Caused By Crimean-Congo Hemorrhagic Fever Virus Research Articles

A Novel Drug Candidate for Sepsis Targeting Heparanase by Inhibiting Cytokine Storm.

Sepsis is an infection-triggered, rapidly progressive systemic inflammatory syndrome with a high mortality rate. Currently, there are no promising therapeutic strategies for managing this disease in the clinic. Heparanase plays a crucial role in the pathology of sepsis, and its inhibition can significantly relieve related symptoms. Here, a novel heparanase inhibitor CV122 is rationally designed and synthesized, and its therapeutic potential for sepsis with Lipopolysaccharide (LPS) and Cecal Ligation and Puncture (CLP)-induced sepsis mouse models are evaluated. It is found that CV122 potently inhibits heparanase activity in vitro, protects cell surface glycocalyx structure, and reduces the expression of adhesion molecules. In vivo, CV122 significantly reduces the systemic levels of proinflammatory cytokines, prevents organ damage, improves vitality, and efficiently protects mice from sepsis-induced death. Mechanistically, CV122 inhibits the activity of heparanase, reduces its expression in the lungs, and protects glycocalyx structure of lung tissue. It is also found that CV122 provides effective protection from organ damage and death caused by Crimean-Congo hemorrhagic fever virus (CCHFV) infection. These results suggest that CV122 is a potential drug candidate for sepsis therapy targeting heparanase by inhibiting cytokine storm.

Systems-level temporal immune-metabolic profile in Crimean-Congo hemorrhagic fever virus infection

Crimean-Congo hemorrhagic fever (CCHF) caused by CCHF virus (CCHFV) is one of the epidemic-prone diseases prioritized by the World Health Organisation as public health emergency with an urgent need for accelerated research. The trajectory of host response against CCHFV is multifarious and remains unknown. Here, we reported the temporal spectrum of pathogenesis following the CCHFV infection using genome-wide blood transcriptomics analysis followed by advanced systems biology analysis, temporal immune-pathogenic alterations, and context-specific progressive and postinfection genome-scale metabolic models (GSMM) on samples collected during the acute (T0), early convalescent (T1), and convalescent-phase (T2). The interplay between the retinoic acid-inducible gene-I-like/nucleotide-binding oligomerization domain-like receptor and tumor necrosis factor signaling governed the trajectory of antiviral immune responses. The rearrangement of intracellular metabolic fluxes toward the amino acid metabolism and metabolic shift toward oxidative phosphorylation and fatty acid oxidation during acute CCHFV infection determine the pathogenicity. The upregulation of the tricarboxylic acid cycle during CCHFV infection, compared to the noninfected healthy control and between the severity groups, indicated an increased energy demand and cellular stress. The upregulation of glycolysis and pyruvate metabolism potentiated energy generation through alternative pathways associated with the severity of the infection. The downregulation of metabolic processes at the convalescent phase identified by blood cell transcriptomics and single-cell type proteomics of five immune cells (CD4+ and CD8+ T cells, CD14+ monocytes, B cells, and NK cells) potentially leads to metabolic rewiring through the recovery due to hyperactivity during the acute phase leading to post-viral fatigue syndrome.

Evaluation of the immunogenicity of a Crimean-Congo hemorrhagic fever virus vaccine candidate in mice developed based on a baculovirus Zera nanoparticle delivery system.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV), which can cause severe clinical disease and even death in humans. In recent years, the disease has spread to a wider area, posing a major public health threat to China as well as the Middle East, Europe and Africa, and there is no safe and effective vaccine to prevent the disease. Recently, it has been shown that using the Zera fusion to target proteins can enhance immunogenicity and improve the potential for developing viral vaccines. Based on this finding, in this study, two vaccine candidates, Zera-Gn and Zera-Np, were prepared using an insect baculovirus system expressing CCHFV glycoprotein (Gn) and nucleocapsid protein (Np) fused with Zera tags, and evaluated for immunogenicity in BALB/c mice. The obtainedresults showed that both Zera-Gn and Zera-Np recombinant nanoparticles were successfully expressed, and Zera-Gn had good induction of humoral and cellular immunity in mice, and its immunogenicity was significantly higher than that of Zera-Np. The results indicated that Zera-Gn self-assembled nanoparticles prepared by fusing Zera tags with CCHFV spike-in protein Gn have the potential to be a candidate vaccine for CCHF, and this study provides a reference for the development of Zera self-assembled nanoparticle vaccine for CCHF.

Virus-Derived DNA Forms Mediate the Persistent Infection of Tick Cells by Hazara Virus and Crimean-Congo Hemorrhagic Fever Virus

Crimean-Congo hemorrhagic fever (CCHF) is a severe disease of humans caused by CCHF virus (CCHFV), a biosafety level (BSL)-4 pathogen. Ticks of the genus Hyalomma are the viral reservoir, and they represent the main vector transmitting the virus to its hosts during blood feeding. We have previously shown that CCHFV can persistently infect Hyalomma-derived tick cell lines. However, the mechanism allowing the establishment of persistent viral infections in ticks is still unknown. Hazara virus (HAZV) can be used as a BSL-2 model virus instead of CCHFV to study virus/vector interactions. To investigate the mechanism behind the establishment of a persistent infection, we developed an in vitro model with Hyalomma-derived tick cell lines and HAZV. As expected, HAZV, like CCHFV, persistently infects tick cells without any sign of cytopathic effect, and the infected cells can be cultured for more than 3 years. Most interestingly, we demonstrated the presence of short viral-derived DNA forms (vDNAs) after HAZV infection. Furthermore, we demonstrated that the antiretroviral drug azidothymine triphosphate could inhibit the production of vDNAs, suggesting that vDNAs are produced by an endogenous retrotranscriptase activity in tick cells. Moreover, we collected evidence that vDNAs are continuously synthesized, thereby downregulating viral replication to promote cell survival. Finally, vDNAs were also detected in CCHFV-infected tick cells. In conclusion, vDNA synthesis might represent a strategy to control the replication of RNA viruses in ticks allowing their persistent infection. IMPORTANCE Crimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne viral disease caused by CCHF virus (CCHFV). Ticks of the genus Hyalomma can be persistently infected with CCHFV representing the viral reservoir, and the main vector for viral transmission. Here we showed that tick cells infected with Hazara virus, a nonpathogenic model virus closely related to CCHFV, contained short viral-derived DNA forms (vDNAs) produced by endogenous retrotranscriptase activity. vDNAs are transitory molecules requiring viral RNA replication for their continuous synthesis. Interestingly, vDNA synthesis seemed to be correlated with downregulation of viral replication and promotion of tick cell viability. We also detected vDNAs in CCHFV-infected tick cells suggesting that they could represent a key element in the cell response to nairovirus infection and might represent a more general mechanism of innate immunity against RNA viral infection.

Development of a novel recombinant ELISA for the detection of Crimean-Congo hemorrhagic fever virus IgG antibodies

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral infection caused by Crimean-Congo hemorrhagic fever virus (CCHFV). Serological screening of CCHF is important and current ELISA use antigens prepared from virus which is expensive due to requirement of high bio-containment facilities. In this study, we aimed to develop a new recombinant ELISA. For this purpose, CCHFV genome were expressed as 13 proteins in E. coli and among them abundantly purified recombinant Nucleocapsid protein (rNP) and Mucin-like variable domain (rMLD) were used as antigen in ELISA (Rec-ELISA). Rec-ELISA using rNP, rMLD and a combination of both (rNP/rMLD) were probed with acute (n = 64; collected between days 1 and 7 after onset of symptoms), convalescent (n = 35; collected 8 days after onset of symptoms), consecutive sera (n = 25) of confirmed CCHF cases and control sera (n = 43). The sensitivity and specificity of Rec-ELISA using rNP/rMLD were 73% and 98% in acute cases and 97% and 98% in convalescent cases. The median interquartile absorbance value to discriminate the acute and convalescent phases of CCHF was significantly higher with ELISA using rNP/rMLD (P < 0.0001) compared to rNP (P > 0.05) and rMLD (P = 0.001). These results indicate that the Rec-ELISA using rNP/rMLD may be very useful to diagnose convalescent CCHF cases especially in field studies.

Serological and molecular study of Crimean-Congo Hemorrhagic Fever Virus in cattle from selected districts in Uganda

BackgroundCrimean-Congo Hemorrhagic Fever (CCHF) is a severe tick-borne viral hemorrhagic disease caused by Crimean-Congo Hemorrhagic Fever Virus (CCHFV) that poses serious public health challenges in many parts of Africa, Europe and Asia. MethodsWe examined 500 cattle sera samples from five districts for CCHFV antibodies using in-house and commercially available (IDVet) ELISA, Immunofluorescent assay (IFA) and Real-time polymerase chain reaction (RT-PCR). Results500 cattle (73.8 % females) were analyzed; CCHFV seropositivity was 12.6 % (n = 63) and 75.0 % (n = 375) with the in-house and IDVet ELISAs, respectively. Seropositivity was associated with geographical location, increasing age, being female, and having a higher tick burden. Twenty four out of the 37 (64.8 %) were seropositive for CCHFV using IFA and all were negative for virus on RT-PCR. The IFA results were more comparable to IDVet (κcoefficient = 0.88, p = <0.01) than to in-house (κcoefficient = 0.32, p = 0.02). ConclusionsOur study confirmed the presence and high prevalence of anti−CCHF antibodies in cattle based on three methods from all the five study districts, confirming presence and exposure of CCHFV. Given the zoonotic potential for CCHFV, we recommend a multidisciplinary public health surveillance and epidemiology of CCHFV in both animals and humans throughout the country.

Fine mapping epitope on glycoprotein Gc from Crimean-Congo hemorrhagic fever virus

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis, caused by CCHF virus (CCHFV) and which there are no diagnostic or therapeutic strategies. The C-terminus of glycoprotein (Gc) encoded by the CCHFV M gene is responsible for CCHFV binding to cellular receptors and acts as a neutralizing-antibody target. In this study, a modified biosynthetic peptide technique (BSP) was used to identify fine epitopes of Gc from the CCHFV YL04057 strain using rabbit antiserum against CCHFV-Gc. Six B cell epitopes (BCEs) and one antigenic peptide (AP) were identified: E1 (88VEDASES94), E2 (117GDRQVEE123), E3 (241EIVTLH246), AP-4 (281DFQVYHVGNLLRGDKV296), E5a (370GDTP QLDL377), E5b (373PQLDLKAR380), and E6 (443HVRSSD448). Western blotting analysis showed that each epitope interacted with the positive serum of sheep that had been naturally infected with CCHFV, and the results were consistent with that of Dot-ELISA. The multiple sequence alignment (MSA) revealed high conservation of the identified epitopes among ten CCHFV strains from different areas, except for epitopes AP-4 and E6. Furthermore, three-dimensional structural modeling showed that all identified epitopes were located on the surface of the Gc “head” domain. These mapped epitopes of the CCHFV Gc would provide a basis for further increase our understanding CCHFV glycoprotein function and the development of a CCHFV epitope-based diagnostics vaccine and detection antigen.

The role of Treg population in pathogenesis of Crimean Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a severe human infection caused by CCHF virus (CCHFV). Today, although the literature on CCHF pathogenesis is still limited, it is thought to be associated with immunosuppression in the early phase of infection followed by pro-inflammatory immune response that may lead to fatal outcomes. The aim of this study is to investigate the role of regulatory T-cells (Treg cells) in the pathogenesis of CCHFV.Peripheral blood mononuclear cell samples collected from 14 acute CCHF patients with mild disease course and 13 healthy subjects were included in this study. Treg expression and functional levels were analyzed by flow cytometry. Treg cells were identified as CD4+CD25 + CD127dim cells, and their functional levels were compared by measuring their ability to suppress CD69 and CD154 expression by activated T-cells.The flow cytometry analysis revealed that total T-cell and helper T-cell levels did not vary between the two groups. In contrast, CCHF patients displayed higher Treg cell levels but lower Treg suppressive activities when compared with control subjects.This is the first study on the involvement of Treg cells in CCHF pathogenesis. Our results indicate that even though Treg cell levels are elevated during acute phase of CCHF infection, not all generated Treg cells has immunosuppressive capacity, and therefore may not represent ‘true’ Treg cell population. Future studies on the intrinsic mechanisms responsible for the reduced Treg inhibitory activities are required for further enlightening the CCHF pathogenesis, especially in the acute phase of the disease.

Genomic Characterization of Crimean-Congo Hemorrhagic Fever Virus in Hyalomma Tick from Spain, 2014.

Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne disease caused by CCHF virus (CCHFV). Ticks in the genus Hyalomma are the main vectors and reservoirs of CCHFV. In Spain, CCHFV was first detected in Hyalomma ticks from Cáceres in 2010. Subsequently, two autochthonous CCHF cases were reported in August 2016. In this study, we describe the characterization of the CCHFV genome directly from Hyalomma lusitanicum collected in Cáceres in 2014. Phylogenetic analyses reveal a close relationship with clade III strains from West Africa, with an estimated divergence time of 50 years. The results of this work suggest that CCHFV has been circulating in Spain for some time, and most likely originated from West Africa.

Crimean Congo hemorrhagic fever among the one-humped camel (Camelus dromedaries) in Central Sudan

BackgroundCrimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonotic disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV), a member of the genus Nairovirus in the family Bunyaviridae. CCHF is typically asymptomatic in animals but can be highly fatal in humans approaching case fatality rate of approximately 30%. In the present investigation, a cross sectional study was conducted to determine the prevalence of CCHF and to identify the potential risk factors associated with CCHFV seropositivity among the one-humped camel (Camelus dromedaries) in Central Sudan.MethodsA total of 361 camels selected randomly from six localities were employed in the study. Sera sampled were tested for the presence of CCHFV-specific immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay (ELISA).ResultsCCHFV seropositivity was recorded in 77 out of 361 animals accounting for a prevalence rate of 21.3%. Age (OR = 3.6, CI = 1.72–7.79, p-value = 0.026); locality (OR = 5.85, CI = 1.81–18.83, p- value = 0.003), tick number (OR = 4.6, CI = 1.37–9.81, P-value 0.04); tick control (OR = 2.2, CI, 1.11–4.35, P-value = 0.023) and breed (OR = 6.60, CI = 2.38–18.36, P-value = 0.001) were recorded as potential risk factors for contracting CCHF.ConclusionsThe prevalence of CCHF is significantly high among camels in Khartoum State, Sudan. Age, breed, locality and tick control are considered as potential risk factors for contracting CCHF. This study would be expected to reduce the impact on the livelihood of pastoral communities and ultimately avoid disease spread in human.

Epidemiological survey of Crimean Congo hemorrhagic fever virus in cattle in East Darfur State, Sudan

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease caused by CCHF virus (CCHFV) of the genus Nairovirus in the family Bunyaviridae. CCHFV causes subclinical infection in domestic livestock and an often fatal hemorrhagic illness in humans, with approximately 30% mortality rates. In the present study, a cross-sectional serosurvey was conducted in a total of 282 randomly selected cattle from five localities in East Darfur State, Sudan. The exposure status to CCHF was determined using enzyme-linked immunosorbent assay (ELISA) for detection of CCHFV-specific IgG antibodies in cattle serum samples. The CCHFV-specific IgG antibodies were detected in 54 out of 282 animals, accounting for a 19.14% prevalence rate. Older cattle (>2 years of age) were approximately five times more likely to be infected with the virus (OR=4.90, CI=1.28–18.98, p-value=0.02). Heavily tick-infested cattle (ticks all over the body) were at 11 times higher at risk compared to tick-free animals (OR=11.11, CI=2.86–43.25, p-value=0.01). Grazing system is another factor affecting CCHF, where cattle grazing on open system were 27 times more at risk compared to other grazing systems (OR=27.22, CI=7.46–99.24, p-value=0.001). There was an association between localities and CCHF cattle (OR=0.24, CI=0.07–0.83, p-value=0.02). This study confirms the exposure of cattle to CCHF in East Darfur and identifies potential risk factors associated with the disease. Further epidemiological studies and improved surveillance are urgently needed to prevent a possible outbreak of CCHF among humans in the Darfur region of Sudan.

Crimean-Congo Hemorrhagic Fever

Crimean-Congo hemorrhagic fever (CCHF), a tick-borne viral hemorrhagic fever, is a zoonotic infection that caused by CCHF virus (CCHFV) of the family Bunyaviridae, genus Nairovirus. Transmission occurs mainly by Hyalomma m. marginatum tick exposure. Blood and bloody excretions of the patients are highly infectious and contact of skin and mucous membrane may lead to CCHF transmission. CCHF was described firstly in the Crimean peninsula in 1944, in former So viet Union and in Kelkit Valley in 2002 in Turkey. By the year 2013, it has been notified in more than 30 countries of Asia, the Middle East, Southeastern part of Europe and Africa. The disease is characterized by fever and thrombocytopenia, in severe cases, hemorrhage and shock. Although, the case fatality rate for the infection is generally ranged from 10 to 50%, it was reported as 5% for Turkey. Main targets of CCHFV are immune cells and endothelium. Both innate and adaptive immunity are important for fighting against CCHFV in the host. Headache, fever, fatigue and muscle, joint pain, con junctival injection, facial hyperemia, thrombocytopenia, elevated liver enzymes, hepatomegaly and splenomegaly are the main symptoms and findings for CCHF. Hemorrhagic manifestations including ecchymosis, melena, hematochezia, hematemesis, and epistaxis are commonly seen in severe cases. Supportive treatment is essential and nowadays neither a special drug, nor safe vaccine for humans is available for the treatment and prevention of CCHF. In case of penetrating injury with contaminated material, the oral ribavirin prophylaxis may be offered after the area being washed with soapy water and ethanol. J Microbiol Infect Dis 2014; Special Issue 1: S1-S9

New circulating genomic variant of Crimean-Congo hemorrhagic fever virus in Iran

Crimean-Congo hemorrhagic fever is a viral infection that is caused by Crimean-Congo hemorrhagic fever virus (CCHFV). On May 27, 2012, a woman became ill after accidentally splashing cow's blood into her eyes. Serological and molecular investigations were carried out on the serum of the patient. The test results for serological testing were negative, but RT-PCR was strongly positive for CCHFV. A phylogenetic study on the CCHFV genome sequence showed 50% similarity to a 520-bp region of Russian strains. By combining historical phylogenetic data and current data, it can be surmised that there are potentially more than five circulating CCHFV genomic variants in Iran.

A nosocomial transmission of crimean-congo hemorrhagic fever to an attending physician in north kordufan, Sudan

BackgroundCrimean-Congo hemorrhagic fever (CCHF), a tick-borne disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is a member of the genus Nairovirus in the family Bunyaviridae. Recently, CCHFV has been reported as an important emerging infectious viral pathogen in Sudan. Sporadic cases and multiple CCHF outbreaks, associated with nosocomial chain of transmission, have been reported in the Kordufan region of Sudan.AimsTo confirm CCHF in an index patient and attending physician in North Kordufan region, Sudan, and to provide some information on virus genetic lineages.MethodsAntibody captured ELISA, reverse transcription PCR, partial S segment sequences of the virus and subsequent phylogenetic analysis were used to confirm the CCHFV infection and to determine the virus genetic lineages.ResultsCCHF was confirmed by monitoring specific IgM antibody and by detection of the viral genome using RT-PCR. Treatment with oral ribavirin, replacement with fluid therapy, blood transfusion and administration of platelets concentrate resulted in rapid improvement of the health condition of the female physician. Phylogenetic analysis of the partial S segment sequences of the 2 CCHFV indicates that both strains are identical and belong to Group III virus lineage, which includes viruses from Africa including, Sudan, Mauritania, South Africa and Nigeria.ConclusionFurther epidemiologic studies including, CCHFV complete genome analysis and implementation of improved surveillance are urgently needed to better predict and respond to CCHF outbreaks in the Kordufan region, Sudan.

Lessons of 10 years experience on CCHF in Iran

Background Crimean-Congo Hemorrhagic Fever (CCHF) is a viral zoonotic disease with high mortality rate in humans caused by CCHF virus (CCHFV) belonging to the genus Nairovirus, family Bunyaviridae, and congaing a three segment single-stranded RNA genome. The CCHFV is transmitted to humans by bite of infected ticks, by direct contact with blood or tissues of infected livestock and nosocomially. After Chaharmahal-va-Bakhtiari outbreak in 1999 whose serum samples was sent to South Africa for diagnosis, Arboviruses and Viral Hemorrhagic Fevers Laboratory (As National Reference Lab) was established in 2000 to precise and on time laboratory diagnosis of CCHF in the country. The Lab along with CDC of Iran (national health regulator) and Veterinary organization (control program of tick populations and livestock monitoring) are members of National Expert Committee on Viral Hemorrhagic Fevers (NECVHFs) for surveillance and control of CCHF in Iran.

Detection of Crimean-Congo hemorrhagic fever virus glycoprotein antigens (38.19)

Abstract Crimean-Congo hemorrhagic fever (CCHF) is a viral infection caused by Crimean-Congo hemorrhagic fever virus (CCHFV), a tick-borne virus (Nairovirus) of Bunyaviridae. Viral antigens of CCHFV can be detected by using various immunologic methodologies. We developed two methodologies to detect viral antigens of CCHFV using polyclonal antibodies isolated either from human plasma or from hyperimmunized horse serum. The first methodology is a western blot using human polyclonal antibodies. The second one is an antigen ELISA using horse antibodies. CCHFV isolates from vero-cell cultures were used as a source of the antigens. Additionally, CCHFV isolates obtained from Centers for Disease Control and Prevention (CDC) of USA were used as positive controls. The human polyclonal antibody pool detected several glycoproteins of various sizes ranging from approximately 35 KDa to 80 KDa or higher indicating that humans can develop antibody responses to different epitopes of the viral glycoproteins. Also, the ELISA can be used successfully to detect CCHFV with quite reproducible results. Our results indicated that both antibody sources could be convenient for rapid detection of CCHFV glycoprotein antigens.

日本の周辺国で問題となっているウイルス感染症 ２．クリミア・コンゴ出血熱

Crimean-Congo hemorrhagic fever (CCHF) is an acute infectious disease caused by CCHF virus (CCHFV), a member of the family Bunyaviridae, genus Nairovirus. The case fatality rate of CCHF ranges from 10-40%. Because CCHF is not present in Japan, many Japanese virologists and clinicians are not very familiar with this disease. However, there remains the possibility of an introduction of CCHFV or other hemorrhagic fever viruses into Japan from surrounding endemic areas. Development of diagnostic laboratory capacity for viral hemorrhagic fevers is necessary even in countries without these diseases. At the National Institute of Infectious Diseases, Tokyo, Japan, laboratory-based systems such as recombinant protein-based antibody detection, antigen-capture and pathological examination have been developed. In this review article, epidemiologic and clinical data on CCHF in the Xinjiang Uygur Autonomous Region, compiled through field investigations and diagnostic testing utilizing the aforementioned laboratory systems, are presented. CCHFV infections are closely associated with the environmental conditions, life styles, religion, occupation, and human economic activities. Based on these data, preventive measures for CCHFV infections are also discussed.