Symposium
Laboratory methods of identification of Entamoeba histolytica and its differentiation from look‑alike Entamoeba spp. Subhash Chandra Parija, Jharna Mandal, Dinoop Korol Ponnambath Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research Gorimedu, Puducherry, India
ABSTRACT
KEY WORDS Amebiasis, Entamoeba histolytica, laboratory diagnosis
Entamoeba histolytica, the causative agent of intestinal and extraintestinal amebiasis, is a common parasitic cause of significant morbidity and mortality in the developing countries. Hence, early detection and differentiation of pathogenic E. histolytica from nonpathogenic/commensal Entamoeba spp (Entamoeba dispar/Entamoeba moshkovskii/ Entamoeba bangladeshi) plays a crucial role in clinical management of patients with amebiasis. Most diagnostic tests currently available do not reliably differentiate between the species of Entamoeba and are less sensitive, cumbersome to perform. Molecular‑based methods are highly sensitive, easy to perform and differentiates the pathogenic Entamoeba from nonpathogenic species, serving the criteria for an ideal diagnostic test for amebiasis. Recently, microarray technology has been found to be a promising tool for the diagnostic and epidemiological evaluation of amebiasis.
from asymptomatic colonization to extraintestinal invasive amebiasis. Although six species of Entamoeba have been identified to colonize the human gut, only E. histolytica is known to be pathogenic. Recent review of the literature also point Entamoeba moshkovskii as an agent causing diarrheal episodes in infants. For many decades, the laboratory diagnosis of intestinal amebiasis has been based upon the microscopic examination of stool samples and hence widely known as the 10% disease. However, the recent description of various nonpathogenic Entamoeba species like Entamoeba dispar, E. moshkovskii and the newly described Entamoeba bangladeshi as morphologically indistinguishable forms from E. histolytica has required the need for alternative diagnostic methods for differentiation.[3] Since the last decade, molecular methods have played a key role in accurate diagnosis of various infectious diseases, including amebiasis. Patients with dysentery and importantly 90% of individuals with asymptomatic infection with E. histolytica should be promptly diagnosed to prevent further transmission.
INTRODUCTION Entamoeba histolytica, the etiological agent of amebiasis, is a major parasitic cause of morbidity and death, particularly in developing countries. It is estimated that around 50 million symptomatic cases and 100,000 deaths worldwide/year.[1] In India, 15-20% of the population are affected by this parasite and in Bangladesh 1 in 30 children from an urban slum of Dhaka die of diarrhea or dysentery by his/her 5th year of age.[2] The clinical features of amebiasis has a broad spectrum ranging Address for correspondence Prof. Subhash Chandra Parija, Dean- Research, Senior Professor, Department of Microbiology, Jawaharlal Institute of Post Graduate Medical Education and Research, Puducherry - 605 011, India Email: [email protected] Access this article online Quick Response Code:
Website: www.tropicalparasitology.org
MICROSCOPIC EXAMINATION
DOI:
For ages, amebiasis has been diagnosed based on the demonstration of cyst and/or trophozoite stages of
10.4103/2229-5070.138535
Jul 2014 | Volume 4 | Issue 2 |
90
Tropical Parasitology
Parija, et al.: Laboratory detection of Entamoeba histolytica
E. histolytica. The techniques utilized for microscopic examination were 0.9% saline and Lugol’s/Dobell’s/ D’Antoni iodine wet mount examination, concentration techniques and permanent stained smears of stool and pus aspirates. Microscopic examination of stool/ pus specimen in saline wet mount is a less sensitive technique (sensitivity
Laboratory methods of identification of Entamoeba histolytica and its differentiation from look‑alike Entamoeba spp. Subhash Chandra Parija, Jharna Mandal, Dinoop Korol Ponnambath Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research Gorimedu, Puducherry, India
ABSTRACT
KEY WORDS Amebiasis, Entamoeba histolytica, laboratory diagnosis
Entamoeba histolytica, the causative agent of intestinal and extraintestinal amebiasis, is a common parasitic cause of significant morbidity and mortality in the developing countries. Hence, early detection and differentiation of pathogenic E. histolytica from nonpathogenic/commensal Entamoeba spp (Entamoeba dispar/Entamoeba moshkovskii/ Entamoeba bangladeshi) plays a crucial role in clinical management of patients with amebiasis. Most diagnostic tests currently available do not reliably differentiate between the species of Entamoeba and are less sensitive, cumbersome to perform. Molecular‑based methods are highly sensitive, easy to perform and differentiates the pathogenic Entamoeba from nonpathogenic species, serving the criteria for an ideal diagnostic test for amebiasis. Recently, microarray technology has been found to be a promising tool for the diagnostic and epidemiological evaluation of amebiasis.
from asymptomatic colonization to extraintestinal invasive amebiasis. Although six species of Entamoeba have been identified to colonize the human gut, only E. histolytica is known to be pathogenic. Recent review of the literature also point Entamoeba moshkovskii as an agent causing diarrheal episodes in infants. For many decades, the laboratory diagnosis of intestinal amebiasis has been based upon the microscopic examination of stool samples and hence widely known as the 10% disease. However, the recent description of various nonpathogenic Entamoeba species like Entamoeba dispar, E. moshkovskii and the newly described Entamoeba bangladeshi as morphologically indistinguishable forms from E. histolytica has required the need for alternative diagnostic methods for differentiation.[3] Since the last decade, molecular methods have played a key role in accurate diagnosis of various infectious diseases, including amebiasis. Patients with dysentery and importantly 90% of individuals with asymptomatic infection with E. histolytica should be promptly diagnosed to prevent further transmission.
INTRODUCTION Entamoeba histolytica, the etiological agent of amebiasis, is a major parasitic cause of morbidity and death, particularly in developing countries. It is estimated that around 50 million symptomatic cases and 100,000 deaths worldwide/year.[1] In India, 15-20% of the population are affected by this parasite and in Bangladesh 1 in 30 children from an urban slum of Dhaka die of diarrhea or dysentery by his/her 5th year of age.[2] The clinical features of amebiasis has a broad spectrum ranging Address for correspondence Prof. Subhash Chandra Parija, Dean- Research, Senior Professor, Department of Microbiology, Jawaharlal Institute of Post Graduate Medical Education and Research, Puducherry - 605 011, India Email: [email protected] Access this article online Quick Response Code:
Website: www.tropicalparasitology.org
MICROSCOPIC EXAMINATION
DOI:
For ages, amebiasis has been diagnosed based on the demonstration of cyst and/or trophozoite stages of
10.4103/2229-5070.138535
Jul 2014 | Volume 4 | Issue 2 |
90
Tropical Parasitology
Parija, et al.: Laboratory detection of Entamoeba histolytica
E. histolytica. The techniques utilized for microscopic examination were 0.9% saline and Lugol’s/Dobell’s/ D’Antoni iodine wet mount examination, concentration techniques and permanent stained smears of stool and pus aspirates. Microscopic examination of stool/ pus specimen in saline wet mount is a less sensitive technique (sensitivity
