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Heartwater disease, is a virulent tick-borne disease of ruminants caused by Ehrlichia ruminantium (ER), biologically transmitted by Amblyomma spp. However, in West Africa, the potential of Rhipicephalus microplus (R. microplus) larvae to transmit this bacterium has been demonstrated. Although previous studies have been conducted on heartwater and ER in Burkina Faso, data on infection rate of the bacterium in A. variegatum and R. microplus is lacking in the peri-urban areas. Hence, this study aimed to compensate this gap, focusing on five peri-urban villages around 10-30 km from Bobo-Dioulasso. A total of 359 cattle was examined for ticks collection. However, only adult specimens of the two tick species collected on the same animals were included in the molecular detection of ER by semi-nested PCR. Results revealed a global contact rate of 19% in A. variegatum and 26% in R. microplus without a significant difference between these rates. Thus, while R. microplus invasion in West Africa is accompanied by the transmission of ER to animals, its contact rate with the causal agent of heartwater disease is similar to that with the previous known vector. Such context could impact the heartwater disease epidemiology, mainly in the peri-urban areas where the study was carried out. From previous knowledge and literature, that is the first time such study focusing on E. ruminantium infection rate in ticks in peri-urban areas is conducted. Results suggest the necessity to improve tick control methods in the study areas since both ticks species can transmit the causal agent of heartwater disease to animals.

International audience; Gastrointestinal nematodes are a major threat to small ruminant rearing in the Sahel area, where farmers traditionally use bioactive plants to control these worms, including Acacia nilotica and Acacia raddiana. The main aim of this study was to screen the potential anthelmintic properties of aqueous and acetone extracts of leaves of these two plants based on three in vitro assays: (1) the egg hatch inhibition assay (EHA); (2) the larvae exsheathment inhibition assay (LEIA) using Haemonchus contortus as a model; and (3) an adult mortality test (AMT) applied on Caenorhabditis elegans. For the EHA, only A. raddiana was effective with IC50 = 1.58 mg/mL for aqueous extract, and IC50 = 0.58 mg/mL for acetonic extract. For the LEIA, all extracts inhibited the exsheathment of larvae compared to the controls, and the aqueous extract of A. nilotica was more larvicidal with IC50 = 0.195 mg/mL. In general, all responses to the substances were dose-dependent and were significantly different from the control group (p

Background: The success of current control tools in combatting malaria vectors is well established. However, sustained residual transmission of Plasmodium parasites persists. Mass drug administration (MDA) to humans of the endectocide ivermectin for vector control is receiving increasing attention. However, vectors feeding upon animals escape this promising approach. Zoophagy of mosquitoes sustains both the vector population and endemic population of vector-borne pathogens. Therefore, only a strategy that will combine ivermectin MDAs targeted at humans and their peridomestic animals could be successful at controlling residual malaria transmission. Methods: Burkinabe cattle have been treated with injectable therapeutic dose of ivermectin (0.2 mg/kg of body weight) to render blood meals toxic to field representative populations of Anopheles coluzzii carrying the kdr mutation. Direct skin-feeding assays were performed from 2 to 28 days after injection (DAI) and mosquitoes were followed for their survival, ability to become gravid and fecundity. Membrane feeding assays were further performed to test if an ivermectin blood meal taken at 28 DAI impacts gametocyte establishment and development in females fed with infectious blood. Results: The mosquitocidal effect of ivermectin is complete for 2 weeks after injection, whether 12 days cumulative mortalities were of 75 and 45 % the third and fourth weeks, respectively. The third week, a second ivermectin blood meal at sub-lethal concentrations further increased mortality to 100 %. Sub-lethal concentrations of ivermectin also significantly decreased egg production by surviving females, increasing further the detrimental effect of the drug on vector densities. Although females fitness was impaired by sub-lethal ivermectin blood meals, these did not diminish nor increase their susceptibility to infection. Conclusion: This study demonstrates the potential of integrated MDA of ivermectin to both human and peridomestic cattle to target vector reservoirs of residual malaria transmission. Such integration lies in 'One-Health' efforts being implemented around the globe, and would be especially relevant in rural communities in Africa where humans are also at risk of common zoonotic diseases.

Human African trypanosomiasis (HAT) or sleeping sickness is a major public health problem in sub-Saharan Africa and is due to the kinetoplastid parasite Trypanosoma brucei gambiense in West and Central Africa. The exact role of multiple infections, the basis of clinical diversity observed in patients and the determinism that leads trypanosomes into different body fluids of the host remain opened questions to date. In this paper we investigate, in three Guinean foci, whether strains found in blood, lymph or cerebrospinal fluid (CSF) or in patients at different phase of HAT (phase 1, early phase 2 and late phase 2) are representative of the focus they belong to. Amplifications of parasites directly from body fluids led to substantial amounts of allelic drop outs, especially so for blood and CSF samples, which required data recoding of all homozygous sites into missing data. While controlling for geography, date of sampling and patient's phase of the disease, we found no effect of body fluids in the genetic structure of T. b. gambiense despite the presence of mixed infections. On the contrary, we found that the strains found in patients in different phase of the disease differed genetically, with early phase patients being more likely to be infected with more recent strains than patients at a more advanced phase of the disease. Thus, the combination of date of sampling and patient's status represents a parameter to be controlled for in population genetic structure analyses. Additional studies will also be required to explore further the phenomenon of mixed infections and its consequences.