Entamoeba histolytica (E. histolytica) is an enteric microaerophilic protozoan parasite responsible for millions of cases worldwide. Majority of the infections due to E. histolytica remain asymptomatic; however, it can cause an array of symptoms ranging from devastating dysentery, colitis, and abscesses in different vital organs. The interactions between the E. histolytica and its host are a multifaceted chain of events rather than merely destruction and invasion. There are manifold decisive steps for the establishment of infections by E. histolytica which includes degradation of mucosal layer, adherence to the host epithelium, invasion into the host tissues, and dissemination to vital organs. It is widely hypothesized that, for establishment of infections, the interactions at the intestinal mucosa decides the fate of the disease. The delicate communications between the parasite, the host factors, and the associated bacterial microflora play a significant role in the pathogenesis of E histolytica. In this review, we summarize the interactions between the E. histolytica and it's host at the genetic and immunological interphases emphasizing the crucial role of microbiota in these interactions.

Background: Plants are an important option in the treatment of malaria, especially in endemic regions, and are a less expensive and more accessible alternative with a lower risk of toxicity. Colombia has a great diversity of plants, and evaluation of natural extracts could result in the discovery of new compounds for the development of antimalarial drugs. The purpose of this work was to evaluate the in vitro antiplasmodial activity and the cytotoxicity of plant extracts from the Colombian North Coast against Plasmodium falciparum. Materials and Methods: The antiplasmodial activity of 12 plant species from the Colombian North Coast that are used in traditional medicine was evaluated through in vitro cultures of P. falciparum, and the cytotoxicity of extracts of these species to human cells was determined. Plant extracts with high antiplasmodial activity were subjected to preliminary phytochemical screening. Results: Extracts from five plants had promising antiplasmodial activity. Specifically, Bursera simaruba (Burseraceae) (bark), Guazuma ulmifolia Lam. (Malvaceae) (whole plant), Murraya exotica L. (Rutaceae) (leaves), Hippomane mancinella L. (Euphorbiaceae) (seeds), and Capparis odoratissima Jacq. (Capparaceae) (leaves). Extracts presented 50% inhibitory concentration values between 1 and 9 μg/ml. Compared to no extract, these active plant extracts did not show cytotoxic effects on mononuclear cells or hemolytic activity in healthy human erythrocytes. Conclusions: The results obtained from this in vitro study of antiplasmodial activity suggest that active plant extracts from the Colombian North Coast are promising for future bioassay-guided fractionation to allow the isolation of active compounds and to elucidate their mechanism of action against Plasmodium spp.

Introduction: Dientamoeba fragilis (D. fragilis) diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2% to more than 19% depending upon the population studied. Materials and Methods: This study was based on the examination of 100 stool samples of randomly referred cases in a rural area in Motobus district, Kafr El-Sheikh governorate, Egypt. Our aim was to investigate the presence of D. fragilis in stool of the examined individuals using conventional polymerase chain reaction (PCR) compared to wet mount and trichrome stain with confirmation of infection by transmission electron microscopy. Results: D. fragilis was detected in 13/100 of the stool samples examined using wet mount smears, while trichrome stain detected 17/100. Conventional PCR diagnosed 41 cases of D. fragilis in the studied group. A very good agreement was found between wet mount and trichrome stain for diagnosing D. fragilis, while there was fair agreement between conventional PCR and both microscopy methods. Transmission electron microscope was performed on pooled positive samples that revealed the internal structures of D. fragilis trophozoite with its characteristic nucleus. Conclusions: PCR technique was superior to microscopy for the detection of D. fragilis. Trichrome stain remains vital for microscopic diagnosis.

Context: Cyclosporiasis is an emerging enteric coccidian parasitic disease worldwide, caused by the parasite Cyclospora cayetanensis. There is scanty data from India, especially among immunocompetent patients. Aims: The aim is to evaluate the occurrence of Cyclosporiasis in immunocompetent and immunocompromised patients. Settings and Design: It is a prospective cohort study conducted from June 2006 to May 2018 at our tertiary care center. Materials and Methods: Stool samples were collected from the 900 patients with diarrhea (both immunocompetent and immunocompromised) and 170 healthy controls to look for Cyclospora by modified Kinyoun staining. Statistical Analysis: Mann–Whitney U test/Fisher exact test were used for statistical analysis. Results: Oocysts of C. cayetanensis were detected in 10/900 patients and none of the healthy controls. The median age of patients was 38.5 years (10-65 years) and males (6/10) outnumbered the females in harboring the parasite. Eight patients were immunocompromised (five postrenal transplant cases and one-one patient each with HIV, non-Hodgkin's lymphoma, and juvenile polyarthritis), and two patients were immunocompetent. Cyclospora infection was more common in immunocompromised patients (8/300, 2.67%) than the immunocompetent patients (2/600, 0.33%); P < 0.001. Eight patients responded well to trimethoprim-sulfamethoxazole, one died, and one was lost to follow-up. Coinfection with Cryptosporidium spp. was seen in one patient. Conclusion: Cyclospora causes diarrhea in both immunocompromised and immunocompetent persons. Its burden may be underestimated due to a lack of awareness and appropriate diagnostic methods. Special staining techniques are important for diagnosis as they may be missed by routine microscopy.

Introduction: Housefly (Musca domestica), because of its body structure, filthy and feeding habits, is reported to be capable of carrying a variety of microbes, including potential pathogens, over its body appendages. Aims: This study aimed to investigate M. domestica in Calabar for pathogenic gut parasites, determine its role in parasitic diseases transmission, make appropriate recommendations toward its management and effective control of the associated parasitic diseases, and hence promote the society health status. Settings and Design: This was a cross-sectional study. Materials and Methods: A total of 300 M. domestica specimens (150 each from sanitary and insanitary areas, pooled in batches of five flies per pool) were used for the study. The parasites were detected from the spun deposits of fly body surface wash and gut contents using direct microscopy and formol-ether technique. Statistical Analysis Used: Data were analyzed using Statistical Package for the Social Sciences (SPSS), version 21.0, and Chi-square test at a significant level of P < 0.05. Results: Overall frequency of parasites detection was 46.7%, with helminths and protozoa showing similar frequency, 23.3% each. External body surface of flies recorded a statistically significant higher parasites frequency 76.7% than their gut contents 16.7% (P = 0.000). A statistically significant higher parasite detection rate was observed in the insanitary (63.3%) than in sanitary areas (30.0%) (P = 0.0114). The parasites detected in this study were Entamoeba histolytica/dispar 39.9%, hookworm (21.4%), Ascaris lumbricoides (17.9%), Trichuris trichiura (14.3%), and Giardia intestinalis (7.2%). Conclusion: This study has confirmed M. domestica in Calabar as a mechanical carrier of potential pathogenic gut parasites, especially in the insanitary areas, with E. histolytica/dispar being the most frequently encountered. Effective control of flies' population in the human and animal habitats and increased public awareness on their health hazards are recommended.

Background: Despite the target of elimination of lymphatic filariasis by 2015, a few districts of West Bengal including Bankura district failed to achieve it. Under-coverage and unsupervised consumption of medicines during mass drug administration (MDA) campaign were implicated for the failure. Thereby, directly observed therapy (DOT) and mop up by repeated home visits for MDA were adopted. Objective: The objective of this study is to assess the coverage of anti-filarial medicines distribution and rate of consumption as well as to find out the causes of nonconsumption. Materials and Methods: A cross-sectional survey was conducted in three sub-centers each of three blocks and three wards of Bankura municipality of Bankura district, WB, India, selected through the stratified random sampling method. Information was collected interviewing inhabitants of the house hold selected through the systematic random sampling technique. Results: Overall, appropriate medicine distribution was 82.9% with 95.3% of correct consumption of both medicines under supervision. 91.87% of the respondents were aware about Lymphatic filariasis (LF) of which 89.95% reported swelling of leg/foot/hand, 9.57% as pain, 6.22% fever, and 1.44% reported swelling of testis as symptoms of LF. Altogether 10.6% individual, who consumed any medicine (527), reported AEs, out of that 66.1%, 19.6%, and 14.3% complained of dizziness/headache, nausea/vomiting, and drowsiness, respectively, and 28.6% of them sought consultation with health workers. Conclusion: Substantial supervised consumption in the form DOT in this round too leads to the fact that the effective coverage of MDA has reached the target. It seemed that some segment of the beneficiary is remaining as persistent noncomplaints. Mass mobilization for motivating this persistent defaulter section is the need of the hour.

Context: Amebic liver abscess (ALA) occurs in 3%–9% of the amebiasis cases, with complications seen in 20%–40% of the cases and 2%–18% mortality rate. Successful treatment thus requires the accurate identification of these cases. Aims and Objectives: We aimed to assess the seropositivity and profile of ALA patients in western Rajasthan. Materials and Methods: This retrospective study was conducted at a tertiary care center in western Rajasthan from November 2017 to May 2019. Serological diagnosis of ALA was done by detecting immunoglobulin G (IgG) antibodies in the serum of the patients by ELISA. The derangements in laboratory profile (hematological and biochemical parameters) and ultrasonography findings were assessed from the hospital records. Statistical analysis was performed using Mann–Whitney U-test. Results: Among the total cases (n = 34), 20 were diagnosed as ALA. Twenty-one (61.8%) were positive for anti-amebic IgG antibodies. Among ALA patients, 14 (70%) were >40 years old and only 6 (30%) patients were of age ≤40 years. Male: female ratio was 5.7:1, and ultrasonography records of 15 ALA patients revealed the presence of hepatomegaly (n = 7, 46.7%), pleural effusion (n = 3, 20%), lung collapse (n = 2, 13.3%), and vascular involvement (n = 1, 6.7%). The right lobe of the liver was involved in majority of the patients (n = 12, 80%). Total white blood cell count (P < 0.001), absolute neutrophil count (P = 0.001), total serum bilirubin (P = 0.019), and serum alkaline phosphatase (P = 0.018) were significantly elevated in ALA patients. Conclusions: Seroprevalence shows that ALA still remains the dominant etiology in liver abscess patients in this region. There are significant derangements in the laboratory profile that require a larger study for corroboration.

The free-living amebae of genus Acanthamoeba are an important cause of microbial keratitis. The clinical appearance of Acanthamoeba keratitis (AK) usually mimics viral or fungal keratitis. Thus, microbiological workup plays a significant role in the diagnosis and timely treatment of such cases. We report a retrospective case series of seven culture-confirmed AK cases from a tertiary eye care center in North India. Various risk factors and triggers of infection, clinical presentations, microbiological findings, and management of AK are elucidated.

Lophomonas infection is an emerging parasitic disease-causing respiratory infection. Although common in immunocompromised patient, it has been observed also in some immunocompetent cases. We report the case of a 45-year-old male who presented with productive cough, fever, and chest pain, with marked eosinophilia and cavitary lesion in the X-ray chest. KOH preparation and acid-fast bacilli microscopy of bronchoalveolar lavage (BAL) were negative. Direct microscopic examination of BAL accidentally showed a large number of living Lophomonas species with the movement of flagella. Methylene blue and Giemsa staining showed the plume of flagella and the nucleus. The patient was managed conservatively with metronidazole and get cured. It was concluded that the patient presented with signs and symptoms of pneumonia must be evaluated for rare events also if the patient was not responding with typical management of pneumonia. We reported the first case of this rare entity in Chhattisgarh state in an immunocompetent young Indian male.

Enterobius vermicularis, also known as pinworm or threadworm, is a large intestinal nematode which has a high prevalence among children and peripubertal age in our country. Transmission usually occurs by autoinfection like finger contamination of the embryonated eggs deposited by the gravid female worm on the perianal and perineal region. Globally, only a few reports are there regarding the isolation of the parasite from extra-intestinal sites. These are two rare case reports of ocular enterobiasis. The first case was a middle-aged female and the second one was a 14-year-old girl, both of whom were referred from other tertiary care hospitals to Calcutta School of Tropical Medicine and who presented with discharge of live motile worms from their eyes (conjunctiva). In both the cases, identification was done by saline wet mount and direct microscopy of a gravid female worm. Plano-convex embryonated eggs were also observed. The oval embryonated eggs, plano-convex in shape, and the gravid female, with its cervical alae near the anterior end and straight thin pointed tail, were identified under the microscope. Although E. vermicularis is a very common large intestinal parasitic infestation of children and adolescents, it can also rarely be isolated from unusual sites, which should be taken into account for effective diagnosis and treatment.