Red blood cells' auto-agglutination as an indicator test in human trypanosomiasis.

Spontaneous red blood cells' auto-agglutination was assessed as an indicator for the diagnosis of human African trypanosomiasis. This test is easily carried out by health workers with minimum qualification. It presents a high sensitivity (0.91) and a high predictive value of a negative result (0.99). Although a positive result gives a low indication of infection, the health care workers should refer the patient to a screening centre.

The epidemiological importance of the animal reservoir of Trypanosoma brucei gambiense in the Congo. 2. Characterization of the Trypanosoma brucei complex.

Biological and biochemical characterization of 36 human and 5 animal congolese stocks of Trypanosoma brucei were performed. One human and all the animal stocks showed a quick adaptation to rodent host whereas the other 35 human stocks were characterized by a low virulence degree (Group 1 of T. gambiense). The virulent stocks showed hybridization patterns specific to the gambiense subspecies. Our results confirm the absence of the T. b. brucei subspecies in the Congo and the low prevalence of domestic animals infected with T. b. gambiense (0.5%). Two cycles of human trypanosomiasis may thus occur in Central Africa: a predominant man-to-man cycle with group 1 trypanosomes and a minor cycle involving an animal reservoir.

[The use of sentinel animals for the evaluation of the control of vectors of sleeping sickness: preliminary reports at a Congolese site]. / Utilisation d'animaux sentinelles dans l'évaluation de la lutte centre les vecteurs de la maladie du sommeil. Premiers résultats dans un foyer congolais.

A large-scale control trial against Glossina palpalis palpalis was carried out in the Congo using a new trapping technique. In the same way a test related to the experimental utilization of sentinel animals was performed, concurrently to the classical epidemiological and entomological evaluation. 564 domestic animals (pigs, sheep, goats) were examined parasitologically (wet blood films, Woo/HCT) and serologically (Testryps CATT) in six villages. When a drastic reduction of tsetse populations was achieved (i.e. zero point of apparent density) a parasitological negativation was first noted after one year and a complete serological negativation was observed after two years. If only a relative decrease in the vector's apparent densities occurred, it was related with a lower of sero-parasitological prevalence rate. The use of a serological test which was able to detect Trypanosoma congolense antibodies as the Testryp CATT, is a particularly useful technique for estimating the animal transmission level. These first results give some arguments that a parasitological and serological continuous of sentinel animals as pigs and sheep is a useful mean for evaluating the efficiency of a control campaign against sleeping sickness vectors.

[Endocrine function and African trypanosomiasis. Evaluation of 79 cases]. / Fonction endocrine et trypanosomiase africaine. Bilan de 79 cas.

Although the high frequency of hypogonadism was found during the sleeping sickness, the physiological properties of the gonads have been poorly studied. We reported here the exploration of the gonadotropic axis in 79 patients infected by Trypanosoma brucei gambiense. It has been noted a decrease in oestradiol for 50% of women, in testosterone levels for 50% of men whereas no decrease of pituitary gonadotropins (FSH and LH) was found. The results of the gonad adenohypophyseal tests suggested that the dysfunction may be of central origin. The studies of thyreotropic axis were also examined: a decrease in T3 and FT3 (free fraction) even though T4 was normal. The specific relationship between hypogonadism and trypanosomal infection is discussed in this report.

[Epidemiological importance of the animal reservoir of Trypanosoma brucei gambiense in the Congo. 1. Prevalence of animal trypanosomiasis in the foci of sleeping sickness]. / Importance épidémiologique du réservoir animal à trypanosoma brucei gambiense au Congo. 1. Prévalence des trypanosomoses animales dans les foyers de maladie du sommeil.

Parasitological and serological tests were performed in 1287 domestic animals originating from the Brazzaville area and three sleeping sickness foci in Congo. Nannomonas and Trypanozoon were the only sub-genera present in the blood of animals, with prevalences of 16.9% and 0.5%, respectively. The use of Testryp CATT allowed a better estimation of the real frequency of animal trypanosomiasis which in some foci, was found to be three times higher than the parasitological prevalence. Seven stocks of Trypanozoon were isolated from pigs and sheep. A biochemical analysis indicated that they belonged to the T.b. gambiense sub-species. However, considering the low prevalence of T.b. gambiense infections in animals, it is doubtful that this reservoir plays an important epidemiological role.

The sheep as a potential reservoir of human trypanosomiasis in the Republic of the Congo.

The identical electrophoretic isoenzyme patterns of a human-plasma-resistant Trypanozoon stock from a sheep and of two other stocks from trypanosomiasis patients in the Congo Republic indicated that the sheep stock was probably infective to man. These, and one further human stock from the Congo, closely resembled stocks isolated from man in Liberia and Ivory Coast.

[Fluctuations affecting the measurement of microfilaremia (author's transl)]. / Etude statistique de la variabilité caractérisant les mesures de la microfilarémie capillaire.

A statistical analysis was conducted, in order to compare the variations in values of a) blood samples obtained with several finger-pricks from the same individual in a short period of time, and b) blood samples obtained from the same finger-puncture. No significant difference was observed: both groups seem to follow a negative binomial distribution, the exponent of which is not dependent on the microfilarial count average. This common exponent is roughly equal to the volume of the blood sample, expressed in cmm.