Phenetic and genetic structure of tsetse fly populations (Glossina palpalis palpalis) in southern Ivory Coast

Background: Sleeping sickness, transmitted by G. p. palpalis, is known to be present in the Ivory Coast. G. p. palpalis has recently been reported to occur in several places within the town of Abidjan, including: (i) the Banco forest, (ii) the Abobo Adjame University campus and (iii) the zoological park. Could these three places be treated sequentially, as separate tsetse populations, or should they be taken as one area comprising a single, panmictic population? Methods: The amount of gene flow between these places provides strategic information for vector control. It was estimated by the use of both microsatellite DNA and morphometric markers. The idea was to assess the interest of the faster and much less expensive morphometric approach in providing relevant information about population structure. Thus, to detect possible lack of insect exchange between these neighbouring areas of Abidjan, we used both genetic (microsatellite DNA) and phenetic (geometric morphometrics) markers on the same specimens. Using these same markers, we also compared these samples with specimens from a more distant area of south Ivory Coast, the region of Aniassue (186 km north from Abidjan). Results: Neither genetic nor phenetic markers detected significant differentiation between the three Abidjan G. p. palpalis samples. Thus, the null hypothesis of a single panmictic population within the city of Abidjan could not be rejected, suggesting the control strategy should not consider them separately. The markers were also in agreement when comparing G. p. palpalis from Abidjan with those of Aniassue, showing significant divergence between the two sites. Conclusions: Both markers suggested that a successful control of tsetse in Abidjan would require the three Abidjan sites to be considered together, either by deploying control measures simultaneously in all three sites, or by a continuous progression of interventions following for instance the "rolling carpet" principle. To compare the geometry of wing venation of tsetse flies is a cheap and fast technique. Agreement with the microsatellite approach highlights its potential for rapid assessment of population structure

Chorologie et infection par les trypanosomes de

Dans le but de mettre en place un programme de lutte anti-vectorielle dans la périphérie d’Abidjan (Côte d’Ivoire), des enquêtes ont été effectuées pour évaluer les densités glossiniennes ainsi que les infections par les trypanosomes. Les captures ont été réalisées en saison des pluies et en saison sèche avec des pièges Vavoua posés pendant quatre jours consécutifs sur différents sites (forêt du Banco, Parc zoologique d’Abidjan, domaine de l’Université d’Abobo- Adjamé). Une seule espèce de glossine (Glossina palpalis palpalis) et deux espèces de trypanosomes (Trypanosoma congolense, T. vivax) ont été mises en évidence. La densité apparente par piège et par jour (DAP) est très élevée au Parc zoologique, 54,8 glossines/piège/jour en saison sèche et 28,1 glossines/piège/jour en saison des pluies. À l’Université d’Abobo-Adjamé, la DAP est respectivement de 13,5 et 8,1 glossines/piège/jour en saison des pluies, et en saison sèche, elle n’est que de 0,9 et 0,8 dans la forêt du Banco. L’âge physiologique sur l’ensemble des sites est le suivant : 57,5 % de vieilles pares, 39 % de jeunes pares et 3,6 % de nullipares en saison des pluies. Ces proportions passent à 51,9 % de jeunes pares, 47,1 % de vieilles pares et 1 % de nullipares en saison sèche. Le taux global d’infection est estimé à 20,7 % en saison des pluies et à 20 % en saison sèche. Les analyses statistiques ont montré une différence significative dans la distribution des taux d’infections

Chorologie et infection par les trypanosomes de Glossina palpalis palpalis dans la forêt du Banco et ses reliques, Abidjan (Côte d'Ivoire) = Eco-distribution and trypanosoma infection of glossina palpalis palpalis in the Banco forest of and its relics, Abidjan (Cote d'Ivoire)

In order to implement or) anti-vector programme in the suburb of Abidjan (Cote d'Ivoire), investigations were conducted to assess the tsetse fly densities as well as infection with trypanosomes. Catches were carried out during the rainy season and dry season with Vavoua traps laid during four consecutive days in different sites (Banco forest, Abidjan zoological park, area of the University of Abobo-Adjame). One species of tsetse fly (Glossina palpalis palpalis) and two species of tryponosomes (Trypanosoma congolense, T. vivax) have been revealed. The apparent density per trap per day (DAP) is very high in the zoological park, 54.8 tsetse fly/trap/day during the dry season and 28.1 during the rainy season. At the University of Abobo-Adjame, the DAP is respectively 13.5 and 8.1 tsetse fly/trap/day during the rainy season, and in the dry season it is only 0.9 and 0.8 in the Banco Forest. The physiological age on all sites is as follows: 57.5% of old porous, 39% of young porous and 3.6% of nulliparous in the rainy season. These proportions vary to 51.9% of young porous, 47.1% of old porous and 1% of nulliporous in the dry season. The overall infection fate is estimated at 20.7% in the rainy season and 20% in the cry season. Statistical analysis have showed a significant difference in the distribution of infection rates

Low prevalence of intestinal helminth infections among primary school children in Tengrela, northern Côte d’Ivoire

Intestinal helminthiasis are endemic in Côte d’Ivoire and represent a real health problem because of health burden particularly in children. In order to eliminate the disease as a public health problem the Ministry of Health and Public Hygiene has been implementing mass drug administration in primary schools since 2012. Five years later, a cross-sectional study (October 2016 to January 2017) was conducted among 515 primary school children aged 4-15 in the department of Tengrela to estimate the prevalence of intestinal helminthiasis and to identify the species causing these parasite infections in order to develop preventive measure. Single stool samples were analysed using the direct smear in saline solution and Kato-Katz techniques. The overall intestinal helminths prevalence was 3.3% (CI 95% = 2.0-5.1). Hookworms (1.0%) and, Trichiuris trichiura (1.0%) were the predominante parasites followed by Ascaris lumbricoides (0.8%), and Hymenolepis nana (0.6%). No polyparasitism case was noted. Walking bare feet was associated to the occurrence of the parasitism (p=0.015). However, gender, age, the faecal disposal system and the mode of drinking water supply were not linked to the intestinal parasitism (p>0.05). The intestinal helminthiasis among primary school children in Tengrela are dominated by the hookworm Trichuris trichiura and Ascaris lumbricoides infections. It is important to provide health education for wearing shoes to avoid infection of skin-penetrators. Interventions aimed to improve sanitation access should be highlighted in the recommendations for the control of intestinal helminthiasis.Keywords: Intestinal helminthiasis; school children; Tengrela; Côte d’Ivoir