Concomitant Occurrence of Hepatitis A and a Pyogenic Liver Abscess: A Pediatric Case.

Pyogenic liver abscess (PLA) and hepatitis A are common in developing countries. As there is an overlap of clinical features, a diagnosis of dual infection can be missed. Here, we present the case of a five-year-old male who presented with abdominal pain, fever, and jaundice diagnosed as a complicated liver abscess with concurrent hepatitis A. To our knowledge, this is the first case where a PLA co-existed with hepatitis A. Simultaneous infection should be considered when a patient with liver abscess presents with jaundice, especially in areas where both diseases are endemic. Early diagnosis of both is crucial as PLA is a potentially fatal disease and co-infection with hepatitis A may worsen clinical outcomes.

Enteropathogenic Escherichia coli modulates the virulence and pathogenicity of Entamoeba dispar.

Amoebiasis is a disease caused by Entamoeba histolytica, affecting the large intestine of humans and occasionally leading to extra-intestinal lesions. Entamoeba dispar is another amoeba species considered commensal, although it has been identified in patients presenting with dysenteric and nondysenteric colitis, as well as amoebic liver abscess. Amoebic virulence factors are essential for the invasion and development of lesions. There is evidence showing that the association of enterobacteria with trophozoites contributes to increased gene expression of amoebic virulence factors. Enteropathogenic Escherichia coli is an important bacterium causing diarrhea, with high incidence rates in the world population, allowing it to interact with Entamoeba sp. in the same host. In this context, this study aims to evaluate the influence of enteropathogenic Escherichia coli on ACFN and ADO Entamoeba dispar strains by quantifying the gene expression of virulence factors, including galactose/N-acetyl-D-galactosamine-binding lectin, cysteine proteinase 2, and amoebapores A and C. Additionally, the study assesses the progression and morphological aspect of amoebic liver abscess and the profile of inflammatory cells. Our results demonstrated that the interaction between EPEC and ACFN Entamoeba dispar strains was able to increase the gene expression of virulence factors, as well as the lesion area and the activity of the inflammatory infiltrate. However, the association with the ADO strain did not influence the gene expression of virulence factors. Together, our findings indicate that the interaction between EPEC, ACFN, and ADO Entamoeba dispar strains resulted in differences in vitro and in vivo gene expression of Gal/GalNAc-binding lectin and CP2, in enzymatic activities of MPO, NAG, and EPO, and consequently, in the ability to cause lesions.

Real-time loop-mediated isothermal amplification (real-time LAMP) assay for rapid diagnosis of amoebic liver abscess.

Among the parasitic diseases, amoebic liver abscess (ALA) ranks second to malaria in terms of mortality. Due to the poor sensitivity of conventional diagnostic methods, there is a need for the development of effective and rapid diagnostic methods for ALA. Thus, the purpose of this work was to develop a real-time loop-mediated isothermal amplification (RT-LAMP) assay specific to Entamoeba histolytica. Further, we compared the performance of real-time LAMP with conventional and real-time PCR (RT-PCR) targeting 18S small subunit ribosomal RNA (18S SSU rRNA) gene of E. histolytica in patients with ALA. A total of 126 liver samples were obtained for the study. Of these, 96 aspirated pus samples were obtained from patients suffering from an ALA (serology confirmed, anti-amoebic immunoglobulin IgG positive), 19 aspirated pus samples from patients with pyogenic liver abscess (PLA, 16S RNA gene positive) and 11 autopsy liver tissues. The results showed that the DNA of E. histolytica was detected in 81 samples by conventional PCR, 93 by RT-PCR and 95 by RT-LAMP. The analytical sensitivity of the RT-LAMP assay was much higher than the other two techniques. RT-LAMP assay was able to amplify up to one copy of the targeted gene of E. histolytica while conventional PCR and RT-PCR could amplify up to 103 and 102 copies of the targeted gene of E. histolytica, respectively. In conclusion, RT-LAMP proved to be a sensitive, specific and rapid test which can be utilised as an effective tool for the diagnosis of ALA.

Novel diagnostic approach for amoebic liver abscess using cell free (cf) DNA: a prospective study.

BACKGROUND: Amoebic liver abscess (ALA) is commonly seen in tropical countries and diagnosis of ALA relies mainly on non-specific serological and imaging techniques as well as PCR from pus. OBJECTIVE: This study evaluated the potential of using cell free DNA (cfDNA) from serum and urine for diagnosing ALA. METHODS: We prospectively evaluated quantitative PCR (qPCR) for detection of cf DNA in serum and urine sample in all liver abscess patients. The samples were collected from patients reporting to emergency ward of Postgraduate Institute of Medical Education and Research, Chandigarh, India with symptoms suggestive of liver abscess. Real time PCR was done to detect cf DNA in serum and urine by targeting 99-bp unit of small subunit rRNA of Entamoeba histolytica and conventional PCR for pus. RESULTS: A total 113 samples (serum and urine) and 100 pus samples were analysed. A total of 62 ALA patients were confirmed; with maximum 57 patients detected by qPCR for cfDNA in the serum, 55 patients by PCR on pus aspirate and 50 ALA patients by qPCR for cfDNA in urine sample. Therefore, the sensitivity of qPCR for detection of cf DNA in serum was 91.94% and for urine was 80.65%. CONCLUSION: A total of 11.2% of ALA patients were diagnosed only through detection of E. histolytica cf DNA in their serum and urine. Detection of cfDNA from serum, urine of ALA has a potential role in future especially for developing countries as it is a rapid, sensitive and patient friendly diagnostic approach.

Liver abscess with extension into the Inferior Vena Cava: Case series of a rare complication.

Liver abscess is a common disease, however, it is a rare cause of venous thrombosis. The incidence of amoebic and pyogenic liver abscess in developing countries is high, however, the occurrence of inferior vena cava thrombosis secondary to liver abscess is a very rare and life-threatening complication. Computed tomography (CT) scan is an ideal investigation tool for diagnosing the various complications associated with liver abscess. Here we describe 3 cases of liver abscess in patients who developed a rare vascular complication of inferior vena cava. Liver abscesses should be considered as a rare cause of IVC thrombosis in the correct clinical context. All the patients were managed with ultrasound-guided pigtail insertion and antimicrobial agents.

Mediastinal extension of amoebic liver abscess: A case report on the rare thoracic complication of Entamoeba histolytica.

Amoebic liver abscess is one frequently encountered intra-abdominal infection, caused by Entamoeba histolytica and has various abdominal and thoracic life-threatening complications. Herein, describe a case of a 30-year-old female, who suffered from multiple amoebic liver abscesses and presented with massive right-sided pleural effusion. She was managed with recommended antibiotics and pigtail catheter for liver abscess and an intercostal drainage tube for massive pleural effusion. However, postintercostal drainage, her chest X-ray demonstrated a right mediastinal shadow, which was confirmed as an intrathoracic extension of the hepatic liver abscess on computed tomography. An ultrasound-guided pigtail catheter was manipulated and placed at the site of thoracic communication. This led to clinical and radiological improvement, but unfortunately, she developed ventilator-acquired pneumonia and died due to her illness. The case represents an uncommon complication of amoebic liver abscess, which is rarely described and adds more knowledge on the thoracic complexities of this infectious disease.

Investigating genetic polymorphism in E. histolytica isolates with distinct clinical phenotypes.

Amoebiasis is an infection caused by enteric protozoa, most commonly Entamoeba histolytica, and is globally considered a potentially severe and life-threatening condition. To understand the impact of the parasite genome on disease outcomes, it is important to study the genomes of infecting strains in areas with high disease prevalence. These studies aim to establish correlations between parasite genotypes and the clinical presentation of amoebiasis. We employ a strain typing approach that utilizes multiple loci, including SREHP and three polymorphic non-coding loci (tRNA-linked array N-K2 and loci 1-2 and 5-6), for high-resolution analysis. Distinct clinical phenotype isolates underwent amplification and sequencing of studied loci. The nucleotide sequences were analysed using Tandem Repeats Finder to detect short tandem repeats (STRs). These patterns were combined to assign a genotype, and the correlation between clinical phenotypes and repetitive patterns was statistically evaluated. This study found significant polymorphism in the size and number of PCR fragments at SREHP and 5-6 locus, while the 1-2 locus and NK2 locus showed variations in PCR product sizes. Out of 41 genotypes, two (I6 and I41) were significantly associated with their respective disease outcomes and were found in multiple isolates. We observed that I6 was linked with a symptomatic outcome, with a statistically significant p-value of 0.0183. Additionally, we found that I41 was associated with ALA disease outcome, with a p-value of 0.0089. Our study revealed new repeat units not previously reported, unveiling the genetic composition of E. histolytica strains in India, associated with distinct disease manifestations.

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.

Amoebic Liver Abscess: A disease native to Oman?

Objectives: Amoebic liver abscess (ALA) is endemic to many areas of the world. This study sought to investigate the epidemiology, presentation, laboratory tests and imaging characteristics of ALA in Oman and ultimately determine whether it is native to Oman or originated abroad. Methods: This case series study was conducted at the Royal Hospital, Muscat, Oman, from January 2013 to December 2017 with patients older than 13 years and having a discharge diagnosis of ALA. Patient data were extracted from the Royal Hospital patient database. Results: 22 patients were included in the study-18 Omani patients and four expatriates. Only two Omanis had a history of traveling abroad. There were 15 male patients and seven were female with an average age of 45.2 years. The most common presentation was abdominal pain, which was seen in 17 patients. Fever was seen in 13 patients. Alanine transferase was found to be elevated in 13 patients. The majority of patients (90%) had no symptomatic infections prior to developing ALA. Conclusion: The data suggests that ALA is endemic to Oman, considering the high number of local patients and lack of travel abroad in this population. As the number of patients treated for ALA is rather small, it can be concluded that the occurrence of ALA is much lower in Oman than in other endemic areas. The majority of patients had no prior symptomatic infections; thus, a method of control involves screening to prevent amoebic spread.

Ubiquitin of Entamoeba histolytica induces antibody response in patients with invasive amoebiasis.

Entamoeba histolytica causes amoebic liver abscess (ALA) in humans. The injury of target cells by E. histolytica includes processes controlled by the ubiquitin Ehub. Previously, we found immunodominance of Ehub glycan moieties using immunized rabbits. In this work, we analysed dominance of antibodies to the glycoprotein Ehub in the sera from 52 patients with ALA. Controls were sera from 20 healthy people living in endemic areas with a high seroprevalence of antibodies to amoebas, and 20 patients with alcoholic hepatitis (AH) to rule out the cross-reaction of Ehub with autoantibodies induced by liver damage. Antigens were trophozoite extract, glycoprotein Ehub and the recombinant protein E. histolytica recombinant ubiquitin (rEhub). The sera from healthy volunteers and patients with AH do not have antibodies to glycoprotein Ehub. Surprisingly, only the antibodies from patients with ALA recognized the glycoprotein Ehub, and some sera gave a faint reaction with the recombinant protein, especially because evolutionarily, the ubiquitin is conserved between species. This is the first report demonstrating that antibodies to ubiquitin Ehub are induced exclusively in patients with invasive amoebiasis, and the antibody response is mainly to the glycoprotein, indicating glycans are immunodominant. Inhibitors of the Ehub glycans could be potential treatment for amoebiasis by selectively damaging trophozoites.

Prevalence of Amoebiasis and Associated Complications in India: A Systematic Review.

PURPOSE: Intestinal protozoan parasites are responsible for diarrheal diseases causing significant morbidity and mortality. Entamoeba histolytica is the principle protozoan parasite associated with diarrheal infections. The infection is often associated with inaccessibility to clean drinking water and poor sanitary conditions in low- and middle-income countries including India. A comprehensive systematic review was performed to evaluate a reliable nationwide estimate for prevalence and geographic distribution of amoebiasis in India and the complications associated with it. METHODS: We used the PRISMA guidelines to perform a systematic review and meta-analysis of articles published between the year 2001-2020. Two English language databases PubMed and Web of Science were searched to achieve relevant studies. RESULTS: Initial searches resulted in 467 studies out of which 64 eligible articles involving data from 289,659 human subjects from 12 states and 4 union territories were included in the final analysis. Prevalence of amoebiasis ranged from 3-23% in asymptomatic population, 0.64-11% in symptomatic patients and 1-17.5% in HIV-infected patients. Highest prevalence was seen in Tamil Nadu, Andaman Nicobar Island and North East India. Extra intestinal invasion of Entamoeba histolytica leading to complications such as amoebic liver abscess, amoebic colitis, colonic perforation and ameboma were also reported. Such complications have the potential to increase healthcare burden and may prove to be fatal. CONCLUSION: Amoebiasis remains a significant public health issue in India responsible for diarrheal diseases causing significant morbidity and mortality. Entamoeba histolytica is the principle protozoan parasite associated with amoebiasis. Public health efforts should be directed towards its control and better diagnostic methods should be employed for distinguishing between pathogenic and non-pathogenic species of Entamoeba.

Ascorbic Acid Ameriolates Liver Damage by Myeloperoxidase Oxidative Products in a Hamster Model of Amoebic Liver Abscess.

Entamoeba histolytica is a protozoan-pathogen-causing amoebic liver abscess (ALA). After amoeba establishment in the liver, it causes abundant infiltrate of neutrophils. Liver tissue damage by neutrophils results in part from anti-amoebic oxidative intermediates, including reactive oxygen species (ROS), reactive nitrogen species (RNS), and hypochlorous acid (HOCl), derived from the myeloperoxidase (MPO) enzyme. Ascorbic acid (ASC) is an antioxidant that acts as a scavenger for ROS and NOS-derived free radicals. No previous information regarding the effect of ASC concerning the participation of MPO in an experimental model of ALA in hamsters has been reported. Thus, the aim of the present work was to analyze the effect of ASC on acute ALA development and to measure the activity and gene expression of the MPO enzyme. Hamsters were treated with ASC (800 mg/kg) and then intrahepatically inoculated with E. histolytica trophozoites. Animals were sacrificed at 3, 6, and 12 h post-inoculation (p.i.), and liver samples were collected. The percentage of lesions, amoeba in situ count, MPO activity, and mpo gene expression were ascertained. Compared to ALA hamsters without ASC treatment as the control group (CT), the ALA group treated with ASC had a significant decrease in liver lesions (all p.i. hours) and viable amoeba count (12 h p.i.) and an increase in MPO activity (12 h p.i.) and mpo gene expression (6 h/12 h p.i.). These data suggest that ASC ameliorated liver damage caused by oxidizing products via modulation of mpo expression and activity.

Hepatic aneurysm in patients with amoebic liver abscess. A review of cases in literature.

INTRODUCTION: Entamoeba histolytica is a protozoan parasite with worldwide distribution, higher in countries with poor sanitation due to its oral-faecal way of transmission. It is the causative agent of amoebic colitis and extraintestinal amoebiasis, and accounts for 40 000-100 000 deaths yearly. Amoebiasis can be complicated by liver abscess in 9% of cases. Rarely, vascular complications have been reported. Aneurysms of the hepatic artery have been described, rarely, in patients with amoebic hepatic abscess. AIM AND METHODS: Aim of our study was to describe clinical presentation, details of vascular lesions, treatment and outcome of patients with a history of amoebiasis complicated by hepatic abscess and aneurysm of hepatic vessels (key words "Amoebiasis AND aneurysm). RESULTS: Six case report were included. Mean age of patients was of 44.8 ± 8 years (range 31-52). All patients were male. Leucocytosis, anaemia, fever, abdominal pain, hematemesis, haemobilia, melena and hepatomegaly were the most frequently reported signs and symptoms. Aneurysms lesions occurred in hepatic artery or in its branches. In 2 cases rupture occurred. In 3 cases aneurysm embolization has been successful in treating arterial lesion. Spontaneous regression after abscess drainage occurred in 2 cases. Uneventful recovery was reported in the five patients with available follow up data. CONCLUSIONS: Hepatic artery aneurysms may complicate amoebiasis in patients with hepatic abscess. Notwithstanding the high burden of the disease, majorly in developing countries, only data from sporadic case report are available, suggesting underreporting bias. Further studies are needed to better understand the vascular involvement in this setting of parasitological interest.

A Case Series of Amoebic Liver Abscess in Patients With COVID-19 Infection.

Background: Globally, amoebiasis is the second leading cause of death due to parasitic diseases. Amoebic liver abscess (ALA) as an opportunistic infection in recently recovered COVID 19 disease patients has not been reported earlier. Methods: We present here a case series of 13 patients of ALA admitted during the month of May 2021 in BLK hospital, New Delhi, and had recently recovered from COVID 19 disease. Results: Out of 13, eight patients had moderate, and one had severe COVID 19 disease. All these patients had received steroids for the management of COVID 19 disease. The remaining 4 (30%) patients had mild disease. The mean age of our patients was 50 years (37-81 years). Out of 13 patients, nine (70%) were male, 5 were diabetic, 2 were hypertensive, and none were alcoholic. The most common presentation was fever (11/13) followed by upper abdomen pain (10/13). The mean time of symptom (fever or pain abdomen) onset from COVID 19 positivity date was 19 days (range 15-23 days). A complication the in form of localized intraperitoneal rupture was common in these patients and was seen in more than 50% (7/13) of patients. All the patients were managed with IV Metronidazole and abscess aspiration. All the patients were discharged, and the mean hospital stay was 6.6 days. Conclusion: We report here an increase in the incidence of ALA in recently recovered COVID 19 patients and propose that it is most likely due to alteration in the immune state of these patients. It is important for physicians to investigate for liver abscess in patients who present again with fever and/or pain abdomen within 2 weeks of COVID 19 recovery.

Hepatic artery pseudo-aneurysm rupturing into hepato-gastric fistula, a rare cause of massive upper gastrointestinal hemorrhage: Case report.

Hepatic artery pseudo-aneurysm and hepato-fastric fistula are extremely rare clinical entities, which can be caused as complications of amoebic liver abscess. Herein, we report a 45- year old man, who presented with history of hematemesis since last 1 day, melena since last 3 days and fever since last 5 days. On physical examination, he was hemodynamically stable, pallor was noted. Abdominal examination revealed tenderness over the right-upper quadrant. Per-rectal examination showed evidences of melena. Esophagogastroduodenoscopy revealed stomach communicating anteriorly with the abscess cavity from the surrounding, possibly from liver. There was no evidence of fresh bleed during the procedure. The abscess was drained and sent for microbiological evaluation. Computed tomographic angiography revealed a well defined saccular outpouching arising from common hepatic artery with surrounding ill-defined hypodensity around segment V and IVb of liver. Patient underwent transfemoral endovascular coil embolization. Post embolisation, DSA showed complete occlusion of pseudo-aneurysm. He was discharged on oral metronidazole and was doing well on 8-month follow-up with no episodes of rebleed.

Enhanced Drainage Protocol in Large Amoebic Liver Abscess.

Background Amebic liver abscess (ALA) contributes significantly to morbidity and mortality in patients of the developing world. Even though medical management is the primary modality of treatment, 15% of the cases are refractory and require intervention for drainage. Pigtail catheterization is inefficient and results in a long duration of hospital stay. So, we conducted a prospective observational study to determine the efficacy and safety of drainage of large ALA using a wide bore 24 French (Fr) drain compared with a conventionally used 10 Fr pigtail catheter. Materials and Methods A single center prospective observational study was conducted over a period of 5 years and data of 122 patients was collected. After starting empirical medical therapy, patients underwent drainage of ALA with either a 10 French pigtail or a 24 Fr drain. The primary outcome variables were resolution of clinical symptoms such as fever and pain in abdomen, length of hospital stay, and resolution of abscess on imaging at day 3. Secondary outcome was complications related to the procedures. Results Data of 122 patients was collected. Males constituted a vast majority (96%) of the study population and the fifth decade was the most common age group involved. Alcoholics had a higher chance of developing a large ALA. Sixty-eight patients underwent drainage of the ALA using a 24 Fr drain which resulted in faster resolution of symptoms (2.4 vs. 5.1 days, p -value 0.033), a shorter duration of catheter in situ (6.4 vs. 13.2, p -value 0.011), and a faster drainage of ALA (residual volume at day 3; 177 vs. 212 mL, p -value 0.021). Twenty-eight patients had a biliary communication of which 26 required therapeutic endoscopic retrograde cholangiopancreatography. Conclusion In patients with a large ALA, placement of a wide bore 24 Fr catheter hastens recovery of the patients when compared with drainage with a standard 10 Fr pigtail catheter. Placement of a biliary stent serves as a useful adjunct for their management and it may obliviate the need for a major biliary diversion surgery.

Amoebic liver abscess in a COVID-19 patient: a case report.

BACKGROUND: Amoebiasis is a parasitic disease caused by Entamoeba histolytica, which affects people living in low- and middle-income countries and has intestinal and extraintestinal manifestations. To date, knowledge on coronavirus disease 2019 (COVID-19) coinfection with enteric parasites is limited, and E. histolytica coinfection has not been previously described. Here we present the case of a patient with COVID-19 who, during hospitalisation, presented a clinical picture consistent with an amoebic liver abscess (ALA). CASE PRESENTATION: A 54-year-old man, admitted as a suspected case of COVID-19, presented to our hospital with dyspnoea, malaise, fever and hypoxaemia. A nasopharyngeal swab was positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse-transcription polymerase chain reaction. After 7 days, he developed diarrhoea, choluria and dysentery. An abdominal ultrasound showed a lesion compatible with a liver abscess; stool examination revealed E. histolytica trophozoites, and additional serology for E. histolytica was positive. After 12 days of treatment with metronidazole, ceftazidime and nitazoxanide, the patient reported acute abdominal pain, and an ultrasound examination revealed free liquid in the abdominal cavity. An emergency exploratory laparotomy was performed, finding 3000 mL of a thick fluid described as "anchovy paste". Computed tomography scan revealed a second abscess. He ended up receiving 21 days of antibiotic treatment and was discharged with satisfactory improvement. CONCLUSION: Here we present, to the best of our knowledge, the first report of ALA and COVID-19 co-presenting. Based on their pathophysiological similarities, coinfection with SARS-CoV-2 and E. histolytica could change the patient's clinical course; however, larger studies are needed to fully understand the interaction between these pathogens.

Amoebic Liver Abscess: Rare Entity in Recent Times.

Intestinal amoebiasis and sequelae such as amoebic liver abscess are rarely reported in the era of modern medicine. Atypical presentation of amoebic liver abscess with high false-positive results on serology in endemic regions poses major diagnostic issues in the developing nations of the world. We report a case of amoebic liver abscess and describe the imaging appearances in a 59-year-old female. A detailed medical history was elicited to determine the etiology of amoebic liver abscess. Furthermore, the diagnosis was confirmed based on serological tests. Percutaneous aspiration of the amoebic liver abscess was performed, and treatment was initiated with intravenous metronidazole followed by diloxanide furoate. The patient has been on follow-up since three months with a negative stool examination and with no complaints of recurrence.

South American Entamoeba dispar strains produce amoebic liver abscesses with different pathogenicities and evolutionary kinetics.

Amoebiasis is a protozoan disease caused by Entamoeba histolytica, and presents a geographic distribution of worldwide amplitude, high incidence, sometimes accompanied by severe clinical manifestations such as amoebic colitis and Amoebic Liver Abscess (ALA), remaining as a public health problem in developing countries. Entamoeba dispar is another species of amoeba that infects approximately 12% of the world's population, and it has previously been classified as noninvasive. However, E. dispar has already been isolated from patients with symptomatic non-dysenteric colitis, as well as its DNA sequences were detected and genotyped in samples from patients with dysenteric colitis, and patients with ALA, suggesting that this species could also be involved in the development of lesions in the large intestine and liver of human beings. In this context, this study aims to evaluate the ability of isolated strains of Entamoeba dispar in South America to cause liver damage, and to better characterize histopathological findings in 3, 8, 12 and 16 days after infection (DAI). Firstly, we assessed whether trophozoites from MCR, ACFN, ICS, ADO and VEJ E. dispar strains, and EGG Entamoeba histolytica strain differed in their in vitro phagocytosis ability, being related to greater ability to phagocyte with greater virulence. Then, we investigate and characterize histopathological changes present in the liver of mice induced by different strains of E. dispar. Our results demonstrated that trophozoites from E. dispar strains are capable of phagocyting human erythrocytes, but in lower amounts than Entamoeba histolytica. In addition, we described and characterized the lesions in different periods after infection by different E. dispar strains, and identified ACFN as the most pathogenic strain, followed by MCR. The large areas of necrosis produced by the ACFN strain as the eighth DAI, which also show high parasitism, led to 100% mortality. On the other hand, the ICS, ADO and VEJ strains did not produce mortality, and this was correlated with the presence of well-developed chronic granulomatous inflammation, necrosis absorption throughout the infection, and regeneration of the liver parenchyma. The greater pathogenicity of the ACFN strain strongly suggests that this strain could be producing higher levels of virulence factors. As the experimental infection, the heterogeneity of biological behavior of different Entamoeba dispar strains could be involved in the development of undiagnosed human clinical conditions.

Secondary pleuropulmonary amoebiasis due to liver abscess rupture: A complication case report in low resource setting.

BACKGROUND: Pleuropulmonary amoebiasis caused by complications of amoebic liver abscess (ALA) is rare. CASE PRESENTATION: A 23 years old male, presented with shortness of breath, cough with yellowish phlegm, right chest pain, fever, bulging stomach, yellow eyes, and swelling of both legs. Abdominal ultrasound and CT scan thorax and abdomen revealed right fluidopneumothorax and liver abscess. Serological testing leads to Entamoeba histolytica infection, which was treated with metronidazole but no significant improvement on empyema and abscess liver size. Surgery was performed after percutaneous aspiration drainage failed to evacuate the abscess. HE and PAS staining from surgical tissue showed Entamoeba hystolitica infection. DISCUSSION: Serological testing and radiological examination will be more useful in the early detection of cases of Entamoeba hystolitica infection. Surgery may be considered when purulent drainage does not show improvement in the patient's condition. CONCLUSION: ALA complication that causes pulmonary empyema can be surgically treated if the pus cannot be drained.