Granulomatous amebic encephalitis due to Acanthamoeba spp. usually occurs in chronically ill and debilitated individuals. Some of these patients may have received immunosuppressive therapy. Another infection due to Acanthamoeba spp. has been corneal ulcerations which usually occur after minimal trauma to the corneal epithelium (1). In contrast, primary amebic meningoencephalitis due to Naegleria fowleri usually occurs in healthy, young individuals with a history of swimming in heated swimming pools, in manmade lakes or with recent contact with contaminated water and practising water-related sports. Subclinical infections due to free-living amebas are probably common in healthy individuals with the protozoa living as "normal flora" in the nose and throat. It is possible that in humans, antibodies and cell-mediated immunity protect the host in such ordinary circumstances against invasive infection. In debilitated and chronically ill individuals, depressed cellmediated immunity may allow these protozoa to proliferate, allowing a fulminant "opportunistic" infection to develop. In the case of acanthamoebic keratitis, it is important to keep in mind that the temperature and moist environment of the eye serve as a good medium for the growth and proliferation of the amebas and is not necessarily associated with immunosuppression but rather with trauma. This review confirms that opportunistic free-living amebic infections occur with increased frequency in patients treated with steroids, radiotherapy, chemotherapeutic drugs or with broad-spectrum antibiotics and suggest that the mechanism of such infection may be depressed cell-mediated immunity or some other alteration of the immune system, like acquired immunodeficiency syndrome (AIDS).

Adolescent↗

PubMedDate not supplied

Prevalence and epidemiological significance of Trypanosoma cruzi infection among Latin American immigrants in Berlin, Germany.

A survey was conducted among Latin American immigrants living in Berlin to investigate the presence of Trypanosoma cruzi infection and to evaluate possible risk factors. One hundred persons were interviewed about risk factors (rural origin, contact with the reduviid bug) and evaluated serologically. The sera were tested with indirect immunofluorescence (IIF). All samples seroreactive with IIF were additionally evaluated with an ELISA for T. cruzi antibodies. To rule out cross-reactivity all seroreactive sera were tested with IIF for Leishmania infantum antibodies. Two persons were seroreactive in IIF and ELISA and three were seroreactive in the IIF only. The overall seroprevalence according to WHO criteria was therefore 2% (2/100). All samples were negative for Leishmania antibodies. Only one of the seropositive persons showed a risk factor for T. cruzi infection in their medical history. These findings suggest that routine serologic testing of Latin Americans is indicated to reduce the risk of transmission by blood transfusion and congenital transmission.

Adult↗

PubMedDate not supplied

[Inferences from data obtained by enzyme immunoassay of Toxoplasma IgG and IgM antibodies].

The enzyme-linked immunosorbent assay for Toxoplasma IgG antibodies is useful for the detection of infections. The quantitative test results do not allow any conclusion on the stadium of infection. A positive test result of the enzyme-linked immunosorbent assay for Toxoplasma IgM antibodies (EIA-IgM) may indicate an active but can be observed also in chronic infections. For the separation of the phases of infections other tests should be applied and follow-up studies by EIA-IgM should be performed.

Antibodies, Protozoan↗

PubMedDate not supplied

[Evolutionary phases and cycles and taxonomic position of Toxoplasma gondii].

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Toxoplasma↗