Tsetse fly

Tsetse flies are major arthropod vectors of trypanosomes that cause debilitating African animal trypanosomiasis. The emergence of drug-resistant trypanosomes is a common problem in sub-Saharan Africa. This study aimed to identify tsetse flies' seasonal variation in apparent densities and their infection rates and the occurrence of drug-resistant trypanosomes. Tsetse flies were collected from Lambwe, Kenya, during May and September 2021. Genomic DNA was extracted from them, and the ITS1 gene was amplified to detect Trypanosoma infection with subsequent species determination...

Human African trypanosomiasis (HAT), or sleeping sickness, continues to be a major threat to human health in 36 countries throughout sub-Saharan Africa with up to 60 million people at risk. Over the last decade there have been several advances in this area, some of which are discussed in this overview. Due to the concerted efforts of several bodies, including better identification and treatment of cases and improved tsetse fly vector control, the number of cases of HAT has declined dramatically. The clinical heterogeneity of HAT has also been increasingly recognised and the disease, while usually fatal if untreated or inadequately treated, does not always have a uniformly fatal outcome...

African trypanosomiasis is a significant vector-borne disease of humans and animals in the tsetse fly belt of Africa, particularly affecting production animals such as cattle, and thus, hindering food security. Trypanosoma congolense (T. congolense), the causative agent of nagana, is livestock's most virulent trypanosome species. There is currently no vaccine against trypanosomiasis; its treatment relies solely on chemotherapy. However, pathogenic resistance has been established against trypanocidal agents in clinical use...

African trypanosomiasis is a vector-borne disease of animals and humans in the tsetse fly belt of Africa. Trypanosoma congolense ("nagana") is the most pathogenic trypanosome in livestock and causes high morbidity and mortality rates among cattle. In the absence of effective preventative vaccines, the management of trypanosomiasis relies on chemoprophylaxis and/or -therapy. However, the trypanocides in clinical use exhibit poor oral bioavailability and toxicity, and therapeutic failures occur because of resistant strains...

BACKGROUND: Significant progress has been made towards African sleeping sickness elimination in the last decade. Indeed, the World Health Organization (WHO) global goal of eliminating the chronic form of the disease as a public health problem was achieved in 2020 (i.e., < 2,000 new cases per year). Vector control has played an important role in achieving this goal. In this study, we evaluated the impact of the insecticide impregnated Tiny Targets on tsetse fly densities and their infection rates with Trypanosoma spp in the Campo sleeping sickness focus of South Cameroon...

Tsetse flies ( Glossina spp.; Diptera: Glossinidae) are viviparous flies that feed on blood and are found exclusively in sub-Saharan Africa. They are the only cyclic vectors of African trypanosomes, responsible for human African trypanosomiasis (HAT) and animal African trypanosomiasis (AAT). In this study, we employed high throughput sequencing of the 16S rRNA gene to unravel the diversity of symbiotic bacteria in five wild and three laboratory populations of tsetse species ( Glossina pallidipes , G. morsitans , G...

Livestock are important reservoirs for many zoonotic diseases, however the effects of livestock on human and environmental health extend well beyond direct disease transmission. In this retrospective ecological cohort study we use pre-existing data and the parametric g-formula, which imputes potential outcomes to quantify mediation, to estimate three hypothesized mechanisms by which livestock can influence human African trypanosomiasis (HAT) risk: the reservoir effect, where infected cattle and pigs are a source of infection to humans; the zooprophylactic effect, where preference for livestock hosts exhibited by the tsetse fly vector of HAT means that their presence protects humans from infection; and the environmental change effect, where livestock keeping activities modify the environment in such a way that habitat suitability for tsetse flies, and in turn human infection risk, is reduced...

Critical thermal maximum (CTmax ) describes the upper thermal tolerance of an animal where biological functions start to fail. A period of acclimation can enhance CTmax through plasticity, potentially buffering animals from extreme temperatures caused by climate change. Basal and acclimated CTmax vary within and between species and may be explained by traits related to thermal physiology, such as body size and sex. Differences in CTmax have not been established among species of tsetse fly (Glossina spp.), vectors of animal and human African trypanosomiasis...

Thermal stress during development can prime animals to cope better with similar conditions in later life. Alternatively, negative effects of thermal stress can persist across life stages and result in poorer quality adults (negative carryover effects). As mean temperatures increase due to climate change, evidence for such effects across diverse taxa is required. Using Glossina morsitans morsitans , a species of tsetse fly and vector of trypanosomiasis, we asked whether (i) adaptive developmental plasticity allows flies to survive for longer under food deprivation when pupal and adult temperatures are matched; or (ii) temperature stress during development persists into adulthood, resulting in a greater risk of death...

Developmental regulation of mitochondrial uridine insertion/deletion editing in Trypanosoma brucei is necessary to modulate parasite metabolism as it shifts from dependence on glycolysis for ATP production in the mammalian bloodstream form (BSF) to oxidative phosphorylation in the insect procyclic form (PCF). However, the timing and stimuli that regulate mRNA editing have been poorly characterized. Here, we utilized a pleomorphic T. brucei strain and quantitative RT-PCR and droplet digital PCR analyses to evaluate the changes in total mRNA abundance and editing as parasites progressively differentiate from slender BSF to PCF and investigate the effect of individual stimuli on mitochondrial gene expression...

Trypanosoma brucei occupies distinct niches throughout its life cycle, within both the mammalian and tsetse fly hosts. The immunological and biochemical complexity and variability of each of these environments require a reshaping of the protein landscape of the parasite both to evade surveillance and face changing metabolic demands. In kinetoplastid protozoa, including T. brucei, post-transcriptional control mechanisms are the primary means of gene regulation, and these are often mediated by RNA-binding proteins...

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...

BACKGROUND: Tsetse flies are cyclical vectors of African trypanosomiasis (AT). The flies have established symbiotic associations with different bacteria that influence certain aspects of their physiology. Vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by bacterial endosymbionts amongst other factors. Symbiotic interactions may provide an avenue for AT control. The current study provided prevalence of three tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria...

Tsetse flies, the vectors of African trypanosomes are of key medical and economic importance and one of the constraints for the development of Africa. Tsetse fly control is one of the most effective and sustainable strategies used for controlling the disease. Knowledge about population structure and level of gene flow between neighbouring populations of the target vector is of high importance to develop appropriate strategies for implementing effective management programmes. Microsatellites are commonly used to identify population structure and assess dispersal of the target populations and have been developed for several tsetse species but were lacking for Glossina brevipalpis...

The primary vector of the trypanosome parasite causing human and animal African trypanosomiasis in Uganda is the riverine tsetse fly Glossina fuscipes fuscipes (Gff). Our study improved the Gff genome assembly with whole genome 10× Chromium sequencing of a lab reared pupae, identified autosomal versus sex-chromosomal regions of the genome with ddRAD-seq data from 627 field caught Gff, and identified SNPs associated with trypanosome infection with genome-wide association (GWA) analysis in a subset of 351 flies...

ConspectusTyrosine sulfation is a post-translational modification (PTM) that modulates function by mediating key protein-protein interactions. One of the early proteins shown to possess this PTM was hirudin, produced in the salivary glands of the medicinal leech Hirudo medicinalis , whereby tyrosine sulfation led to a ∼10-fold improvement in α-thrombin inhibitory activity. Outside of this pioneering discovery, the involvement of tyrosine sulfation in modulating the activity of salivary proteins from other hematophagous organisms was unknown...

Lipid metabolism is critical for insect reproduction, especially for species that invest heavily in the early developmental stages of their offspring. The role of symbiotic bacteria during this process is understudied but likely essential. We examined the role of lipid metabolism during the interaction between the viviparous tsetse fly ( Glossina morsitans morsitans ) and its obligate endosymbiotic bacteria ( Wigglesworthia glossinidia ) during tsetse pregnancy. We observed increased CTP:phosphocholine cytidylyltransferase ( cct1 ) expression during pregnancy, which is critical for phosphatidylcholine biosynthesis in the Kennedy pathway...

Human African trypanosomiasis is a life-threatening parasitic infection transmitted by the tsetse fly in sub-Saharan Africa. The most common form is caused by Trypanosoma brucei gambiense , with humans as the main reservoir. Diagnosis in the field requires microscopic examination performed by specifically trained personnel. After over two decades of sustained efforts, the incidence of the disease is strongly declining, and some historically endemic countries are no longer detecting cases. The World Health Organization (WHO) has targeted the elimination of transmission of gambiense human African trypanosomiasis by 2030, defined as zero autochthonous cases for at least five consecutive years...

Human African Trypanosomiasis (HAT) is caused by Trypanosoma brucei which is transmitted by the tsetse fly insect vector ( Glossina spp). It is one of the 20 Neglected Tropical Diseases (NTD) listed by the WHO. These diseases affect the poorest and most vulnerable communities, for which the WHO has established a dedicated 2021-2030 roadmap. At the time of Alphonse Laveran, HAT devastated the African continent. In the 1960s, the disease was nearly under control, but it strongly re-emerged in the 1990s. A coordinated effort of all stakeholders, with national control programs as the main actors, a strong contribution of research and important donations by the private sector, allowed to decrease the HAT burden significantly...

BACKGROUND: Human African trypanosomiasis (HAT) is a parasitic infection that may lead to death if left untreated. This disease is caused by a protozoan parasite of the genus Trypanosoma and is transmitted to humans through tsetse fly bites. The disease is widespread across Sub-Saharan Africa, with 70% of cases in recent reports in the Democratic Republic of the Congo and an average of less than 1000 cases are declared annually. Since there is no appropriate treatment for HAT, steroidal and triterpenoid saponins have been reported to be effective in in vitro studies and might serve as scaffolds for the discovery of new treatments against this disease...