Related Experiment Video
Updated: Aug 21, 2026

Discovery of New Intracellular Pathogens by Amoebal Coculture and Amoebal Enrichment Approaches
Published on: October 27, 2013
[Outbreak of amoebiasis in a Dutch family; tropics unexpectedly nearby]
W M Edeling1, J J Verweij, C Ij Ponsioen
1Afd. Infectieziekten, Centrum voor Infectieziekten, Leids Universitair Medisch Centrum, Postbus 9600, 2300 RC Leiden.
Abstract:
An amoebic liver abscess, amoebic dysentery and asymptomatic cyst passage were diagnosed in a father, a mother and one of their three children, respectively. One of the other children had been in the tropics, but only after the father's symptoms had begun. All three family members were infected with the same strain of Entamoeba histolytica as determined by polymerase chain reaction (PCR)-based DNA typing. The source of infection was most probably in Southern Italy where the family regularly spent their summer holidays. All three infected patients recovered after drug treatment. In a patient with a liver abscess or colitis, amoebiasis should be considered even in the absence of a history of a stay in the tropics. Stool samples should be examined for amoebic cysts and trophozoites. PCR analysis of parasite DNA extracted directly from stool samples makes differentiation between the morphologically identical cysts of E. histolytica and the non-pathogenic Entamoeba dispar possible. In addition, serum antibodies to E. histolytica are almost always present in symptomatic patients. Invasive infections with E. histolytica require treatment with a tissue amoebicidal drug, followed by a contact amoebicide to prevent recurrence. Currently, paromomycin is considered to be the first-line luminal amoebicide because of its efficacy and safety.
Insights
A family contracted the same Entamoeba histolytica strain, leading to amoebiasis diagnoses including liver abscess and dysentery. This highlights the need to consider amoebiasis even without tropical travel history.
Area of Science:
- Medical Parasitology
- Infectious Diseases
- Molecular Diagnostics
Background:
- Amoebiasis, caused by Entamoeba histolytica, is a significant parasitic infection.
- Diagnosis can be challenging due to morphologically similar non-pathogenic species.
Observation:
- A family presented with amoebiasis, including liver abscess and dysentery, infected by the same Entamoeba histolytica strain.
- The likely source of infection was identified as a non-tropical location (Southern Italy).
Findings:
- Polymerase chain reaction (PCR)-based DNA typing confirmed a single strain of Entamoeba histolytica in all infected family members.
- PCR enables differentiation between pathogenic E. histolytica and non-pathogenic Entamoeba dispar.
- Symptomatic patients typically exhibit serum antibodies to E. histolytica.
Implications:
- Amoebiasis should be considered in patients with liver abscess or colitis, irrespective of tropical travel history.
- Diagnostic strategies should include stool examination for amoebic cysts/trophozoites and PCR analysis.
- Effective treatment involves tissue amoebicidal drugs followed by luminal amoebicides like paromomycin.
Related Concept Videos
Amebiasis
Investigation of Disease Outbreaks
Giardiasis
Toxoplasmosis
Fungal Phylum Microsporidia
American Trypanosomiasis

