Serological evidence and factors associated with Crimean-Congo haemorrhagic fever in sheep in Burkina Faso

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is caused by an orthonairovirus transmitted by bites from infected ticks or by direct contact with blood or tissues of infected ticks, viraemic patients or viraemic livestock.

OBJECTIVE

It was implemented to access the seropositivity and associated factors with CCHF in sheep in two provinces in Burkina Faso.

METHODS

Three hundred and sixty-four sheep sera have been taken from 73 herds in four municipalities and two provinces. The double-antigen sandwich ELISA test was used to test for antibodies against CCHF virus (CCHFV). Data have also been collected using questionnaire to assess factors associated with CCHF seropositivity.

RESULTS

Fifty-four (54 out to 364 sheep were seropositive given an overall seropositivity of 14.8% (95% confidence interval [CI]: 10.9%-19.8%) with an adjusted seropositivity of 13.1%. The study showed that 15.6% (95% CI: 10.2-21.0) and 14.1% (95% CI: 9.2-19.1) of sheep in the provinces of Mouhoun and Kénédougou, respectively, had antibodies against CCHFV. The highest seropositivity was found in Dédougou municipality (24.4%). The study showed that sheep from the municipalities of Dédougou (AOR = 8.4; 95% CI: 2.2-31.8), N'dorola (AOR = 14.7; 95% CI: 3.8-56.8), Sindou (AOR = 4.9; 95% CI: 1.2-20.7), sheep aged between 27 and 36 months (AOR = 6.4; 95% CI: 2.3-17.3) and sheep with ticks (AOR = 24.8; 95% CI: 7.7-80.1) were more likely to be seropositive to CCHF.

CONCLUSIONS

The study revealed that sheep in Burkina Faso experienced contacts with CCHFV and suggests the importance of implementing control action in the country.

CD8+ T-cells target the Crimean-Congo haemorrhagic fever virus Gc protein to control the infection in wild-type mice

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a serious viral hemorrhagic fever caused by the CCHF virus (CCHFV). Spread by the bites of infected ticks or handling of viremic livestock, human disease is characterized by a non-specific febrile illness that can rapidly progress to fatal hemorrhagic disease. No vaccines or antivirals are available. Case fatality rates can vary but can be higher than 30%, although sub-clinical infections are often unrecognized and unreported. Yet, while most humans infected with CCHFV will survive the infection, often with little-to-no symptoms, the host responses that control the infection are unknown.

METHODS

Here we investigated the role of cellular immunity in control of CCHFV infection in an immunocompetent mouse model.

FINDINGS

We found that CD8+ T-cells are crucial for efficient control of the acute infection and rapidly acquired CCHFV-specific antiviral effector functions such as production of antiviral cytokines and degranulating in response to CCHFV peptides. We further identified the minimal CD8+ T-cell epitopes in the viral Gc proteins and that infection of mice lacking IFNγ resulted in worsened disease and higher viral loads.

INTERPRETATION

Together our data suggest that CD8+ T-cells are important for control of acute CCHFV infection likely through production of antiviral cytokines.

FUNDING

This work was supported by the Intramural Research Program of the NIH.

Epidemic intelligence data of Crimean-Congo haemorrhagic fever, European Region, 2012 to 2022: a new opportunity for risk mapping of neglected diseases

BackgroundThe Epidemic Intelligence from Open Sources (EIOS) system, jointly developed by the World Health Organisation (WHO), the Joint Research Centre (JRC) of the European Commission and various partners, is a web-based platform that facilitate the monitoring of information on public health threats in near real-time from thousands of online sources.AimsTo assess the capacity of the EIOS system to strengthen data collection for neglected diseases of public health importance, and to evaluate the use of EIOS data for improving the understanding of the geographic extents of diseases and their level of risk.MethodsA Bayesian additive regression trees (BART) model was implemented to map the risk of Crimean-Congo haemorrhagic fever (CCHF) occurrence in 52 countries and territories within the European Region between January 2012 and March 2022 using data on CCHF occurrence retrieved from the EIOS system.ResultsThe model found a positive association between all temperature-related variables and the probability of CCHF occurrence, with an increased risk in warmer and drier areas. The highest risk of CCHF was found in the Mediterranean basin and in areas bordering the Black Sea. There was a general decreasing risk trend from south to north across the entire European Region.ConclusionThe study highlights that the information gathered by public health intelligence can be used to build a disease risk map. Internet-based sources could aid in the assessment of new or changing risks and planning effective actions in target areas.

First serological evidence of Crimean-Congo haemorrhagic fever virus in transhumant bovines in Italy

Crimean-Congo haemorrhagic fever (CCHF) is an emerging tick-borne disease caused by the arbovirus Crimean-Congo haemorrhagic fever virus (CCHFV; family Nairoviridae). Given the public health impact, CCHF is considered a priority disease for the European Union. This study describes the first detection of anti-CCHFV antibodies in transhumant bovines in Italy. Sera from 794 cattle collected across Basilicata region (Southern Italy) were screened using a commercial ELISA kit. The animal-level and herd-level seroprevalences detected were 1.89% [95%CI: 1.12-3.1] and 29.63% [95%CI: 15.68-48.65], respectively. Results of the χ² test for trend show that the exposure to CCHFV was significantly associated with increasing age, with the odds 5 times higher in 11-22-year old cattle than 1-4-year old cattle. The detection of antibodies against CCHFV in indigenous cattle indicates that the infection occurred in the study area and may warrant further consideration. Additionally, no significant spatial clustering of CCHF infection was detected, supporting the hypothesis that the disease is widespread in the region. Further studies at larger scale are needed to identify the areas at higher risk of zoonotic infection. A One Health approach should be implemented to better understand the disease risk and dynamics in the country, which effectively address the related public health threat.

Widespread exposure to Crimean-Congo haemorrhagic fever in Uganda might be driven by transmission from Rhipicephalus ticks: Evidence from cross-sectional and modelling studies

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a widespread tick-borne viral infection, present across Africa and Eurasia, which might pose a cryptic public health problem in Uganda. We aimed to understand the magnitude and distribution of CCHF risk in humans, livestock and ticks across Uganda by synthesising epidemiological (cross-sectional) and ecological (modelling) studies.

METHODS

We conducted a cross-sectional study at three urban abattoirs receiving cattle from across Uganda. We sampled humans (n = 478), livestock (n = 419) and ticks (n = 1065) and used commercially-available kits to detect human and livestock CCHF virus (CCHFV) antibodies and antigen in tick pools. We developed boosted regression tree models to evaluate the correlates and geographical distribution of expected tick and wildlife hosts, and of human CCHF exposures, drawing on continent-wide data.

FINDINGS

The cross-sectional study found CCHFV IgG/IgM seroprevalence in humans of 10·3% (7·8-13·3), with antibody detection positively associated with reported history of tick bite (age-adjusted odds ratio = 2·09 (1·09-3·98)). Cattle had a seroprevalence of 69·7% (65·1-73·4). Only one Hyalomma tick (CCHFV-negative) was found. However, CCHFV antigen was detected in Rhipicephalus (5·9% of 304 pools) and Amblyomma (2·9% of 34 pools) species. Modelling predicted high human CCHF risk across much of Uganda, low environmental suitability for Hyalomma, and high suitability for Rhipicephalus and Amblyomma.

INTERPRETATION

Our epidemiological and ecological studies provide complementary evidence that CCHF exposure risk is widespread across Uganda. We challenge the idea that Hyalomma ticks are consistently the principal reservoir and vector for CCHFV, and postulate that Rhipicephalus might be important for CCHFV transmission in Uganda, due to high frequency of infected ticks and predicted environmental suitability.

FUNDING

UCL Global Challenges Research Fund (GCRF) and Pan-African Network on Emerging and Re-Emerging Infections (PANDORA-ID-NET) funded by the European and Developing Countries Clinical Trials Partnership (EDCTP) under the EU Horizon 2020 Framework Programme for Research and Innovation.

Vaccine efficacy trials for Crimean-Congo haemorrhagic fever: Insights from modelling different epidemiological settings

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a priority emerging pathogen for which a licensed vaccine is not yet available. We aim to assess the feasibility of conducting phase III vaccine efficacy trials and the role of varying transmission dynamics.

METHODS

We calibrate models of CCHF virus (CCHFV) transmission among livestock and spillover to humans in endemic areas in Afghanistan, Turkey and South Africa. We propose an individual randomised controlled trial targeted to high-risk population, and use the calibrated models to simulate trial cohorts to estimate the minimum necessary number of cases (trial endpoints) to analyse a vaccine with a minimum efficacy of 60%, under different conditions of sample size and follow-up time in the three selected settings.

RESULTS

A mean follow-up of 160,000 person-month (75,000-550,000) would be necessary to accrue the required 150 trial endpoints for a target vaccine efficacy of 60 % and clinically defined endpoint, in a setting like Herat, Afghanistan. For Turkey, the same would be achieved with a mean follow-up of 175,000 person-month (50,000-350,000). The results suggest that for South Africa the low endemic transmission levels will not permit achieving the necessary conditions for conducting this trial within a realistic follow-up time. In the scenario of CCHFV vaccine trial designed to capture infection as opposed to clinical case as a trial endpoint, the required person-months is reduced by 70 % to 80 % in Afghanistan and Turkey, and in South Africa, a trial becomes feasible for a large number of person-months of follow-up (>600,000). Increased expected vaccine efficacy > 60 % will reduce the required number of trial endpoints and thus the sample size and follow-time in phase III trials.

CONCLUSIONS

Underlying endemic transmission levels will play a central role in defining the feasibility of phase III vaccine efficacy trials. Endemic settings in Afghanistan and Turkey offer conditions under which such studies could feasibly be conducted.

Emergence of Hyalomma marginatum and Hyalomma rufipes adults revealed by citizen science tick monitoring in Hungary

Hyalomma ticks are important vectors of Crimean-Congo haemorrhagic fever virus (CCHFV) and other pathogens. They are frequently carried as immatures from Africa, the Middle East and Mediterranean areas to temperate Europe via migratory birds and emergence of adults has been reported in many countries where it has so far been considered non-endemic. This study aimed to implement the first steps of the DAMA (Document, Assess, Monitor, Act) protocol by monitoring the potential arrival of adult Hyalomma ticks in Hungary applying citizen-science methods. Ticks were collected from April to December 2021 by asking volunteer participants through a self-made website to look for large, quickly moving, striped-legged hard ticks on themselves, their pets and livestock. Owing to an intensive media campaign, the project website had more than 31,000 visitors within 7 months; 137 specimens and several hundred photos of hard ticks were submitted by citizen scientists from all over the country. Beside Ixodes ricinus, Dermacentor reticulatus, Dermacentor marginatus and Haemaphysalis inermis, a specimen from a dog was morphologically identified as a male Hyalomma marginatum and another removed from a cow as a male Hyalomma rufipes. The dog and the cow had never been abroad, lived approximately 280 km apart, so the two Hyalomma observations can be considered separate introductions. Amplification of the partial mitochondrial cytochrome C oxidase subunit I gene was successfully run for both specimens. Sequencing confirmed the morphological identification for both ticks. Based on the phylogenetic analyses, the Hy. marginatum individual most likely belongs to the Eurasian population and the Hy. rufipes tick to a clade of mixed sequences from Europe and Africa. We summarize the scattered historical reports about the occurrence of Hyalomma ticks and CCHFV in Hungary. Our data highlight the effectiveness of citizens science programmes in the monitoring and risk assessment of CCHFV emergence and preparedness in the study area.

Experiences of Indian Council of Medical Research with tick-borne zoonotic infections: Kyasanur Forest disease & Crimean-Congo haemorrhagic fever in India with One Health focus

Emergence and re-emergence of several pathogens have been witnessed by this century in the form of outbreaks, epidemics and pandemics. In India, the influencing factor that promotes dissemination of emerging and re-emerging viral infections is the biogeographical zones: a megadiverse country, characterized by varied geographical, climatic conditions and ever-changing socio-economical and geopolitical issues. These influence the movement of humans and animals and add layers of complexity for the identification and timely management of infectious diseases. This review focuses on two tick-borne infections: Crimean-Congo haemorrhagic fever (CCHF) and Kyasanur forest disease (KFD). In the last two decades, these viruses have emerged and caused outbreaks in different parts of India. KFD virus was initially identified in 1957 and was known to be endemic in Karnataka State while CCHF virus was first identified during 2010 in Gujarat State, India. These viruses have managed to emerge in new areas within the last decade. With changing epidemiology of these arboviruses, there is a probability of the emergence of these viruses from new areas in future. The investigations on these two diseases under the One Health focus involved early detection, quickly developing diagnostic tools, identifying stakeholders, capacity building by developing collaboration with major stakeholders to understand the epidemiology and geographical spread in domestic animal reservoirs and tick vectors in the affected areas, developing laboratory network, providing diagnostic reagents and biosafety and laboratory diagnosis training to the network laboratories to control these diseases.

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.

Treatment of Crimean-Congo Haemorrhagic Fever by Favipiravir in a Patient with Novel Coronavirus Co-Infection

Introduction

Crimean-Congo haemorrhagic fever (CCHF) is a lethal zoonotic disease caused by an RNA virus that is a member of the Nairovirus genus in the Bunyaviridae family from the arbovirus group. CCHF is transmitted by Hyalomma ticks through direct contact with the blood and other bodily fluids of patients or infected animals.

Case description

A 65-year-old man was admitted to the emergency unit with dry cough, myalgia and fever. He was treated with favipiravir. He had disseminated intravascular coagulopathy with thrombocytopenia in the setting of COVID-19 infection. He tested positive for both COVID-19 and CCHF. By the end of the fifth day of treatment, his laboratory parameters and clinical symptoms had normalized.

Conclusion

Favipiravir is currently on the market for treating COVID-19 infection worldwide. It has also been used to treat CCHF in laboratory animals. To the best of our knowledge this is the first report of CCHF successfully treated with favipiravir, which could be a key drug for treating human CCHF.

LEARNING POINTS

Clinicians should be alert for concomitant viral infections such as Crimean-Congo haemorrhagic fever, which share similar clinical and laboratory findings to COVID-19.The effectiveness of favipiravir for viral infections other than influenza and COVID-19, such as Crimean-Congo haemorrhagic fever, should be elucidated.

Molecular Epidemiology and Phylogeny of Crimean-Congo Haemorrhagic Fever (CCHF) Virus of Ixodid Ticks in Khorasan Razavi Province of Iran

Background:

Crimean–Congo hemorrhagic fever (CCHF) is a fatal disease caused by Nairovirus classified within the Bunyaviridae family. The virus is transmitted to humans through the bites of infected ticks or direct contact with viremic animals or humans. The current study aimed to detect the virus genome in ticks from Khorasan Razavi Province.

Methods:

One hundred hard ticks were collected randomly from 100 sheep in four different areas of the province. Collected ticks were kept alive and identified. All the ticks were analyzed for the presence of CCHF virus genome using reverse transcriptase polymerase chain reactions (RT-PCR).

Results:

The identified ticks were belonging to Hyalomma marginatum (16% female and 6% male), Rhipicephalus turanicus (52% female and 25% male), and Dermacentor raskemensis (1%). The CCHF virus genome was found in Hyalomma marginatum (5% male from Taibad and Sabzevar region and 1% female from Taibad). Genetic analysis of the virus genome isolated from two regions (Sabzevar and Taibad) showed 100% identity.

Conclusion:

This study indicated that CCHF should be regarded as a risk-borne infection in this province. Therefore, special health management is needed to control this disease.

Crimean-Congo haemorrhagic fever (CCHF) virus-specific antibody detection in blood donors, Castile-León, Spain, summer 2017 and 2018

BackgroundCrimean-Congo haemorrhagic fever virus (CCHFV) is considered an emerging or even a probable re-emerging pathogen in southern Europe. Presence of this virus had been reported previously in Spain in 2010.AimWe aimed to evaluate the potential circulation of CCHFV in western Spain with a serosurvey in asymptomatic adults (blood donors).MethodsDuring 2017 and 2018, we conducted a CCHFV serosurvey in randomly selected asymptomatic blood donors from western Spain. Three assays using specific IgG antibodies against CCHFV were performed: the VectoCrimea ELISA test, an in-house ELISA and indirect immunofluorescence (EuroImmun) test with glycoprotein and nucleoprotein.ResultsA total of 516 blood donors participated in this cross-sectional study. The majority of the study participants were male (68.4%), and the mean age was 46.3 years. Most of the participants came from rural areas (86.8%) and 68.6% had contact with animals and 20.9% had animal husbandry practices. One in five participants (109/516, 21.1%) were engaged in at-risk professional activities such as agriculture and shepherding, slaughtering, hunting, veterinary and healthcare work (mainly nursing staff and laboratory technicians). A total of 15.3% of the participants were bitten by ticks in the days or months before the date of sampling. We detected anti-CCHFV IgG antibodies with two diagnostic assays in three of the 516 individuals and with one diagnostic assay in six of the 516 individuals.ConclusionSeroprevalence of CCHFV was between 0.58% and 1.16% in Castile-León, Spain. This is the first study in western Spain that showed circulation of CCHFV in healthy people.

Detection of new Crimean-Congo haemorrhagic fever virus genotypes in ticks feeding on deer and wild boar, Spain

Crimean-Congo haemorrhagic fever virus (CCHFV) is the causative agent of the severe tick-borne, often fatal, zoonotic Crimean-Congo haemorrhagic fever (CCHF), which is widely distributed worldwide. The CCHFV transmission to humans occurs through tick bite, crushing of engorged ticks or contact with infected host blood. Previously, CCHFV genotype Africa III was reported in Spain. Given the emergence of CCHF and the role of ticks in pathogen maintenance and transmission, we investigated the presence and genotype identity of the virus in tick species parasitizing abundant wild host species in south-western Spain. A total of 613 adult ticks were collected from hunter-harvested wild ungulates in twenty locations throughout south-western Spain. Ticks were identified, nucleic acids were extracted, RNA was analysed by a nested RT-PCR targeting CCHFV S segment, and the amplicons were sequenced. According to the 212-bp sequence amplified, the presence of CCHFV human genotype Europe V was detected in Hyalomma lusitanicum and Dermacentor marginatus ticks collected from red deer, fallow deer and Eurasian wild boar in different locations from south-western Spain. Genotype Africa IV was also detected in a H. lusitanicum tick collected from a red deer. The detection of CCHFV in different tick species collected from various wild hosts and localities provided strong evidence of widespread CCHFV presence in the region, suggesting that the circulation of the virus in Spain requires more attention. Additionally, the identification of the CCHFV genotype Europe V in ticks suggested that its introduction in Spain was probably from Eastern Europe.

An overview of the viral haemorrhagic fevers for the primary care doctor

The viral haemorrhagic fevers are infectious diseases that often cause life-threatening illnesses. These diseases are common in the tropical areas of the world, and travel history to an endemic area together with recognising signs and symptoms is essential to aid diagnosis. Treatment is often supportive, and infection control measures need to be instituted early at the point of entry. In this article, we will provide an approach to a patient with viral haemorrhagic fevers in a primary healthcare setting.

Seroprevalence of Crimean-Congo haemorrhagic fever among three selected risk human groups in disease-endemic region of Pakistan

The occurrence of Crimean-Congo haemorrhagic fever (CCHF) in humans is linked with animals living in close vicinity, and information on the incidence of CCHF at the human-animal interface is scarce. Therefore, the current study was designed to identify the high-risk groups of individuals linked with animals in the Chakwal district of Pakistan having a history of CCHF cases in humans. In subject matter, coupled with risk factor analysis, we performed a sero-based CCHF surveillance in three selected risk groups of humans including abattoir workers (n = 137), milkmen (n = 169) and animal handlers (n = 147). Sera samples and questionnaire-based data were collected from each of the participants and screened for anti-CCHFV IgG antibodies using enzyme-linked immunosorbent assay. The highest seroprevalence was observed in animal handlers (n = 14, 9.52%, 95% CI: 4.68-13.99) followed by abattoir workers (n = 9, 6.57%, 95% CI: 2.42-10.72) and milkmen (n = 3, 1.78%, 95% CI: 0.24-4.24). The risk of seropositivity was significantly associated with humans linked with tick-infested animals (OR: 11.0, 95% CI: 1.5-83.0, p = .002), old age >40 years (OR: 6.6, 95% CI: 2.7-16.0, p < .0001), illiteracy (OR: 4.3, 95% CI: 1.5-13.0, p = .004) and humans without knowledge about CCHF (OR: 7.6, 95% CI: 1.8-33.0, p = .0009). The findings of the current study highlighted the seroprevalence of CCHF in high-risk groups of humans living in a disease-endemic area of Pakistan and highlight the need for well-integrated disease surveillance in the future to better comprehend disease control interventions.

Crimean-Congo haemorrhagic fever in a middle Anatolian city: five years of experience

We evaluated the epidemiological features and main risk factors of Crimean-Congo haemorrhagic fever (CCHF) in Corum, where the disease is endemic, by retrospectively analysing the medical records of all patients diagnosed with CCHF over five years. Diagnosis was made by the detection of virus RNA via reverse transcription polymerase chain reaction or by demonstrating IgM antibody of CCHF virus with an ELISA blood test. Of 399 patients, 22 (5.5%) patients died but we could show that the rates of incidence and mortality have decreased over the years. Early referral to health facilities, increased awareness and experience of health personnel working in high-risk areas may well be the main factor.

Crimean-Congo haemorrhagic fever in a Greek worker returning from Bulgaria, June 2018

We report a tick-borne case of severe Crimean-Congo haemorrhagic fever (CCHF) imported into Greece from Bulgaria. The patient presented severe thrombocytopenia, hemophagocytosis, haemodynamic instability, large haematomas and altered mental status. Supportive treatment and ribavirin were administered. Symptoms started one day after the tick was removed; the patient was discharged from the hospital 26 days after symptom onset. No secondary cases were observed. Phylogenetically the CCHF virus strain belongs to clade Europe 1.

A case of Crimean-Congo haemorrhagic fever imported in Greece: Contact tracing and management of exposed healthcare workers

Background

Nosocomial transmission is a major mode of infection of Crimean-Congo haemorrhagic fever (CCHF). In May 2018, a patient with CCHF was hospitalised in Greece.

Objective

Our aim was to present the management of healthcare workers (HCWs) to the CCHF case.

Methods

Contact tracing, risk assessment and follow-up of exposed HCWs were performed. Testing (RT-PCR and/or serology) was offered to contacts. Post-exposure prophylaxis (PEP) with ribavirin was considered for high-risk exposures.

Results

Ninety-one HCWs were exposed to the case. Sixty-six HCWs were grouped as high-risk exposures. Ribavirin PEP was offered to 29 HCWs; seven agreed to receive prophylaxis. Forty-one HCWs were tested for CCHF infection; none was found positive. Gaps in infection control occurred.

Discussion

CCHF should be considered in patients with compatible travel history and clinical and laboratory findings. Early clinical suspicion and laboratory confirmation are imperative for the implementation of appropriate infection control measures. Ribavirin should be considered for high-risk exposures. Infection control capacity for highly pathogenic agents should increase.

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.

Development of vaccines against Crimean-Congo haemorrhagic fever virus

Crimean-Congo haemorrhagic fever virus (CCHFV) is a deadly human pathogen of the utmost seriousness being highly lethal causing devastating disease symptoms that result in intense and prolonged suffering to those infected. During the past 40years, this virus has repeatedly caused sporadic outbreaks responsible for relatively low numbers of human casualties, but with an alarming fatality rate of up to 80% in clinically infected patients. CCHFV is transmitted to humans by Hyalomma ticks and contact with the blood of viremic livestock, additionally cases of human-to-human transmission are not uncommon in nosocomial settings. The incidence of CCHF closely matches the geographical range of permissive ticks, which are widespread throughout Africa, Asia, the Middle East and Europe. As such, CCHFV is the most widespread tick-borne virus on earth. It is a concern that recent data shows the geographic distribution of Hyalomma ticks is expanding. Migratory birds are also disseminating Hyalomma ticks into more northerly parts of Europe thus potentially exposing naïve human populations to CCHFV. The virus has been imported into the UK on two occasions in the last five years with the first fatal case being confirmed in 2012. A licensed vaccine to CCHF is not available. In this review, we discuss the background and complications surrounding this limitation and examine the current status and recent advances in the development of vaccines against CCHFV.

Plant-produced Crimean-Congo haemorrhagic fever virus nucleoprotein for use in indirect ELISA

Crimean-Congo haemorrhagic fever (CCHF) is a disease of serious public concern caused by the CCHF virus (CCHFV). Anti-CCHFV IgG in humans can be detected using ELISA with native antigen prepared from cell cultures which have been infected with virus or from brain tissue of suckling mice which have been inoculated with virus. However, the preparation of these reagents requires high biosafety levels and is expensive. A safer, more cost-effective recombinantly-produced NP reagent is desirable. Recently, plants have been shown to be a cost-effective and safe system for expression of recombinant proteins. This work describes cloning of the CCHFV NP gene into three different plant expression systems and comparison of expression in Nicotiana benthamiana. The highest expressing construct was selected. Expressed NP was purified by ammonium sulphate fractionation prior to histidine affinity chromatography. Purified NP was tested in an indirect ELISA to determine if the recombinant antigen was able to detect anti-CCHFV IgG in sera from convalescent patients. Plant-produced NP detected IgG antibodies against CCHFV in 13/13 serum samples from convalescent patients and 0/13 samples collected from volunteers with no history of CCHFV infection. Results were compared with commercially available immunofluorescent assays and 100% concordance was obtained between the two assays. This suggests that a full evaluation of the plant produced NP for application as a safe recombinant is warranted.

A case of endocarditis mimicking Crimean-Congo haemorrhagic fever

Infective endocarditis (IE) is life-threatening condition with a highly variable clinical presentation. We report a case of acute IE with delayed diagnosis which resulted due to an initial misdiagnosis of Crimean Congo Hemorrhagic Fever (CCHF) in an endemic area. A case was due to Staphylococcus aureus and requiring valve replacement. They serve to emphasize the importance of careful history taking, physical examination and a broad range of different diagnostic techniques in the context of suspected viral hemorrhagic fever.

Hyalomma ticks on northward migrating birds in southern Spain: Implications for the risk of entry of Crimean-Congo haemorrhagic fever virus to Great Britain

Crimean-Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over-dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB.

Crimean-Congo haemorrhagic fever in travellers: A systematic review

Background

The recent Ebola epidemic has increased public awareness of the risk of travel associated viral haemorrhagic fever (VHF). International preparedness to manage imported cases Ebola virus infection was inadequate, highlighted by cases of nosocomial transmission. Crimean-Congo haemorrhagic fever (CCHF) is a re-emerging tick-borne VHF centred in the Eurasian region, affecting a large geographical area and with human-to-human transmission reported, especially in the healthcare setting.

Objectives

To systematically review the characteristics of travel associated Crimean-Congo haemorrhagic fever.

Methods

A systematic review of travel-associated cases of CCHF was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement protocol. PubMed, SCOPUS, Science Citation Index (SCI) and ProMED databases were searched for reports published between January 1960 and January 2016. Three independent reviewers selected and reviewed studies and extracted data.

Results

21 cases of travel associated CCHF were identified, of which 12 died (3 outcome unknown) and 4 secondary (nosocomial) infections were reported. Risk occupations or activities for CCHF infection were reported in 8/12 cases when data were available. Travel from Asia to Asia occurred in 9 cases, Africa to Africa occurred in 5 cases, Africa to Europe in 3 cases, Asia to Europe in 2 cases and Europe to Europe in 2 cases.

Conclusion

CCHF related to travel is rare, is generally associated with at risk activities/occupation and is frequently fatal. Key to early diagnosis and prevention of nosocomial transmission is an understanding of CCHF risk factors and the geographical distribution of CCHF. International travel to CCHF endemic areas is increasing and clinicians and laboratory personnel managing returning travellers should maintain a high index of suspicion.

Molecular detection of Crimean-Congo haemorrhagic fever virus in ticks collected from infested livestock populations in a New Endemic Area, South of Iran

OBJECTIVE

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with potentially fatal systemic effects on man. We aimed to determine the presence of CCHF virus among collected ticks from domestic livestock from October 2012 to September 2013.

METHODS

A total of 1245 hard and soft ticks were collected from naturally infested ruminants in Marvdasht County, Fars Province, south of Iran. Nine tick species and one unidentified species in four disparate genera were detected. A total of 200 ticks were randomly selected and analysed by reverse transcription-polymerase chain reaction (RT-PCR) for the presence of CCHF virus genome.

RESULTS

The viral genome was detected in 4.5% (9 samples) of the studied tick population. The infected ticks belonged to the species of Hyalomma marginatum' Hyalomma anatolicum and Rhipicephalus sanguineus. The viruses detected in these three tick species were clustered in the same lineage as Matin and SR3 strains in Pakistan and some other Iranian strains. These results indicate that the ticks were wildly infected with a genetically closely related CCHF virus in the region.

CONCLUSION

Regular controls and monitoring of livestock to reduce the dispersion of ticks and providing information to those involved in high-risk occupations are urgently required.

Healthcare-associated Crimean-Congo haemorrhagic fever in Turkey, 2002-2014: a multicentre retrospective cross-sectional study

Healthcare-related transmission of Crimean-Congo haemorrhagic fever (CCHF) is a well-recognized hazard. We report a multicentre retrospective cross-sectional study undertaken in Turkey in 2014 in nine hospitals, regional reference centres for CCHF, covering the years 2002 to 2014 inclusive. Data were systematically extracted from charts of all personnel with a reported health care injury/accident related to CCHF. Blood samples were tested for CCHF IgM/IgG by enzyme-linked immunosorbent assay and/or viral nucleic acid detection by PCR after the injury. Fifty-one healthcare-related exposures were identified. Twenty-five (49%) of 51 resulted in laboratory-confirmed infection, with a 16% (4/25) overall mortality. The main route of exposure was needlestick injury in 32/51 (62.7%). A potential benefit of post-exposure prophylaxis with ribavirin was identified.

Rhipicephalus rossicus, a neglected tick at the margin of Europe: a review of its distribution, ecology and medical importance

Rhipicephalus rossicus (Ixodida: Ixodidae) is a three-host tick with a broad host spectrum that includes wild animals, pets, livestock and humans. Despite its local abundance in certain areas, most of the available information on R. rossicus was published decades ago, mainly by former soviet authors. Its distribution largely overlaps the Eurasian steppe. However, its range may be more extensive than is currently known because this species may have been misidentified as Rhipicephalus sanguineus, principally in areas where the latter species is present. Although R. rossicus has been occasionally reported to feed on people, little attention has been given to its medical importance. It has been shown to have a vectorial role in the transmission of Francisella tularensis, Crimean-Congo haemorrhagic fever virus and West Nile virus. However, the vectorial importance of R. rossicus may be significantly greater, mainly as the closely related species R. sanguineus s.l. is known to transmit a very wide spectrum of pathogens. The probably underestimated vectorial role of R. rossicus may represent a hidden public health threat.

Surgical protocol for confirmed or suspected cases of Ebola and other highly transmissible diseases

Outbreaks of viral haemorrhagic fevers such as Ebola can lead to imported cases in Europe and America. The eventuality of surgery in the setting of Ebola Virus Disease (EVD) is low, but the Spanish Association of Surgeons elaborated a surgical protocol for EVD.

INDICATION

Elective surgical procedures are not indicated. Emergency cases can be considered in: persons under investigation, possible cases and early confirmed cases. In some conditions usually treated by surgery a medical treatment can be tested.

HOSPITALS AND TEAMS

All cases must be treated in high technology hospitals. These hospitals must be equipped with adequate means for healthcare provider's protection. All members of the healthcare team should practice thorough simulation prior to caring for a possible Ebola patient.

SURGICAL PROTOCOL

This protocol is based on international guidelines on use of Personal Protective Equipment, protocols of other scientific societies, and specific recommendations for the operating room environment.

Characteristics of patients admitted to the emergency department due to tick bite

Crimean-Congo haemorrhagic fever (CCHF) is a tick-borne disease endemic in Turkey since 2002. Çorum is one of the leading five cities in Turkey in which CCHF disease is seen most. We studied characteristics of the patients with tick bites in our emergency department (ED) and determined the fatality rate of the disease in city of Çorum for the first time. We retrospectively analysed the characteristics of the patients admitted to our ED from the medical files of 21,680 patients in a 5-year period. The number of patients with definite diagnosis and who have died was determined. Our results demonstrated that the fatality rate of CCHF in Çorum is 6.78%. Among 21,680 patients, blood samples of 970 patients were sent to an advanced centre in Ankara for polymerase chain reaction (PCR) testing. Results of 560 patients were reported to be PCR (+) and 38 of them have died.

Knowledge and attitudes of emergency nurses towards Crimean-Congo haemorrhagic fever in endemic regions of Turkey

This study was carried out in order to determine knowledge and attitudes of emergency nurses about Crimean-Congo haemorrhagic Fever. This descriptive research was carried out where the disease is frequent, in six cities in Turkey. One hundred forty-three nurses who worked in the emergency room were recruited to the study. Data were collected with a questionnaire form and were analysed by chi-squared test. The mean age of the nurses was 31.0 ± 5.7 years. It was determined that 68.8% of the nurses claimed to have sufficient knowledge about the disease, 99.3% said that it was a virus that caused the disease, and 94.3% said that health-care personnel exposed to it were under great risk. It was concluded that most of the nurses had relatively good knowledge about the disease and that they did not want to run the high risk of infection and mortality by treating patients who had the disease.

Efficacy of high-dose methylprednisolone in patients with Crimean-Congo haemorrhagic fever and severe thrombocytopenia

Crimean-Congo haemorrhagic fever (CCHF) is an acute viral haemorrhagic disease that is now endemic in south eastern Iran. The most important factor associated with mortality is a platelet count of less than 50,000/mL. The purpose of this study is to compare treated cases with severe thrombocytopenia using ribavirin with high-dose methylprednisolone (HDMP) with patients receiving ribavirin without HDMP. A clinical trial was conducted for confirmed patients with CCHF and severe thrombocytopenia (platelet count less than 50,000/mL) admitted to Boo-Ali Hospital in Zahedan between January 2010 and October 2011. The intervention group was given oral ribavirin, supportive managements and HDMP and the controls were treated with ribavirin and supportive management. Following HDMP therapy in hospitalized patients with severe thrombocytopenia, the platelet count increased within 36 h and the leukocyte count within 48 h of the beginning of treatment. Fewer in the intervention group required a transfusion of blood products than in the controls (P < 0.001). No one in the intervention group died. It seems that high-dose methylprednisolone is effective in the treatment of patients with CCHF. The increased platelet count and reduction of blood product requirement for severe CCHF patients after receiving HDMP are promising results. Further investigation is necessary in order to determine the efficacy of corticosteroid and its effect on outcome.