Surveillance and Laboratory Detection System of Crimean-Congo Haemorrhagic Fever in Iran

Crimean-Congo Hemorrhagic Fever Presented in Dengue Epidemic: A Case Report

In Pakistan, hemorrhagic diseases, including dengue and Crimean-Congo hemorrhagic fever (CCHF), are common. Therefore, an accurate diagnosis is challenging in the early stages of sickness owing to geographic overlap and early clinical similarities between the two disorders. A 35-year-old man who had previously experienced hematemesis and high-grade fever presented to our hospital. Despite receiving supportive care for a preliminary diagnosis of dengue hemorrhagic fever, the patient's condition worsened. The results of the dengue IgM antibody test were negative. On the fourth day of admission, a qualitative polymerase chain reaction test for CCHF virus RNA was performed, and the result returned positive. All medical personnel and attendants who had contact with the patient had to receive ribavirin prophylaxis, which required significant investment in resources. Because CCHF can have long-term financial and health repercussions for contacts, including healthcare personnel in developing nations, it is essential to identify and treat it as soon as possible. It is necessary to keep track of dengue and CCHF cases more closely to develop predictors of disease diagnosis that are reasonably trustworthy, affordable, and quick. These predictors can aid in directing future choices regarding the care of similar situations. Ultimately, such an approach might result in improved cost control in environments with limited resources. Consideration should also be given to patients who receive ribavirin prophylaxis.

Crimean‐Congo hemorrhagic fever in the COVID‐19 pandemic: A case study

In the COVID‐19 pandemic, the overlap of clinical features between other viral infections makes a reliable diagnosis difficult in the initial stage of illness. We describe a confirmed case of CCHF in Tehran Province during this year, who was first misdiagnosed as COVID‐19 infection.

New Insight for the Prognosis of CCHF: Clinical, Laboratory and Sonography Findings

BACKGROUND

Crimean Congo Hemorrhagic Fever (CCHF) is an acute and fatal disease with various clinical and paraclinical characteristics.

INTRODUCTION

In this article, we report data on confirmed CCHF cases from Iran and describe the association between studying factors and outcomes of the disease.

METHODS

In the study design, we evaluated demographic characteristics, clinical, laboratory and sonographic findings of 160 CCHF confirmed cases during 2003 and 2012 in Zabol (A city in Sistan and Baluchestan province of Iran). The association between these factors and the fatal outcome were evaluated by regression analysis.

RESULTS

The disease had a fatal outcome in 7 (4.4%) patients. Females had more severe symptoms and higher odds for death (odds ratio11.57, p=0.005). Leukocytosis (p<0.001), PT (p<0.001) and PTT (p=0.008) elongation, AST (p=0.010) and ALT (p>0.001) elevation were significantly associated with fatal outcome. CNS related symptoms (odds ratio 5.9, p=0.027) in clinical examination and ascites (odds ratio 38.4, p=0.012) and liquid in the pelvic cavity (odds ratio 24.2, p=0.004) were also identified as risk factors of death in this study.

CONCLUSION

Our data suggest that in addition to clinical and laboratory findings practitioners consider sonography for CCHF prognosis.

The effect of climate variables on the incidence of Crimean Congo Hemorrhagic Fever (CCHF) in Zahedan, Iran

Background

The Crimean-Congo Hemorrhagic fever (CCHF) is endemic in Iran and has a high fatality rate. The aim of this study was to investigate the association between CCHF incidence and meteorological variables in Zahedan district, which has a high incidence of this disease.

Methods

Data about meteorological variables and CCHF incidence was inquired from 2010 to 2017 for Zahedan district. The analysis was performed using univariate and multivariate Seasonal Autoregressive Integrated Moving Average (SARIMA) models and Generalized Additive Models (GAM) using R software. AIC, BIC and residual tests were used to test the goodness of fit of SARIMA models, and R² was used to select the best model in GAM/GAMM.

Results

During the years under study, 190 confirmed cases of CCHF were identified in Zahedan district. The fatality rate of the disease was 8.42%. The disease trend followed a seasonal pattern. The results of multivariate SARIMA showed the (0,1,1) (0,1,1)₁₂ model with maximum monthly temperature lagged 5 months, forecasted the disease better than other models. In the GAM, monthly average temperature lagged 5 months, and the monthly minimum of relative humidity and total monthly rainfall without lag, had a nonlinear relation with the incidence of CCHF.

Conclusions

Meteorological variables can affect CCHF occurrence.

New geographical area on the map of Crimean-Congo hemorrhagic fever virus: First serological evidence in the Hungarian population

Crimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne disease that is endemic in Africa, Asia, the Middle East, and the Balkan region of Europe; the disease is spreading northwards following widespread distribution of the main vector, Hyalomma marginatum, which was first found in Hungary in 2011. The aim of this pilot sero-surveillance study was to assess CCHF seroprevalence in Hungary. A total of 2700 serum samples obtained from healthy volunteer blood donors were screened using an in-house immunofluorescence assay and a commercially available ELISA kit. We found ten (0.37 %) seropositive donors. The western and central regions proved to be the most affected areas, with a prevalence of 2.97 %. Higher positivity was found among male donors (0.55 %) and younger donors (18-34 years; 0.78 %). Based on these results, a more extended surveillance focusing on specific at-risk populations and animals is advised. The results should also raise the awareness of clinicians and other high-risk populations, such as foresters and hunters, about the emerging threat of CCHF in Hungary.

New aspects about Crimean-Congo hemorrhagic fever (CCHF) cases and associated fatality trends: A global systematic review and meta-analysis

Crimean-Congo hemorrhagic fever (CCHF) is the most popular tick-borne disease causing by Crimean-Congo hemorrhagic fever virus (CCHFV). There are several valuable reviews considering some fields of the CCHF aspects. While there is no a systematic review about means and trends of CCHF cases and fatality rate, means and trends of CCHF cases and fatality rates of human occupations involved in CCHF. Therefore, this meta-analysis review performed to highlight and provide a global detailed of the above CCHF aspects. Among 398 collected papers, 173 papers were become this meta-analysis review. The study results confirm that an apparent increasing CCHF cases occurred through the past decades. The trends of annually and periodically CCHF cases and fatality rates were also increased. The means of annually and periodically CCHF cases and fatality rates were 57 and 432 cases, and 10 cases and 32.2 % and 49 cases and 28.8 %, respectively. The means of annually and periodically CCHF fatality rates are about one-tenth of CCHF human cases. The mean of CCHF fatality rates in Africa (22.0 %) is lower than Asia (33.5 %) and Europe (33.8 %). Among occupations involved in CCHF, agricultural (28.9 %), health-care (19.2 %) and slaughterhouse (16.7 %) workers, and farmers (13.9 %) had the maximum CCHF fatality rates in order. Based on literature review of CCHFV S-segment aspects, several clades and genotypes are reported to distribute in Africa, Asia and Europe regions. There are very wide fields to investigate the epidemiology characteristics of CCHFV clades, genotypes and their distribution in the future.

Crimean-Congo hemorrhagic fever: An update

Crimean-Congo hemorrhagic fever (CCHF) is a severe form of hemorrhagic fever caused by a virus of the genus Nairovirus. The amplifying hosts are various mammal species that remain asymptomatic. Humans are infected by tick bites or contact with animal blood. CCHF has a broad geographic distribution and is endemic in Africa, Asia (in particular the Middle East) and South East Europe. This area has expanded in recent years with two indigenous cases reported in Spain in 2016 and 2018. The incubation period is short with the onset of symptoms in generally less than a week. The initial symptoms are common to other infectious syndromes with fever, headache, myalgia and gastrointestinal symptoms. The hemorrhagic syndrome occurs during a second phase with sometimes major bleeding in and from the mucous membranes and the skin. Strict barrier precautionary measures are required to prevent secondary and nosocomial spread. CCHF may be documented by PCR detection of the virus genome during the first days after the onset of illness, and then by serological testing for IgM antibodies as from the 2nd week after infection. Patient management is mainly based on supportive care. Despite a few encouraging retrospective reports, there is no confirmed evidence that supports the use of ribavirin for curative treatment. Nevertheless, the World Health Organization continues to recommend the use of ribavirin to treat CCHF, considering the limited medical risk related to short-term treatment. The prescription of ribavirin should however be encouraged post-exposure for medical professionals, to prevent secondary infection.

High Incidence of a Novel Rickettsia Genotype in Parasitic Haemaphysalis longicornis from China-North Korea Border

Ticks are notorious vectors for various pathogens that cause infections in animals and humans worldwide. Rickettsia spp., a zoonotic tick-borne pathogen that could be used as a weapon agent, is widely spread in China. In the present study, ticks were collected for species identification and Rickettsia screening. PCR amplification targeting the tick 18s rRNA gene was first conducted for species validation, and then, amplification was conducted for the Rickettsia housekeeping gene for the infection rate and phylogenetic analysis. The collected ticks were identified as Haemaphysalis longicornis, 7.36% of which were Rickettsia-positive. The phylogenetic analysis showed that the Rickettsia in the parasitic ticks belonged to a novel genotype, whose closest genetic relationship was with Rickettsia heilongjiangenesis. The samples were collected in Dandong, a city on the border between China and North Korea. Considering the geographical and biological situations of the sampling sites, more extensive surveillance and risk evaluation of the tick species and tick-borne diseases are required.

Co-circulation of Crimean-Congo Hemorrhagic Fever virus strains Asia 1 and 2 between the border of Iran and Pakistan

Crimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne viral disease that is transmitted by numerous species of ticks, which serve both as a reservoir and vector of CCHF virus (CCHFV). Molecular and serological tests were undertaken on hard ticks (Ixodidae spp.) and samples from livestock were collected in 2015 from Chabahar County in Southeast Iran. Using RT-PCR, the ticks were tested for the presence of CCHFV. In addition, seven livestock were serologically tested for the presence of IgG antibodies using an ELISA test. IgG antibodies against CCHFV were detected in one of 7 of the livestock that were tested. In total, 49 ticks including five species: Rhipicephalus sanguineus, Hyalomma anatolicum, Hy. asiaticum, Hy. dromedarii and Hy. marginatum with a prevalence of 46.9%, 32.7%, 4.1%, 4.1% and 2.1% respectively were identified. CCHFV was detected in three ticks among 49 collected ticks. The ticks infected with CCHFV belonged to the genus Hyalomma and Rhipicephalus. Phylogenetic analysis demonstrated that two sequences clustered in clade IV (Asia-1) and one sequence was located within clade IV (Asia-2). Most of the animal and human CCHF cases of the country are reported from Sistan and Baluchistan provinces. Regular monitoring programs in the tick population and livestock are needed in the future.

Seroepidemiology and risk factors of Crimean-Congo Hemorrhagic Fever among butchers and slaughterhouse workers in southeastern Iran

OBJECTIVE

Crimean-Congo Haemorrhagic Fever (CCHF) is a viral zoonotic disease. Butchers and slaughterhouse workers are considered to be high risk occupational groups for the disease. Sistan and Baluchistan province is an area in southeastern Iran which is endemic for CCHF, and the most confirmed cases of the disease are reported from this province. The aim of this study was to investigate the seroprevalence of CCHF and risk factors for seropositivity among them in Sistan and Baluchistan province in 2011.

METHODS

Questionnaire data and blood sample collection were carried out for each participant and the sera samples were sent to the national reference laboratory for ELISA IgG testing.

RESULTS

In this study, the seroprevalence of CCHF among 190 butchers and slaughterhouse workers from 11 counties was 16.49%. 79% of participants were aware that they were at risk of zoonosis and 39.7% did not use any personal protective equipment during their work. Of 31 CCHF IgG positive individuals in this study, eleven individuals had a previous record of CCHF infection in 57 months prior to the study.

CONCLUSIONS

High seroprevalence of CCHF among butchers and slaughterhouse workers and minimal use of personal protective equipment's during daily work indicates the need for training courses, for these groups to increase their knowledge, attitude and practice with respect to zoonosis.

The emergence of arthropod-borne viral diseases: A global prospective on dengue, chikungunya and zika fevers

Arthropod-borne viruses (arboviruses) present a substantial threat to human and animal health worldwide. Arboviruses can cause a variety of clinical presentations that range from mild to life threatening symptoms. Many arboviruses are present in nature through two distinct cycles, the urban and sylvatic cycle that are maintained in complex biological cycles. In this review we briefly discuss the factors driving the emergence of arboviruses, such as the anthropogenic aspects of unrestrained human population growth, economic expansion and globalization. Also the important aspects of viruses and vectors in the occurrence of arboviruses epidemics. The focus of this review will be on dengue, zika and chikungunya viruses, particularly because these viruses are currently causing a negative impact on public health and economic damage around the world.

The evaluation of abdominal findings in Crimean-Congo hemorrhagic fever

OBJECTIVE

Crimean-Congo hemorrhagic fever (CCHF) is a widely seen, fatal disease and is endemic to some countries. It affects many organs in the abdomen. Comprehensive radiological study of CCHF is quite rare. This study will use multiple detector computed tomography (MDCT) to investigate if there is a relationship between clinical laboratory measurements and abdominal findings in CCHF and discuss our findings in the light of the literature.

MATERIALS AND METHODS

We retrospectively evaluated the medical records of 443 patients diagnosed with CCHF in our hospital between April 1, 2008 and September 30, 2014. Fifty-one patients had undergone abdominal MDCT examination.

RESULTS

The most common findings seen in abdominal MDCT were intra-abdominal free fluid and hepatomegaly. Gallbladder wall thickening, heterogeneity in mesenteric, omental fatty tissue, and splenomegaly were other common findings. Subcutaneous fat tissue edema, intramuscular hemorrhage, duodenal wall thickening, colon wall thickening, pancreatitis, and acute renal failure were among the rare findings seen in abdominal MDCT. Comparison of these findings to the clinical laboratory parameters showed a strong relationship between intra-abdominal free fluid and platelet count.

CONCLUSION

Our study is the first comprehensive study on abdominal MDCT findings of CCHF. We detected a strong relationship between patients' platelet count and abdominal free liquid. Therefore, it should be kept in mind that abdominal free fluid can be among clinical manifestations in patients with platelet counts ≤50000 and that this manifestation can become aggravated.

Novel, In-House, SYBR Green Based One-Step rRT-PCR: Rapid and Accurate Diagnosis of Crimean-Congo Hemorrhagic Fever Virus in Suspected Patients From Iran

BACKGROUND

The Crimean-Congo hemorrhagic fever (CCHF) virus causes severe disease in humans, with a high mortality rate. Since, there is no approved vaccine or specific treatment for CCHF, an early and accurate diagnosis, as well as reliable surveillance, is essential for case management and patient improvement.

OBJECTIVES

For this research, our aim was to evaluate the application of a novel SYBR Green based one-step real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) assay for the in-house diagnosis of the CCHF virus.

PATIENTS AND METHODS

In this experimental study, the highly conserved S-region sequence of the CCHF viral genome was first adapted from GenBank, and the specific primers targeting this region were designed. Then, the viral RNA was extracted from 75 serum samples from different patients in eastern Iran. The sensitivity and specificity of the primers were also evaluated in positive serum samples previously confirmed to have the CCHF virus, by this one-step rRT-PCR assay, as well as a DNA sequencing analysis.

RESULTS

From a total of 75 suspected serum samples, 42 were confirmed to be positive for CCHF virus, with no false-positives detected by the sequencing results. After 40 amplification cycles, the melting curve analysis revealed a mean melting temperature (Tm) of 86.5 ± 0.6°C (quite different from those of the primer-dimers), and the positive samples showed only a small variation in the parameters. In all of the positive samples, the predicted length of 420 bp was confirmed by electrophoresis. Moreover, the sensitivity test showed that this assay can detect less than 20 copies of viral RNA per reaction.

CONCLUSIONS

This study showed that this novel one-step rRT-PCR assay is a rapid, reliable, repeatable, specific, sensitive, and simple tool for the detection of the CCHF virus.

Predicting CCHF incidence and its related factors using time-series analysis in the southeast of Iran: comparison of SARIMA and Markov switching models

Crimean-Congo haemorrhagic fever (CCHF) is endemic in the southeast of Iran. This study aimed to predict the incidence of CCHF and its related factors and explore the possibility of developing an empirical forecast system using time-series analysis of 13 years' data. Data from 2000 to 2012 were obtained from the Health Centre of Zahedan University of Medical Sciences, Climate Organization and the Veterinary Organization in the southeast of Iran. Seasonal autoregressive integrated moving average (SARIMA) and Markov switching models (MSM) were performed to examine the potential related factors of CCHF outbreaks. These models showed that the mean temperature (°C), accumulated rainfall (mm), maximum relative humidity (%) and legal livestock importation from Pakistan (LIP) were significantly correlated with monthly incidence of CCHF in different lags (P < 0·05). The modelling fitness was checked with data from 2013. Model assessments indicated that the MSM had better predictive ability than the SARIMA model [MSM: root mean square error (RMSE) 0·625, Akaike's Information Criterion (AIC) 266·33; SARIMA: RMSE 0·725, AIC 278·8]. This study shows the potential of climate indicators and LIP as predictive factors in modelling the occurrence of CCHF. Our results suggest that MSM provides more information on outbreak detection and can be a better predictive model compared to a SARIMA model for evaluation of the relationship between explanatory variables and the incidence of CCHF.

Single-Stranded RNA Viruses

In this chapter, we describe 73 zoonotic viruses that were isolated in Northern Eurasia and that belong to the different families of viruses with a single-stranded RNA (ssRNA) genome. The family includes viruses with a segmented negative-sense ssRNA genome (families Bunyaviridae and Orthomyxoviridae) and viruses with a positive-sense ssRNA genome (families Togaviridae and Flaviviridae). Among them are viruses associated with sporadic cases or outbreaks of human disease, such as hemorrhagic fever with renal syndrome (viruses of the genus Hantavirus), Crimean–Congo hemorrhagic fever (CCHFV, Nairovirus), California encephalitis (INKV, TAHV, and KHATV; Orthobunyavirus), sandfly fever (SFCV and SFNV, Phlebovirus), Tick-borne encephalitis (TBEV, Flavivirus), Omsk hemorrhagic fever (OHFV, Flavivirus), West Nile fever (WNV, Flavivirus), Sindbis fever (SINV, Alphavirus) Chikungunya fever (CHIKV, Alphavirus) and others. Other viruses described in the chapter can cause epizootics in wild or domestic animals: Geta virus (GETV, Alphavirus), Influenza A virus (Influenzavirus A), Bhanja virus (BHAV, Phlebovirus) and more. The chapter also discusses both ecological peculiarities that promote the circulation of these viruses in natural foci and factors influencing the occurrence of epidemic and epizootic outbreaks

Evaluation of cases with a preliminary diagnosis of Crimean- Congo hemorrhagic fever and comparison of characteristics in patients admitted to a secondary care hospital in Kastamonu, Turkey

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is an endemic disease in Turkey. The clinical presentation and laboratory findings are not specific especially in cases without hemorrhagic findings.

OBJECTIVE

We aimed to evaluate CCHF cases and compare them with non-CCHF cases in terms of their characteristics during admission.

METHODS

Cases with a preliminary diagnosis of CCHF at a secondary care hospital in Kastamonu in 2013 were evaluated, retrospectively. Cases testing RNA/IgM positive were considered as CCHF. Cases testing both RNA and IgM negative were considered as non-CCHF. The two groups were then compared in terms of their clinical, laboratory and epidemiological characteristics during admission.

RESULTS

A total of 41 cases were tested and CCHF was found in 46.3% of cases. Fatality was 5.3% in CCHF cases. The frequency of tick bites and CK elevation in CCHF cases was significantly higher than non-CCHF cases (p<0.05). There were no significant differences between the two groups regarding other characteristics (p>0.05).

CONCLUSIONS

In cases with a preliminary diagnosis of CCHF, especially in cases without a history of tick bite and with normal CK levels during admission, performing tests for the differential diagnosis may be advisable without waiting for the results of tests for CCHF.

Clinical symptoms and laboratory findings supporting early diagnosis of Crimean-Congo hemorrhagic fever in Iran

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic disease, which is usually transmitted to humans by tick bites or contact with blood or other infected tissues of livestock. Patients suffering from CCHF demonstrate an extensive spectrum of clinical symptoms. As it can take considerable time from suspecting the disease in hospital until reaching a definitive diagnosis in the laboratory, understanding the clinical symptoms and laboratory findings of CCHF patients is of paramount importance for clinicians. The data were collected from patients who were referred to the Laboratory of Arboviruses and Viral Hemorrhagic Fevers at the Pasteur institute of Iran with a primary diagnosis of CCHF between 1999 and 2012 and were assessed by molecular and serologic tests. Referred patients were divided into two groups: patients with a CCHF positive result and patients with a CCHF negative result. The laboratory and clinical findings of these two groups were then compared. Two-thousand five hundred thirty-six probable cases of CCHF were referred to the laboratory, of which 871 cases (34.3%) were confirmed to be CCHF. Contact with infected humans and animals increased the CCHF infection risk (P < 0.001). A tick bite was not a risk factor. Fever; bleeding, vomiting, leucopoenia, thrombocytopenia, and increases in alanine transaminase (ALT) and aspartate transaminase (AST) levels were also indicative of CCHF infection. Accurate and speedy diagnosis of CCHF and appropriate treatment play an important role in patient survival and the application of the findings of this study can prove helpful as a key for early diagnosis.

A case report of crimean congo hemorrhagic Fever in ostriches in iran

Crimean Congo hemorrhagic fever (CCHF) is a viral zoonosis, which is usually transmitted via tick bites or close contact with infected blood or tissue. This disease can cause a case fatality rate of up to 25%-30% in humans. CCHF Infection in birds is less documented. An ostrich can reproduce viruses and can also play the role of a mechanical vector, by transporting infected ticks without becoming ill. In March 2007, three butchers and one worker in an ostrich farm were infected with CCHF in central part of Iran. Considering the role ostriches play in transmitting the disease, serum samples from five ostriches of that farm were taken and sent to the laboratory for CCHF ELISA tests. The result of the IgG test was positive for one (20%) of the ostriches. At the same time, serum samples of eight sheep from the same farm were sent for IgG testing, two (25%) of which were positive. This was the first report of CCHF infection of an ostrich in Iran and tracing CCHF IgG against this ostrich and the afore-mentioned sheep may have revealed that the disease in the worker was the cause of transmission of this disease from these animals or their ticks.

Crimean-Congo hemorrhagic fever in Iran

The presence of Crimean-Congo hemorrhagic fever virus (CCHFV) in Iran was first identified in studies of livestock sera and ticks in the 1970s, but the first human infection was not diagnosed until 1999. Since that time, the number of cases of CCHF in Iran has markedly increased. Through January 2012, articles in the published literature have reported a total of 870 confirmed cases, with 126 deaths, for a case fatality rate (CFR) of 17.6%. The disease has been seen in 26 of the country's 31 provinces, with the greatest number of cases in Sistan and Baluchestan, Isfahan, Fars, Tehran, Khorasan, and Khuzestan provinces. The increase in CCHF in Iran has paralleled that in neighboring Turkey, though the number of cases in Turkey has been much larger, with an overall CFR of around 5%. In this article, we review the features of CCHF in Iran, including its history, epidemiology, animal and tick reservoirs, current surveillance and control programs, diagnostic methods, clinical features and experience with ribavirin therapy, and consider possible explanations for the difference in the CFR of CCHF between Iran and Turkey. The emergence of CCHF in Iran calls for countermeasures at many levels to protect the population, but also provides opportunities for studying the epidemiology, diagnosis and management of the disease.

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

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

Nosocomial infection of Crimean-Congo haemorrhagic fever in eastern Iran: case report

An outbreak of Crimean-Congo haemorrhagic fever occurred in the county of Birjand in eastern Iran in November 2011. Four cases were involved in this outbreak. Two patients died after admission to hospital, one of whom was a nurse who acquired the infection nosocomially, and the others were treated successfully.

Preliminary study of dengue virus infection in Iran

Dengue fever is one of the most important arthropod-borne viral diseases of public health significance. It is endemic in most tropical and subtropical parts of the world, many of which are popular tourist destinations. The presence of dengue infection was examined in Iranian patients who were referred to the Arboviruses and Viral Haemorrhagic Fevers Laboratory of the Pasteur Institute of Iran and tested negative for Crimean-Congo Haemorrhagic Fever (CCHF) between 2000 and 2012. Serum samples from these patients were tested for the presence of specific IgG and IgM and viral nucleic acid in blood. Of the 300 sera tested, 15 (5%) were seropositive, and 3 (1%) were both serologically and PCR positive. Of the 15 seropositive cases, 8 (53.3%) had travelled to endemic areas including Malaysia (5, 62.5%), India (2, 25%) and Thailand (1, 12.5%). In contrast, 7 (46.7%) of the cases had not reported travelling abroad. Of these, six cases were from the Sistan and Baluchistan province in southeast Iran and neighbouring Pakistan. Travellers play a key role in the epidemiology of dengue infection in Iran and it is recommended that travellers to endemic areas take precautionary measures to avoid mosquito bites.

Relationship between Crimean-Congo hemorrhagic fever virus strains circulating in Iran and Turkey: possibilities for transborder transmission

Crimean-Congo hemorrhagic fever (CCHF) is an important zoonotic viral disease that is asymptomatic in infected livestock, but poses a serious threat to humans. The high fatality rate may be due to phylogenetic variations in the virus, transmission routes, and a lack of an efficient surveillance system for the disease. The geographical features of the eastern and southeastern borders of Turkey may facilitate transmission of viruses between countries of the region. Therefore in this study we focused on the genetic relationship between Turkish and Iranian CCHF viruses based on their S-segment sequences. The research was performed on a total of 104 blood samples from small ruminants reared in southwest Iran. The results of phylogenetic analysis showed that Iranian CCHF virus isolates were closely related to human-originating Turkish Group II viruses from a European lineage reported previously.

Seroepidemiological survey of Crimean-Congo hemorrhagic fever among sheep in Mazandaran province, northern Iran

Crimean-Congo hemorrhagic fever (CCHF) is a disease prevalent among humans and animals and is endemic in Iran. Although CCHF has been reported in all of its neighboring provinces, in Mazandaran in northern Iran there have been no reports of any cases of human infection. This research has been carried out to clarify the epidemiological aspects of CCHF infection among sheep in various geographical regions of Mazandaran province. In this survey, 270 blood samples were collected from sheep in eastern, central, and western Mazandaran between 2010 and 2011, and the specific ELISA test for CCHF virus was carried out on the blood samples in the National Reference Laboratory in the Pasteur Institute, Tehran, Iran. The CCHF infection rate according to this study was 3.7%. A weak statistical relationship (p=0.063) was seen between the different geographical regions, with a gradual decrease in the infection rate noted, stretching from the eastern to the western portions of the province (eastern 6.8%, central 2.8%, and western 0%). Older sheep were 2.7 times more likely to be infected with the virus (OR 2.70; 95% CI 1.50,4.87; p<0.001). As the infection rate in Mazandaran is low among sheep, and as yet there have been no reports of human infection in this province, CCHF disease is not considered a serious health problem in Mazandaran. It is recommended that further research be carried out on other animals, high-risk human groups, and ticks, in order to more completely reveal the status of the disease in this province.

Crimean-Congo hemorrhagic fever, Kazakhstan, 2009-2010

We evaluated Crimean-Congo hemorrhagic fever (CCHF) surveillance data from southern Kazakhstan during 2009–2010 and found both spatial and temporal association between reported tick bites and CCHF cases. Public health measures should center on preventing tick bites, increasing awareness of CCHF signs and symptoms, and adopting hospital infection control practices.

Reverse transcription PCR-based detection of Crimean-Congo hemorrhagic fever virus isolated from ticks of domestic ruminants in Kurdistan province of Iran

Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal viral vector-borne zoonosis which has a mortality rate of up to 30% without treatment in humans. CCHF virus is transmitted to humans by ticks, predominantly from the Hyalomma genus. Following the report of two confirmed and one suspected death due to CCHF virus in Kurdistan province of Iran in 2007, this study was undertaken to determine the fauna of hard ticks on domestic ruminants (cattle, sheep, and goats) and their possible infection with CCHF virus using reverse transcription PCR technique. This is the first detection of CCHF virus in ticks from the Kurdistan province of Iran. Overall, 414 ixodid ticks were collected from two districts in this province. They represented four genera from which 10 separate species were identified. The Hyalomma genus was the most abundant tick genus (70%). It was the only genus shown to be infected with the CCHF virus using RT-PCR technique. The number of ticks positive for CCHF virus was 5 out of 90 (5.6%) adult ticks. The three remaining genera (Haemaphysalis, Rhipicephalus, and Dermacentor) were all negative following molecular survey. Four of the five virally-infected ticks were from cattle mainly in the Sanandaj district. We concluded that CCHF virus is present in the Hyalomma ticks on domestic ruminants (cattle) in Kurdistan province of Iran.

Serological evaluation of Crimean-Congo hemorrhagic fever in humans with high-risk professions living in enzootic regions of Isfahan province of Iran and genetic analysis of circulating strains

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease that is asymptomatic in infected livestock, but causes a serious threat to humans with a mortality rate up to 50%. Although the CCHF virus (CCHFV) is often transmitted by ticks, livestock-to-human and human-to-human transmission also occurs. In the current study, we focused on CCHF in the province of Isfahan, located in the center of Iran and deemed to be the second most infected province. Human and livestock sera and resident ticks in the livestock are collected from different regions of the province and analyzed with specific IgG ELISA and RT-PCR tests. Overall, 12% and 12.7% of studied human and livestock populations were IgG positive, respectively. The genome of CCHFV was detected in 9% of ticks resident in livestock involved in this survey. The CCHFV isolates from infected ticks were genetically examined. Nucleotide sequence of the S-segment revealed that the different isolates were closely related to each other, with nucleotide sequence identities higher than 98%. Phylogenetic analysis demonstrated that a variant isolate clustered with the Iraq strain. This high proportion of IgG-positive sera and nearly high proportion of infected ticks increases the risk of CCHF outbreaks in the province and probably posits a great danger to other provinces.

Metagenomic analysis of fever, thrombocytopenia and leukopenia syndrome (FTLS) in Henan Province, China: discovery of a new bunyavirus

Since 2007, many cases of fever, thrombocytopenia and leukopenia syndrome (FTLS) have emerged in Henan Province, China. Patient reports of tick bites suggested that infection could contribute to FTLS. Many tick-transmitted microbial pathogens were tested for by PCR/RT-PCR and/or indirect immunofluorescence assay (IFA). However, only 8% (24/285) of samples collected from 2007 to 2010 tested positive for human granulocytic anaplasmosis (HGA), suggesting that other pathogens could be involved. Here, we used an unbiased metagenomic approach to screen and survey for microbes possibly associated with FTLS. BLASTx analysis of deduced protein sequences revealed that a novel bunyavirus (36% identity to Tehran virus, accession: HQ412604) was present only in sera from FTLS patients. A phylogenetic analysis further showed that, although closely related to Uukuniemi virus of the Phlebovirus genus, this virus was distinct. The candidate virus was examined for association with FTLS among samples collected from Henan province during 2007–2010. RT-PCR, viral cultures, and a seroepidemiologic survey were undertaken. RT-PCR results showed that 223 of 285 (78.24%) acute-phase serum samples contained viral RNA. Of 95 patients for whom paired acute and convalescent sera were available, 73 had serologic evidence of infection, with 52 seroconversions and 21 exhibiting a 4-fold increase in antibody titer to the virus. The new virus was isolated from patient acute-phase serum samples and named Henan Fever Virus (HNF virus). Whole-genome sequencing confirmed that the virus was a novel bunyavirus with genetic similarity to known bunyaviruses, and was most closely related to the Uukuniemi virus (34%, 24%, and 29% of maximum identity, respectively, for segment L, M, S at maximum query coverage). After the release of the GenBank sequences of SFTSV, we found that they were nearly identical (>99% identity). These results show that the novel bunyavirus (HNF virus) is strongly correlated with FTLS.

Initially in 2007, and again between 2008 and 2010, cases of a life-threatening disease with sudden fever, thrombocytopenia, and leukopenia were reported in Henan Province, China. Patient reports of tick bites suggested that this disease could be infectious or tick-transmitted. Many patients were provisionally diagnosed with human granulocytic anaplasmosis (HGA). However, only 24 of 285 (8%) had objective evidence of HGA, suggesting that other pathogens likely contributed to fever, thrombocytopenia and leukopenia syndrome (FTLS). Illumina sequencing was used for direct detection in clinical samples of pathogens possibly associated with FTLS. A novel bunyavirus was found only in samples from FTLS patients. Further epidemiologic and laboratory investigation confirmed that the novel bunyavirus was associated with FTLS. The results illustrate that metagenomic analysis is a powerful method for the discovery of novel pathogenic agents. Combined with epidemiologic investigation, it could assist in rapid diagnosis of unknown diseases and distinguish them from other diseases with similar symptoms caused by known pathogens.

Ribavirin for patients with Crimean-Congo haemorrhagic fever: a systematic review and meta-analysis

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a potentially fatal tick-borne infection. The virus is widely distributed around the world and reports of sporadic cases and outbreaks have recently increased significantly. Some authors have proposed that ribavirin improves survival in CCHF and this view appears to be widely accepted.

METHODS

We evaluated the efficacy of ribavirin in reducing mortality by conducting a systematic review and meta-analysis. We included randomized controlled trials and observational studies that compared the outcomes of CCHF patients who were treated with ribavirin with those of patients that were not treated. The main endpoint we assessed was survival. We also evaluated secondary endpoints, i.e. adverse events, length of stay in the hospital, time taken for laboratory values to return to normal and requirement for blood products. A pooled estimate of the relative risks for survival from each study was obtained by using random effects models.

RESULTS

One randomized controlled trial and seven observational studies met our inclusion criteria. Most observational studies suffered from different types of bias due to inappropriate selection of controls. Compilation of data from all included studies showed that ribavirin did not improve survival in CCHF (relative risk 1.06, 95% confidence interval 0.97-1.16). Analysis of secondary endpoints did not suggest a clinically significant beneficial effect either.

CONCLUSIONS

Our systematic review and meta-analysis revealed that the available data in the literature are inadequate to support a claim of efficacy of ribavirin in CCHF. We believe a real uncertainty exists over the benefit of ribavirin in the treatment of CCHF, which necessitates the urgent conduct of a randomized placebo-controlled trial.

Crimean--Congo hemorrhagic fever: a molecular survey on hard ticks (Ixodidae) in Yazd province, Iran

OBJECTIVE

To determine the rate of Crimean--Congo hemorrhagic fever virus (CCHFV) infection in hard ticks (Ixodidae) in Yazd province of Iran.

METHODS

A molecular survey on hard ticks (Ixodidae) was conducted in Yazd province during 2008-2009. A total of 140 hard ticks (three genera and 7 species) were collected from randomly selected villages and were exanimate for presence of CCHFV reverse transcription--polymerase chain reaction (RT-PCR) method.

RESULTS

CCHFV genome was found in 5.71% of hard ticks. All positive ticks were from Hyalomma genus. Positive ticks including: Hyalomma dromedarii, Hyalomma marginatum, Hyalomma anatolicum, Hyalomma detritum, Hyalomma asiaticum. We were not able to find virus in in Rhipicephalus sanguineus and Dermacentor marginatus. Results exhibited that Hyalomma is the main vector in the study area.

CONCLUSIONS

Due to the presence of virus in 24 provinces' out of 31, we recommend the use of acaricides and repellent to prevent disease transmission among humans. Greta care should be taken by the people who are working in slaughter houses.

Geographical distribution and surveillance of Crimean-Congo hemorrhagic fever in Iran

Crimean-Congo hemorrhagic fever (CCHF) is viral hemorrhagic fever caused by CCHF virus, which belongs to the family Bunyaviridae and the genus Nairovirus. The virus is transmitted to humans via contact with blood and tissue from infected livestock, a tick bite, or contact with an infected person. Since 2000, we have shown the disease to be prevalent in 23 out of 30 provinces of Iran. Among those, Sistan-va-Baluchistan, Isfahan, Fars, Tehran, Khorasan, and Khuzestan demonstrated the highest infection, respectively. Notably, Sistan-va-Baluchistan province, southeast of Iran, has the highest prevalence of CCHF, and has shown to be present since at least 2000. Phylogenetic study of the CCHF virus genome isolated from Iranian patients showed a close relationship with the CCHF Matin strain (Pakistan). Our epidemiological data in the last decade have implied that the severity and fatality rate of the disease has ranged variably in different provinces of Iran. More pathogenesis and phylogenetic studies should therefore be investigated to clarify these differences.

A survey of Crimean-Congo haemorrhagic fever in livestock and ticks in Ardabil Province, Iran during 2004-2005

Crimean-Congo haemorrhagic fever (CCHF) is a viral haemorrhagic fever caused by the CCHF virus. It is mainly transmitted to humans and animals by ticks. In recent y, large numbers of livestock have been transported across the border areas of Ardabil Province resulting in an outbreak of CCHF in the adjacent districts. A comprehensive study was carried out to assess the epidemiological aspects of the disease in this province. In the study area, 130 ticks were collected from randomly selected villages and classified into 9 species of hard tick and 2 species of soft tick. All ticks were analyzed for the presence of CCHF virus genome using gel-based and real-time reverse transcriptase polymerase chain reactions (RT-PCR). The results showed CCHF infection in almost 28% of ticks collectively. Also, of 56 livestock sera, around 39% were IgG-positive. The presence of anti-CCHF virus IgG antibodies and the CCHF virus genome in ticks points to a great hidden threat of an outbreak in these districts. Those in high-risk professions in this province should be informed and trained on the risk of CCHF with urgency.

Differential activation profiles of Crimean-Congo hemorrhagic fever virus- and Dugbe virus-infected antigen-presenting cells

Crimean-Congo hemorrhagic fever virus (CCHFV) is a highly pathogenic, tick-borne member of the family Bunyaviridae and the genus Nairovirus. To better elucidate the pathogenesis of CCHFV, we analysed the host innate immune response induced in antigen-presenting cells (APCs) infected in vitro by CCHFV. Monocyte-derived dendritic cells (DCs) and macrophages (MPs) were both shown to be permissive for CCHFV and to replicate the virus, as monitored by genomic and antigenomic strand quantification. Virus replication was, however, controlled, corroborating an efficient alpha interferon-induced response. The upregulation of CD-83 and CD-86 indicated that CCHFV induced a partial maturation of DCs, which were also shown to activate the secretion of interleukin (IL)-6 and IL-8, but no tumour necrosis factor alpha (TNF-alpha). On the other hand, in MPs, CCHFV infection elicited a high IL-6 and TNF-alpha response and a moderate chemokine response. Nevertheless, when we compared these APC responses with those seen after infection with Dugbe virus (DUGV), a mildly pathogenic virus genetically close to CCHFV, we found that, in spite of some similarities, DUGV induced a higher cytokine/chemokine response in MPs. These results suggest that CCHFV is able to inhibit the activation of inflammatory mediators selectively in infection in vitro and that these differences could be relevant in pathogenesis.

Animal health: harmonisation and distribution of pathogen detection and differentiation tools

Quality and safe meat production and livestock husbandry are important foci for addressing the wider underlying economic and political challenges. In the last few years, an intense focus of the scientific community has been placed on breakouts of livestock diseases especially in Asia, which have spread into neighbouring countries including Europe. These outbreaks had a serious impact on the livelihood of the farmers as well as the economy of the affected countries. Given this, the establishment of a network of diagnostic facilities is a great demand both at the national and regional levels. In most of the cases, diagnostic assays are either not available or they are not validated. The aim of this collaborative network was to: 1 Distribute and harmonize diagnostic tools required for pathogen detection and differentiation. 2 Build the capacity to ensure the conduction of integrated disease control measures.