Search Results (61)

Understanding the risk factors for vector-borne diseases, such as Crimean–Congo hemorrhagic fever (CCHF), is critical for effective public health strategies. This study aims to identify and map the environmental and climatic determinants influencing the distribution of Hyalomma marginatum, the primary vector of CCHF, in Türkiye, using a Multi-Criteria Decision Analysis (MCDA) approach. A rapid literature review was conducted to identify environmental, climatic, and methodological criteria used in MCDA studies on vector-borne diseases. Semi-structured interviews with local experts from Armenia, Serbia, and Türkiye provided fine-scale data on vector presence. These criteria were analyzed using the Analytic Hierarchy Process (AHP) and combined with Weighted Linear Combination (WLC) within the MCDA framework to produce risk maps for H. marginatum occurrence in Türkiye. Key environmental and climatic factors influencing H. marginatum distribution, such as temperature, humidity, vegetation, and precipitation, were identified. The MCDA analysis highlighted high-risk regions in Türkiye with elevated suitability for the vector, correlating with areas of human CCHF cases. MCDA risk maps are valuable tools for public health officials, enabling targeted surveillance and interventions. By integrating diverse environmental and climatic variables, this study enhances the understanding of CCHF dynamics and supports the development of focused control strategies. Full article

Ticks from the Hyalomma genus have recently garnered public attention in countries in Northern and Central Europe, as they are transported by migratory birds and might have established stable populations due to climate warming. The main threat associated with Hyalomma ticks is their ability to transmit Crimean–Congo hemorrhagic fever virus (CCHFV), which can be fatal in up to 40% of cases. Here, we collected Hyalomma ticks from migratory birds during annual ringing actions in the spring seasons of 2023 and 2024. Four ticks were found on birds from the Acrocephalus genus and two on Hippolais icterina. The ticks were examined for the presence of Rickettsia spp., Babesia microti, Babesia divergens, Coxiella burnetii, Borreliella burgdorferi (s. l.), Anaplasma phagocytophilum, West Nile virus, and CCHF virus (CCHFV). The collected H. rufipes specimens were negative for tested pathogens, except for two ticks collected in 2024, which were positive for Rickettsia aeschlimannii. The data show that Hyalomma ticks are efficiently transported on birds preferring reedbeds or deciduous trees. The possibility of the occurrence of CCHF or rickettsiosis (induced by R. aeschlimannii) is currently assessed as low. Nevertheless, we have shown the transfer of Hyalomma ticks to Poland and indicated the need for careful future epidemiological monitoring of the presence of Hyalomma ticks. Full article

Crimean–Congo hemorrhagic fever virus (CCHF-V) and Ebola virus are lethal pathogens that cause widespread outbreaks of hemorrhagic fever. Both diseases can be transmitted through contact with the bodily fluids of infected individuals, but as an arbovirus, CCHF-V is primarily transmitted through tick bites. Both of these viruses are classified as Risk Group 4 due to the appreciable health threat they pose. To date, there are few effective treatments available to combat these deadly hemorrhagic fevers. Consequently, identifying and characterizing ion channels (viroporins) encoded in the viral genomes may lead to potential targeted drug development. Therefore, using bacteria-based genetic assays, two viroporin candidates from CCHF-V and Ebola have been examined, and their proposed structures have been modeled to aid in further drug discovery. The results indicate that CCHF-V-gp exhibits channel activity, which is indistinguishable from established viroporins found in other viruses. In contrast, our experimental approach was unable to uncover a viroporin candidate in the Ebola virus. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a zoonotic viral disease endemic to parts of Africa, Asia and southeastern Europe. Bulgaria is one of the few European countries with the consistent annual reporting of human CCHF cases. This study provides a descriptive overview of 24 confirmed CCHF cases in Bulgaria between 2015 and 2024. Laboratory confirmation was performed by an enzyme-linked immunosorbent assay (ELISA) and/or real-time reverse transcriptase polymerase chain reaction (RT-qPCR) testing. Common findings included fever, fatigue, gastrointestinal symptoms, thrombocytopenia, leukopenia, liver dysfunction and coagulopathy. Two fatal cases were recorded. Two samples collected in 2016 and 2024 were subjected to whole-genome sequencing. Phylogenetic analysis showed that both strains clustered within the Turkish branch of the Europe 1 genotype and shared high genetic similarity with previous Bulgarian strains, as well as strains from neighboring countries. These findings suggest the long-term persistence of a genetically stable viral lineage in the region. Continuous molecular and clinical surveillance is necessary to monitor the evolution and public health impact of CCHFV in endemic areas. Full article

Crimean-Congo Haemorrhagic Fever Virus (CCHFV) is an emerging zoonotic pathogen with a high case fatality risk. Its primary vectors, Hyalomma spp. ticks, are expanding their geographic range, raising concerns about the increasing risk of Crimean-Congo Haemorrhagic Fever (CCHF) outbreaks in Europe. Migratory birds contribute considerably to the spread of Hyalomma ticks, transporting immature forms over long distances during spring migrations. Additionally, climate change plays a crucial role in this expansion by creating favorable conditions for Hyalomma spp. survival and dispersal. This review explores the interplay between Hyalomma spp. ecology as vectors of CCHFV, the role of migratory birds and the impact of climate change on the dispersal of CCHFV across Europe. Understanding these dynamics is essential for assessing future risks, improving surveillance strategies, and implementing effective public health interventions. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease, causing clinical presentations ranging from asymptomatic infection to fatal viral hemorrhagic fever. Throughout the course of CCHF, the levels of certain biomarkers, such as platelets (PLTs), white blood cells (WBCs), C-reactive protein (CRP), and interleukin-6 (IL-6), may vary, decreasing below or rising above normal limits. This study aimed to investigate the role of parameters such as WBC/PLT, WBC/IL-6, WBC/CRP, and WBC/D-dimer ratios in predicting disease prognosis in patients diagnosed with CCHF. The study population consisted of 60 CCHF patients and 30 controls. Statistically significant differences were observed in hemoglobin (HGB), PLT, WBC, activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen, and d-dimer values between the patients and controls. Statistically significant differences were observed in WBC/aPTT, WBC/fibrinogen, WBC/D-dimer, and WBC/IL-6 values between the patient and control groups. WBC/INR and WBC/fibrinogen values were lower in fatal cases compared to survivors. WBC/D-dimer and WBC/IL-6 values, on the other hand, were higher in fatal cases compared to survivors. In patients requiring intensive care unit (ICU), WBC/PLT, WBC/INR, WBC/aPTT, and WBC/fibrinogen values were higher compared to those who did not. However, WBC/D-dimer and WBC/IL-6 values were lower in patients requiring ICU compared to those who did not. Full article

Background/Objectives: Crimean–Congo hemorrhagic fever virus (CCHFV) is an emerging, widely distributed zoonotic tick-borne pathogen. The virus causes severe disease in humans, and numerous wild and domestic animals act as reservoirs of it. Unfortunately, there are no effective therapies or safe vaccines commercialized nowadays for this particular virus. As CCHF (Crimean–Congo hemorrhagic fever) is a serious threat to public health, there is an urgent need to investigate the development of safe and effective vaccination strategies further. Methods: In this work, we have employed two immunization platforms based on protein nanoparticles and a modified vaccinia Ankara (MVA) viral vector using the nucleoprotein (NP) as the target antigen. The humoral and cellular immune responses were characterized by ELISA, ICS, and cytokine measurement. Results: This work shows that a single dose of the vaccine candidates was not as immunogenic as the heterologous vaccination using nanoparticles and MVA. A prime with NP nanoparticles (NS-NP) and a boost with MVA-expressing NP were capable of triggering significant levels of humoral and cellular immune responses against CCHFV in mice. Conclusions: Our study shows that the NS-NP/MVA-NP vaccination strategy effectively elicits a robust humoral and cellular immune response in a mouse model, emphasizing its potential as a protective approach against CCHFV lineages. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic viral disease prevalent in Africa. While infection is asymptomatic in animals, it can cause severe illness with hemorrhagic manifestations and high mortality rates in humans. This study aimed to determine the seroprevalence and potential risk factors of CCHF in wild (rodents, birds) and domestic (cattle, horses) animals in Benin. A cross-sectional study was carried out from 2022 to 2024 with the assistance of cattle breeders, hunters, farmers and bushmeat sellers in 15 districts found in three agroecological zones in the country. A total of 366 serum samples were analyzed, comprising 254 collected from wild animals and 112 from domestic animals. Among the wild animals tested, 1.18% (95% CI: 0.31–3.70; n = 3) were seropositive for antibodies against CCHF virus (CCHFV). The seroprevalence rates were 3.7% (95% CI: 0.19–20.89) in squirrels, 5.88% (95% CI: 0.31–30.76) in hares and 1.19% (95% CI: 0.06–7.38) in giant rats. In domestic animals, anti-CCHFV antibodies were detected in 38 of the 112 samples, resulting in an overall seroprevalence of 33.93% (95% CI: 25.42–43.56). Specifically, antibodies were identified in 34 out of 81 cattle (41.98%, 95% CI: 31.26–53.46) and 4 out of 24 horses (16.67%, 95% CI: 5.48–38.19). No positive samples were reported in pigeons. This study provides the first seroprevalence data on CCHF in wild and domestic animals in Benin. It highlights the risk and epidemiological dynamics of the disease and underscores the need for further investigations into tick vectors and human populations. Full article

Crimean–Congo hemorrhagic fever (CCHF) is fatal in 10 to 40% of cases. It is caused by CCHF virus (CCHFV). Symptoms include fever, headache, myalgia, and often hemorrhage and other complications. This report shows that CCHF may resemble HELLP syndrome (hemolysis, elevated liver enzymes, low platelets). We report CCHF in a pregnant mother with fever and suspected HELLP syndrome, who survived, and her infant (week 36), who died six days after C-section. The high CCHF viral load and bacterial sepsis may have jointly contributed to the death of the infant. CCHF should be considered as a differential diagnosis of HELLP syndrome in regions where this viral disease is endemic. Full article

Crimean–Congo hemorrhagic fever (CCHF) is a serious tick-borne disease with a wide geographical distribution. Classified as a level 4 biosecurity risk pathogen, CCHF can be transmitted cross-species due to its aerosol infectivity and ability to cause severe hemorrhagic fever outbreaks with high morbidity and mortality. However, current methods for detecting anti-CCHFV antibodies are limited. This study aimed to develop a novel luciferase immunosorbent assay (LISA) for the detection of CCHFV-specific IgG antibodies. We designed specific antigenic fragments of the nucleoprotein and evaluated their sensitivity and specificity in detecting IgG in serum samples from mice and horses. In addition, we compared the efficacy of our LISA to a commercial enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that the optimal antigen for detecting anti-CCHFV IgG was located within the stalk cut-off domain of the nucleoprotein. The LISA exhibited high specificity for serum samples from indicated species and significantly higher sensitivity (at least 128 times) compared with the commercial ELISA. The proposed CCHFV-LISA has the potential to facilitate serological diagnosis and epidemiological investigation of CCHFV in natural foci, providing valuable technical support for surveillance and early warning of this disease. Full article

Ticks are temporary ectoparasites that serve as vectors for a wide range of pathogens affecting both wildlife and humans. In Greece, research on the prevalence of tick-borne pathogens in wildlife is limited. This study investigates the presence of pathogens, including Anaplasma spp., Babesia spp., Bartonella spp., Rickettsia spp., as well as tick-borne encephalitis (TBE), and Crimean–Congo hemorrhagic fever (CCHF) viruses, in ticks collected from 28 wild animals across 10 different animal species. Ticks were manually harvested and identified using molecular methods, with sequencing confirming the presence of Hyalomma aegyptium, H. marginatum, H. anatolicum, Ixodes frontalis, and I. ventalloi. Among the pathogens detected, R. aeschlimannii was the most prevalent, particularly in H. aegyptium ticks from tortoises. Additionally, R. africae was identified in H. aegyptium from tortoises, marking the first report of this pathogen in this tick species in Greece. Hemolivia mauritanica, an apicomplexan parasite commonly found in Testudo tortoises, was also detected. No evidence of Babesia spp., Anaplasma spp., Bartonella spp., or viral nucleic acid was found. Phylogenetic analysis revealed close genetic relationships between the detected Rickettsia species and those previously reported in neighboring regions. These findings underscore the role of wildlife in the epidemiology of tick-borne pathogens in Greece and highlight the need for comprehensive surveillance to prevent future outbreaks. Full article

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease transmitted by ticks of the genus Hyalomma and caused by a virus of the Nairoviridae family. In humans, the virus can generate different clinical presentations that can range from asymptomatic to mild illness or produce an hemorrhagic fever with a mortality rate of approximately 30%. The virus pathogenicity and the lack of effective treatment or vaccine for its prevention make it an agent of concern from a public health point of view. The main transmission route is tick bites, so people most exposed to this risk are more likely to become infected. Another risk group are veterinarians and livestock farmers who are in contact with the blood and other fluids of animals that are mostly asymptomatic. Finally, due to its first phase with a non-characteristic symptomatology, there exists a risk of nosocomial infection. It is endemic in Africa, the Balkans, the Middle East, and those Asian countries south of the 50th parallel north, the geographical limit of the main vector. Recently, autochthonous cases have been observed in areas of Europe where the virus was not previously present. Human cases have been detected in Greece, Bulgaria, and Spain. Spain is one of the most affected countries, with a total of 17 autochthonous cases detected since 2013. In other countries, such as France, the virus is present in ticks and animals but has not spread to humans. A high-quality epidemiological surveillance system in these countries is essential to avoid the expansion of this virus to new areas and to limit the impact of current cases. Full article

Crimean-Congo hemorrhagic fever (CCHF) and Rift Valley fever (RVF) are among the list of emerging zoonotic diseases that require special attention and priority. RVF is one of the six priority diseases selected by the Senegalese government. Repeated epidemic episodes and sporadic cases of CCHF and RVF in Senegal motivated this study, involving a national cross-sectional serological survey to assess the distribution of the two diseases in this country throughout the small ruminant population. A total of 2127 sera from small ruminants (goat and sheep) were collected in all regions of Senegal. The overall seroprevalence of CCHF and RVF was 14.1% (IC 95%: 12.5–15.5) and 4.4% (95% CI: 3.5–5.3), respectively. The regions of Saint-Louis (38.4%; 95% CI: 30.4–46.2), Kolda (28.3%; 95% CI: 20.9–35.7), Tambacounda (22.2%; 95% CI: 15.8–28.6) and Kédougou (20.9%; 95% CI: 14.4–27.4) were the most affected areas. The risk factors identified during this study show that the age, species and sex of the animals are key factors in determining exposure to these two viruses. This study confirms the active circulation of CCHF in Senegal and provides important and consistent data that can be used to improve the surveillance strategy of a two-in-one health approach to zoonoses. Full article

Wildlife serve as potential microbial reservoirs, accounting for approximately 70% of emerging infectious diseases. Crimean–Congo hemorrhagic fever virus (CCHFV), which causes Crimean–Congo hemorrhagic fever (CCHF) in humans, is a highly pathogenic tick-borne virus prevalent in several parts of Asia, Africa, and Europe with high case fatality rates. Several CCHFV cases have been reported in Asia, the Middle East, Africa, and Southern and Eastern Europe. The disease is endemic in several parts of western China, particularly Xinjiang. Ticks of the genus Hyalomma have been identified as a principal vector and reservoir for CCHFV, although other tick species may also have a crucial role in maintaining CCHFV in endemic regions. On infection, CCHF begins as a nonspecific febrile illness that can progress to severe hemorrhagic manifestations with a higher case fatality due to the unavailability of vaccines or other therapeutic agents. In this study, we collected tissue samples from a wild dead Chinese serow (Capricornis milneedwardsii) and three Naemorhedus griseuses from Deqin County, Tibetan Autonomous Prefecture, Yunnan, China, to investigate for contagious viruses that could be transmitted to humans. We identified a novel CCHFV strain, YNDQL-415G, in the liver tissue of a dead C. milneedwardsii. We performed nucleotide and amino acid sequence homology on the full-length viral genome. The results revealed significant homology between the viral S segment to that of the Africa1 strain, while the M and L segments showed similarity with the Asia CCHFV strain, indicating potential gene reassortment in the YNDQL-415G strain. The genetic characterization of a novel CCHFV strain from a dead C. milneedwardsii raises concerns about the possibility of a new zoonotic infection. A regular survey program is recommended to track the distribution of wild animals as well as the viruses they may transmit to humans and other domestic mammals in the region. Full article

(1) Background: Crimean–Congo hemorrhagic fever (CCHF) is an emerging tick-borne disease endemic in Africa, Asia, the Middle East, and the Balkan and Mediterranean regions of Europe. Although no human CCHF cases have been reported, based on vector presence, serological evidence among small vertebrates, and the general human population, Hungary lies within high evidence consensus for potential CCHF introduction and future human infection. Thus, the aim of our pilot serosurvey was to assess CCHF seropositivity among cattle and sheep as indicator animals for virus circulation in the country. (2) Methods: In total, 1905 serum samples taken from free-range cattle and sheep in 2017 were tested for the presence of anti-CCHF virus IgG antibodies using commercial ELISA and commercial and in-house immunofluorescent assays. (3) Results: We found a total of eleven reactive samples (0.58%) from five administrative districts of Hungary comprising 8 cattle and 3 sheep. The most affected regions were the south–central and northwestern parts of the country. (4) Conclusions: Based on these results, more extended surveillance is advised, especially in the affected areas, and there should be greater awareness among clinicians and other high-risk populations of the emerging threat of CCHF in Hungary and Central Europe. Full article