patients should be cared for in the ICU and ambecides should be started without delay. Pericardiocentesis usually confirms the diagnosis and improves the general condition of the patient. Aspiration of the accumulated fluid should be performed urgently in cardiac tamponade; repeated aspiration may be needed. Surgical drainage should be done if needed. Acanthamoeba, a free-living ameba, may also infect the lungs in the form of pulmonary nodular infiltration and pulmonary edema in association with amebic meningoencephalitis in immunocompromised patients. It usually spreads to the meninges of the brain by way of the blood from its primary lesion in the lung or skin. Early diagnosis and institution of treatment may be life saving for these patients. A literature review shows that HIV/AIDS patients are not prone to infection with E histolytica. It is now clear that there are an increasing number of HIV-seropositive patients among amebic liver abscess patients, however, which suggests that although the incidence of intestinal infection is not high among HIV-seropositive or AIDS patients they are more susceptible to an invasive form of the disease.     

Hypocholesterolemia in Patients with an Amebic Liver Abscess

Background/Aims

Many parasites induce changes in the lipid profiles of the host. Cholesterol increases the virulence of Entamoeba histolytica in animal models and in vitro culture. This study aimed to determine, in patients with an amebic liver abscess, the correlation between cholesterol and other features, such as the size and number of abscesses, standard hematological and serum chemistry profiles, liver tests, and duration of hospital stay.

Methods

A total of 108 patients with an amebic liver abscess and 140 clinically healthy volunteers were investigated. Cholesterol and triglycerides were measured in the sera. The data from medical observations and laboratory tests were obtained from the clinical records.

Results

A total of 93% of patients with an amebic liver abscess showed hypocholesterolemia not related to any of the studied parameters. Liver function tests correlated with the size of the abscess. The most severe cases of amebic liver disease or death were found in patients whose cholesterol levels continued to decrease despite receiving antiamebic treatment and hospital care.

Conclusions

Our results show that the hypocholesterolemia observed in patients with an amebic liver abscess is not related to any of the clinical and laboratory features analyzed. This is the first study relating hypocholesterolemia to severity of hepatic amebiasis.     

Fulminant hepatic failure secondary to amebic abscesses

Summary A patient presented with fulminant hepatic failure which rapidly led to his death. At postmortem examination, he had several amebic abscesses secondarily infected with bacteria, one of which had ruptured intraperitoneally, and another of which had occluded major hepatic veins of the right lobe of the liver. In addition, pylephlebitis and occlusion of several right portal venous radicies were noted. Microscopic examination of the right lobe revealed marked sinusoidal congestion and large areas of infarction with severe panlobular necrosis. Fuiminant hepatic failure secondary to complications of amebic abscess has been reported infrequently but should be considered in patients with this presentation who have visited or inhabited areas endemic for amebiasis.