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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.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.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.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.

The epidemiological behaviour of the main extraintestinal complication due to E. histolytica (amoebic liver abscess, ALA) has been little explored in developing countries. Since Mexico meets the characteristics to be considered as endemic, the aim of this work was to analyze the national surveillance data (seven years) of ALA issued by the General Directorate of Epidemiology. An analysis of cases and incidence of ALA (2014-2020) was performed in the annual reports issued by the GDE in Mexico. Cases and incidence of ALA were classified by year, incidence, age group, sex and seasons. Geographical distribution map for the whole country of ALA was constructed. The cases and mean incidence of ALA did not shown significant variation during the study period. Of the total cases accumulated, Sonora, Sinaloa, Nayarit, Colima and Zacatecas states showed the most incidence by ALA. Male sex of 24-44 years old showed higher ALA cases. No temporal behaviour was identified between the ALA cases. In Mexico, the incidence of ALA remains unchanged, however, it should not be underestimated since the monitoring programs for the search for new cases have not yet been implemented mainly in endemic states. These results summarize the priority in the national ALA report.

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.

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and amoebic liver abscess in humans, affecting millions of people worldwide. This pathogen possesses a two-stage life cycle consisting of an environmentally stable cyst and a pathogenic amoeboid trophozoite. As cysts can be ingested from contaminated food and water, this parasite is prevalent in underdeveloped countries and poses a significant health burden. Until recently there was no reliable method for inducing stage conversion in E. histolytica in vitro. As such, the reptilian pathogen, Entamoeba invadens, has long-served as a surrogate. Much remains unclear about stage conversion in these parasites and current treatments for amoebiasis are lacking, as they cause severe side effects. Therefore, new therapeutic strategies are needed. The genomes of these parasites remain enigmatic as approximately 54% of E. histolytica genes and 66% of E. invadens genes are annotated as hypothetical proteins. In this study, we characterized two hypothetical proteins in the Entamoeba species, EIN_059080, in E. invadens, and its homolog, EHI_056700, in the human pathogen, E. histolytica. EHI_056700 has no homolog in the human host. We used an RNAi-based silencing system to reduce expression of these genes in E. invadens and E. histolytica trophozoites. Loss of EIN_059080 resulted in a decreased rate of encystation and an increased rate of erythrophagocytosis, an important virulence function. Additionally, mutant parasites were more susceptible to oxidative stress. Similarly, loss of EHI_056700 in E. histolytica trophozoites resulted in increased susceptibility to oxidative stress and glucose deprivation, but not to nitrosative stress. Unlike the E. invadens mutants, E. histolytica parasites with decreased reduced expression of EHI_056700 exhibited a decreased rate of erythrophagocytosis of and adhesion to host cells. Taken together, these data suggest that these hypothetical proteins play a role in stage conversion, virulence, and the response to stress in the Entamoebae. Since parasites with reduced expression of EHI_056700 show decreased virulence functions and increased susceptibility to physiologically relevant stressors, EHI_056700 may represent a possible therapeutic target for the treatment of amoebiasis.

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 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).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.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.