Use of a monoclonal antibody in an enzyme immunoassay for the detection of Entamoeba histolytica in fecal specimens

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of Entamoeba histolytica in human feces, using both a monoclonal antibody and rabbit antisera. It detected from less than 1 to 57 trophozoites of 6 E. histolytica strains. Stool specimens were positive by ELISA in 18 of 22 (82%) patients with E. histolytica and in 3 of 186 (2%) of patients without demonstrable E. histolytica in their stools. The latter included one from a child living near an asymptomatic cyst carrier and another from a traveler with giardiasis who had recently taken antibiotics. One hundred eight of 183 microscopy-and ELISA-negative specimens contained other parasites including Giardia (49 specimens), Endolimax nana (24), Entamoeba coli (21), Iodamoeba butschlii (2), and Entamoeba hartmanni (1). This ELISA for E. histolytica is a simple, sensitive and specific diagnostic tool.

[Pathology of the natal cleft]

After defining the limits of the natal cleft, the author explains the process of establishing a precise diagnosis on the basis skin lesion. He describes successively: non-infiltrating eruptions or intertrigo, pigmented lesions, papular, papular-nodular, tuberculoid and tumoral eruptions, vegetating lesions, ulcerating and suppurative lesions. In each paragraph, he stresses the lesions which are usually confined to the natal cleft.

The detection of serotonin: an additional approach in diagnosing amebiasis

The diagnosis of amebiasis is often difficult and time consuming. Entamoeba histolytica has been shown to contain serotonin. This fact might be exploited in the clinical setting. Assaying for serotonin may provide valuable diagnostic information.

Cellulose acetate precipitation test in sero-diagnosis of amoebiasis

Cellulose acetate precipitation (CAP) test for the detection of antibody against Entamoeba histolytica using the axenic antigen, was performed on the 127 serum samples obtained from patients with amoebic liver abscess (14), amoebic hepatitis (21), amoebic dysentry (11), amoebic colitis (31), other parasitic infestations (25) and normal individuals (25). The percent positivity was 100, 95.23, 90.9, 67.74 and 16 and 12 respectively whereas the corresponding figures for the indirect immunoflourescence (IFAT) test were 100, 100, 100, 74.19, 12 and 8 respectively. Although CAP is not as good a test as IFAT, yet it can be recommended for routine testing due to its sensitivity, speed of performance and applicability to a single serum sample.

Immunodiagnosis of amoebiasis

Serological studies were done on 127 cases using three different techniques namely indirect haemagglutination (IHA), indirect fluorescent antibody test (IFT) and counter immunoelectrophoresis (CIEP) to detect antiamoebic antibodies. All amoebic liver abscess cases showed significant titre of antibodies by all the three tests used. In the group of patients suffering from amoebic pathology of liver, 90.47 per cent were positive by IHA, 100 per cent by IFT and 85.71 per cent by CIEP respectively. Among amoebic dysentry and amoebic colitis cases 81.81 per cent and 80.64 per cent respectively were positive by IHA. The corresponding figures for IFT were 100 per cent and 74.19 per cent and for CIEP 90.90 per cent and 64.51 per cent respectively. Follow up study showed no significant fall in antibody titre in nine cases studied upto 10 weeks after treatment. Amoebic antigen could be detected in pus from all the nine cases with amoebic liver abscess by CIEP test.

Rectal ameboma

Although rare, invasive amebiasis should be considered in the differential diagnosis of rectal disease suggesting carcinoma. In the case reported, rectal ameboma was responsible for the patient's rectal pain, hematochezia and weight loss.

[A case of a single pleural localization of amebiasis]

The diagnostic of isolated pleural amebiasis is exceptional even in endemic countries. The reported observation illustrates this eventuality. The relation of this clinical factor leads to a general review on the pleuro-pulmonary manifestations of amebiasis, their mechanism and their treatment.