Congo
Dotaz
Zobrazit nápovědu
Infections of humans with the tick-borne Crimean-Congo hemorrhagic fever virus (CCHFV) can cause a severe hemorrhagic fever with case fatality rates of up to 80%. Most humans are infected by tick bite, crushing infected ticks by hand or by unprotected contact with blood of viremic mammals. Next to the notified human CCHF cases, the real distribution and the situation in animals in Southeastern Europe are nearly unknown. Since domestic ruminants play a crucial role in the life cycle of the vector ticks and the transmission and amplification of the virus, the antibody prevalence in those animals is a good indicator for the presence of CCHFV in a region. Therefore, the prevalence of CCHFV-specific antibodies was investigated in domestic ruminants of different regions of Bulgaria and Turkey. Sera of 1165 ruminants were tested and a prevalence of up to 90% was identified. The overall prevalence for Bulgaria was 26% and for Turkey 57%. The results highlight the risk of human infections in those regions and the importance of the investigation of the prevalence in animals for identification of risk areas. This article provides a unique overview about published CCHFV antibody prevalence in animals in comparison to human incidences in different areas of Bulgaria and Turkey. Although it will help to complete the understanding of the CCHFV situation in these countries, it also demonstrates the lack of unpublished and published data even in these highly endemic areas.
- Klíčová slova
- Crimean–Congo hemorrhagic fever virus: CCHFV, ELISA, domestic animals, epidemiology,
- MeSH
- hemoragická horečka krymská krev epidemiologie veterinární MeSH
- klíšťata virologie MeSH
- lidé MeSH
- přežvýkavci MeSH
- protilátky virové krev MeSH
- séroepidemiologické studie MeSH
- virus krymsko-konžské hemoragické horečky izolace a purifikace MeSH
- zoonózy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Bulharsko epidemiologie MeSH
- Turecko epidemiologie MeSH
- Názvy látek
- protilátky virové MeSH
OBJECTIVES: The aim of this study was to detect the seroprevalence of Crimean-Congo haemorrhagic fever virus (CCHFV) in patients with fever of unknown origin (FUO) in endemic (Kyzylorda) and non-endemic (Almaty) oblasts of Kazakhstan. METHODS: Paired serum samples from 802 patients with FUO were collected. Serum samples were investigated by ELISA to detect IgG and IgM antibodies against CCHFV. Sera with suspected acute infection were further investigated by RT-PCR to detect the viral RNA. RESULTS: IgG antibodies were detected in 12.7% of the sera from both oblasts. Acute infection was shown by IgM ELISA in four patients from Kyzylorda, with only one developing severe CCHF. Viral RNA was found by RT-PCR in the other three patients' sera. Phylogenetic analysis of partial L and S segments revealed CCHFV genotype Asia 2 and a possible reassortment between the genotypes Asia 1/Asia 2. Animal husbandry, such as working with cattle and horses, was significantly associated with CCHFV seropositivity. CONCLUSIONS: The antibodies and viral RNA detected in sera indicate that mild or even asymptomatic CCHFV infections are presented in Kazakhstan. This study describes the circulation of CCHFV in the so far non-endemic Almaty oblast for the first time. In conclusion, physicians treating patients with FUO in Kazakhstan should be aware of mild CCHF.
- Klíčová slova
- Crimean–Congo haemorrhagic fever virus, Fever of unknown origin, Kazakhstan, Reassortment,
- MeSH
- dospělí MeSH
- ELISA MeSH
- hemoragická horečka krymská komplikace epidemiologie MeSH
- horečka neznámého původu etiologie MeSH
- koně MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- protilátky virové krev MeSH
- RNA virová krev MeSH
- séroepidemiologické studie MeSH
- skot MeSH
- virus krymsko-konžské hemoragické horečky genetika imunologie MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- skot MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kazachstán epidemiologie MeSH
- Názvy látek
- protilátky virové MeSH
- RNA virová MeSH
Crimean Congo hemorrhagic fever virus (CCHFV) is a highly virulent tick-borne pathogen that causes hemorrhagic fever in humans. The geographic range of human CCHF cases largely reflects the presence of ticks. However, highly similar CCHFV lineages occur in geographically distant regions. Tick-infested migratory birds have been suggested, but not confirmed, to contribute to the dispersal. Bats have recently been shown to carry nairoviruses distinct from CCHFV. In order to assess the presence of CCHFV in a wide range of bat species over a wide geographic range, we analyzed 1,135 sera from 16 different bat species collected in Congo, Gabon, Ghana, Germany, and Panama. Using a CCHFV glycoprotein-based indirect immunofluorescence test (IIFT), we identified reactive antibodies in 10.0% (114/1,135) of tested bats, pertaining to 12/16 tested species. Depending on the species, 3.6%-42.9% of cave-dwelling bats and 0.6%-7.1% of foliage-living bats were seropositive (two-tailed t-test, p = 0.0447 cave versus foliage). 11/30 IIFT-reactive sera from 10 different African bat species had neutralizing activity in a virus-like particle assay. Neutralization of full CCHFV was confirmed in 5 of 7 sera. Widespread infection of cave-dwelling bats may indicate a role for bats in the life cycle and geographic dispersal of CCHFV.
- MeSH
- Chiroptera * krev virologie MeSH
- hemoragická horečka krymská * krev epidemiologie MeSH
- lidé MeSH
- virus krymsko-konžské hemoragické horečky * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Německo epidemiologie MeSH
- Panama epidemiologie MeSH
- střední Afrika epidemiologie MeSH
African pangolins are hunted for their meat and for use in local traditional medicine, as well as for their scales, which are trafficked internationally, especially to growing Asian markets. Pangolin's population genetic structure can be used to trace the geographic origins of trafficked scales, but substantial sampling gaps across pangolins' ranges hinder these efforts. In this study, we documented population structure and dynamics in the two species of African pangolin, the white-bellied pangolin (Phataginus tricuspis) and the giant pangolin (Smutsia gigantea) in the underexplored Republic of Congo. Using the mitochondrial control region and two nuclear markers (beta-fibrinogen and titin), we identified high genetic diversity in both species. We document a distinct mitochondrial lineage of the white-bellied pangolin, which was most likely shaped by river barriers together with dynamics of forest refugia related to the climatic shifts during the Pleistocene. We detected population growth in the white-bellied pangolin coinciding with a dry period during the Pleistocene, suggesting some ability for this typically forest-dwelling species to persist under diverse environmental conditions. Using landscape genetics, we found all but one of the pangolins we sampled at bush meat markets originated locally. A single individual appeared to have been imported to Congo from Cameroon. These findings significantly contribute to our understanding of pangolin population biology and local trade dynamics. In addition, our data from a previously unstudied part of pangolins' ranges will help us to better understand international wildlife trafficking patterns and to target conservation and protection strategies for these highly vulnerable species.
- Klíčová slova
- Congo Basin, Conservation genetics, Genetic diversity, Pangolins, Phylogeography, Population structure, Wildlife trade,
- MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- luskouni * genetika MeSH
- mitochondriální DNA genetika MeSH
- populační dynamika MeSH
- populační genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kongo MeSH
- Názvy látek
- mitochondriální DNA MeSH
Crimean-Congo haemorrhagic fever orthonairovirus (CCHFV) is a negative-sense, single-stranded RNA virus with a segmented genome and the causative agent of a severe Crimean-Congo haemorrhagic fever (CCHF) disease. The virus is transmitted mainly by tick species in Hyalomma genus but other ticks such as representatives of genera Dermacentor and Rhipicephalus may also be involved in virus life cycle. To improve our understanding of CCHFV adaptation to its tick species, we compared nucleotide composition and codon usage patterns among the all CCHFV strains i) which sequences and other metadata as locality of collection and date of isolation are available in GenBank and ii) which were isolated from in-field collected tick species. These criteria fulfilled 70 sequences (24 coding for S, 23 for M, and 23 for L segment) of virus isolates originating from different representatives of Hyalomma and Rhipicephalus genera. Phylogenetic analyses confirmed that Hyalomma- and Rhipicephalus-originating CCHFV isolates belong to phylogenetically distinct CCHFV clades. Analyses of nucleotide composition among the Hyalomma- and Rhipicephalus-originating CCHFV isolates also showed significant differences, mainly in nucleotides located at the 3rd codon positions indicating changes in codon usage among these lineages. Analyses of codon adaptation index (CAI), effective number of codons (ENC), and other codon usage statistics revealed significant differences between Hyalomma- and Rhipicephalus-isolated CCHFV strains. Despite both sets of strains displayed a higher adaptation to use codons that are preferred by Hyalomma ticks than Rhipicephalus ticks, there were distinct codon usage preferences observed between the two tick species. These findings suggest that over the course of its long co-evolution with tick vectors, CCHFV has optimized its codon usage to efficiently utilize translational resources of Hyalomma species.
- MeSH
- fylogeneze * MeSH
- fyziologická adaptace genetika MeSH
- hemoragická horečka krymská virologie genetika MeSH
- Ixodidae virologie genetika MeSH
- klíšťata virologie genetika MeSH
- virus krymsko-konžské hemoragické horečky * genetika MeSH
- využití kodonu MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The Lower Congo Basin is characterized by a mangrove-lined estuary at its mouth and, further upstream, by many hydrogeographical barriers such as rapids and narrow gorges. Five localities in the mangroves and four from (upstream) left bank tributaries or pools were sampled. On the gills of Coptodon tholloni, Coptodon rendalli, Hemichromis elongatus, Hemichromis stellifer and Tylochromis praecox, 17 species of parasites (Dactylogyridae & Gyrodactylidae, Monogenea) were found, eight of which are new to science. Six of these are herein described: Cichlidogyrus bixlerzavalai n. sp. and Cichlidogyrus omari n. sp. from T. praecox, Cichlidogyrus calycinus n. sp. and Cichlidogyrus polyenso n. sp. from H. elongatus, Cichlidogyrus kmentovae n. sp. from H. stellifer and Onchobdella ximenae n. sp. from both species of Hemichromis. On Cichlidogyrus reversati a ridge on the accessory piece was discovered that connects to the basal bulb of the penis. We report a putative spillback effect of the native parasites Cichlidogyrus berradae, Cichlidogyrus cubitus and Cichlidogyrus flexicolpos from C. tholloni to the introduced C. rendalli. From our results, we note that the parasite fauna of Lower Congo has a higher affinity with the fauna of West African and nearby freshwater ecoregions than it has with fauna of other regions of the Congo Basin and Central Africa.
Le cours du Bas Congo est caractérisé par un estuaire bordé de mangroves et, plus en amont, par de nombreuses barrières hydro-géographiques formées de rapides ou de gorges étroites. Nous avons échantillonné dans cinq localités au niveau des mangroves et dans quatre autres en amont sur la rive gauche du fleuve, dans des affluents ou des étangs. Nous avons trouvé, sur les branchies de Coptodon tholloni, Coptodon rendalli, Hemichromis elongatus, Hemichromis stellifer et Tylochromis praecox, 17 espèces de parasites (Dactylogyridae et Gyrodactylidae, Monogenea), dont huit sont nouvelles pour la science. Six d’entre elles sont décrites ici : Cichlidogyrus bixlerzavalai n. sp. et Cichlidogyrus omari n. sp. sur T. praecox, Cichlidogyrus calycinus n. sp. et Cichlidogyrus polyenso n. sp. sur H. elongatus, Cichlidogyrus kmentovae n. sp. sur H. stellifer et Onchobdella ximenae n. sp. sur les deux espèces d’Hemichromis. Nous décrivons, chez Cichlidogyrus reversati, une arête sur la pièce accessoire qui la connecte avec l’ampoule basale basal du pénis. Nous notons un probable transfert latéral des espèces autochtones Cichlidogyrus berradae, Cichlidogyrus cubitus et Cichlidogyrus flexicolpos de C. tholloni vers l’espèce introduite C. rendalli. Nos résultats montrent que la faune parasitaire du Bas Congo présente plus d’affinités avec les faunes d’Afrique de l’Ouest ou des écorégions d’eau douce voisines, qu’avec celles des autres parties du bassin du Congo ou de l’Afrique Centrale.
- MeSH
- biodiverzita MeSH
- cichlidy anatomie a histologie parazitologie MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- infekce červy třídy Trematoda epidemiologie parazitologie veterinární MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- ploštěnci klasifikace genetika izolace a purifikace MeSH
- sladká voda parazitologie MeSH
- žábry parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kongo epidemiologie MeSH
Crimean-Congo haemorrhagic fever (CCHF) is the most widely distributed tick-borne viral disease in humans and is caused by the Crimean-Congo haemorrhagic fever virus (CCHFV). The virus has a broader distribution, expanding from western China and South Asia to the Middle East, southeast Europe, and Africa. The historical known distribution of the CCHFV vector Hyalomma marginatum in Europe includes most of the Mediterranean and the Balkan countries, Ukraine, and southern Russia. Further expansion of its potential distribution may have occurred in and out of the Mediterranean region. This study updated the distributional map of the principal vector of CCHFV, H. marginatum, in the Old World using an ecological niche modeling approach based on occurrence records from the Global Biodiversity Information Facility (GBIF) and a set of covariates. The model predicted higher suitability of H. marginatum occurrences in diverse regions of Africa and Asia. Furthermore, the model estimated the environmental suitability of H. marginatum across Europe. On a continental scale, the model anticipated a widespread potential distribution encompassing the southern, western, central, and eastern parts of Europe, reaching as far north as the southern regions of Scandinavian countries. The distribution of H. marginatum also covered countries across Central Europe where the species is not autochthonous. All models were statistically robust and performed better than random expectations (p < 0.001). Based on the model results, climatic conditions could hamper the successful overwintering of H. marginatum and their survival as adults in many regions of the Old World. Regular updates of the models are still required to continually assess the areas at risk using up-to-date occurrence and climatic data in present-day and future conditions.
- MeSH
- hemoragická horečka krymská * epidemiologie MeSH
- Ixodidae * MeSH
- lidé MeSH
- nemoci přenášené klíšťaty * MeSH
- virus krymsko-konžské hemoragické horečky * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
Schistosomiasis is a snail-borne disease that has a considerable impact on human and animal health, particularly in sub-Saharan Africa. The intermediate hosts of the schistosome parasites are freshwater snails of the genera Biomphalaria Preston, 1910 and Bulinus Müller, 1781. In order to identify existing gaps in the spread of the disease in the Democratic Republic of Congo (DRC), this study compiled the available knowledge of the distribution, population dynamics and ecology of the intermediate hosts of schistosomiasis. A systematic literature search was conducted in PubMed, Embase and Scopus for all malacological studies on schistosoma intermediate hosts in DRC published between 1927 and October 2022. A total of 55 records were found, of which 31 met the inclusion criteria: these were published field and experimental studies conducted in the DRC and focused on snails as intermediate hosts of schistosomes. The analysis of these studies revealed that more up-to-date data on the distribution of snail intermediate hosts in the DRC are needed. Moreover, ecological factors have been less studied for Bulinus species than for Biomphalaria species. These factors play a crucial role in determining suitable snail habitats, and the lack of comprehensive information poses a challenge in snail control. This review makes it clear that there are no current malacological data in the DRC. There is a clear need for molecular and ecological research to update the exact species status and population dynamics of all potential intermediate host species. This will facilitate targeted snail control measures that complement drug treatment in the control of schistosomiasis in the country.
- Klíčová slova
- Africa., Bilharzia, Biomphalaria, Bulinus, malacology, snails,
- MeSH
- Biomphalaria * parazitologie MeSH
- Bulinus parazitologie MeSH
- hlemýždi parazitologie MeSH
- lidé MeSH
- Schistosoma fyziologie MeSH
- schistosomóza * epidemiologie veterinární MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- systematický přehled MeSH
- Geografické názvy
- Konžská demokratická republika epidemiologie MeSH
During colonial times, Nile tilapia Oreochromis niloticus (Linnaeus, 1758) was introduced into non-native parts of the Congo Basin (Democratic Republic of the Congo, DRC) for the first time. Currently, it is the most farmed cichlid in the DRC, and is present throughout the Congo Basin. Although Nile tilapia has been reported as an invasive species, documentation of historical introductions into this basin and its consequences are scant. Here, we study the genetic consequences of these introductions by genotyping 213 Nile tilapia from native and introduced regions, focusing on the Congo Basin. Additionally, 48 specimens from 16 other tilapia species were included to test for hybridization. Using RAD sequencing (27,611 single nucleotide polymorphisms), we discovered genetic admixture with other tilapia species in several morphologically identified Nile tilapia from the Congo Basin, reflecting their ability to interbreed and the potential threat they pose to the genetic integrity of native tilapias. Nile tilapia populations from the Upper Congo and those from the Middle-Lower Congo are strongly differentiated. The former show genetic similarity to Nile tilapia from the White Nile, while specimens from the Benue Basin and Lake Kariba are similar to Nile tilapia from the Middle-Lower Congo, suggesting independent introductions using different sources. We conclude that the presence of Nile tilapia in the Congo Basin results from independent introductions, reflecting the dynamic aquaculture history, and that their introduction probably leads to genetic interactions with native tilapias, which could lower their fitness. We therefore urge avoiding further introductions of Nile tilapia in non-native regions and to use native tilapias in future aquaculture efforts.
- Klíčová slova
- RAD sequencing, cichlid, genetic integrity, genetic structure, independent introductions, invasive species,
- MeSH
- cichlidy * genetika MeSH
- metagenomika MeSH
- vodní hospodářství MeSH
- zavlečené druhy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Konžská demokratická republika MeSH
Dromedaries are an important livestock, used as beasts of burden and for meat and milk production. However, they can act as an intermediate source or vector for transmitting zoonotic viruses to humans, such as the Middle East respiratory syndrome coronavirus (MERS-CoV) or Crimean-Congo hemorrhagic fever virus (CCHFV). After several outbreaks of CCHFV in the Arabian Peninsula, recent studies have demonstrated that CCHFV is endemic in dromedaries and camel ticks in the United Arab Emirates (UAE). There is no apparent disease in dromedaries after the bite of infected ticks; in contrast, fever, myalgia, lymphadenopathy, and petechial hemorrhaging are common symptoms in humans, with a case fatality ratio of up to 40%. We used the in-solution hybridization capture of 100 annotated immune genes to genotype 121 dromedaries from the UAE tested for seropositivity to CCHFV. Through univariate linear regression analysis, we identified two candidate genes belonging to the innate immune system: FCAR and CLEC2B. These genes have important functions in the host defense against viral infections and in stimulating natural killer cells, respectively. This study opens doors for future research into immune defense mechanisms in an enzootic host against an important zoonotic disease.
- Klíčová slova
- Camelus dromedarius, Old World camel, in-solution hybridization capture, tick, vector-borne infection, zoonosis,
- MeSH
- genetická predispozice k nemoci genetika MeSH
- genotyp MeSH
- hemoragická horečka krymská genetika imunologie virologie MeSH
- infestace klíšťaty imunologie parazitologie MeSH
- klíšťata imunologie fyziologie virologie MeSH
- koronavirové infekce genetika imunologie virologie MeSH
- kuřecí embryo MeSH
- lidé MeSH
- odolnost vůči nemocem genetika imunologie MeSH
- přirozená imunita genetika imunologie MeSH
- rizikové faktory MeSH
- velbloudi genetika imunologie virologie MeSH
- virus krymsko-konžské hemoragické horečky imunologie fyziologie MeSH
- zoonózy genetika imunologie virologie MeSH
- zvířata MeSH
- Check Tag
- kuřecí embryo MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Spojené arabské emiráty MeSH