Crimean-Congo haemorrhagic fever

Species distribution and ecological suitability analysis for potential tick vectors of Kyasanur forest disease in the Western Ghats of Kerala

Kyasanur forest disease (KFD) is a tick-borne zoonotic viral disease with an estimated case fatality rate of 3% to 5% in humans. The KFD virus is transmitted to both humans and animals by infected ticks, primarily the Haemaphysalis species. Our study was undertaken following reports of five confirmed cases and three deaths due to KFD in Malappuram district of Kerala in 2014 to determine the diversity of Ixodidae ticks on vegetation and their possible infection with the KFD virus. Overall, 3502 hard ticks belonging to three genera and eight species were collected from two forest divisions. Haemaphysalis was the predominant tick species (92.72%). Tick positivity for the KFD virus was 4 (5.33%) of 75 pools of ticks tested. Kyasanur forest disease viral RNA was detected from the genera Haemaphysalis and Amblyomma. The KFD virus was detected in 2 of 35 pools (5.71%) of Haemaphysalis spinigera, 1 of 30 pools (3.33%) of Haemaphysalis turturis, and 1 of 3 pools (3.33%) of Amblyomma integrum from the south forest division. The ticks reached their peak density between December and February and then decreased from the end of May. The temperature in the area ranges from 28°C to 30°C, which is suitable for tick survival.

Vaginal bleeding as a sign of Crimean-Congo hemorrhagic fever infection: a case report

Background

Crimean–Congo hemorrhagic fever is a severe vector-borne viral hemorrhagic fever with considerable mortality in humans. This disease is endemic in Afghanistan, and its incidence rate has rapidly increased in recent years. This infection can cause a broad range of hemorrhage manifestations including epistaxis, petechial or purpuric rashes, hematemesis, and melena; however, vaginal bleeding is also reported as a rare manifestation.

Case presentation

We report the case of a previously healthy 30-year-old Afghan female of shepherding occupation, with a sudden onset of fever, generalized body pain, epistaxis, and vaginal bleeding. She was admitted to the hospital after 7 days of symptom manifestation, with predominant signs being high fever, vaginal bleeding, and elevated liver enzymes. The serological test result for Crimean–Congo hemorrhagic fever was positive. She was treated with oral ribavirin and discharged with normal parameters.

Conclusions

People in high-risk professions in endemic areas should be informed that vaginal bleeding is a serious symptom and requires immediate action and, therefore, might be attributed to nongynecologic disorders.

Plant-Derived Recombinant Vaccines against Zoonotic Viruses

Emerging and re-emerging zoonotic diseases cause serious illness with billions of cases, and millions of deaths. The most effective way to restrict the spread of zoonotic viruses among humans and animals and prevent disease is vaccination. Recombinant proteins produced in plants offer an alternative approach for the development of safe, effective, inexpensive candidate vaccines. Current strategies are focused on the production of highly immunogenic structural proteins, which mimic the organizations of the native virion but lack the viral genetic material. These include chimeric viral peptides, subunit virus proteins, and virus-like particles (VLPs). The latter, with their ability to self-assemble and thus resemble the form of virus particles, are gaining traction among plant-based candidate vaccines against many infectious diseases. In this review, we summarized the main zoonotic diseases and followed the progress in using plant expression systems for the production of recombinant proteins and VLPs used in the development of plant-based vaccines against zoonotic viruses.

Structural basis of synergistic neutralization of Crimean-Congo hemorrhagic fever virus by human antibodies

Crimean-Congo hemorrhagic fever virus (CCHFV) is the most widespread tick-borne zoonotic virus, with a 30% case fatality rate in humans. Structural information is lacking in regard to the CCHFV membrane fusion glycoprotein Gc—the main target of the host neutralizing antibody response—as well as antibody–mediated neutralization mechanisms. We describe the structure of prefusion Gc bound to the antigen-binding fragments (Fabs) of two neutralizing antibodies that display synergy when combined, as well as the structure of trimeric, postfusion Gc. The structures show the two Fabs acting in concert to block membrane fusion, with one targeting the fusion loops and the other blocking Gc trimer formation. The structures also revealed the neutralization mechanism of previously reported antibodies against CCHFV, providing the molecular underpinnings essential for developing CCHFV–specific medical countermeasures for epidemic preparedness.

In silico Design of a Crimean-Congo Hemorrhagic Fever Virus Glycoprotein Multi-Epitope Antigen for Vaccine Development

Objective

There is no licensed vaccine available to prevent the severe tick-borne disease Crimean-Congo hemorrhagic fever (CCHF), caused by the CCHF virus (CCHFV). This study sought to show that a combination of computational methods and data from published literature can inform the design of a multi-epitope antigen for CCHFV that has the potential to be immunogenic.

Methods

Cytotoxic and helper T-cell epitopes were evaluated on the CCHFV GPC using bioinformatic servers, and this data was combined with work from previous studies to identify potentially immunodominant regions of the GPC. Regions of the GPC were selected for generation of a model multi-epitope antigen in silico, and the percent residue identity and similarity of each region was compared across sequences representing the widespread geographical and ecological distribution of CCHFV.

Results

Eleven multi-epitope regions were joined together with flexible linkers in silico to generate a model multi-epitope antigen, termed EPIC, which included 812 (75.7%) of all predicted epitopes. EPIC was predicted to be antigenic by two independent bioinformatic servers, suggesting that multi-epitope antigens should be explored further for CCHFV vaccine development.

Conclusion

The results presented within this manuscript provide information for potential targets within the CCHFV GPC for guiding future vaccine development.

Immunogenicity of a DNA-Based Sindbis Replicon Expressing Crimean-Congo Hemorrhagic Fever Virus Nucleoprotein

Crimean–Congo hemorrhagic fever virus (CCHFV) infrequently causes hemorrhagic fever in humans with a case fatality rate of 30%. Currently, there is neither an internationally approved antiviral drug nor a vaccine against the virus. A replicon based on the Sindbis virus vector encoding the complete open reading frame of a CCHFV nucleoprotein from a South African isolate was prepared and investigated as a possible candidate vaccine. The transcription of CCHFV RNA and recombinant protein production by the replicon were characterized in transfected baby hamster kidney cells. A replicon encoding CCHFV nucleoprotein inserted in plasmid DNA, pSinCCHF-52S, directed transcription of CCHFV RNA in the transfected cells. NIH-III heterozygous mice immunized with pSinCCHF-52S generated CCHFV IgG specific antibodies with notably higher levels of IgG2a compared to IgG1. Splenocytes from mice immunized with pSinCCHF-52S secreted IFN-γ and IL-2, low levels of IL-6 or IL-10, and no IL-4. No specific cytokine production was registered in splenocytes of mock-immunized mice (p < 0.05). Thus, our study demonstrated the expression of CCHFV nucleoprotein by a Sindbis virus vector and its immunogenicity in mice. The spectrum of cytokine production and antibody profile indicated predominantly Th1-type of an anti-CCHFV immune response. Further studies in CCHFV-susceptible animals are necessary to determine whether the induced immune response is protective.

Which scoring system is effective in predicting mortality in patients with Crimean Congo hemorrhagic fever? A validation study

We aimed to decide which scoring system is the best for the evaluation of the course of Crimean-Congo Hemorrhagic Fever (CCHF) by comparing scoring systems such as qSOFA (quick Sequential Organ Failure Assessment), SOFA (Sequential Organ Failure Assessment), APACHE II (Acute Physiology and Chronic Health Evaluation II) and SGS (Severity Grading System) in centers where patients with CCHF were monitored. The study was conducted with patients diagnosed with CCHF in five different centers where the disease was encountered most commonly. Patients having proven PCR and/or IgM positivity for CCHF were included in the study. The scores of the scoring systems on admission, at the 72^nd hour and at the 120^th hour were calculated and evaluated. The data of 388 patients were obtained from five centers and evaluated. SGS, SOFA and APACHE II were the best scoring systems in predicting mortality on admission. All scoring systems were significant in predicting mortality at the 72^nd and 120^th hours. On admission, there was a correlation between the qSOFA, SOFA and APACHE II scores and the SGS scores in the group of survivors. All scoring systems had a positive correlation in the same direction. The correlation coefficients were strong for qSOFA and SOFA, but poor for APACHE II. A one-unit rise in SGS increased the probability of death by 12.818 times. qSOFA did not provide significant results in predicting mortality on admission. SGS, SOFA and APACHE II performed best at admission and at the 72^nd and 120^th hours.

Association between guilds of birds in the African-Western Palaearctic region and the tick species Hyalomma rufipes, one of the main vectors of Crimean-Congo hemorrhagic fever virus

Introduction

The ecology of the vertebrate host contributes to the geographical range expansion of ticks. In this study, we investigated which tick taxa that infest and are dispersed by birds along African-Western Palaearctic flyways during northward migration, and whether bird ecology was associated with tick taxa.

Materials and methods

Ticks were collected from birds trapped at bird observatories in Spain, Italy, Greece, and Israel during the spring migration of 2014 and 2015, using mist nets. The tick-infested bird species were classified into guilds, using different combinations of the variables: migration distance, wintering region, foraging behaviour, and winter habitat. Ticks were molecularly determined to genus and species level by sequencing fragments of the 12S ribosomal DNA (rDNA) gene and by phylogenetic inference, using the Maximum Likelihood algorithm. Data were analysed using descriptive measures, graphs, Chi2 tests, the Tukey-Kramer test, and a parametric linear model (generalized linear model) in order to analyse and adjust for characteristics in the bird guilds and their relationship to collected tick taxa.

Results

Most (84.2%) of the 10,209 trapped birds were long-distance migrants, of which 2.4% were infested by ticks. The most common tick species was Hyalomma rufipes (77.7%; 447/575), a known vector and reservoir of Crimean-Congo hemorrhagic fever virus. Bird guilds containing only long-distance migrants with wintering areas in Africa were associated with the tick species H. rufipes (p < 0.0001). Furthermore, bird winter habitat was associated with H. rufipes (p = 0.003); with bird species overwintering in open habitat (p = 0.014) and wetlands (p = 0.046) having significantly more H. rufipes as compared to birds with a winter habitat comprising forest and shrubs (p = 0.82).

Conclusions

With climate change, the likelihood of establishment of permanent Hyalomma populations in central and northern Europe is increasing. Thus, surveillance programs for monitoring the risk of introduction and establishment of H. rufipes in the Western-Palaearctic should be established. Our study suggests that migratory bird species wintering in African open habitats and wetlands are good candidates for monitoring potential introduction.

Phylogenetic analysis of Crimean-Congo hemorrhagic fever virus in inner Mongolia, China

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne arbovirus that can cause bleeding and death in humans. The mortality rate in humans is between 5 and 30%. The pathogen is prevalent in more than 30 countries in the world. In China, the CCHFV has been reported in Xinjiang province but not in Inner Mongolia province yet. In this report, we phylogenetically analyzed a new CCHFV strain, HANM-18, identified from Hyalomma asiaticum and Hyalomma dromedarii collected in Alxa Left Banner and Alxa Right Banner of Inner Mongolia, China. Complete sequences of CCHFV were obtained by the nested PCR technique and used for phylogenetic analysis of the identity and evolutionary relationship with other CCHFV strains. Our results showed that the S and L fragments of the HANM-18 strain had a high percentage of identity with strains in Xinjiang, China. The M fragment was significantly homologous to South African isolates. In addition, these data also indicate that the HANM-18 strain may have been prevalent in northwestern Inner Mongolia for many years. This discovery will be helpful in CCHF prevention and control in Inner Mongolia, and it also adds new evidence to the epidemiology of CCHF in China.

Crimean-Congo haemorrhagic fever-induced liver injury: A systematic review and meta-analysis

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a fatal acute tick-borne viral infection and substantial emerging global public health threat. This illness has a high case fatality rate of up to 40%. The liver is one of the important target organs of the CCHF virus.

OBJECTIVE

The aim of this meta-analysis to evaluate the correlation between CCHF and liver injury and draw more generalised inferences about the abnormal serum markers of liver injury such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) in CCHF patients.

METHODS

A literature search was accomplished for published eligible articles with MEDLINE/PubMed and Embase databases. All eligible observational studies and case series were included from around the world. The inclusion criteria were articles describing liver injury biomarkers amongst patients diagnosed with CCHF.

RESULTS

Data from 18 studies, consisting of 1238 patients with CCHF were included in this meta-analysis. Overall pooled incidence of at least one raised liver injury biomarker was 77.95% (95% CI, I²  =  88.50%, P < .0001). Similarly, pooled incidence of elevated AST and ALT was 85.92% (95% CI, I²  = 85.27%, P < .0001) and 64.30% (95% CI, I²  =  88.32%, P < .0001), respectively. Both Egger and Begg-Mazumdar's tests detected no apparent publication bias in all three meta-analyses (P > .05).

CONCLUSION

Our study shows that CCHF has a very detrimental effect on liver function. Abnormal liver function may lead to poor prognosis and increased morbidity and mortality in CCHF patients. Hence, Physicians must recognise and continuously monitor these biomarkers, since these markers may aid in early stratification of prognosis and the prevention of severe outcomes in infection with such a high case fatality rate.

Development of a protective inactivated vaccine against Crimean-Congo hemorrhagic fever infection

Crimean-Congo hemorrhagic fever (CCHF) is an emerging zoonotic infectious disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV). The first clinical CCHF infection was described in 1944 in the Crimean Peninsula, exclusively in humans, with case-fatality rates exceeding 30%. The increasing number of cases, high mortality rate, and lack of effective therapy make CCHF a serious threat to public health and a potential bioterrorism agent. The present study evaluated the development, immunogenicity, and immune response durations for cell-culture-derived inactivated vaccine (CCVax) formulations in comparison with those of mouse-brain-derived vaccine (MBVax) formulations. In this study, the Kelkit06 CCHF virus strain was propagated in both suckling mice and Vero E6 cells, and purified with a sucrose gradient. Formalin-inactivated vaccine candidates were formulated at various doses [low dose (LD), 5 μg; medium dose (MD), 10 μg; high dose (HD), 20 μg)] and mixed with an alum adjuvant. BALB/c mice received the same doses of the vaccine formulations three times at 3-week intervals. The humoral endpoint IgG responses were evaluated and compared for the MBVax and CCVax treatments. The duration of the presence of IgG and neutralizing antibody (Ab) titers was evaluated and compared until up to 1 year after immunization. The humoral IgG responses indicated that the CCVax and MBVax candidates enhanced the IgG endpoint titers in a dose-dependent manner, which were induced more strongly in all the CCVax groups than in the MBVax mice. The fold changes in neutralizing Ab levels were also found to be higher in the CCVax groups: between 2- and 7.6-fold after the second week of the last immunization. The neutralization titers peaked 4 months after immunization in all the vaccine-receiving groups, but these were still comparable at the end of the first year. The CCVax formulations induced higher IgG and neutralizing Ab titers at all the measured time points. In this study, we showed that cell-culture-purified and formalin-inactivated vaccine candidates induced strong and robust immunity in vaccinated mice dose-dependently, more so than mouse-brain-derived vaccines.

Sequential determination of viral load, humoral responses and phylogenetic analysis in fatal and non-fatal cases of Crimean-Congo hemorrhagic fever patients from Gujarat, India, 2019

Background

Thirty-four CCHF cases (17 fatal; 17 survived) were confirmed from Gujarat state, India during the year 2019. We aimed to find out the viral load, antibody kinetics, cytokine profile and phylogenetic analysis between fatal and non- fatal cases.

Methods

Thirty four cases were included in this study. Blood and urine samples were collected from all the cases on the day of admission to hospital. Non-fatal cases were followed weekly for understanding the profile of viral kinetics, anti-CCHFV IgM and IgG antibodies. We also quantified the cytokines in both fatal and non-fatal cases. For epidemiological correlation, livestock were screened for anti-CCHF IgG antibodies and the tick pool specimens were tested by real time RT-PCR. Virus isolation was attempted on tick pools and human specimens and phylogenetic analysis performed on human and ticks complete genome sequences.

Results

CCHF cases were detected throughout year in 2019 with the peak in August. Out of 34 cases, eight secondary CCHF cases were reported. Cases were predominantly detected in males and in 19–45 years age group (55.88%). The persistence of viremia was observed till 76^th POD (post onset date) in one case whereas anti-CCHFV IgM and IgG was detected amongst these cases from the 2^nd and 20^th POD respectively. Positivity observed amongst livestock and tick pools were was 21.57% and 7.4% respectively. The cytokine analysis revealed a significant increase in the level of serum IL-6, IL-10 and IFN-γ during the acute phase of the infection, but interestingly IL-10 lowered to normal upon clearance of the virus in the clinically recovered case. Fatal cases had high viral RNA copy numbers. Bleeding from one or two mucosal sites was significantly associated with fatality (OR-16.47;p-0.0034 at 95% CI). We could do CCHF virus isolation from two cases. Phylogenetic analysis revealed circulation of re-assortment of Asian-West African genotypes in humans and ticks.

Conclusions

The persistence of CCHF viral RNA was detected till 76^th POD in one of the survivors. The circulation of a re-assortment Asian-West African genotype in a CCHF case is also reported first time from India.

Crimean Congo hemorrhagic fever is a zoonotic tick-borne viral hemorrhagic disease. This disease is reported from Europe, Mediterranean, north-western China, central Asia, Africa, and the Middle East. Several outbreaks of CCHF were reported from Gujarat and Rajasthan states, India from 2011 to 2019. In this study, we discuss the clinical, molecular, serological, and the cytokine data of 34 CCHF cases (17 fatal and 17 survived) which were detected from Gujarat state in the year 2019. A sequential weekly follow up of the CCHF survivors was performed to understand the viral kinetics and the antibody profile. Interestingly, the presence of persistence CCHF viral RNA was observed till 76^th POD in one of the survivors. To our knowledge, we are reporting this long term persistence of viremia for the first time. We also observed that the anti-CCHFV IgM detection in the serum samples starts as soon as 2^nd POD but anti-CCHFV IgG antibody could be detected in the majority of the cases only after the 28^th POD. The cytokine analysis revealed a significant increase in the level of serum IL-6, IL-10 and IFN-γ during the acute phase of the infection, but interestingly IL-10 lowered to normal upon clearance of the virus in the clinically recovered case. We did the phylogenetic analysis and concluded the circulation of the Asian-West African re-assortment genotype in humans, which has not been reported from India prior to this study.

Tick-Borne Pathogens and Diseases in Greece

Tick-borne diseases (TBDs) are recognized as a serious and growing public health epidemic in Europe, and are a cause of major losses in livestock production worldwide. This review is an attempt to present a summary of results from studies conducted over the last century until the end of the year 2020 regarding ticks, tick-borne pathogens, and tick-borne diseases in Greece. We provide an overview of the tick species found in Greece, as well as the most important tick-borne pathogens (viruses, bacteria, protozoa) and corresponding diseases in circulation. We also consider prevalence data, as well as geographic and climatic conditions. Knowledge of past and current situations of TBDs, as well as an awareness of (risk) factors affecting future developments will help to find approaches to integrated tick management as part of the ‘One Health Concept’; it will assist in avoiding the possibility of hotspot disease emergencies and intra- and intercontinental transmission. Increased surveillance in Greece is required to ensure clear and effective policies for TBD control.

Crimean-Congo hemorrhagic fever: A pediatric case responding to plasmapheresis treatment

Crimean-Congo hemorrhagic fever (CCHF) is a life-threatening tick-borne viral infection. The most important step in the treatment of CCHF is supportive therapy. Ribavirin is the recommended antiviral agent for infected patients. We present a case of a child who presented to our pediatric intensive care unit due to CCHF and was treated with plasmapheresis and ribavirin. A previously healthy seven-month-old male infant presented to the emergency room with a fever of 39.5 °C, nosebleed, cough, vomiting, and weakness. We decided to apply plasmapheresis treatment due to multiple organ failure associated with thrombocytopenia, acute liver failure, and a family history of death from the disease. Plasmapheresis was performed in three sessions. By the sixth day of his admission to the intensive care unit, the patient's clinical condition had improved and his laboratory values had returned to normal, so he was transferred to the infectious diseases service in stable condition.

Discovery and Surveillance of Tick-Borne Pathogens

Within the past 30 yr molecular assays have largely supplanted classical methods for detection of tick-borne agents. Enhancements provided by molecular assays, including speed, throughput, sensitivity, and specificity, have resulted in a rapid increase in the number of newly characterized tick-borne agents. The use of unbiased high throughput sequencing has enabled the prompt identification of new pathogens and the examination of tick microbiomes. These efforts have led to the identification of hundreds of new tick-borne agents in the last decade alone. However, little is currently known about the majority of these agents beyond their phylogenetic classification. Our article outlines the primary methods involved in tick-borne agent discovery and the current status of our understanding of tick-borne agent diversity.

Seroepidemiologic Survey of Crimean-Congo Hemorrhagic Fever Virus in Logging Communities, Myanmar

Crimean-Congo hemorrhagic fever virus (CCHFV) is endemic in Asia, infecting many animal hosts, but CCHFV has not been reported in Myanmar. We conducted a seroepidemiologic survey of logging communities in Myanmar and found CCHFV exposure was common (9.8%) and exposure to wild animal blood and body fluids was associated with seropositivity.

Fatal Case of Crimean-Congo Hemorrhagic Fever Caused by Reassortant Virus, Spain, 2018

In August 2018, a fatal autochthonous case of Crimean-Congo hemorrhagic fever was confirmed in western Spain. The complete sequence of the viral genome revealed circulation of a new virus because the genotype differs from that of the virus responsible for another case in 2016. Practitioners should be alert to possible new cases.

Crimean-Congo Hemorrhagic Fever Virus in Humans and Livestock, Pakistan, 2015-2017

We detected Crimean-Congo hemorrhagic fever virus infections in 4 provinces of Pakistan during 2017–2018. Overall, seroprevalence was 2.7% in humans and 36.2% in domestic livestock. Antibody prevalence in humans was highest in rural areas, where increased contact with animals is likely.

First Serological Evidence of Crimean-Congo Hemorrhagic Fever Virus and Rift Valley Fever Virus in Ruminants in Tunisia

Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley fever virus (RVFV, Phenuiviridae family) are zoonotic vector-borne pathogens with clinical relevance worldwide. Our study aimed to determine seroprevalences of these viruses and potential risk factors among livestock (cattle, sheep, and goats) in Tunisia. Sera were tested for antibodies against CCHFV (n = 879) and RVFV (n = 699) using various enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence assays (IIFA). The overall seroprevalence of IgG antibodies was 8.6% (76/879) and 2.3% (16/699) against CCHFV and RVFV, respectively. For CCHF seropositivity bioclimatic zones and breed were potential risk factors for the three tested animal species; while the season was associated with cattle and sheep seropositivity, tick infestation was associated with cattle and goats seropositivity and age as a risk factor was only associated with cattle seropositivity. Age and season were significantly associated with RVFV seropositivity in sheep. Our results confirm the circulation of CCHFV and RVFV in Tunisia and identified the principal risk factors in ruminants. This knowledge could help to mitigate the risk of ruminant infections and subsequently also human infections.

Development of a Novel Multi-Epitope Vaccine Against Crimean-Congo Hemorrhagic Fever Virus: An Integrated Reverse Vaccinology, Vaccine Informatics and Biophysics Approach

Crimean-Congo hemorrhagic fever (CCHF) is a highly severe and virulent viral disease of zoonotic origin, caused by a tick-born CCHF virus (CCHFV). The virus is endemic in many countries and has a mortality rate between 10% and 40%. As there is no licensed vaccine or therapeutic options available to treat CCHF, the present study was designed to focus on application of modern computational approaches to propose a multi-epitope vaccine (MEV) expressing antigenic determinants prioritized from the CCHFV genome. Integrated computational analyses revealed the presence of 9 immunodominant epitopes from Nucleoprotein (N), RNA dependent RNA polymerase (RdRp), Glycoprotein N (Gn/G2), and Glycoprotein C (Gc/G1). Together these epitopes were observed to cover 99.74% of the world populations. The epitopes demonstrated excellent binding affinity for the B- and T-cell reference set of alleles, the high antigenic potential, non-allergenic nature, excellent solubility, zero percent toxicity and interferon-gamma induction potential. The epitopes were engineered into an MEV through suitable linkers and adjuvating with an appropriate adjuvant molecule. The recombinant vaccine sequence revealed all favorable physicochemical properties allowing the ease of experimental analysis in vivo and in vitro. The vaccine 3D structure was established ab initio. Furthermore, the vaccine displayed excellent binding affinity for critical innate immune receptors: TLR2 (-14.33 kcal/mol) and TLR3 (-6.95 kcal/mol). Vaccine binding with these receptors was dynamically analyzed in terms of complex stability and interaction energetics. Finally, we speculate the vaccine sequence reported here has excellent potential to evoke protective and specific immune responses subject to evaluation of downstream experimental analysis.

A case of Crimean-Congo hemorrhagic fever with the bacteremia of Clostridium perfringens

Crimean-Congo hemorrhagic fever (CCHF) is a worldwide tick-borne viral infection in humans. The aim of the study is to report a case of a female patient with severe CCHF with the bacteremia of Clostridium perfringens. An 18-year-old woman admitted to the emergency department with sudden onset of fever, nausea and vomiting, myalgia, headache, generalized abdominal pain. It was learned that the patient was living in a rural area and had a history of tick bite 3 days before the admission. At laboratory examination, bicytopenia, abnormal liver function tests, and abnormal coagulation parameters were observed. The diagnosis of the case was confirmed with a positive real-time polymerase chain reaction. On the third day of hospitalization, she had an increase in abdominal pain, confusion, and respiratory distress. She was transferred to the intensive care unit for close monitoring. On the fifth day of hospitalization, she developed fever again. Catheter and peripheral anaerobic blood cultures grew C. perfringens. No evidence of perforation was observed on abdominal tomography. It has been successfully treated with a multidisciplinary approach. CCHF demonstrates different types of clinical presentations, except for common symptoms of fever and hemorrhage. A case of CCHF with C. perfringens bacteremia has not been previously reported before.

Prevalence and phylogenetic analysis of Crimean-Congo hemorrhagic fever virus in ticks collected from Punjab province of Pakistan

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease of human that caused by CCHF virus. To study the epidemiological distribution of CCHFV, 2183 tick samples were collected from sheep, goats, cattle and buffalo of different livestock farms of ten districts of Punjab province of Pakistan. Detection of CCHFV was done using enzyme link immunosorbent assay (ELISA) after proper identification of tick samples. The partial S-segment of CCHFV from ELISA positive tick samples was amplified by PCR and sequenced to determine the genotype of CCHFV. Out of2183 collected tick samples, 1913 ticks belonged to 5 species of genus Hyalomma as H. antolicum (48%), H. marginatum (30.2%), H. rufipes (10.82%), H. impressum (5.43%) and H. dromedarii (5.27%). While 270 ticks belonged to 3 species of genus Rhipicephalus as R. microplus (44.8%), R. sanguineus (32.22%) and R. turanicus (24.8%). The overall antigenic prevalence of CCHFV was found to be 12.13% in collected tick samples and 21 tick pools were sequenced for partial S-segment of CCHFV. All of the 21 tick pools were clustered in genotype IV (Asia-1). The highest prevalence of CCHFV was found in district Chakwal (24.13%) followed by Mianwali (23.68%), Rawalpindi (23.07%), Attock (20.0%), Rajanpur (10.52%) and Lahore (8.33%). In positive tick pools, the highest prevalence of CCHFV antigen was found in H. antolicum (39.6%) followed by H. marginatum (30.18%), H. rufipes (13.2%), H. impressum (3.77%), H. dromedarii (1.88%), R. microplus (5.66%) and R. sanguineus (5.66%). The current study confirms the presence of CCHFV in the ticks population of Punjab. The CCHF virus present in Punjab belongs to Asia-1 genotype. It is important to control the tick infestation of the animals present in these areas. So that the transmission cycle of CCHF can be inhibited.

The first pediatric case of hemophagocytic lymphohistiocytosis secondary to Crimean-Congo haemorrhagic fever successfully treated with therapeutic plasma exchange accompanying ribavirin and intravenous immunoglobulin

Although Crimean-Congo hemorrhagic fever (CCHF) is mild and self-limited in children, some patients may develop excessive bleeding, massive liver necrosis, and multiple organ failure associated with secondary hemophagocytic lymphohistiocytosis (HLH) induced by cytokine storm. Treatment of CCHF is mainly symptomatic and supportive. The efficacy of ribavirin, which is the only antiviral drug in the treatment of CCHF, remains controversial. Although therapeutic plasma exchange (TPE) has been shown to beneficial in small case series with primary and secondary HLH, there is no pediatric patient with HLH secondary to CCHF treated with TPE in the literature. In this report, we describe the first pediatric patient who was successfully recovered from HLH secondary to CCHF with ribavirin, intravenous immunoglobulin, and TPE.

Serologic and molecular evidence for circulation of Crimean-Congo hemorrhagic fever virus in ticks and cattle in Zambia

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis with a high case fatality rate in humans. Although the disease is widely found in Africa, Europe, and Asia, the distribution and genetic diversity of CCHF virus (CCHFV) are poorly understood in African countries. To assess the risks of CCHF in Zambia, where CCHF has never been reported, epidemiologic studies in cattle and ticks were conducted. Through an indirect immunofluorescence assay, CCHFV nucleoprotein-specific serum IgG was detected in 8.4% (88/1,047) of cattle. Among 290 Hyalomma ticks, the principal vector of CCHFV, the viral genome was detected in 11 ticks. Phylogenetic analyses of the CCHFV S and M genome segments revealed that one of the detected viruses was a genetic reassortant between African and Asian strains. This study provides compelling evidence for the presence of CCHFV in Zambia and its transmission to vertebrate hosts.

Crimean-Congo hemorrhagic fever (CCHF) is a severe viral disease mainly transmitted by ticks. Effective prophylactics and therapeutics have not been established for this disease yet. While CCHF is endemic in Africa, information on the distribution and genetic diversity of CCHF virus (CCHFV) is quite limited in many Sub-Saharan African countries. In this study, we conducted serologic and molecular epidemiologic investigations for CCHFV infection in cattle and ticks in Zambia. Serologic screening revealed that 8.4% of cattle were tested positive for CCHFV-specific IgG. Hyalomma ticks infected with CCHFV were also identified by genetic screening. Phylogenetic analyses showed that one of the CCHFVs detected in Zambia was a genetic reassortant between African and Asian CCHFV strains. Currently, Zambia is considered CCHF-free country because CCHF cases have never been reported. However, the findings in this study indicate that CCHFV is maintained in Hyalomma ticks and occasionally transmitted to vertebrate hosts such as cattle in Zambia. Further epidemiologic studies and continuous monitoring of CCHFV infection should be implemented in the southern African region.

Risk factors associated with exposure to Crimean-Congo haemorrhagic fever virus in animal workers and cattle, and molecular detection in ticks, South Africa

Crimean-Congo haemorrhagic fever (CCHF) is a severe tick-borne viral zoonosis endemic to parts of Africa, Europe, the Middle East and Central Asia. Human cases are reported annually in South Africa, with a 25% case fatality rate since the first case was recognized in 1981. We investigated CCHF virus (CCHFV) seroprevalence and risk factors associated with infection in cattle and humans, and the presence of CCHFV in Hyalomma spp. ticks in central South Africa in 2017-18. CCHFV IgG seroprevalence was 74.2% (95%CI: 64.2-82.1%) in 700 cattle and 3.9% (95%CI: 2.6-5.8%) in 541 farm and wildlife workers. No veterinary personnel (117) or abattoir workers (382) were seropositive. The prevalence of CCHFV RNA was significantly higher in Hyalomma truncatum (1.6%) than in H. rufipes (0.2%) (P = 0.002). Seroprevalence in cattle increased with age and was greater in animals on which ticks were found. Seroprevalence in cattle also showed significant geographic variation. Seroprevalence in humans increased with age and was greater in workers who handled livestock for injection and collection of samples. Our findings support previous evidence of widespread high CCHFV seroprevalence in cattle and show significant occupational exposure amongst farm and wildlife workers. Our seroprevalence estimate suggests that CCHFV infections are five times more frequent than the 215 confirmed CCHF cases diagnosed in South Africa in the last four decades (1981-2019). With many cases undiagnosed, the potential seriousness of CCHF in people, and the lack of an effective vaccine or treatment, there is a need to improve public health awareness, prevention and disease control.

Crimean-Congo Haemorrhagic Fever (CCHF) in animals: Global characterization and evolution from 2006 to 2019

This study describes the global distribution and temporal evolution of Crimean-Congo haemorrhagic fever (CCHF) during the period 2006-2019, using the information officially reported to the World Organisation for Animal Health (OIE) by the National Veterinary Services of 210 countries. Eight per cent (CI 95% 4-12) of the countries reported the disease as present at least once during the study period, whereas 82% (CI 95% 77-87) as absent. Information on CCHF status lacked for 10% (CI 95% 6-13) of the countries. The majority of the countries (46%, CI 95% 39-53) never declared CCHF as notifiable, whereas only 27% (CI 95% 21-33) reported the disease as notifiable during the large majority (≥76%) of the study period. The percentage of countries that routinely applied some CCHF control measures were as following: 14% (CI 95% 9-18) passive surveillance, 3% (CI 95% 0.9-5) active surveillance and 1% (CI 95% -0.2-3) control of vector. The time series analysis indicates a significant decreasing trend in the percentage of countries reporting no information, whereas the percentage of countries applying disease control measures significantly increase. This finding may reflect the increased awareness on the importance of the disease and the increased efforts to monitor virus circulation in animals through the application of surveillance programmes. Out of 25 countries reporting cases in humans since 2006, only 12 report cases in animals, pointing out the lack of surveillance capacity in animal populations for some countries. The paucity of CCHF notifications in animals may also reflect the difficulty in identifying the infection due to absent or mild clinical signs. Given that the implementation of surveillance programmes by the Veterinary Services is an essential tool for monitoring the virus circulation and prevent its further spread, National Veterinary Services should keep monitoring and reporting information on CCHF, and at the same time, they should improve the quality and accuracy of the information provided.

Residual and Late Onset Symptoms Appeared in a Patient with Severe Fever with Thrombocytopenia in a Convalescence Stage

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by Dabie bandavirus (formerly SFTS virus, SFTSV). Its manifestations during the convalescent phase have not been widely described. We report a patient presenting with hematospermia, fatigue, myalgia, alopecia, insomnia, and depression during the recovery phase of SFTS. Since these symptoms are widely observed in patients with viral hemorrhagic fevers, there might be common mechanisms between SFTS and other viral hemorrhagic fevers. Close monitoring may be required during the recovery phase of SFTS.

Update on prevalence and distribution pattern of tick-borne diseases among humans in India: a review

In the present scenario, tick-borne diseases (TBDs) are well known for their negative impacts on humans as well as animal health in India. The reason lies in their increased incidences due to global warming, environmental and ecological changes, and availability of suitable habitats. On a global basis, they are now considered a serious threat to human as well as livestock health. The major tick-borne diseases in India include Kyasanur forest disease (KFD), Crimean-congo hemorrhagic fever (CCHF), Lyme disease (LD), Q fever (also known as coxiellosis), and Rickettsial infections. In recent years, other tick-borne diseases such as Babesiosis, Ganjam virus (GANV), and Bhanja virus (BHAV) infections have also been reported in India. The purpose of this paper is to review the history and the current state of knowledge of tick-borne diseases in the country. The conclusion of this review is extending the requirement of greater efforts in research and government management for the diagnosis and treatment and as well as prevention of these diseases so that tick-borne disease burden should be minimizing in India.

Ocular manifestations of emerging viral diseases

Emerging infectious diseases (EIDs) are an increasing threat to public health on a global scale. In recent times, the most prominent outbreaks have constituted RNA viruses, spreading via droplets (COVID-19 and Influenza A H1N1), directly between humans (Ebola and Marburg), via arthropod vectors (Dengue, Zika, West Nile, Chikungunya, Crimean Congo) and zoonotically (Lassa fever, Nipah, Rift Valley fever, Hantaviruses). However, specific approved antiviral therapies and vaccine availability are scarce, and public health measures remain critical. Patients can present with a spectrum of ocular manifestations. Emerging infectious diseases should therefore be considered in the differential diagnosis of ocular inflammatory conditions in patients inhabiting or returning from endemic territories, and more general vigilance is advisable in the context of a global pandemic. Eye specialists are in a position to facilitate swift diagnosis, improve clinical outcomes, and contribute to wider public health efforts during outbreaks. This article reviews those emerging viral diseases associated with reports of ocular manifestations and summarizes details pertinent to practicing eye specialists.

Worldwide epidemiology of Crimean-Congo Hemorrhagic Fever Virus in humans, ticks and other animal species, a systematic review and meta-analysis

There are uncertainties about the global epidemiological data of infections due to Crimean-Congo hemorrhagic fever virus (CCHFV). We estimated the global case fatality rate (CFR) of CCHFV infections and the prevalence of CCHFV in humans, ticks and other animal species. We also explored the socio-demographic and clinical factors that influence these parameters. In this systematic review with meta-analyses we searched publications from database inception to 03rd February 2020 in Pubmed, Scopus, and Global Index Medicus. Studies included in this review provided cross-sectional data on the CFR and/or prevalence of one or more targets used for the detection of CCHFV. Two independent investigators selected studies to be included. Data extraction and risk of bias assessment were conducted independently by all authors. Data collected were analysed using a random effect meta-analysis. In all, 2345 records were found and a total of 312 articles (802 prevalence and/or CFR data) that met the inclusion criteria were retained. The overall CFR was 11.7% (95% CI = 9.1-14.5), 8.0% (95% CI = 1.0-18.9), and 4.7% (95% CI = 0.0-37.6) in humans with acute, recent, and past CCHFV infections respectively. The overall CCHFV acute infections prevalence was 22.5% (95% CI = 15.7-30.1) in humans, 2.1% (95% CI = 1.3-2.9) in ticks, and 4.5% (95% CI = 1.9-7.9) in other animal species. The overall CCHFV recent infections seroprevalence was 11.6% (95% CI = 7.9-16.4) in humans and 0.4% (95% CI = 0.0-2.9) in other animal species. The overall CCHFV past infections seroprevalence was 4.3% (95% CI = 3.3-5.4) in humans and 12.0% (95% CI = 9.9-14.3) in other animal species. CFR was higher in low-income countries, countries in the WHO African, South-East Asia and Eastern Mediterranean regions, in adult and ambulatory patients. CCHFV detection rate in humans were higher in CCHFV suspected cases, healthcare workers, adult and hospitalized patients, ticks of the genus Ornithodoros and Amblyomma and in animals of the orders Perissodactyla and Bucerotiformes. This review highlights a significant disease burden due to CCHFV with a strong disparity according to country income levels, geographic regions, various human categories and tick and other animal species. Preventive measures in the light of these findings are expected.

Spatial Distribution of Ticks (Arachniada: Argasidae and Ixodidae) and Their Infection Rate to Crimean-Congo Hemorrhagic Fever Virus in Iran

Background:

The Crimean-Congo Hemorrhagic Fever (CCHF) is one of the most important arthropod-borne viral diseases with a mortality rate of about 30% among humans. The disease, caused by a Nairovirus, is transmitted to humans and animals by hard and soft ticks. This study aimed to determine the distribution of soft and hard ticks in the past three decades in Iran with an emphasis on the vectors of the CCHF virus.

Methods:

In this study, all studies that were carried out in different regions of Iran from 1979 to 2018 and their results were published in prestigious journals were used to create a database. The distribution of ticks was mapped using ArcMap10.3.

Results:

Based on the results, nine genera and 37 species of soft and hard ticks were recorded in Iran. So far, six genera and 16 species of hard and soft ticks were reported to be infected with the CCHF virus. The infection to this virus was reported from 18 out of 31 provinces, with a high rate in Sistan and Baluchistan as well as Khuzestan provinces. The highest levels of CCHF infection belonged to Hyalomma marginatum and H. anatolicum.

Conclusion:

The main vectors of CCHF, H. marginatum and H. anatolicum, were reported in more than 38.7% of Iran's provinces, and these two species were identified as invasive species in Iran. Thus, control activities should be strengthened to avoid the outbreaks of CCHF.

Tick infestation on the lower eyelid in an elderly female: a case report

This article presents a case of tick infestation of the lower eyelid. A 58-year-old female presented to Ophthalmology OPD at Nepalgunj medical college with a small whitish lesion on medial aspect of the left lower eyelid since 7 days. On a detailed ocular examination, a tick was found to be masquerading as a pustule. This case report emphasizes the relation of tropical diseases in ophthalmology and the subsequent need of understanding the pathophysiological aspect of tropical diseases to avoid further systemic complications.

Epidemiological Aspects of Crimean-Congo Hemorrhagic Fever in Western Europe: What about the Future?

Crimean-Congo hemorrhagic fever virus (CCHFV) is an arthropod-borne virus (arbovirus), mainly transmitted by ticks, belonging to the genus Orthonairovirus (family Nairoviridae, order Bunyavirales). CCHFV causes a potentially severe, or even fatal, human disease, and it is widely distributed in Africa, Asia, eastern Europe and, more recently, in South-western Europe. Until a few years ago, no cases of Crimean-Congo hemorrhagic fever (CCHF) had been reported in western Europe, with the exception of several travel-associated cases. In 2010, the CCHFV was reported for the first time in South-western Europe when viral RNA was obtained from Hyalomma lusitanicum ticks collected from deer in Cáceres (Spain). Migratory birds from Africa harboring CCHFV-infected ticks and flying to Spain appear to have contributed to the establishment of the virus (genotype III, Africa-3) in this country. In addition, the recent findings in a patient and in ticks from deer and wild boar of viral sequences similar to those from eastern Europe (genotype V, Europe-1), raise the possibility of the introduction of CCHFV into Spain through the animal trade, although the arrival by bird routes cannot be ruled out (Africa-4 has been also recently detected). The seropositive rates of animals detected in regions of South-western Spain suggest an established cycle of tick-host-tick in certain areas, and the segment reassortment detected in the sequenced virus from one patient evidences a high ability to adaptation of the virus. Different ixodid tick genera can be vectors and reservoirs of the virus, although Hyalomma spp. are particularly relevant for its maintenance. This tick genus is common in Mediterranean region but it is currently spreading to new areas, partly due to the climate change and movement of livestock or wild animals. Although to a lesser extent, travels with our pets (and their ticks) may be also a factor to be considered. As a consequence, the virus is expanding from the Balkan region to Central Europe and, more recently, to Western Europe where different genotypes are circulating. Thus, seven human cases confirmed by molecular methods have been reported in Spain from 2016 to August 2020, three of them with a fatal outcome. A One Health approach is essential for the surveillance of fauna and vector populations to assess the risk for humans and animals. We discuss the risk of CCHFV causing epidemic outbreaks in Western Europe.

Crimean-Congo Hemorrhagic Fever Virus (CCHFV): A Silent but Widespread Threat

Purpose of Review

This review is aimed at highlighting recent research and articles on the complicated relationship between virus, vector, and host and how biosurveillance at each level informs disease spread and risk.

Recent Findings

While human cases of CCHFV and tick identification in non-endemic areas in 2019–2020 were reported to sites such as ProMed, there is a gap in recent published literature on these and broader CCHFV surveillance efforts from the late 2010s.

Summary

A review of the complex aspects of CCHFV maintenance in the environment coupled with high fatality rate and lack of vaccines and therapeutics warrants the need for a One-Health approach toward detection and increased biosurveillance programs for CCHFV.

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.

Comparison of diagnostic performances of ten different immunoassays detecting anti-CCHFV IgM and IgG antibodies from acute to subsided phases of Crimean-Congo hemorrhagic fever

Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a geographically widespread tick-borne arbovirus that has been recognized by the WHO as an emerging pathogen needing urgent attention to ensure preparedness for potential outbreaks. Therefore, availability of accurate diagnostic tools for identification of acute cases is necessary. A panel comprising 121 sequential serum samples collected during acute, convalescent and subsided phase of PCR-proven CCHFV infection from 16 Kosovar patients was used to assess sensitivity. Serum samples from 60 healthy Kosovar blood donors were used to assess specificity. All samples were tested with two IgM/IgG immunofluorescence assays (IFA) from BNITM, the CCHFV Mosaic 2 IgG and IgM indirect immunofluorescence tests (IIFT) from EUROIMMUN, two BlackBox ELISAs for the detection of CCHFV-specific IgM and IgG antibodies (BNITM), two Anti-CCHFV ELISAs IgM and IgG from EUROIMMUN using recombinant structural proteins of CCHFV antigens, and two ELISAs from Vector-Best (IgM: μ-capture ELISA, IgG: indirect ELISA using immobilized CCHFV antigen). Diagnostic performances were compared between methods using sensitivity, specificity, concordance and degree of agreement with particular focus on the phase of the infection. In early and convalescent phases of infection, the sensitivities for detecting specific IgG antibodies differed for the ELISA test. The BlackBox IgG ELISA yielded the highest, followed by the EUROIMMUN IgG ELISA and finally the VectorBest IgG ELISA with the lowest sensitivities. In the subsided phase, the VectorBest IgM ELISA detected a high rate of samples that were positive for anti-CCHFV IgM antibodies. Both test systems based on immunofluorescence showed an identical sensitivity for detection of anti-CCHFV IgM antibodies in acute and convalescent phases of infection. Available serological test systems detect anti-CCHFV IgM and IgG antibodies accurately, but their diagnostic performances vary with respect to the phase of the infection.

MicroRNA analysis from acute to convalescence in Crimean Congo hemorrhagic fever

Crimean Congo hemorrhagic fever (CCHF) is one of the most important viral infections and is caused by Crimean Congo hemorrhagic fever orthonairovirus (CCHFV). Severity of CCHF can vary from a mild and nonspecific illness to a severe disease with fatal outcomes. MicroRNAs (miRNAs) have an increasing impact on the different pathways of viral infections. Within the transition process from acute phase to convalescence with 18 CCHF patients, we investigated the impacts on miRNA via microarray for the first time. We also compared miRNA gene expression in 16 severe and 15 mild cases. We identified Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathways associated with significant miRNAs utilizing DIANA TOOLS mirPath v.3. In this study, miR-15b-5p and miR-29a-3p were significantly downregulated in statistical terms; miR-4741, miR-937-5p, miR-6068, miR-7110-5p, miR-6126, and miR-7107-5p were upregulated in acute cases in comparison with convalescent patients (p ≤ .05). In total, 28 miRNAs (8 downregulated, 20 upregulated) were differentially expressed in severe CCHF patients as compared with mild cases (p ≤ .05). Whereas miR-6732-3p, miR-4436b-5p, miR-483-3p, and miR-6807-5p had the highest downregulation, miR-532-5p, miR-142-5p, miR-29c-3p, and let-7f-5p had the highest upregulation in severe patients in comparison with mild cases. Consequently, we determined that CCHF-induced miRNAs are associated with antiviral and proinflammatory pathways in acute and severe cases. In comparison with convalescence, these miRNAs in acute period may be therapeutic targets.

Identification of a new orthonairovirus associated with human febrile illness in China

The genus Orthonairovirus, which is part of the family Nairoviridae, includes the important tick-transmitted pathogens Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, as well as many other poorly characterized viruses found in ticks, birds and mammals^1,2. In this study, we identified a new orthonairovirus, Songling virus (SGLV), from patients who reported being bitten by ticks in Heilongjiang Province in northeastern China. SGLV shared similar genomic and morphological features with orthonairoviruses and phylogenetically formed a unique clade in Tamdy orthonairovirus of the Nairoviridae family. The isolated SGLV induced cytopathic effects in human hepatoma cells in vitro. SGLV infection was confirmed in 42 hospitalized patients analyzed between 2017 and 2018, with the main clinical manifestations being headache, fever, depression, fatigue and dizziness. More than two-thirds (69%) of patients generated virus-specific antibody responses in the acute phase. Taken together, these results suggest that this newly discovered orthonairovirus is associated with human febrile illness in China.

[Crimean-Congo hemorrhagic fever, a future health problem in France?]

The Crimean-Congo hemorrhagic fever virus (CCHFV) is the etiological agent of a severe hemorrhagic fever affecting Africa, Asia and southern Europe. Climate changes of recent decades have recently led to a rise in the distribution of this virus. Still few scientific data are available on the biology of its vector, the tick, or its own biology, but the proven presence of human infections observed in Spain and animals with positive serology in Corsica should focus our attention on this pathogen. This review takes stock of the epidemiologic evolution of CCHF in Europe, notably in France.

Evaluation of neutrophil to lymphocyte ratio in predicting the prognosis of Crimean-Congo haemorrhagic fever

Crimean-Congo haemorrhagic fever (CCHF) is a severe form of haemorrhagic fever identified in parts of Africa, Asia, Eastern Europe and the Middle East. CCHF continues to be a justifiable cause of concern for people in rural areas where the disease is endemic. A total of 151 patients, diagnosed with CCHF, were evaluated retrospectively. The demographic characteristics of these patients and the relationship between the neutrophil-lymphocyte ratio (NLR) at admission and survival were examined. There were 21 (13.9%) deaths. There was no relationship between age, gender and mortality, but elevated neutrophil-lymphocyte ratio (NLR) on admission was statistically associated with mortality. NLR is a laboratory marker that can be studied even in medical centres with limited facilities and may be helpful in predicting the clinical course of the disease.

New circulation of genotype V of Crimean-Congo haemorrhagic fever virus in humans from Spain

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a widespread tick-borne viral disease caused by the Crimean-Congo haemorrhagic fever virus (CCHFV). CCHFV has been implicated in severe viral haemorrhagic fever outbreaks. During the summer of 2016, the first two cases with genotype III (Africa 3) were reported in Spain. The first objective of our study was to determine the presence of CCHFV among patients with febrile illness during the spring and summer periods in 2017 and 2018. Finally, we perform a phylogenetic analysis to determine the genotype of the virus.

METHODOLOGY

We prospectively evaluated patients aged 18 years and older who came to the emergency department at the Salamanca's University Hospital (HUS) with fever. Specific IgM and IgG antibodies against CCHFV by ELISA and one immunofluorescence assay against two different proteins (nucleoprotein and glycoprotein C) was done. Moreover, molecular detection by Real Time PCR was performed in all collected samples. A phylogenetic analysis was carried out to genetically characterize CCHFV detected in this study.

PRINCIPAL FINDINGS

A total of 133 patients were selected. The mean age was 67.63 years and 60.9% were male. One-third of the patients presented an acute undifferentiated febrile illness. Three patients had anti-CCHFV IgG antibodies, suggesting a previous infection. One patient had anti-CCHFV IgM antibodies and a confirmatory RT-PCR. Phylogenetic analysis indicated that the virus corresponds to the European genotype V. This patient came to the emergency department at HUS in August 2018 presenting an acute febrile syndrome with thrombopenia and liver impairment.

CONCLUSIONS

We describe a new circulation of European genotype V CCHFV in Spain. Moreover, this study suggests that CCHFV is an identifiable cause of febrile illness of unknown origin in Spain. Thus, CCHF could be suspected in patients with fever, liver damage, and/or haemorrhagic disorders, particularly in people with risk activities who present in the spring or summer.

T-Cells and Interferon Gamma Are Necessary for Survival Following Crimean-Congo Hemorrhagic Fever Virus Infection in Mice

Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne febrile illness with wide geographic distribution. In humans, the disease follows infection by the Crimean-Congo hemorrhagic fever virus (CCHFV) and begins as flu-like symptoms that can rapidly progress to hemorrhaging and death. Case fatality rates can be as high as 30%. An important gap in our understanding of CCHF are the host immune responses necessary to control the infection. A better understanding of these responses is needed to direct therapeutic strategies to limit the often-severe morbidity and mortality seen in humans. In this report, we have utilized a mouse model in which mice develop severe disease but ultimately recover. T-cells were robustly activated, differentiated to produce antiviral cytokines, and were critical for survival following CCHFV infection. We further identified a key role for interferon gamma (IFNγ) in survival following CCHFV infection. These results significantly improve our understanding of the host adaptive immune response to severe CCHFV infection.

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

BACKGROUND

Crimean-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.

METHODS

We 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).

RESULTS

500 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 (κ_coefficient = 0.88, p = <0.01) than to in-house (κ_coefficient = 0.32, p = 0.02).

CONCLUSIONS

Our 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.

An Insight into Nanomedicinal Approaches to Combat Viral Zoonoses

BACKGROUND

Emerging viral zoonotic diseases are one of the major obstacles to secure the "One Health" concept under the current scenario. Current prophylactic, diagnostic and therapeutic approaches often associated with certain limitations and thus proved to be insufficient for customizing rapid and efficient combating strategy against the highly transmissible pathogenic infectious agents leading to the disastrous socio-economic outcome. Moreover, most of the viral zoonoses originate from the wildlife and poor knowledge about the global virome database renders it difficult to predict future outbreaks. Thus, alternative management strategy in terms of improved prophylactic vaccines and their delivery systems; rapid and efficient diagnostics and effective targeted therapeutics are the need of the hour.

METHODS

Structured literature search has been performed with specific keywords in bibliographic databases for the accumulation of information regarding current nanomedicine interventions along with standard books for basic virology inputs.

RESULTS

Multi-arrayed applications of nanomedicine have proved to be an effective alternative in all the aspects regarding the prevention, diagnosis, and control of zoonotic viral diseases. The current review is focused to outline the applications of nanomaterials as anti-viral vaccines or vaccine/drug delivery systems, diagnostics and directly acting therapeutic agents in combating the important zoonotic viral diseases in the recent scenario along with their potential benefits, challenges and prospects to design successful control strategies.

CONCLUSION

This review provides significant introspection towards the multi-arrayed applications of nanomedicine to combat several important zoonotic viral diseases.

Decoding the RNA viromes in rodent lungs provides new insight into the origin and evolutionary patterns of rodent-borne pathogens in Mainland Southeast Asia

BACKGROUND

As the largest group of mammalian species, which are also widely distributed all over the world, rodents are the natural reservoirs for many diverse zoonotic viruses. A comprehensive understanding of the core virome of diverse rodents should therefore assist in efforts to reduce the risk of future emergence or re-emergence of rodent-borne zoonotic pathogens.

RESULTS

This study aimed to describe the viral range that could be detected in the lungs of rodents from Mainland Southeast Asia. Lung samples were collected from 3284 rodents and insectivores of the orders Rodentia, Scandentia, and Eulipotyphla in eighteen provinces of Thailand, Lao PDR, and Cambodia throughout 2006-2018. Meta-transcriptomic analysis was used to outline the unique spectral characteristics of the mammalian viruses within these lungs and the ecological and genetic imprints of the novel viruses. Many mammalian- or arthropod-related viruses from distinct evolutionary lineages were reported for the first time in these species, and viruses related to known pathogens were characterized for their genomic and evolutionary characteristics, host species, and locations.

CONCLUSIONS

These results expand our understanding of the core viromes of rodents and insectivores from Mainland Southeast Asia and suggest that a high diversity of viruses remains to be found in rodent species of this area. These findings, combined with our previous virome data from China, increase our knowledge of the viral community in wildlife and arthropod vectors in emerging disease hotspots of East and Southeast Asia. Video abstract.

Ticks and Tick-Borne Diseases of Livestock in the Middle East and North Africa: A Review

Ticks are important vectors of an array of viral, bacterial and protozoan pathogens resulting in a wide range of animal and human diseases. There is limited information in the literature about tick species in the Middle East and North Africa (MENA) countries, even though they have suitable climate and vegetation for ticks and their hosts. We reviewed the occurrence of tick species and the pathogens they transmit from the MENA on published papers from 1901-2020. We found taxonomic records of 55 tick species infesting livestock representing the following eight genera: Ornithodoros, Otobius, Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes, and Rhipicephalus. In addition, 15 pathogens were recorded causing diseases of significance, with Crimean-Congo hemorrhagic fever, theileriosis, babesiosis and anaplasmosis being widely distributed diseases in the region. In recent decades, there has been increasing trends in disease occurrence and movement associated with global movement of humans and global trade of animals. We suggest that disease control and prevention could be achieved effectively through good integration between public health, veterinary medicine and animal management, and ecological approaches. We recommend further research in the areas of tick ecology and tick born-disease transmission. Furthermore, we suggest evaluation and improvement of disease control policies in the region.

Purtscher-like Retinopathy Associated with Crimean-Congo Hemorrhagic Fever: A Case Report

PURPOSE

To describe retinal findings and spectral-domain optical coherence tomographic (SD-OCT) features of a patient with Crimean-Congo hemorrhagic fever (CCHF) presenting as Purtscher-like retinopathy.

CASE REPORT

A 70-year-old woman presented with the emerging bilateral blurring of vision. She had been diagnosed with CCHF one week ago and hospitalized in another hospital for treatment of disease. Fundoscopy of the patient revealed cotton-wool spots, retinal whitening areas, and few retinal hemorrhages in a Purtscher-like configuration in both eyes. Spectral-domain optical coherence tomography revealed inner retinal hyperreflectivity corresponding to the cotton-wool spots in both eyes, and also showed subretinal fluid in the left eye. Without any treatment retinal lesions and inner retinal hyperreflectivity on SD-OCT regressed within one month.

CONCLUSION

Crimean-Congo hemorrhagic fever is known to cause mild ocular disease, and may also cause Purtscher-like retinopathy. It is important to aware of the ocular findings of CCHF.

Immunocompetent mouse model for Crimean-Congo hemorrhagic fever virus

Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne febrile illness with wide geographic distribution. CCHF is caused by infection with the Crimean-Congo hemorrhagic fever virus (CCHFV) and case fatality rates can be as high as 30%. Despite causing severe disease in humans, our understanding of the host and viral determinants of CCHFV pathogenesis are limited. A major limitation in the investigation of CCHF has been the lack of suitable small animal models. Wild-type mice are resistant to clinical isolates of CCHFV and consequently, mice must be deficient in type I interferon responses to study the more severe aspects of CCHFV. We report here a mouse-adapted variant of CCHFV that recapitulates in adult, immunocompetent mice the severe CCHF observed in humans. This mouse-adapted variant of CCHFV significantly improves our ability to study host and viral determinants of CCHFV-induced disease in a highly tractable mouse model.