Dermal trypanosomes in seropositive suspects of gambiense human African trypanosomiasis in Côte d'Ivoire.

In the population at risk of gambiense human African trypanosomiasis (gHAT), the prevalence of extravascular parasite carriage remains unclear. Here, we conducted an observational clinical study in the hypo-endemic gHAT foci of Sinfra and Bonon in Côte d'Ivoire from 2019 to 2022. A total of 74 individuals were enrolled, including 45 suspects previously found positive at least once in a serological test for gHAT and followed by the national elimination programme of Côte d'Ivoire, as well as 29 seronegative controls.

Unravelling genetic differentiation between Glossina brevipalpis populations from two distant National Parks in Mozambique.

African trypanosomosis (AT), caused by protozoan parasites of the genus Trypanosoma, has plagued the African continent for centuries, affecting both humans and animals. Its principal vector, tsetse flies, can be found across sub-Saharan Africa. Vector control represents an efficient way to reduce the burden of AT.

Challenges and lessons from a vector control campaign targeting Glossina palpalis palpalis in an isolated protected forest area in Abidjan, Côte d'Ivoire.

Vector control (VC) is one of the strategies employed to manage African trypanosomoses. This study aimed at assessing the effectiveness of a VC campaign against Glossina palpalis palpalis using tiny targets (TTs) impregnated with insecticide in an isolated, protected forest in Abidjan, Côte d'Ivoire, while considering ecological, genetic, and operational factors. Between January 2020 and September 2022, 2,712 TTs were deployed at 684 sites, covering a total area of 1.

Evaluation of the AnTat A/B and LiTat A/B primers for the detection of Trypanosoma bruceigambiense.

Elimination of gambiense human African trypanosomiasis (gHAT) as a public health problem has been reached or is in sight in a number of endemic foci and the next step is now to reach the elimination of transmission. The ability to detect Trypanosomabruceigambiense (T.b.

Trypanosoma brucei gambiense group 2 experimental in vivo life cycle: from procyclic to bloodstream form.

Trypanosoma brucei gambiense (Tbg) group 2 is a subgroup of trypanosomes able to infect humans and is found in West and Central Africa. Unlike other agents causing sleeping sickness, such as Tbg group 1 and Trypanosoma brucei rhodesiense, Tbg2 lacks the typical molecular markers associated with resistance to human serum. Only 36 strains of Tbg2 have been documented, and therefore, very limited research has been conducted despite their zoonotic nature.

Tsetse fly ecology and risk of transmission of African trypanosomes related to a protected forest area at a military base in the city of Abidjan, Côte d'Ivoire.

African trypanosomoses, whose pathogens are transmitted by tsetse flies, are a threat to animal and human health. Tsetse flies observed at the military base of the French Forces in Côte d'Ivoire (FFCI base) were probably involved in the infection and death of military working dogs. Entomological and parasitological surveys were carried out during the rainy and dry seasons using "Vavoua" traps to identify tsetse fly species, their distribution, favorable biotopes and food sources, as well as the trypanosomes they harbor.

Evolution of Gene Expression during a Transition from Environmental to Genetic Sex Determination.

Genetic sex determination (GSD) can evolve from environmental sex determination (ESD) via an intermediate state in which both coexist in the same population. Such mixed populations are found in the crustacean Daphnia magna, where non-male producers (NMP, genetically determined females) coexist with male producers (MP), in which male production is environmentally inducible and can also artificially be triggered by exposure to juvenile hormone. This makes Daphnia magna a rare model species for the study of evolutionary transitions from ESD to GSD.

Long-term prevalence data reveals spillover dynamics in a multi-host (Artemia), multi-parasite (Microsporidia) community.

In the study of multi-host parasites, it is often found that host species contribute asymmetrically to parasite transmission. Yet in natural populations, identifying which hosts contribute to parasite transmission and maintenance is a recurring challenge. Here, we approach this issue by taking advantage of natural variation in the composition of a host community.

Sexual selection and inbreeding: Two efficient ways to limit the accumulation of deleterious mutations.

Theory and empirical data showed that two processes can boost selection against deleterious mutations, thus facilitating the purging of the mutation load: inbreeding, by exposing recessive deleterious alleles to selection in homozygous form, and sexual selection, by enhancing the relative reproductive success of males with small mutation loads. These processes tend to be mutually exclusive because sexual selection is reduced under mating systems that promote inbreeding, such as self-fertilization in hermaphrodites. We estimated the relative efficiency of inbreeding and sexual selection at purging the genetic load, using 50 generations of experimental evolution, in a hermaphroditic snail ().

Detecting Wahlund effects together with amplification problems: Cryptic species, null alleles and short allele dominance in Glossina pallidipes populations from Tanzania.

Population genetics is a convenient tool to study the population biology of non-model and hard to sample species. This is particularly true for parasites and vectors. Heterozygote deficits and/or linkage disequilibrium often occur in such studies and detecting the origin of those (Wahlund effect, reproductive system or amplification problems) is uneasy.

Bioinvasion Triggers Rapid Evolution of Life Histories in Freshwater Snails.

Biological invasions offer interesting situations for observing how novel interactions between closely related, formerly allopatric species may trigger phenotypic evolution in situ. Assuming that successful invaders are usually filtered to be competitively dominant, invasive and native species may follow different trajectories. Natives may evolve traits that minimize the negative impact of competition, while trait shifts in invasives should mostly reflect expansion dynamics, through selection for colonization ability and transiently enhanced mutation load at the colonization front.

Experimental Evidence for the Negative Effects of Self-Fertilization on the Adaptive Potential of Populations.

Self-fertilization is widely believed to be an "evolutionary dead end" [1, 2], increasing the risk of extinction [3] and the accumulation of deleterious mutations in genomes [4]. Strikingly, while the failure to adapt has always been central to the dead-end hypothesis [1, 2], there are no quantitative genetic selection experiments comparing the response to positive selection in selfing versus outcrossing populations. Here we studied the response to selection on a morphological trait in laboratory populations of a hermaphroditic, self-fertile snail under either selfing or outcrossing.

Cryptic microsporidian parasites differentially affect invasive and native Artemia spp.

We investigated the host specificity of two cryptic microsporidian species (Anostracospora rigaudi and Enterocytospora artemiae) infecting invasive (Artemia franciscana) and native (Artemia parthenogenetica) hosts in sympatry. Anostracospora rigaudi was on average four times more prevalent in the native host, whereas E. artemiae was three times more prevalent in the invasive host.

Cytological, molecular and life cycle characterization of Anostracospora rigaudi n. g., n. sp. and Enterocytospora artemiae n. g., n. sp., two new microsporidian parasites infecting gut tissues of the brine shrimp Artemia.

Two new microsporidia, Anostracospora rigaudi n. g., n.

Why join groups? Lessons from parasite-manipulated Artemia.

Grouping behaviours (e.g. schooling, shoaling and swarming) are commonly explicated through adaptive hypotheses such as protection against predation, access to mates or improved foraging.