Experimental transmission of Monanema nilotica El Bihari & coll., 1977, a filaria with skin-dwelling microfilaria parasitic in African murids

The value of Monanema of murids as experimental models of ocular lesions due to onchocerciasis would be greatly increased if we could experiment with several host and parasite species since, in many cases, the lesions induced are more significant when the host-parasite association is poorly adapted. The life cycle of 2 isolates of Monanema nilotica is completed, one from Lemniscomys striatus from the Central african Republique and the other from Arvicanthis niloticus of Mali. As in M. globulosa, infective larvae develop in Ixodidae (Rhipicephalus sanguineus and Hyalomma truncatum); 20 to 30 larvae inoculated into the murids suffice for a patent infection.     

Traditional Leafy Vegetables in Senegal: Diversity and Medicinal Uses

Six administrative regions of Senegal were investigated. Forty species of vegetable leaves which are traditionally consumed in Senegal have been inventoried. All species are members of twenty-one families the most numerous of which are Amaranthaceae Juss., Malvaceae Juss., Moraceae Link., the Papilionaceae Giseke and Tiliaceae Juss. The species are subdivided into three groups: cultivated leafy vegetables, plants gathered annually, perennial sub-ligneous and ligneous species. The gathered species represent 67.5% of the inventory, 40.7% of which is ligneous. Cultivated species account for 32.5% of the inventory. The species are consumed for their medicinal properties, nutritive value and eating habits linked to specific ethnic traditions. During the drought years, with the scarcity of main food (millet, mays) consumption of leafy vegetables is high. All species reported except Sesuvium portulacastrum L. are consumed like vegetable herbs. The species of Hibiscus are eaten in spinach and condiment form while Sesuvium portulacastrum L is cooked in salad. Of the forty species examined, eleven are widely consumed. Within the entire study area, Hibiscus sabdariffa predominates among species consumed, followed by Moringa oleifera Lam. and Senna obtusifolia Link. A high consumption level of some species like amarante, Corchorus tridens L., Corchorus aestuans L., Leptadenia hastata Decne. and Vigna unguiculata (L.) Walp is confined to certain areas. In addition to their consumption as vegetables, the medicinal uses of 57.5% of these is of primary importance. The most commonly exploited parts are, respectively, leaf (40%), roots (20%), and bark (13.3%). Among the numerous pathologies treated, abscess, constipation, and rheumatism are predominant followed by aphrodisiac uses. The Amaranthus spp. L., Leptadenia hastata Decne., Senna obtusifolia Link., Adansonia digitata L. and Tamarindus indica L. are species with multiple medicinal uses.     

Traditional tea drinking in Senegal. A real source of fluoride intake for the population.

Tea drinking after meals is a traditional practice in Senegal where more than 80% of the population from 15 to 60 years old drink tea. According to the tradition, in one session, each tea consumer has to drink 3 cups of decocted tea. The content of a cup is about 30 ml of liquid. Some people drink tea three times daily, that is to say after each meal. Tea plant is rich in fluoride. To determine the effective intake of the Senegalese population from this source, we measured the fluoride concentration not only for each component of the prepared tea but also for each cup of prepared tea. For this study, we used the two main kinds of tea existing locally. The analyses have been done at Rochester, NY Eastman Dental Center, Oral Biology Dept Fluoride Laboratory using the Taves Microdiffusion Method and the fluoride Ion Specific Electrode. The results so that the mean total fluoride concentration of each cup, from the first to the third one, is: 4.0 mg F-/L, 7.436 mg F-/L and 1.230 mg F-/L. It means that on an average in one session, a Senegalese tea consumer has a daily fluoride intake of 1.139 mg F-/L when taking in count the total fluoride and drinking only 90 ml of tea. If we consider the ionic fluoride the amount of daily ingested fluoride for someone who takes only 3 tea-pots of 30 ml each, is 0.830 mg. To conclude, we state that this traditional practice may have a caries preventive effect. Further studies will be grateful for that practice when setting up a caries preventive program in our country. We will also be careful in extending that practice to children less than 8 years old because it might cause dental fluorosis as in Senegal the optimal dose of fluoride is 0.8 mg F-/L.     

A clonal view of αβ T cell responses

Quantitative analyses of antigen (Ag)-specific αβ T cell populations have provided a large body of information on the natural course of T cell immune responses. New tools are now available to determine the clonal composition of Ag-specific pools in individual responders, an approach which offers direct insights into the generation of T cell immune responses and establishment of protective immunity. The present review discusses the parameters that determine the composition of Ag-specific T cell responses. Emphasis is placed on the role of the naive αβ T cell repertoire and on the dynamics of individual Ag-specific T cell clones during the successive phases of an immune response.     

Unusual form of neurocysticercosis associated with HIV infection

Concurrent infection with Taenia solium and HIV would be expected to occur more frequently because of the increasing frequency of HIV infection in endemic areas of cysticercosis. However, little is known about the influence of HIV infection on the frequency and the clinical course of cysticercosis. Giant cysts and racemose forms of neurocysticercosis seem to be more frequent in HIV-infected patients and may be secondary to an uncontrolled parasitic growth because of an impaired cell-mediated immune response. We report an unusual case of epidural spinal racemose neurocysticercosis revealed by compression of cauda equina in an HIV-infected man and discuss the potential interactions between T. solium and HIV infections.     

Dynamic behavior of T cells and thymocytes in lymphoid organs as revealed by two-photon microscopy

The initial application of two-photon imaging to the study of lymphoid tissues has provided a dramatic glimpse into how cells of the immune system move and interact in their native environments. In this review we summarize what we have learned so far and point out areas for future investigation using this approach.     

Epidemiological and clinical aspects of blackwater fever among African children suffering frequent malaria attacks

Blackwater fever (BWF), one of the commonest causes of death of Europeans living in Africa at the beginning of the twentieth century, but rarely diagnosed since the 1950s, is related to Plasmodium falciparum malaria but there is considerable debate and controversy about its aetiology. From 1990 to 2000, the whole population of Dielmo, a village in Senegal, was involved in a prospective study of malaria. Three cases of BWF occurred in 3 children aged 4, 7 and 10 years, belonging to a subgroup of children who suffered malaria attacks every 4 to 6 weeks over many years, who had received repeated quinine treatment. The spread of chloroquine resistance, by increasing the use of more toxic alternative drugs, may expose endemic populations to a high incidence of severe side effects of antimalarials.     

Investigation of a shigellosis outbreak in a rural zone of Senegal

The investigation of this outbreak took place in Niakhar (IRD project study area), a rural area located 150 km East of Dakar. Covering 30 villages, with a population of about 30,000 inhabitants, the area has been under demographic and epidemiological surveillance. In 1999, the surveillance allowed 973 cases of shigellosis to be recorded out of 1,751 cases of dysenteric diarrhoeas. The outbreak reached a peak during the raining season (73% of the cases in September and October). All the villages and all age groups were concerned. The attack rate in the population was 3%. During the same period, 22 deaths were attributed to shigellosis, leading to a lethality of 2.3%. Children under five were the most affected. The bacteriological examination isolated S. flexneri in 72% of 12 stools samples and S. dysenteriae A1 (SD1) in 14%. All serotypes were resistant to ampicillin and susceptible to quinolones. Susceptibility to cotrimoxazole was unconstant. Apart from the usual factors involved in the spread of diarrhoeas, the main reason evoked to explain the duration of the epidemic has been the lack of adequate emergency antibiotherapy treatment. Quinolones, recommended by the health authorities, could not be provided by health services. The identification of the SD1 serotype confirmed its involvement in the outbreak of shigellosis. The exact role of S. flexneri in shigellosis epidemics should be further studied.     

Insulin therapy in childhood type 1 diabetes: Knowledge and practice in Senegal

IntroductionChildhood type 1 diabetes (T1D) is a chronic condition with serious repercussions on both the quality of life of the child and the family. Insulin therapy is the cornerstone of optimal blood sugar control. The main objective of our study was to assess the level of knowledge of physicians about insulin therapy in diabetes.MethodsThis was a multicenter survey over a period of 5 months (from March 5 to August 2, 2018). It took place in five reference university hospital centers in the Dakar region.ResultThe number of doctors interviewed in our study was 82, 47.6% of whom were confirmed pediatricians or pediatricians in the process of specialization. The number of years of experience in the field of diabetes was on average 3 years. Fast-acting regular insulins were recommended by 75.6% of doctors and mixtures of insulin (intermediate and rapid-acting) by 50% of doctors. Overall, 91% of doctors recommend a variation in insulin injection sites. The “basal bolus” treatment regimen with insulin analogs was recommended by 50% of doctors, while 31.7% recommended it with human insulin. Regarding adapting insulin doses for leisure and sports activities, more than half (54.9%) of the doctors had to reduce the doses.ConclusionThis study enabled us to assess the level of knowledge of insulin therapy among doctors caring for children with diabetes in Senegal, which proved to be limited. We recommend the reinforcement and follow-up of training on the management of T1D for providers at the different facilities.