Prognostic factors, pathophysiology and novel biomarkers in Crimean-Congo hemorrhagic fever

Crimean Congo Hemorrhagic Fever Virus for Clinicians-Virology, Pathogenesis, and Pathology

Crimean-Congo hemorrhagic fever (CCHF), caused by CCHF virus, is a tickborne disease that can cause a range of illness outcomes, from asymptomatic infection to fatal viral hemorrhagic fever; the disease has been described in >30 countries. We conducted a literature review to provide an overview of the virology, pathogenesis, and pathology of CCHF for clinicians. The virus life cycle and molecular interactions are complex and not fully described. Although pathogenesis and immunobiology are not yet fully understood, it is clear that multiple processes contribute to viral entry, replication, and pathological damage. Limited autopsy reports describe multiorgan involvement with extravasation and hemorrhages. Advanced understanding of CCHF virus pathogenesis and immunology will improve patient care and accelerate the development of medical countermeasures for CCHF.

An Evaluation of the Hitit Index in Differential Diagnosis of Crimean-Congo Hemorrhagic Fever in the Emergency Department

Background and Objectives: Crimean-Congo Hemorrhagic Fever (CCHF) is a viral zoonotic infection, which is seen over a wide geographic area. The mortality rate is in inverse proportion to the ability of patients to access healthcare services. Therefore, early identification of patients is extremely important. The aim of this study was to test the sensitivity and specificity of the Hitit Index in the differentiation of CCHF cases at the time of presentation at the Emergency Department and to evaluate the agreement of this index with molecular (CCHFV RNA) and/or serological diagnostic tests (ELISA-CCHF IgM). Materials and Methods: The patients included were those who presented at the Emergency Department (ED) with the complaint of a tick bite or those identified as potential CCHF cases as a result of complaints and/or laboratory findings. For cases that met the study inclusion criteria, the Hitit Index score was calculated automatically from the parameters included in the index formula uploaded to the automation system in the ED at the time of presentation. Through comparisons of the agreement of the Hitit Index with the CCHFV-RNA and/or IgM results the power of the Hitit Index for differentiation of CCHF cases in ED was evaluated. Results: The data of 273 patients were analyzed. There was a history of tick bite in 236 (86%) cases. Of the evaluated cases, 110 (40.2%) were hospitalized; CCHF positivity was determined in 72 (26.4%). The Hitit Index values calculated in ED and at 24 h after hospitalization were determined to be significant in the prediction of the CCHF cases (p < 0.001, AUC = 0.919 (0.887-0.951); p < 0.001, AUC = 0.902 (0.841-0.962). For a cut-off point of 0 of the Hitit Index evaluated in ED, the classification success was found to have a sensitivity of 75% and specificity of 88% (PPV-NPV). For a cut-off point of 0 of the Hitit Index evaluated at 24 h after hospitalization, the classification success was found to have a sensitivity of 79.7% and specificity of 84% (PPV-NPV). Conclusions: The defined form of the Hitit Index can be used in the differentiation of CCHF cases in ED with high sensitivity and specificity levels. Just as evaluation with the Hitit Index prevents unnecessary hospitalization, it can also contribute to reducing mortality rates with the early identification of CCHF cases.

Viral load: We need a new look at an old problem?

The concept of viral load was introduced in the 1980s to measure the amount of viral genetic material in a person's blood, primarily for human immunodeficiency virus (HIV). It has since become crucial for monitoring HIV infection progression and assessing the efficacy of antiretroviral therapy. However, during the coronavirus disease 2019 pandemic, the term "viral load" became widely popularized, not only for the scientific community but for the general population. Viral load plays a critical role in both clinical patient management and research, providing valuable insights for antiviral treatment strategies, vaccination efforts, and epidemiological control measures. As measuring viral load is so important, why don't researchers discuss the best way to do it? Is it simply acceptable to use raw Ct values? Relying solely on Ct values for viral load estimation can be problematic due to several reasons. First, Ct values can vary between different quantitative polymerase chain reaction assays, platforms, and laboratories, making it difficult to compare data across studies. Second, Ct values do not directly measure the quantity of viral particles in a sample and they can be influenced by various factors such as initial viral load, sample quality, and assay sensitivity. Moreover, variations in viral RNA extraction and reverse-transcription steps can further impact the accuracy of viral load estimation, emphasizing the need for careful interpretation of Ct values in viral load assessment. Interestingly, we did not observe scientific articles addressing different strategies to quantify viral load. The absence of standardized and validated methods impedes the implementation of viral load monitoring in clinical management. The variability in cell quantities within samples and the variation in viral particle numbers within infected cells further challenge accurate viral load measurement and interpretation. To advance the field and improve patient outcomes, there is an urgent need for the development and validation of tailored, standardized methods for precise viral load quantification.

Predictive epidemiological, clinical and laboratory parameters in the diagnosis of Crimean-Congo hemorrhagic fever

Background: The aim of this study is to determine predictive parameters that can be used in the differential diagnosis of Crimean-Congo Hemorrhagic Fever (CCHF) and other diseases with similar clinical and laboratory findings. Materials & methods: In this study, epidemiological, clinical and laboratory parameters of 107 CCHF-positive and 71 CCHF-negative patients were compared. Results: Alanine amino transferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, red blood cell, hemoglobin and hematocrit were significantly higher in CCHF-positive patients, whereas total and direct bilirubin, alkaline phosphatase, prothrombin time, international normalization ratio, white blood cell, C-reactive protein and procalcitonin were higher in CCHF-negative patients. In binary logistic regression analysis, an increase in activated partial thromboplastin time level was identified as an independent predictor of having CCHF, while alanine amino transferase, white blood cell and C-reactive protein elevations were identified as independent predictors of not having CCHF. Conclusion: In endemic areas where PCR and serological tests are delayed, knowing the predictive parameters may be of vital importance in the early diagnosis of CCHF.

Genotypes of the Congo-Crimean Hemorrhagic Fever Virus Occurring in the Turkestan Region

Background: The Turkestan region of Kazakhstan is the natural focus of the Congo-Crimean hemorrhagic fever (CCHF). Every year, some of the patients treated in hospitals are not included in official statistics and remain in the group of possible cases of CCHF. Objectives: This study aimed to verify the genotypes of the CCHF virus (CCHFV) in the Turkestan region and Shymkent City. Methods: Twelve blood samples from patients with CCHF were studied, the diagnosis of which was verified on the basis of positive specific immunoglobulins IgM to the virus. To isolate viral RNA, we used a special MAGNO-sorb kit. To detect RNA, CCHFV was used with a set of Amplisens CCHFV-FL by real-time polymerase chain reaction (PCR) using a Rotor-Gene Q device. For the reverse transcription reaction, we used a set of Reverta-L. Results: The study of the genome sequence of CСHFV from GenBank demonstrated that isolates from the Turkestan region belonged to genetic groups Asia-1 and Asia-2. Conclusions: For the first time in Kazakhstan’s history, a phylogenetic analysis of RNA sequences of viruses from patients with CCHF was performed in the Turkestan region, as a result of which genetic groups Asia-1, reassortant Asia-1, and Asia-2 were established

Crimean-Congo Hemorrhagic Fever Case Series: a Chronology of Biochemical and Hematological Parameters

Introduction

Crimean-Congo hemorrhagic fever (CCHF) is a widespread tick-borne zoonotic disease. Sporadic outbreaks of CCHF occur in endemic regions, including Pakistan. The clinical spectrum of the illness varies from asymptomatic seroconversion to severe disease which may end in death. The treatment is supportive, including blood and blood products. There is multi-organ involvement in CCHF including acute hepatitis, thrombocytopenia, coagulopathy, acute kidney injury (AKI), and encephalopathy. Hematological and biochemical parameters may identify patients at substantial risk of worse outcomes. Early detection of the disease and forecasting the clinical course may be helpful. This case series aims to evaluate the trends of hematological and biochemical parameters among the survivors and non-survivors of CCHF.

Methods

All consecutive patients aged 16 years and above admitted to the isolation unit of Hayatabad Medical Complex, Peshawar, Pakistan between 1^st July and 30^th July 2022 with the diagnosis of CCHF were included in this case series. The diagnosis of CCHF was made by detecting viral ribonucleic acid by a polymerase chain reaction. For all patients, age, gender, address, occupation, clinical presentation, history of contact with animals, and travel history were recorded. All the vitals were taken regularly. The hematological (complete blood count) and biochemical parameters (serum creatinine, alanine aminotransferase (ALT), and C-reactive protein (CRP)) were documented daily. The blood group was determined for all the cases.

Results

Out of 17 cases, the majority (16 cases, 94.1%) were male and butchers (eight cases, 47.1%) by profession. All cases had significant contact with animals. Four patients (23.5%) died. Three out of the four non-survivors (75%) had ALT < 5 times the upper limit of normal with a static pattern of liver enzymes without much decline in ALT till death. One non-survivor (25%) had marked elevation of ALT at presentation, which had a declining trend till death. Seven out of 13 survivors (53.8%) had moderate to marked elevation in the level of ALT at presentation. The ALT showed a downward trend during the course of illness in all these patients. The remaining survivors (six out of 13, 46.2%) had a mild elevation of ALT and 50% of them showed improvement in the ALT level during hospitalization. All patients had thrombocytopenia at presentation. None of the non-survivors showed a persistent increase in the platelet count, and three cases remained severely thrombocytopenic at the time of death. However, the trend in platelet count among all the survivors was increasing. The CRP level in the majority (three out of four cases, 75%) of the non-survivors remained elevated till death, while all survivors showed a progressive decline in CRP level. A majority (11 out of 17 cases) had blood group B. Half of the non-survivors (two out of four cases) and the majority of the survivors (nine out of 13 cases) had blood group B. AKI was found in all non-survivors, while all the survivors had normal renal function throughout the course.

Conclusion

A persistently raised ALT and CRP level, a persistently low or decreasing platelet count, and AKI were associated with mortality. Blood group B was the commonest blood group among patients of CCHF, which is not reflective of the blood group distribution of the general population from which this case series has been reported.

Prognostic Value of Hemogram-Derived Ratios in Patients with Crimean-Congo Hemorrhagic Fever

Background: Crimean-Congo hemorrhagic fever (CCHF) is an emerging infectious disease that has epidemic and pandemic potential and causes mortality. Predicting the outcome of the disease is important to guide the management of patients and prevent mortality. Materials and Methods: This study aimed to investigate hemogram parameters and hemogram-derived ratios for predicting mortality in 207 patients with CCHF (survivors = 177, nonsurvivors = 30). Results: Compared with the survivor group, the nonsurvivor group had higher neutrophils, neutrophil-to-lymphocyte ratio (NLR), derived NLR (d-NLR), and aspartate aminotransferase (AST), AST-to-lymphocyte ratio index (ALRI) on admission and third day of hospitalization. Higher white blood cells (WBCs), lower platelet-to-lymphocyte ratio on admission, and lower lymphocytes, and monocytes on the third day were found in the nonsurvivor group. Evaluating the change of admission and the third day of laboratory values, a downward trend in neutrophils, NLR, d-NLR, ALRI, and an upward trend in WBCs were found statistically significant in the survivor group. These dynamic changes were not found in the nonsurvivor group. AST (third day) and ALRI (third day) had the highest area under the curve (AUC) in the receiver operating characteristic analysis (0.939 and 0.934, respectively; p-value is <0.0001 for all). The NLR on the third day than on admission had a higher AUC, the optimal cutoff value was 1.44, which resulted in a sensitivity of 93.33 and a specificity of 40.34 (AUC: 0.790, p < 0.0001). The d-NLR on the third day had a higher AUC (with a sensitivity of 81.48 and a specificity of 67.43) than on admission (0.781 and 0.669, respectively). Conclusion: CCHF is a common vector-borne disease and mortality rates are high. This study revealed that NLR, d-NLR, and ALRI can be used as biomarkers to predict mortality. Patients who survived had better improvement in hemogram parameters and ratios. Therefore, patients who do not show this improvement should be followed more closely.

Endothelial Dysfunction, HMGB1, and Dengue: An Enigma to Solve

Dengue is a viral infection caused by dengue virus (DENV), which has a significant impact on public health worldwide. Although most infections are asymptomatic, a series of severe clinical manifestations such as hemorrhage and plasma leakage can occur during the severe presentation of the disease. This suggests that the virus or host immune response may affect the protective function of endothelial barriers, ultimately being considered the most relevant event in severe and fatal dengue pathogenesis. The mechanisms that induce these alterations are diverse. It has been suggested that the high mobility group box 1 protein (HMGB1) may be involved in endothelial dysfunction. This non-histone nuclear protein has different immunomodulatory activities and belongs to the alarmin group. High concentrations of HMGB1 have been detected in patients with several infectious diseases, including dengue, and it could be considered as a biomarker for the early diagnosis of dengue and a predictor of complications of the disease. This review summarizes the main features of dengue infection and describes the known causes associated with endothelial dysfunction, highlighting the involvement and possible relationship between HMGB1 and DENV.

Crimean-Congo Hemorrhagic Fever Beyond Ribavirin: A Systematic Review

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne virus endemic to a vast geographical area spanning from Africa to the shores of the Mediterranean Sea and north to the Balkans. The infection carries a high case fatality rate, which prompts the development of new treatment and prophylactic measures. This review explores the different treatment and prophylactic measures found in recent literature. For this purpose, we used Medical Subject Headings (MeSH) as well as PubMed advanced search. The inclusion criteria included full-text studies conducted on humans and in the English language. We found that plasma exchange was associated with a decrease in mortality rates. Similarly, the use of immunoglobulins proved effective in decreasing the severity and mortality risk. Ribavirin use was determined as a post-exposure prophylaxis drug with no statistically significant difference in oral or intravenous routes of administration. More studies should be conducted on CCHF as the number of outbreaks and endemic areas seem to be on the rise. For the time being, supportive therapy along with adjuvant antivirals appear to be the main course of management of CCHF. However, the need for definitive therapeutic agents and guidelines is warranted.

A case of Crimean Congo hemorrhagic fever complicated with acute pulmonary embolism

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is one of the common causes of tick-borne hemorrhagic infections. The study aims to report a case of a female patient with severe CCHF with pulmonary embolism.

CASE REPORT

A 61-year-old woman admitted to the emergency department with complaints of high fever, nausea, and weakness. The patient was dealing with animal husbandry and had a tick bite history. At laboratory findings, bicytopenia, abnormal liver function tests, and elevated coagulation parameters were observed. Real-time plymerase chain reaction confirmed the diagnosis of CCHF. Three sessions of plasmapheresis were performed due to continued fever and worsening in laboratory values. Pulmonary embolism was detected in computerized thorax tomography carried out due to respiratory alkalosis on the 6th day. She was successfully treated with supportive and anticoagulation therapy.

CONCLUSION

CCHF demonstrates different types of clinical presentations apart from fever and hemorrhage. Acute pulmonary embolism is a rare complication that has not been reported before.

Efficacy of therapeutic plasma exchange in patients with Crimean-Congo hemorrhagic fever

OBJECTIVE

To examine the efficacy of therapeutic plasma exchange (TPE) in patients critically ill with Crimean-Congo hemorrhagic fever (CCHF).

METHODS

Patients with CCHF received supportive treatment (ST) or TPE. After laboratory and clinical evaluations, the patients were divided into mild, moderate, and severe CCHF groups according to the severity score index (SSI). To assess the efficacy of TPE, the incubation period, time of admission to hospital, hospitalization duration, mortality rate and times to recovery of the platelet count and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were compared between patients receiving ST and TPE.

RESULT

A total of 119 confirmed CCHF cases was analyzed. The median SSIs were 7 in the TPE group and 5 in the ST group. The SSI stages, median incubation times and admission times were similar in the two groups. However, the duration of hospitalization was longer in the TPE group. The overall mortality rates were 9% (3 of 33 patients) in the TPE group and 16% (5 of 31 patients) in the ST group; the difference was significant. The platelet count recovered after a median of 6 (4-7) days in the ST group.

CONCLUSION

The mortality rate was lower in the TPE group than in the ST group, but the duration of hospitalization and the time to platelet recovery were longer in the TPE group than in the ST group. TPE did not contribute significantly to the prognosis of patients with intermediate-severity CCHF. However, TPE might be efficacious in patients with severe CCHF.

Association Between Severity Grading Score And Acute Phase Reactants In Patients With Crimean Congo Hemorrhagic Fever

As the COVID-19 pandemic continues, countries still have to struggle with their endemic diseases such as Crimean-Congo hemorrhagic fever (CCHF). Severity grading score (SGS) is a practical approach and may shed light on the course of the CCHF, whose pathogenesis is not clearly understood, and have no effective treatments. It is aimed to assess the association between SGS and acute phase reactants (APR). Laboratory-confirmed patients were categorized by severity scores, and the relationship between APR and SGS was evaluated. A significant correlation between SGS and C-reactive protein (CRP) was found (p < 0.001). High SGS was associated with mortality and high CRP levels were used to predict the mortality at the beginning of the hospital admission. To predict the outcome of the disease and for appropriate patient management, SGS and APR can be used simultaneously.

Analysis of Pediatric Intensive Care Unit Admissions for Crimean–Congo Hemorrhagic Fever in Turkey

Objective The aim of this study was to determine the clinical characteristics, course of disease, and outcomes of patients admitted to our pediatric intensive care unit (PICU) for Crimean–Congo hemorrhagic fever (CCHF).

Methods Data of all patients with CCHF who were admitted to PICU during a 3-year period and whose diagnosis was confirmed by serological methods or polymerase chain reaction were retrospectively reviewed. Their presenting characteristics, treatments, and outcomes were extracted from the hospital's electronic database. Disease severity scoring was performed using the severity scoring index and severity grading score system.

Results The data of 22 of 123 patients with suspected CCHF who were admitted to PICU were evaluated. Among them, 68.2% were males and mean age of all patients was 13.4 ± 2.2 years. The average length of stay of 10 patients was >10 days. On average, 3.72 units of platelet suspension per patient was transfused. In the course of the disease, the highest laboratory values were reached on day 3 of admission.

Conclusion Poor CCHF outcome depends on thrombocytopenia severity, prolonged coagulation tests, high-liver enzyme levels, and disseminated intravascular coagulation. Poor outcomes can be avoided by CCHF awareness and preparedness, early diagnosis of the disease, and supportive treatment with appropriate fluid and blood product transfusion. Randomized controlled trials on prophylactic transfusion and ribavirin use are needed.

Dual RNA-Seq characterization of host and pathogen gene expression in liver cells infected with Crimean-Congo Hemorrhagic Fever Virus

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus that can cause a hemorrhagic fever in humans, with a case fatality rate of up to 40%. Cases of CCHFV have been reported in Africa, Asia, and southern Europe; and recently, due to the expanding range of its vector, autochthonous cases have been reported in Spain. Although it was discovered over 70 years ago, our understanding of the pathogenesis of this virus remains limited. We used RNA-Seq in two human liver cell lines (HepG2 and Huh7) infected with CCHFV (strain IbAr10200), to examine kinetic changes in host expression and viral replication simultaneously at 1 and 3 days post infection. Through this, numerous host pathways were identified that were modulated by the virus including: antiviral response and endothelial cell leakage. Notably, the genes encoding DDX60, a cytosolic component of the RIG-I signalling pathway and OAS2 were both shown to be dysregulated. Interestingly, PTPRR was induced in Huh7 cells but not HepG2 cells. This has been associated with the TLR9 signalling cascade, and polymorphisms in TLR9 have been associated with poor outcomes in patients. Additionally, we performed whole-genome sequencing on CCHFV to assess viral diversity over time, and its relationship to the host response. As a result, we have demonstrated that through next-generation mRNA deep-sequencing it is possible to not only examine mRNA gene expression, but also to examine viral quasispecies and typing of the infecting strain. This demonstrates a proof-of-principle that CCHFV specimens can be analyzed to identify both the virus and host biomarkers that may have implications for prognosis.

Hitit Index to distinguish patients with and without Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is fatal. Therefore, it is very important to use an inexpensive, easily accessible, quick and accurate screening index based on clinical signs and laboratory parameters to identify patients suspected of having CCHF. Laboratory test results on the day of hospitalization for 268 inpatients suspected of having CCHF were used to calculate the laboratory section of the Hitit Index, while 65 of these were also monitored daily during their hospital stay to develop the clinical section of the Hitit Index. Two-hundred CCHF-negative outpatients were also evaluated. One-hundred and forty-nine inpatients were CCHF-positive and 119 inpatients were CCHF-negative. The Hitit Index is 5.6 - (5.3*lymphocyte) - (0.02*fibrinogen) - (12*direct bilirubin) + (0.04*AST) + (0.32*hematocrit) - (0.5*neutrophil) - (0.07*CKD-EPI) - (0.001*CK) ± conjunctival hyperemia (+1.5 in conjunctival hyperemia presence and -1.5 in conjunctival hyperemia absence). In 65 inpatients monitored daily, Hitit Index results for CCHF-positive and negative inpatients were 6.10(1.90-12.30) and -5.35(-8.83- -1.95), while CCHF-negative outpatients were -10.99(-15.64- -6.95) (P < 0.001), respectively. On hospitalization day, just one inpatient was false-negative in 27 CCHF-positive inpatients, while four were false-positive among 38 CCHF-negative inpatients using the Hitit Index. After 24 h, just one inpatient was diagnosed falsely among 27 CCHF-positive and 38 CCHF-negative inpatients, and there was no change after 48 h. Management of patients living in endemic regions suspected of having CCHF could be achieved within minutes using the Hitit Index. Patients with Hitit Index less than zero can be monitored as outpatients, while patients with Hitit Index results above zero must be hospitalized in infectious diseases wards. This study was not registered since it was retrospective.

Diagnostic tests for Crimean-Congo haemorrhagic fever: a widespread tickborne disease

Crimean-Congo haemorrhagic fever (CCHF) is a widespread tickborne disease that circulates in wild and domestic animal hosts, and causes severe and often fatal haemorrhagic fever in infected humans. Due to the lack of treatment options or vaccines, and a high fatality rate, CCHF virus (CCHFV) is considered a high-priority pathogen according to the WHO R&D Blueprint. Several commercial reverse transcriptase PCR (RT-PCR) and serological diagnostic assays for CCHFV are already available, including febrile agent panels to distinguish CCHFV from other viral haemorrhagic fever agents; however, the majority of international laboratories use inhouse assays. As CCHFV has numerous amplifying animal hosts, a cross-sectoral 'One Health' approach to outbreak prevention is recommended to enhance notifications and enable early warning for genetic and epidemiological shifts in the human, animal and tick populations. However, a lack of guidance for surveillance in animals, harmonisation of case identification and validated serodiagnostic kits for animal testing hinders efforts to strengthen surveillance systems. Additionally, as RT-PCR tests tend to be lineage-specific for regional circulating strains, there is a need for pan-lineage sensitive diagnostics. Adaptation of existing tests to point-of-care molecular diagnostic platforms that can be implemented in clinic or field-based settings would be of value given the potential for CCHFV outbreaks in remote or low-resource areas. Finally, improved access to clinical specimens for validation of diagnostics would help to accelerate development of new tests. These gaps should be addressed by updated target product profiles for CCHFV diagnostics.

Therapeutic management of Crimean-Congo haemorrhagic fever

Crimean-Congo haemorrhagic fever has been reported in more than 30 countries in Africa, Asia, the Middle East and Eastern Europe, with an increasing incidence in recent years, especially in Europe. Because no specific treatments have demonstrated efficacy, supportive treatment is essential, as well as the provision of a centre with the appropriate means to guarantee the safety of its healthcare professionals. Laboratory monitoring of thrombocytopenia, severe coagulopathy or liver failure is of critical importance. Patients with Crimean-Congo haemorrhagic fever should be admitted to High Level Isolation Units where appropriate biocontainment procedures can prevent nosocomial transmission through infected fluids or accidents with contaminated material. In case of high-risk exposures, early administration of ribavirin should be considered.

Yellow Fever Virus: Diagnostics for a Persistent Arboviral Threat

Yellow fever (YF) is the prototypical hemorrhagic fever and results from infection with yellow fever virus (YFV), which is endemic to regions of Africa and South America. Despite the availability of an effective vaccine, YFV continues to cause disease throughout regions where it is endemic, including intermittent large outbreaks among undervaccinated populations. A number of diagnostic methods and assays have been described for the detection of YFV infection, including viral culture, molecular testing, serology, and antigen detection. Commercial diagnostics are not widely available, and testing is generally performed at a small number of reference laboratories. The goal of this article, therefore, is to review available clinical diagnostics for YFV, which may not be familiar to many practitioners outside areas where it is endemic. Additionally, we identify gaps in our current knowledge about YF that pertain to diagnosis and describe interventions that may improve YFV detection.

Therapeutic management of Crimean-Congo haemorrhagic fever

Crimean-Congo haemorrhagic fever has been reported in more than 30 countries in Africa, Asia, the Middle East and Eastern Europe, with an increasing incidence in recent years, especially in Europe. Because no specific treatments have demonstrated efficacy, supportive treatment is essential, as well as the provision of a centre with the appropriate means to guarantee the safety of its healthcare professionals. Laboratory monitoring of thrombocytopenia, severe coagulopathy or liver failure is of critical importance. Patients with Crimean-Congo haemorrhagic fever should be admitted to High Level Isolation Units where appropriate biocontainment procedures can prevent nosocomial transmission through infected fluids or accidents with contaminated material. In case of high-risk exposures, early administration of ribavirin should be considered.

Cutaneous Findings of Crimean-Congo Hemorrhagic Fever: a Study of 269 Cases

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease. We aimed to investigate the cutaneous manifestations of CCHF and reveal their associations with fatality. Two hundred and sixty-nine patients diagnosed with CCHF were assessed. Skin findings were observed in 170 (63.2%) patients. A facial rash was the most common cutaneous finding (n = 82, 30.5%). In severe cases, hemorrhagic cutaneous manifestations (petechiae and ecchymoses) were recognized. A statistically significant correlation was obtained between cutaneous manifestations and fatality, and it was determined that there was a strong positive correlation between fatality and ecchymosis (r = 567, p < 0.001). In addition, a logistic regression analysis was performed, and death occurred 4.69 times more in those with skin signs than in those without. We hypothesize that CCHF patients with ecchymosis are at the highest risk and that cutaneous findings can contribute to the prognosis of CCHF.

Crimean-Congo haemorrhagic fever virus: Past, present and future insights for animal modelling and medical countermeasures

Crimean–Congo haemorrhagic fever (CCHF) is a widespread tick‐borne viral zoonosis with a case‐fatality rate ranging from 9% to 50% in humans. Although a licensed vaccine to prevent infection by the CCHF virus (CCHFV) exists, its ability to induce neutralizing antibodies is limited and its efficacy against CCHFV remains undetermined. In addition, controlling CCHF infections by eradication of the tick reservoir has been ineffective, both economically and logistically, and the treatment options for CCHF remain limited. In this review, we first critically discuss the existing animal models to evaluate therapeutics for CCHF. We then review the therapeutic options for CCHF that have been investigated in human cases, followed by investigational drugs that have been evaluated in pre‐clinical studies. We highlight the importance of understanding human prognostic factors in developing an animal model for CCHF that recapitulates hallmarks of human disease and its implication for selecting therapeutic candidates.

Peripheral Blood Biomarkers of Disease Outcome in a Monkey Model of Rift Valley Fever Encephalitis

Rift Valley Fever (RVF) is an emerging arboviral disease of livestock and humans. Although the disease is caused by a mosquito-borne virus, humans are infected through contact with, or inhalation of, virus-laden particles from contaminated animal carcasses. Some individuals infected with RVF virus (RVFV) develop meningoencephalitis, resulting in morbidity and mortality. Little is known about the pathogenic mechanisms that lead to neurologic sequelae, and thus, animal models that represent human disease are needed. African green monkeys (AGM) exposed to aerosols containing RVFV develop a reproducibly lethal neurological disease that resembles human illness. To understand the disease process and identify biomarkers of lethality, two groups of 5 AGM were infected by inhalation with either a lethal or a sublethal dose of RVFV. Divergence between lethal and sublethal infections occurred as early as 2 days postinfection (dpi), at which point CD8+ T cells from lethally infected AGM expressed activated caspase-3 and simultaneously failed to increase levels of major histocompatibility complex (MHC) class II molecules, in contrast to surviving animals. At 4 dpi, lethally infected animals failed to demonstrate proliferation of total CD4+ and CD8+ T cells, in contrast to survivors. These marked changes in peripheral blood cells occur much earlier than more-established indicators of severe RVF disease, such as granulocytosis and fever. In addition, an early proinflammatory (gamma interferon [IFN-γ], interleukin 6 [IL-6], IL-8, monocyte chemoattractant protein 1 [MCP-1]) and antiviral (IFN-α) response was seen in survivors, while very late cytokine expression was found in animals with lethal infections. By characterizing immunological markers of lethal disease, this study furthers our understanding of RVF pathogenesis and will allow the testing of therapeutics and vaccines in the AGM model.IMPORTANCE Rift Valley Fever (RVF) is an important emerging viral disease for which we lack both an effective human vaccine and treatment. Encephalitis and neurological disease resulting from RVF lead to death or significant long-term disability for infected people. African green monkeys (AGM) develop lethal neurological disease when infected with RVF virus by inhalation. Here we report the similarities in disease course between infected AGM and humans. For the first time, we examine the peripheral immune response during the course of infection in AGM and show that there are very early differences in the immune response between animals that survive infection and those that succumb. We conclude that AGM are a novel and suitable monkey model for studying the neuropathogenesis of RVF and for testing vaccines and therapeutics against this emerging viral pathogen.

Autochthonous Crimean-Congo Hemorrhagic Fever in Spain

Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed, viral, tickborne disease. In Europe, cases have been reported only in the southeastern part of the continent. We report two autochthonous cases in Spain. The index patient acquired the disease through a tick bite in the province of Ávila - 300 km away from the province of Cáceres, where viral RNA from ticks was amplified in 2010. The second patient was a nurse who became infected while caring for the index patient. Both were infected with the African 3 lineage of this virus. (Funded by Red de Investigación Cooperativa en Enfermedades Tropicales [RICET] and Efficient Response to Highly Dangerous and Emerging Pathogens at EU [European Union] Level [EMERGE].).

Global research trends of World Health Organization's top eight emerging pathogens

BACKGROUND

On December 8th, 2015, World Health Organization published a priority list of eight pathogens expected to cause severe outbreaks in the near future. To better understand global research trends and characteristics of publications on these emerging pathogens, we carried out this bibliometric study hoping to contribute to global awareness and preparedness toward this topic.

METHOD

Scopus database was searched for the following pathogens/infectious diseases: Ebola, Marburg, Lassa, Rift valley, Crimean-Congo, Nipah, Middle Eastern Respiratory Syndrome (MERS), and Severe Respiratory Acute Syndrome (SARS). Retrieved articles were analyzed to obtain standard bibliometric indicators.

RESULTS

A total of 8619 journal articles were retrieved. Authors from 154 different countries contributed to publishing these articles. Two peaks of publications, an early one for SARS and a late one for Ebola, were observed. Retrieved articles received a total of 221,606 citations with a mean ± standard deviation of 25.7 ± 65.4 citations per article and an h-index of 173. International collaboration was as high as 86.9%. The Centers for Disease Control and Prevention had the highest share (344; 5.0%) followed by the University of Hong Kong with 305 (4.5%). The top leading journal was Journal of Virology with 572 (6.6%) articles while Feldmann, Heinz R. was the most productive researcher with 197 (2.3%) articles. China ranked first on SARS, Turkey ranked first on Crimean-Congo fever, while the United States of America ranked first on the remaining six diseases. Of retrieved articles, 472 (5.5%) were on vaccine - related research with Ebola vaccine being most studied.

CONCLUSION

Number of publications on studied pathogens showed sudden dramatic rise in the past two decades representing severe global outbreaks. Contribution of a large number of different countries and the relatively high h-index are indicative of how international collaboration can create common health agenda among distant different countries.