Post-transcriptional reprogramming by thousands of mRNA untranslated regions in trypanosomes.

Although genome-wide polycistronic transcription places major emphasis on post-transcriptional controls in trypanosomatids, messenger RNA cis-regulatory untranslated regions (UTRs) have remained largely uncharacterised. Here, we describe a genome-scale massive parallel reporter assay coupled with 3'-UTR-seq profiling in the African trypanosome and identify thousands of regulatory UTRs. Increased translation efficiency was associated with dosage of adenine-rich poly-purine tracts (pPuTs). An independent assessment of native UTRs using machine learning based predictions confirmed the robust correspondence between pPuTs and positive control, as did an assessment of synthetic UTRs. Those 3'-UTRs associated with upregulated expression in bloodstream-stage cells were also enriched in uracil-rich poly-pyrimidine tracts, suggesting a mechanism for developmental activation through pPuT 'unmasking'. Thus, we describe a cis-regulatory UTR sequence 'code' that underpins gene expression control in the context of a constitutively transcribed genome. We conclude that thousands of UTRs post-transcriptionally reprogram gene expression profiles in trypanosomes.

The Influence of Environmental Conditions and Coinfection by Blood-Feeding Parasites on Red Blood Cell Physiology of an Ectothermic Host.

AbstractVector-borne blood parasites cause myriad sublethal effects and can even be deadly to endotherms, but far less is known about their impacts on ectothermic hosts. Moreover, the pathologies documented in endotherms are generally linked to infection by blood parasites rather than by their vectors. Here, we measured hematocrit, hemoglobin, and relative proportions of immature red blood cells to evaluate the physiological effects of two blood-feeding parasites and coinfection on ectothermic hosts, differentiating among pathological responses, extrinsic factors, and natural variations. We investigated a population of wild eastern hellbender salamanders (Cryptobranchus alleganiensis), which harbor leeches (Placobdella appalachiensis) that transmit blood parasites (Trypanosoma spp.) to their hosts, often resulting in coinfection. We observed seasonal changes in host hematology corresponding to water temperature and demonstrated their ability to modulate hematological parameters in response to acute stress. We reveal seasonal relationships between parasite dynamics and host physiology, in which peak parasitemia occurred when hosts had seasonally high hematocrit and hemoglobin concentrations. We found that coinfected individuals expressed symptoms of anemia, including a regenerative response to depletion of their red blood cells. We also documented a more pronounced pathological response to leech vectors than to the trypanosomes they transmit. Our research underscores the complex interactions between host physiology, multiple parasites, and environmental factors and highlights the pathologies associated with the vector in coinfections. Given the contributions of climate change and disease in the rapid global decline of ectotherms such as amphibians, our study provides timely foundational insights into multiple factors that influence their red blood cell physiology.

Domestic dogs as reservoirs for African trypanosomiasis in Mambwe district, eastern Zambia.

The control of African trypanosomiasis (AT) in Eastern and Southern Africa, including Zambia, faces huge challenges due to the involvement of wild and domestic animal reservoirs. Free-roaming dogs in wildlife-populated and tsetse-infested villages of Zambia's Mambwe district are exposed to infectious tsetse bites. Consuming fresh raw game meat and bones further exacerbates their risk of contracting AT. We focus on the reservoir role of such dogs in maintaining and transmitting diverse species of trypanosomes that are infective to humans and livestock in Zambia's Mambwe district. A cohort of 162 dogs was enrolled for follow-up at 3 different time points from June to December 2018 in selected villages of Malama, Mnkhanya, and Nsefu chiefdoms of Mambwe district, eastern Zambia. Blood and serum were screened for AT by microscopy, GM6 ELISA, PCR (ITS1 and SRA), and Sanger sequencing. Out of the 162 dogs in the cohort, 40 were lost to follow-up and only 122 remained traceable at the end of the study. GM6 ELISA detected Trypanosoma antibodies in 121 dogs (74.7%) and ITS1-PCR detected DNA involving single and mixed infections of T. congolense, T. brucei, and suspected T. simiae or T. godfreyi in 115 dogs (70.9%). The human-infective T. b. rhodesiense was detected by SRA PCR in 67 dogs (41.4%), and some sequence data that support the findings of this study have been deposited in the GenBank under accession numbers OL961811, OL961812, and OL961813. Our study demonstrates that the Trypanosoma reservoir community in Zambia is wider than was thought and includes domesticated dogs. As dogs are active carriers of human and livestock-infective trypanosomes, they pose a risk of transmitting AT in endemic villages of Mambwe district as they are neglected and left untreated. To fully bring AT under control, countries such as Zambia where the role of animal reservoirs is important, should not limit their prevention and treatment efforts to livestock (especially cattle) but also include dogs that play an integral part in most rural communities.

Extracellular vesicles released by Trypanosoma evansi: induction analysis and proteomics.

Trypanosoma evansi is a unicellular protozoan responsible for causing a disease known as "surra," which is found in different regions of the world and primarily affects horses and camels. Few information is known about virulence factors released from the parasite within the animals. The organism can secrete extracellular vesicles (EVs), which transport a variety of molecules, including proteins. Before being considered exclusively as a means for eliminating unwanted substances, extracellular vesicles (EVs) have emerged as key players in intercellular communication, facilitating interactions between cells, host cells, and parasites, and even between parasites themselves. Thus, they may be used as potential biomarkers. This study aimed to assess the induction of EVs production by Ca+2, conduct a proteomic analysis of the EVs released by T. evansi, and identify epitopes that could serve as biomarkers. The findings indicated that Ca+2 is not an effective promoter of vesiculation in T. evansi. Furthermore, the proteomic analysis has identified multiple proteins that have been investigated as biomarkers or vaccine antigens, previously. A total of 442 proteins were identified, with 7 of them specifically recognizing 9 epitopes that are unique to T. evansi. At least one of these epitopes of TevSTIB805.9.11580 have been previously identified, which increases the possibility of further investigating its potential as a biomarker.

Quality, supply chain, and use of Trypanocidal drugs among camel keepers in north-eastern Kenya: A cross-sectional study.

The non-cyclic trypanosomiasis (surra), caused by Trypanosoma evansi, and mechanically transmitted by biting flies, hinders camel productivity in Kenya. Trypanocides are the most commonly used drugs to control surra. However, emergence of drug resistance by the parasites is a major limitation to control efforts. There is limited information on the quality of trypanocides, the supply chain and drug-use practices among camel keepers potentially contributing to development of drug resistance in Kenya. We sought to fill this gap by conducting a cross-sectional study among camel keepers in Isiolo and Marsabit counties, Kenya. We mapped the trypanocide drugs supply chain through quantitative and qualitative surveys. We administered a semi-structured questionnaire to camel keepers to generate data on trypanocides-use practices, including the types, sources, person who administers treatment, reconstitution, dosage, route and frequency of administration, among others. Additionally, we tested the quality of trypanocidal drugs retailed in the region. We mapped a total of 55 and 49 agro-veterinary outlets and general (ordinary) shops retailing veterinary drugs in the two counties, respectively. These comprised of 29 and 26 agro-veterinary outlets, as well as 24 and 25 general shops in Isiolo and Marsabit counties, respectively. Overall, the respondents experienced 283 surra cases in the three-month recall period, which were treated with trypanocides. The majority of these cases were diagnosed by camel owners (71.7%) and herders (24.1%). A significant proportion of the cases were treated by camel owners (54.8%), herders (35.3%), the owner's son (3.2%) and veterinary personnel (1.1%) (χ2 = 24.99, p = 0.000). Most of the households sourced the drugs from agro-veterinary outlets (59.0%), followed by general shops (19.8%), veterinary personnel (2.1%), and open-air markets (0.4%) (χ2 = 319.24, p = 0.000). Quinapyramine was the most (56.9%) predominantly used trypanocide in treatment of surra, followed by homidium (19.8%), isometamidium (15.9%), diminazene aceturate (6.7%), and ethidium (0.7%) (χ2 = 340.75, p < 0.000). Only a meager proportion of respondents (15.2%) used the drugs correctly as instructed by the manufacturers. We recorded an association between correct drug usage, with the person who administers the treatment (χ2 = 17.7, p = 0.003), and the type of trypanocide used (χ2 = 19.4, p < 0.001). All the drug samples tested had correct concentrations of active ingredient (100.0%), and therefore of good quality. We have demonstrated that whereas the trypanocides retailed in the region by authorized vendors are of good quality, there is widespread incorrect handling and use of the drugs by unqualified individuals, which may contribute to treatment failure and emergence of trypanocide resistance.

Prevalence of camel trypanosomosis and herders' knowledge, attitude, and practices towards the disease in the pastoral area of southern Ethiopia.

BACKGROUND: Surra is a parasitic disease caused by Trypanosoma evansi that threatens the health and productivity of camels. Despite its significant impact on camels in Ethiopia, surra has not received as much attention as diseases in cattle and other domestic animals. The objective of the study was to estimate the prevalence of surra, identify the potential risk factors and assess the traditional knowledge, attitude and practices of camel herders towards the disease. METHODS: The study used a parasitological and participatory epidemiological (PE) approach. Between February and July 2022, a total of 335 blood samples were collected from camels across three districts and tested using the buffy coat technique. The PE investigation involved six key informant groups consisting of 8 to 12 key persons, and used a semi-structured interview and various PE tools and principles. RESULT: The study found that the prevalence of surra among examined camels was 3.9% (95% CI: 2.1-6.5). The prevalence was significantly higher in camels with a poor body condition score (BCS) (OR = 9.3; 95% CI: 1.8-47.5; p = 0.008) compared with camels with a good BCS. However, district, age, sex, and ethnicity had no effect on the prevalence of surra (p > 0.05). The study also found that the packed cell volume (PCV) was significantly lower (p < 0.0001) in parasitaemic animals (18.92 ± 2.63) than in aparasitaemic animals (25.13 ± 4.56). Camels with poor BCS (22.7 ± 3.5) had a significantly (p < 0.001) lower mean PCV than camels with good BCS (26.2 ± 5.0). The PE investigation showed that all the camel herders were well aware of surra, known locally as Dhukana. The clinical symptoms, the season of high incidence, routes of transmission, impact on production, and control methods were accurately described. Moreover, this study emphasized that surra is the primary disease affecting camel health and productivity. CONCLUSION: The study identified a moderate prevalence of surra in the research area. To reduce surra incidence and associated losses, enhancing veterinary services and providing support for proper camel husbandry practices in the region is recommended. Additionally, future studies should consider using more sensitive and specific techniques like serological and molecular assays, as this study relied on microscopy only.

Tsetse fly density and trypanosoma infection rate in Bedele and Dabo Hana districts of Buno Bedele Zone, Southwest Ethiopia.

BACKGROUND: Trypanosomiasis is an infectious disease caused by parasitic protozoa of the genus Trypanosome and primarily transmitted by tsetse flies. This study aimed to determine the density of tsetse flies and the rate of trypanosome infection in the Bedele and Dabo Hana districts of the Buno Bedele Zone in Ethiopia. RESULTS: A cross-sectional study was conducted from January to February 2023 to catch tsetse flies, determine tsetse density, and estimate the trypanosome infection rate. We used 100 traps (40 NGU, 30 pyramidal, and 30 biconical) to catch the flies. The following standard procedures were followed to identify the specific trypanosome species in the collected tsetse flies: The flies were dissected, and the salivary glands were removed. We placed the salivary glands in a drop of saline solution on a microscope slide. A coverslip was placed over the salivary glands, the slide was examined under a microscope, and the trypanosomes were identified based on their morphology. A total of 3,740 tsetse flies were captured from 100 traps, resulting in an overall apparent density of 18.7 flies per trap per day. Within the study area, only one species of tsetse fly, Glossina tachinoides, was identified. Of the 1,320 dissected Glossina tachinoides, 1.82% were found to be infected with trypanosome parasites. Among these infections, 58.33% were attributed to Trypanosoma congolense, while the remaining 41.67% were caused by Trypanosoma brucei. The infection rate of trypanosomes was significantly higher in female tsetse flies (87.5%) as compared to male flies (12.5%). Furthermore, a significantly higher infection rate was observed in flies older than 20 days (83.33%) and in hunger stage 1 flies (58.33%) compared to hunger stages 2, 3, and 4. CONCLUSIONS: This study highlights the necessity of implementing control and suppression measures targeting the vector (tsetse flies) and the parasite (trypanosomes) to effectively manage and prevent pathogenic animal trypanosomiasis.

Sergentomyia khawi: a potential vector for Leishmania and Trypanosoma parasites affecting humans and animals and insecticide resistance status in endemic areas of Songkhla, southern Thailand.

BACKGROUND: Sand flies serve as crucial vectors in various medical and veterinary diseases. Sand fly-borne diseases pose a significant public health burden globally, as the causative agents can infect a diverse range of hosts, leading to severe consequences such as leishmaniasis and sand fly fever. Additionally, the widespread use of insecticides for agricultural purposes and mosquito control is not specifically targeted at sand flies, potentially leading to resistance development. We investigated sand fly species, their potential role as vectors of various parasitic agents, and insecticide resistance in the endemic regions of Natawi and Sadao districts in Songkhla, Thailand. METHODS: Sand flies were collected using CDC light traps. The collected sand flies were then identified to species level using molecular techniques. Subsequent analyses included the detection of pathogens and the identification of pyrethroid resistance mutations within the voltage-sensitive sodium channel (Vgsc) domain IIS6 gene, followed by sequence analysis. RESULTS: The study identified nine sand fly species belonging to the genera Phlebotomus and Sergentomyia. The DNA of Sergentomyia khawi was the only species found to test positive for one sample of Leishmania orientalis in Sadao district. This finding represents the first detection of L. orientalis in Thailand. Moreover, three samples of Leishmania martiniquensis and four samples of Trypanosoma sp. were found in the Natawi district. No I1011M, L1014F/S, V1016G, or F1020S mutations were detected in Vgsc gene. CONCLUSIONS: The results of this study provide valuable information on sand fly species and the continuous circulation of Leishmania spp. and Trypanosoma spp. in Songkhla, southern Thailand. Moreover, the development of geo-spatial information on vectors, parasites, and insecticide resistance in sand flies has the potential to provide well-informed risk assessments and evidence-based guidance for targeted vector control in Thailand. These results can serve as a foundation for integrating the One Health approach, which is crucial for disease control, considering the diverse ecological interactions among human and/or animal reservoir hosts, parasites, and sand fly vectors.

Trypanosoma spp. infection in urban and wild ecotopes of the caribbean region in Colombia. / Infección por Trypanosoma spp. en murciélagos capturados en ecótopos urbanos y silvestres de la región Caribe en Colombia.

Motivation for the study. The role of bats as hosts of Trypanosoma spp. in the Atlantic department in Colombia, as well as its taxonomic diversity has been poorly studied. Main findings. This is the first report of frequency of infection by Trypanosoma spp. in bats in the Atlántico Department in Colombia. Implications. The great adaptive capacity of bats to different ecological niches and its role as hosts of Trypanosoma spp. for wild and urban ecotopes represents a risk factor in transmission cycles of epidemiological importance. We conducted a study to evaluate the frequency of infection by Trypanosoma spp. in bats captured in wild and urban ecotopes in the Department of Atlántico in the Caribbean region of Colombia from March 2021 to May 2022. Bats were taxonomically identified, and sex, relative age, and reproductive conditions were determined. A blood sample was used for parasitological analysis and DNA extraction to amplify a region of the 18S rRNA. 125 bats were collected, with the most abundant families being Molossidae (62/125; 49.6%) and Phyllostomidae (43/125; 34.4%). Molossus molossus collected in wild habitats showed an infection frequency of 8.1% (5/61) and 4.1% (3/61) through parasitological and molecular analysis, respectively. In comparison, Noctilio albiventris collected in urban habitats showed an infection frequency of 16.6% (2/12) for both analyses. These findings represent the first records of M. molossus harboring trypanosomes for the Department of Atlántico and of N. albiventris harboring trypanosomes in Colombia.

Se evaluó la frecuencia de infección por Trypanosoma spp. en murciélagos capturados en ecótopos silvestres y urbanos del Departamento del Atlántico, en la región Caribe de Colombia, entre marzo de 2021 y mayo de 2022. Se identificaron taxonómicamente los murciélagos y se determinó sexo, edad relativa y condiciones reproductivas. Se utilizó una muestra de sangre para análisis parasitológico y extracción de ADN para la amplificar una región del ARNr 18S. Se capturaron 125 murciélagos, siendo las familias más abundantes Molossidae (62/125; 49,6%) y Phyllostomidae (43/125; 34,4%). Molossus molossus capturado en ecótopos silvestres mostró una frecuencia de infección del 8,1% (5/61) y 4,1% (3/61) mediante análisis parasitológico y molecular, respectivamente. En comparación, Noctilio albiventris capturado en ecótopos urbanos mostró una frecuencia de infección del 16,6% (2/12) para ambos análisis. Estos hallazgos representan los primeros registros de M. molossus albergando Trypanosoma spp. para el Departamento del Atlántico y de N. albiventris albergando Trypanosoma spp. en Colombia. Motivación para realizar el estudio. El rol de los murciélagos como hospederos de Trypanosoma spp. en el Departamento del Atlántico en Colombia, así como su diversidad taxonómica ha sido poco estudiada. Principales hallazgos. Este es el primer reporte de frecuencia de infección por Trypanosoma spp. en murciélagos en el Departamento del Atlántico en Colombia. Implicancias. La gran capacidad de adaptación de los murciélagos a diferentes nichos ecológicos y su rol como hospederos de Trypanosoma spp. en ecótopos silvestres y urbanos representa un factor de riesgo en ciclos de transmisión de importancia epidemiológica.

Electronic von Frey associated with the Mouse Grimace Scale to Assess Allodynia and Pain in Trypanosoma evansi-Infected Mice.

Infectious disease pathogenesis is still a complex field to study. The course of several clinical signs, such as allodynia and pain, may be observed in domestic animals. However, the knowledge of their pathways and correct treatment need controlled experiments, many of them using laboratory animals. Measuring changes in mechanical thresholds of the hind paw and viscera is a useful technique to observe changes in pain perception in rodents. Withdrawal response can be measured first in baseline tests, which creates better control of experimental groups. Subsequent tests can be performed after inducing infection and adding drugs to the protocol. The use of an electronic von Frey apparatus associated with the use of a facial scale to observe pain-like changes allows a simple, precise, and consistent assessment to evaluate allodynia and pain in mice. Thus, experiments using the present methodology for Trypanosoma evansi infection represent a useful method to evaluate allodynia and pain in laboratory-infected animals, which can be applied to the conventional treatment for livestock animals.

Trypanosoma infection and bloodmeal analysis in post-feeding sand flies across Thailand.

Phlebotomine sand flies are recognized as a primary vector of Leishmania and are also suspected vectors of Trypanosoma. The transmission cycle of these parasites relies on the distribution of sand fly vectors, parasites, and reservoir animals. This study aimed to detect Leishmania and Trypanosoma DNA and identify the sources of bloodmeals in post-feeding sand flies captured across Thailand. A total of 42,911 field female sand flies were collected from 11 provinces across Thailand using CDC light traps. Among these, 253 post-feeding sand flies were selected for analysis. The predominant species in this study was Sergentomyia khawi (33.60 %). The DNA was extracted from individual female sand flies. Polymerase chain reaction (PCR), specific to the internal transcribed spacer 1 (ITS1) and the small subunit ribosomal RNA (SSU rRNA) gene regions were used to detect the presence of Leishmania and Trypanosoma DNA, respectively. Additionally, cytochrome c oxidase subunit I (COI) gene region was utilized to identify the sources of host bloodmeals. Leishmania DNA was not detected in any specimens. The analysis of SSU rRNA sequences revealed the presence of Trypanosoma DNA (11.46 %, 29/253) in sand fly samples. Among these samples, T. noyesi (1.58 %, 4/253) was identified in Idiophlebotomus longiforceps and Phlebotomus asperulus, Trypanosoma Anura01+02/Frog2 (1.18 %, 3/253) in Se. khawi, and Trypanosoma Anura04/Frog1 (8.70 %, 22/253) in Se. khawi, Se. hivernus and Grossomyia indica. Bloodmeal analysis utilizing the COI gene revealed a diverse range of vertebrate hosts' blood, including bird, bat, frog and sun skink. Our findings confirm the presence of Trypanosoma DNA and identify the sources of bloodmeals from vertebrate hosts in various sand fly species, suggesting their potential as possible vectors for Trypanosoma in Thailand. Furthermore, our study is the first to provide molecular evidence using the COI gene to identify frogs as a host blood source for sand flies in Thailand. Further studies focusing on the isolation of live parasites in sand flies to confirm vector potential and examining the role of animal reservoirs will enhance our understanding of the host-parasite relationship and enable more efficient control for disease transmission.

Molecular identification of haemoparasites in animals using blood lysate PCR: a quick and inexpensive alternative to purified whole genomic DNA.

Haemoparasitic diseases constitute a significant constraint to economic livestock farming. Diagnostic techniques that are inexpensive, rapid, reliable, and precise are crucial for the management of diseases. In this context, PCR assays are very valuable yet expensive since the samples must be processed before being included in the PCR reaction. Accordingly, the goal of the current study was to lower the PCR costs without jeopardizing the assay's sensitivity and specificity. For that purpose, the alkaline solution was optimized for low cost and quick DNA extraction (blood lysate), and PCR reagents were modified for optimum reaction. In comparison to purified whole blood genomic DNA, the currently developed and optimized blood lysate method was found to be 95.5% less expensive, as well as being equally sensitive and specific for the molecular detection (PCR) of haemoparasites like Babesia, Theileria, Trypanosoma and rickettsiales in cattle, buffaloes, horses, and dogs. The assay was also demonstrated to be quick, less likely to cross-contaminate, and appropriate for use in laboratories with limited resources. Therefore, the currently developed and optimized blood lysate method could serve as a viable alternative to purified whole blood genomic DNA for molecular detection (PCR) of haemoparasites in animals particularly in resource-limited settings.

Prevalence of bovine trypanosomosis and tsetse fly density in Loka Abaya and Derara districts in Sidama Regional State, Ethiopia.

Animal trypanosomosis is a significant livestock disease with economic and social repercussions, reducing the supply of animal products and restricting the utilization of animals for traction and transportation. In Ethiopia, it is prevalent and poses a major hindrance to the advancement of animal production. This repeated cross-sectional study was aimed at assessing seasonal variation in bovine trypanosomosis prevalence and tsetse fly density and identifying the potential risk factors in the Loka Abaya and Derara districts of the Sidama National Regional State. Blood samples were collected from 964 cattle, 484 samples during the dry season, and 480 during the wet season. The buffy coat method was employed to analyze these samples. Furthermore, 78 standard NGU traps were set up at various locations in the two districts during both seasons for entomological investigation. The overall apparent prevalence of trypanosomosis was 9% (95% CI 7.3-11.0), without a significant difference (p > 0.05) between the dry season (7.4%) and wet season (10.6%). The apparent prevalence was significantly higher in Loka Abaya (11.8%) than in Derara (6.3%) district (OR = 2.04; p = 0.003) and in cattle with black coat color (29%) than in mixed color (6.8%) (OR = 5.3; p < 0.001). The majority of infections were caused by Trypanosoma congolense (70%), followed by T. vivax (29%), and mixed infections (1%) with the two species. The average packed cell volume (PCV) was significantly (p < 0.0001) lower in infected animals (20.7 ± 4%) compared to uninfected ones (25.5 ± 5.4%), in cattle examined during the dry season (24.1 ± 6%) versus the wet season (26.1 ± 4.7%), in cattle sampled from the Loka Abaya district (24.2 ± 5.5%) versus Derara district (26 ± 5.3%), and in cattle with poor body condition (23.6 ± 5.7%) compared to those with good body condition (26.5 ± 5.3%). A total of 5282 flies were captured during the study, with 4437 (84%) being tsetse flies (Glossina pallidipes), 439 (8.3%) Tabanids, 190 (3.6%) Stomoxys spp., and 216 (4.1%) Musca spp. The apparent density (AD) of G. pallidipes was 28.4 flies/trap/day, showing no statistically significant difference between wet (32.1) and dry (24.6) seasons (p > 0.05). The AD of G. pallidipes was significantly (p < 0.001) higher in the Loka Abaya district (57.3) than in the Derara district (0.9). The study highlights a moderate trypanosomosis apparent prevalence and high AD of G. pallidipes, showing significant variation between the study districts but no seasonal difference. The observed apparent prevalence of trypanosomosis and tsetse fly density notably affects animal health and productivity. As a result, strategies for vector control like insecticide-treated targets, trypanocidal medications for infected animals, and community-based initiatives such as education and participation in control programs are recommended.

Neglected Tropical Diseases: A Chemoinformatics Approach for the Use of Biodiversity in Anti-Trypanosomatid Drug Discovery.

The development of new treatments for neglected tropical diseases (NTDs) remains a major challenge in the 21st century. In most cases, the available drugs are obsolete and have limitations in terms of efficacy and safety. The situation becomes even more complex when considering the low number of new chemical entities (NCEs) currently in use in advanced clinical trials for most of these diseases. Natural products (NPs) are valuable sources of hits and lead compounds with privileged scaffolds for the discovery of new bioactive molecules. Considering the relevance of biodiversity for drug discovery, a chemoinformatics analysis was conducted on a compound dataset of NPs with anti-trypanosomatid activity reported in 497 research articles from 2019 to 2024. Structures corresponding to different metabolic classes were identified, including terpenoids, benzoic acids, benzenoids, steroids, alkaloids, phenylpropanoids, peptides, flavonoids, polyketides, lignans, cytochalasins, and naphthoquinones. This unique collection of NPs occupies regions of the chemical space with drug-like properties that are relevant to anti-trypanosomatid drug discovery. The gathered information greatly enhanced our understanding of biologically relevant chemical classes, structural features, and physicochemical properties. These results can be useful in guiding future medicinal chemistry efforts for the development of NP-inspired NCEs to treat NTDs caused by trypanosomatid parasites.

Un caso de Chagas agudo en edad pediátrica / Acute Vector-transmitted Chagas in Pediatric Age. A Case Reportt

Presentación del caso. Se trata una niña de siete años de edad, originaria de una zona rural del departamento de San Miguel, quién consultó por presentar fiebre y edema bipalpebral derecho indoloro, de seis semanas de evolución, sin otros síntomas acompañantes. El estudio para el diagnóstico de enfermedad de Chagas fue realizado en una clínica privada; la Inmunoglobulina M para Chagas tuvo un resultado positivo, luego, se realizó la microscopía directa mediante gota al fresco y técnica de Strout con resultado negativo. En las intervenciones comunitarias se identificó la presencia del vector y la positividad del mismo, así como el diagnóstico de un caso crónico en otro miembro de la familia. Intervención terapéutica. Se indicó tratamiento con nifurtimox 150 mg cada ocho horas por 60 días y se realizó el seguimiento clínico de la evolución y control de efectos secundarios del tratamiento y exámenes de laboratorio. Evolución clínica. Evolucionó con leve disminución del apetito, se manejó con protectores gástricos. El concentrado de Strout y la gota al fresco resultaron negativos y los demás exámenes de laboratorio se mantenían en los rangos normales.

Case presentation. A seven-year-old female patient, with no previous medical history, originally from a rural area of the department of San Miguel, who presented febrile process plus long-term right bipalpebral edema of six weeks of evolution, without accompanying symptoms. Immunoglobulin M for Chagas was positive, direct microscopy by fresh drop and Strout technique was performed with negative results. In community interventions, the presence of the vector and its positivity were identified, as well as the diagnosis of a chronic case in another family member. Treatment. The patient was treated with nifurtimox 150 mg every eight hours for 60 days, subsequent controls were performed to investigate side effects of the treatment, and control tests. Outcome. With the treatment, the patient evolved with a slight decrease in appetite, and was managed with gastric protectors. Strout's concentrate and fresh gout were negative and the other laboratory tests were within normal ranges.

Iatrogenic transmission of Trypanosoma evansi infection in camels and its consequences.

Trypanosoma evansi infection has started to become a wide spread phenomena around the camel-rearing areas of North Africa and the Middle East. The disease caused by trypanosomes is locally known as "Surra" and it can seriously impact not only the health of domestic animals but the local economy as well. After taking over the management of a farm containing approximately 700 camels, it was found that a large number were suffering from trypanosome infection and it was of the utmost importance to find the source of this infection. An extensive dive into the records and observations were initially made to identify the infected population. Under closer inspection it was found that the infection was limited mostly to female individuals that had undergone extended reproductive analysis or treatment. Blood samples were taken from each of the individuals for buffy coat test and blood smears. Among the total number of tested camels (n = 590), almost 40% were infected with trypanosomes. The number and percentage of infection correlate with the number of fertility and pregnancy treatments that the camels had undergone. The most severely infected group, underwent between 17 and 20 instances of treatment or tests, had an infection rate of almost 90%. The devastating effect of trypanosomiasis on camel pregnancy and birth were also verified with 61% of all abortions and 82% of all neonatal deaths coming from trypanosome infected individuals. These results clearly demonstrate how damaging iatrogenic infections of T. evansi can be and how simply they could have been prevented.

Molecular detection of trypanosomes of the Trypanosoma livingstonei species group in diverse bat species in Central Cameroon.

Bats are hosts for diverse Trypanosoma species, including trypanosomes of the Trypanosoma cruzi clade. This clade is believed to have originated in Africa and diversified in many lineages worldwide. In several geographical areas, including Cameroon, no data about trypanosomes of bats has been collected yet. In this study, we investigated the diversity and phylogenetic relationships of trypanosomes of different bat species in the central region of Cameroon. Trypanosome infections were detected in six bat species of four bat families, namely Hipposideridae, Pteropodidae, Rhinolophidae, and Vespertilionidae, with an overall prevalence of 29% and the highest infection rate in hipposiderid bat species. All trypanosomes were identified as belonging to the Trypanosoma livingstonei species group with one clade that might represent an additional subspecies of T. livingstonei. Understanding the prevalence, distribution, and host range of parasites of this group contributes to our overall knowledge of the diversity and host specificity of trypanosome species that phylogenetically group at the base of the T. cruzi clade.

A breath of fresh air: impact of insect-borne protozoan parasites on the respiratory system.

The protozoan parasites Plasmodium, Leishmania, and Trypanosoma are transmitted by hematophagous insects and cause severe diseases in humans. These infections pose a global threat, particularly in low-resource settings, and are increasingly extending beyond the current endemic regions. Tropism of parasites is crucial for their development, and recent studies have revealed colonization of noncanonical tissues, aiding their survival and immune evasion. Despite receiving limited attention, cumulative evidence discloses the respiratory system as a significant interface for host-pathogen interactions, influencing the course of (co)infection and disease onset. Due to its pathophysiological and clinical implications, we emphasize that further research is needed to better understand the involvement of the respiratory system and its potential to improve prevention, diagnosis, treatment, and interruption of the chain of transmission.

What is needed to achieve effective and sustainable control of African animal trypanosomosis?

A welcome resurgence in African animal trypanosomosis (AAT) research has resulted in advances in capabilities, foundational datasets, and understanding. Additionally, there is the prospect of the first new trypanocide in >60 years. However, it is vital to ensure that advances translate to improved and sustainable control in the field. A recent meeting, the Symposium on African Livestock Trypanosomes - Tanzania, convened stakeholders from across the spectrum of AAT research and control to ask how this can be achieved. Current constraints on progress were defined, as were critical gaps and opportunities that need addressing. There is a requirement and opportunity for the AAT research community to communicate, collaborate, and coordinate to maintain momentum and achieve the ultimate goal of sustainable AAT control.

Blood parasites of water frogs (Pelophylax esculentus complex) from the Danube Delta, Romania.

Water frogs of the genus Pelophylax host a variety of parasites, from protozoa to helminths. Among the blood parasites, representatives of Apicomplexa, Trypanosoma and Nematoda show the highest prevalence. In this study, we focused on blood parasites of water frogs living in the Danube Delta, Romania. In total, 74 individuals of P. ridibundus and eight individuals of P. esculentus from six localities were examined. Blood parasites were detected microscopically and using a molecular marker (18S rDNA). 89.77% of frogs from all investigated localities were found to be infected with at least one parasitic group, specifically with haemogregarines (84.09%), nematodes (1.14%), and trypanosomes (63.64%). The parasitemia of haemogregarines and trypanosomes differed significantly among the studied locations. There was no statistically significant difference in parasitemia between male and female hosts. However, adults were found to have a significantly higher parasitemia in comparison with subadults infected with haemogregarines. Correlation between parasitemia and the body length of frogs infected with haemogregarines was also significant (r = 0.226). By comparing the 18S rDNA sequences with the corresponding GenBank sequences, Hepatozoon species identified in water frogs showed a close similarity (98.1-99.8%) to Hepatozoon magna. Trypanosomes showed the highest sequence similarity to Trypanosoma sp. isolate R10 clone L2-3, Trypanosoma ranarum, and Trypanosoma cobitis.