[Amebic brain abscess. Apropos of a case]

We report a case of double primary amoebic brain abscess in a 22 year old man, with signs of intracranial hypertension and deficit. Computed tomography found two hypodense lesions, not suggestive of pyogenic abscesses. Aspiration of one of the two abscesses, revealed the organism, and the two abscesses regressed in response to medical treatment. The authors insist on the rarity of these abscesses, their gravity, and the difficulty of the diagnosis.

[Extension of the transmission area of kala-azar caused by Leishmania infantum (Nicolle 1908) to the center and south of Tunisia]

Seventeen (17) parasitologically confirmed cases of infantile kala azar (KA) are reported from 1982 to 1991 in Tunisia, in areas (Gouvernorates of Sidi Bouzid, Kasserine, Sfax, Gafsa and Tozeur) where the disease has never (or exceptionally) been reported before. This tendency to the extension of the KA areas from Northern Tunisia to the Central and Southern parts could be explained by the ecological modifications that occurred in these zones following agriculture development programs that included an important increase of water resources (wells, dams etc...). These modifications probably contributed to the enhancement of the Leishmania infantum vector population densities making it possible for transmission cycles to be implemented and maintained in these areas; the parasite could have been brought with dogs from the North of the country.

Study of circulating immune complexes during the evolution of visceral Mediterranean leishmaniasis

In the present study, sera of 56 children suffering from visceral Mediterranean leishmaniasis were analysed. The incidence of circulating immune complexes (CIC) by ELISA technique using the conglutinin binding assay was 39% before treatment, 28% after the first treatment, and nil at the end of the second one. The C4 levels remain low even after treatment. The anti-leishmania antibodies (AAL) account for 95% of the cases before treatment and 84% after treatment. The rheumatoid factor (FR) also remains with more or less the same frequency (74%) before and after treatment. The search for a correlation between the presence of CIC and the other immunological factors show that the average titre of AAL is higher in the group of patients that have CIC than in the group that does not. The C4 levels are significantly reduced in the CIC positive group of patients, whereas the rate of IgG is significantly increased in the same group. The study of the evolution of CIC under treatment in nine patients shows that they disappear at the end of the treatment, and that the FR reduces but does not disappear.

Anti-leishmanial antibodies during natural infection of Psammomys obesus and Meriones shawi (Rodentia, Gerbillinae) by Leishmania major

Sera from 77 rodents (Psammomys obesus: 64; Meriones (M.) shawi: 10; M. libycus: 3) trapped in a focus of zoonotic cutaneous leishmaniasis (ZCL) (Leishmania (L.) major) were examined for the presence of anti-leishmanial antibodies by the indirect fluorscence antibody technique (IFAT) (L. major antigens) using homologous antiglobulins and/or anti-Rattus conjugates. Sera from 21 animals were positive with titres that ranged from 1: 20 up to 1: 640. The investigation revealed that a good correlation existed between the occurrence of antileishmanial antibodies in the sera and amastigotes in the rodents' ears. The data also suggest the suitability of the IFAT as an epidemiological tool to estimate rates of infection by L. major in Psammomys obesus and Meriones Spp. in foci of ZCL.

A natural auto-inhibitory factor of the terminal complement pathway in serum of Ctenodactylus gondi

The serum of Ctenodactylus gondi, a Tunisian rodent, contains a unique inhibitor of the terminal complement pathway. The auto-inhibitor has been partially characterized as a heat-stable euglobulin that is slightly retarded on a DEAE-ion exchange column at pH 7 and elutes as a symmetrical peak on Sephacryl S-300 in the mol. wt region of approximately 200,000. The inhibitor acts by preventing attachment of cytolytic C5b-9 complexes to natural target cells. It does not appear to affect formation and function of C3-convertase, does not exert inhibitory effects at stages later than C5b-7 formation, and also does not prevent formation of SC5b-9 in serum. That the factor prevents attachment of C5b-7/C5b-9 to cells has been demonstrated in hemolysis model systems using sheep EA + human serum, and in the C3-independent reactive lysis system with the use of ELISA methods and quantitative assays with radioiodinated C8. Addition of partially purified inhibitory factor to human sera or to sera of other animal species abolishes the hemolytic activities of these sera. The inhibitory factor of Gondi serum is the first inhibitor of the terminal pathway which has been shown to be capable of preventing cytolysis of cells undergoing complement attack under physiological conditions. The presence of this factor is probably partially responsible for the remarkable susceptibility of C. gondi towards bacterial and parasitic infections.

[Geography of major parasitosis in Tunisia]

Basing on their personal investigations, literature data and statistic archives, the authors have tried to establish the geographical distribution of the main parasitic diseases in Tunisia which require a curative action together with an action on the environment for their eradication. Three of these disease are transmitted by vectors: Malaria, Leishmaniasis, Schistosomiasis; and three others are transmitted by soil: Hydatidosis, Ancylostomiasis and Strongyloidiasis.

[Seroimmunological profile of kala-azar in Tunisia]

165 sera of patients suffering from kala-azar were collected before and after treatment (N-methyl glucamine: Glucantime ) and analysed for anti-leishmania antibodies by the counter immunoelectrophoresis and fluorescent antibody techniques. Serum immunoglobulins G, A, M and Complement C4 and C3 were studied as well; and C reactive protein, rheumatoid factor and anti-nuclear, anti-mitochondrial and anti-smooth muscle antibodies were investigated. Before treatment, counter immuno-electrophoresis was positive in 63.88% and immunofluorescent antibody test in 94.6%. The analysis of immunoglobulins has shown an increase of IgG in nearly all cases, an increase of IgM in 78.26% of sera tested. Little change has been noted with IgA. C reactive protein has been found in 87.67% and rheumatoid factor in 76.4% of sera examined. In 4 patients, anti-smooth muscle antibodies have been found at a relatively weak dilution. A decrease of complement C4 has been observed whereas complement C3 was slightly increased. After treatment (2 cures of Glucantime ) counter immunoelectrophoresis was positive in 23.07% of cases whereas immunofluorescent antibody test was still positive in 84.62%. IgG remained increases in the whole cases and IgM in only 43,48%. C reactive protein and rheumatoid factor have been found in 14.81% and 50% of cases respectively. Complement C4 remained low whereas complement C3 showed normal mean value. The relationship between the serological disturbances observed and the prognosis were discussed.

[Appendicular taeniasis. Report of 3 cases]

The authors point out three cases of appendicular taeniasis disease into an analytical retrospective study of 5,000 appendicectomies. In these 3 cases the parasite does not induce important processes level with the appendix. The localisation of the parasite is very rare.