[Epidemiological study of bancroftian filariasis in the Logone Valley (North Cameroon) (author's transl)]. / Etude epidémiologique de la bancroftose dans la Vallee du Logone (Nord Cameroun).

In the Logone Valley, Yagoua and the surrounding area, the prevalence of the bancroftian filariasis was measured by means of determinating the microfilarian rate: 22,1 p. 100 in males and 9,8 p. 100 in females. The immunofluorescence test on D viteae frozen sections showed the presence of antibodies in 61,5 p. 100 of the males and 68,2 p. 100 of the females. A balance between the microfilarial rate and the percentage of inhabitants with specific antibodies was observed. Parasitological and immunological examinations appeared to be complementary. The microfilarial density is 19 microfilariae/20 microliter of blood in males and 13 microfilarae/20 microliter in females. Elephantoid extremities of scrota was observed in 13,2 p. 100 of the adult males, all of them having more than 40 years of age. Females are less affected than males. At the beginning of the rainy season, females of A. gambiae were the mosquitos the most frequently caught in the houses.

[Epidemiologic study of dracunculosis in the Podokwos of the Mandara mountains (northern Cameroon)]. / Etude épidémiologique de la dracunculose chez les Podokwos des monts du Mandara (nord Cameroun).

The purpose of the present work is the study of the epidemiological aspects of dracontiasis in an endemic area in Cameroon. The study was undertaken in the central Podokwo settlement in Mora subdivision. It is a mountainous area with a climate characterized by a long dry season, from October to mid-May, and a short rainy season. Two seasonal, streams run across the settlement. The water supply of the community is ensured throughout the year by two well built wells. During the rainy season, shallow unprotected wells are the water sources of about 80% of the inhabitants. Among the 944 subjects studied in our sample, 251 had the disease, corresponding to a prevalence of 26 6%. There is no significant difference between both sexes in the prevalence of the disease in our study. The age group 13-26 years is most affected. The worm load varies from 1 to 5, averagely 1.5. As to the localization of the worms in the body, in 92.7% of cases the worms is located in the lower limbs, the feet alone representing up to 46.8%. Less common sites of localization are the head, the breast, the external genitalia. The maximum rate of infestation is observed between August and September. Desinfection of wells with chemicals would be recommended during this period of time.

[Epidemiologic study of S. haematobium bilharziasis in the rice belt of Yagoua (North Cameroon). I. Prevalence of infestation and evaluation of the parasitic load]. / Etude épidémiologique de la bilharziose à S. haematobium dans le périmètre rizicole de Tagoua (Nord-Cameroun). I. Prévalence de l'infestation et évaluation de la charge parasitaire.

The epidemiological study of urinary bilharziasis concerns family surveys done in four villages, three of them been located in the rice fields and the other one outside these fields: 990 urine examinations are performed by filtration as well as 966 immunological tests, using an hemagglutination technique and the heterologous antigen S. mansoni. The prevalence of bilharziasis varies from a village to the next, as well as the parasitic load, measured by means of number of eggs per 10 ml urine, in relation with the distance separating the village from the artificial water network built by the rice company. In Dabaye 62.4 % of the examined inhabitants are voiding eggs of S. haematobium, in Toukou 56.9 %, in Vele 31.6% and in Zebe 20.1%. In Toukou and Dabaye all teenagers examined were passing eggs in their urine.

[Epidemiologic study of malaria in the rice-growing regions of Yagoua and Maga (North Cameroon)]. / Etude épidémiologique du paludisme dans les régions rizicoles de Yagoua et de Maga (Nord-Camerroun).

The results of the malaria investigation carried out in April 1981 in the irrigated regions of the Logone Valley show that Plasmodium falciparum is the only species o. the genus Plasmodium to be found there. In terms of parasitaemia in blood, the prevalence of malaria is highest in the 5 to 9 year-old age group, whereas fluorescent antibodies are to be found progressively greater quantities as subjects grow older. From the age of 40, 95% of the inhabitants of the region present circulating antibodies in the blood. Plasmodial index of children from 2 to 9 years of age is equal to only 8.5% at the end of the dry season, whereas the spleen index, which is 34.8%, would suggest that malaria is meso-endemic in the region. With regard to the different sites studied, there is no significant difference in the values of the spleen or plasmodial indexes, either next to, or away from surface water. The malaria death rate is highest during the rainy months of August, September and October. The significant rise in the death rate during March corresponds to the concomitant rise in temperature. Entomological studies performed on the species of anophelines resting in the houses, which are gathered in the morning after a pulverization of insecticide, reveal that the dominant anopheline species in June is Anopheles gambiae, a species which, in the rainy season, abounds at water sites which are frequently temporary. On the other hand, in April, the dominant species is Anopheles funestus, which it would seem, develops easily during the dry season in those waterbodies which are artificially maintained all year round in the irrigated areas.