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

Background

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

Methods

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

Results

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

Conclusions

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

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

Investigation of NEAT1, IFNG-AS1, and NRIR expression in Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF), whose causative agent is CCHF orthonairovirus (CCHFV), demonstrates different symptoms in patients. Long noncoding RNAs (lncRNAs) take part in various pathological processes of viral diseases. They are prominent regulators of antiviral immune responses. To our knowledge, this study is the first study to investigate nuclear paraspeckle assembly transcript 1 (NEAT1), interferon (IFN) gamma antisense RNA 1 (IFNG-AS1), and negative regulator of IFN response (NRIR) expression in CCHF in the literature. We selected these lncRNAs because they are related to IFN signal or IFN-stimulated genes. We investigated NEAT1, IFNG-AS1, and NRIR gene expression in patients with CCHF. Total RNA was extracted from blood samples of 100 volunteers and NEAT1, IFNG-AS1, and NRIR expression were measured using a quantitative real-time polymerase chain reaction. NRIR expression was statistically significant in cases versus controls (p < .001), fatals versus controls (p < .001), and fatals versus nonfatals (p = .01). Furthermore, NRIR was found statistically significant at some clinical parameters including alanine aminotransferase (p = .03), international normalized ratio (p = .03), prothrombin time (p = .02), and active partial thromboplastin time (p = .01) in CCHF cases. NEAT1 and IFNG-AS1 expression were downregulated in the case and fatal groups which were compared with controls. Our results demonstrate that NRIR may be important in CCHF pathogenesis and the target of CCHF treatment.

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

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

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

Identification of a novel lineage of Crimean-Congo haemorrhagic fever virus in dromedary camels, United Arab Emirates

Crimean-Congo haemorrhagic fever virus (CCHFV) is a tick-borne virus causing Crimean-Congo haemorrhagic fever (CCHF), a disease reported to have a high fatality rate in numerous countries. The virus is geographically widespread due to its vector, and numerous wild and domestic animals can develop asymptomatic infection. Serological and limited molecular evidence of CCHFV has previously been reported in Camelus dromedarius (the dromedary, or one-humped camel) in the United Arab Emirates (UAE). In this study, 238 camel samples were screened for CCHFV RNA where 16 camel samples were positive for CCHFV by RT-PCR. Analysis of full-length CCHFV genome sequences revealed a novel lineage in camels from the UAE, and potential reassortment of the M segment of the genome.

Glutamine depletion in patients with Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a viral disease. There is not enough knowledge about plasma amino acid levels in CCHF. Therefore, we investigated plasma amino acid levels in patients with CCHF and the association between the levels of these amino acids and disease severity. The plasma amino acid levels (including glutamate [Glu], aspartate [Asp], glutamine [Gln], asparagine [Asn] and gamma-aminobutyric acid [GABA]) in CCHF patients and controls were measured by using liquid chromatography-mass spectrometry. Plasma levels of Gln were lower while Asp, Glu, and GABA levels were higher in patients. In fatal CCHF patients, we found the plasma level of Asn was increased whereas the plasma level of GABA was decreased. This study is the first in the literature to evaluate the plasma Gln, Glu, Asn, Asp, and GABA levels in CCHF patients. We found that the plasma Gln levels were significantly lower in CCHF patients while Asp, Glu, and GABA levels were elevated. Considering that these amino acids are important for immune cells, the plasma amino acid levels of CCHF patients may contribute to the understanding of the pathophysiology of disease and it can be important for supportive treatment of CCHF.

Rotational thromboelastometry alongside conventional coagulation testing in patients with Crimean-Congo haemorrhagic fever: an observational cohort study

BACKGROUND

Data describing the coagulopathy of Crimean-Congo haemorrhagic fever are scarce. We did rotational thromboelastometry (ROTEM) and conventional coagulation testing in patients with Crimean-Congo haemorrhagic fever to increase our understanding of the coagulopathy of this infectious disease.

METHODS

We did a prospective observational cohort study of adults aged 18 years and older and admitted to hospitals with PCR-confirmed Crimean-Congo haemorrhagic fever in Samsun and Tokat, Turkey. Demographic, clinical, and laboratory data were collected and blood samples for ROTEM analysis and coagulation testing were drawn at admission and during hospital admission and convalescence (up to 30 days after onset of illness). For the ROTEM analysis we recorded the following extrinsically activated ROTEM (EXTEM S) variables, with normal ranges indicated: clotting time (38-79 s), clot formation time (34-159 s), amplitude at 10 min after clotting time (43-65 mm), maximum clot firmness (50-72 mm), and maximum lysis (>15% at 1 h). The following fibrin-specific ROTEM (FIBTEM S) variables were also recorded: amplitude at 10 min after clotting time (normal range 7-23 mm) and maximum clot firmness (9-25 mm). Disease severity was assessed by Swanepoel criteria, severity grading score (SGS), and the severity scoring index (SSI), with mild disease defined as meeting no Swanepoel criteria, graded mild by SSI, and graded low risk by SGS.

FINDINGS

Between May 27, 2015, and Aug 2, 2015, 65 patients with confirmed Crimean-Congo haemorrhagic fever were recruited and had blood taken at 110 time points. Most were male (40 [62%] of 65) with mild disease (49 [75%] of 65). Haemorrhage occurred in 13 (20%; 95% CI 11·1-31·8) of 65 patients and 23 (35%) of 65 received blood products (15 received fresh frozen plasma and eight received red blood cell concentrates), and 21 patients received platelet transfusions. At admission, the following EXTEM S variables differed significantly between mild cases and moderate to severe cases: median clotting time 56 s (range 42-81; IQR 48-64) versus 69 s (range 48-164; IQR 54-75; p=0·01); mean amplitude at 10 min after clotting time 45·1 mm (SD 7·0) versus 33·9 mm (SD 8·6; p<0·0001); median clot formation time 147 s (range 72-255; IQR 101-171) versus 197 s (range 98-418; IQR 156-296; p=0·006); and maximum clot firmness 54·4 mm (SD 7·2) versus 45·1 mm (SD 12·5; p=0·003). The EXTEM S variables were compared at different time points; maximum clot firmness (p=0·024) and amplitude at 10 min after clotting time (p=0·090) were lowest on days 4-6 of illness. We found no significant differences in FIBTEM variables between mild and moderate to severe cases (median amplitude at 10 min, 13 mm [range 8-20; IQR 11-15] vs 12 mm [range 6-25; IQR 10-15; p=0·68]; and median maximum clot firmness, 15 mm [range 9-60; IQR 13-21] vs 17 mm [range 7-39; IQR 13-23; p=0·21]); and no hyperfibrinolysis (maximum lysis >15%).

INTERPRETATION

Coagulopathy of Crimean-Congo haemorrhagic fever is related to defects in clot development and stabilisation that are more marked in severe disease than in mild disease. The combination of normal and slightly deranged coagulation screens and FIBTEM results with the absence of hyperfibrinolysis suggests that the coagulopathy of Crimean-Congo haemorrhagic fever relates to platelet dysfunction.

FUNDING

Wellcome Trust, UK Ministry of Defence, and National Institute for Health Research Health Protection Research Unit.

Crimean-Congo hemorrhagic fever (CCHF) seroprevalence: A systematic review and meta-analysis

Crimean-Congo haemorrhagic fever (CCHF) is the most widespread, tick-borne viral disease affecting humans and therefore this paper performed a meta-analysis to highlight seroprevalence features of CCHF in a global context. After a preliminary review of the 396 papers representing areas throughout the world, 206 were selected for detailed meta-analysis. In general the total means of CCHF seroprevalence were, respectively 4.7 and 24.6% for humans and animals; and 17.1, 18.9, 24.3, 29.3 and 27.1% for camels, cattle, goats, sheep and livestock. Statistical analysis revealed a significant difference in seroprevalence between humans and camels (P = 0.043), cattle (P = 0.010), goats (P = 0.015), sheep (P = 0.005) and livestock (P = 0.017). Regionally, there also was a difference between humans, and goats (P = 0.0001), sheep (P = 0.007) and livestock (P = 0.002). Globally, CCHF seroprevalence in at-risk professionals was 7.5 fold greater than in normal humans, while CCHF seroprevalence was 5 fold greater in animals, camels, cattle, goats, sheep and livestock than normal humans. Animal contact, animal husbandry, farming, tick bite history and secretion exposure were the most frequently reported CCHF seropositivity risk factors. This study serves as an important resource for epidemiological discussions related to CCHF and CCHF seroprevalence features, providing specific information in understanding human and animal mean and trend CCHF seroprevalence for different regions of the world and on an aggregate global scale; seroprevalence in at-risk professionals; and total mean and trend CCHF seropositivity involving risk factors.

Effects of platelet function on the haemorrhagic manifestations and mortality in Crimean-Congo haemorrhagic fever

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease which can lead to life-threatening with haemorrhagic manifestations. We aimed here in this study was to evaluate the effect of the platelet count and volume-related indices, such as the mean platelet volume (MPV), platelet distribution width (PDW) which is a measure of platelet anisocytosis and plateletcrit, in the haemorrhagic manifestations and mortality seen in CCHF cases. We retrospectively examined data derived from 173 patients. The age, gender, alanine transaminase (ALT), aspartate transaminase (AST), platelet counts and MPV, PDW and PCT values upon admission (MPV1, PDW1 and PCT1) and those values measured at the time when the PLT was at the lowest level (MPV2, PDW2 and PCT2), haemorrhagic manifestations and the mortality status of patients diagnosed with CCHF were recorded. ALT and AST values were higher among the haemorrhagic patients when compared with the others (p<0.001), while platelet 1 (PLT1), platelet 2 (PLT2), plateletcrit 1 (PCT1), plateletcrit 2 (PCT2) and platelet distribution width 2 (PDW2) values were significantly lower (p=0.001, p<0.001, p=0.002, p<0.001 and p=0.003, respectively). A negative correlation was documented between haemorrhage and the PLT1, PLT2, PCT1, PCT2 and PDW2 (r=-0.255, r=-0.415, r=-0.241, r=-0.377, r=-0.223, respectively); however, there was a positive correlation between haemorrhage and mortality (r=0.34). This was the first study evaluating the platelet functions in CCHF, such as the PLT, PDW and PCT, in CCHF correlated with the mortality and haemorrhagic manifestations. The platelet functions contribute as much to the prediction of haemorrhage and mortality as the PLT. The present study suggests that the PCT and PDW values could be beneficial in anticipating the inclination toward haemorrhage and mortality.

Carbonic anhydrase I-II autoantibodies and oxidative status in long-term follow-up of patients with Crimean-Congo haemorrhagic fever

CONTEXT

Crimean-Congo haemorrhagic fever (CCHF) is a life-threatening acute febrile haemorrhagic disease.

OBJECTIVE

This study was to measure levels of the oxidative stress biomarkers malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) and of CA I-II autoantibodies as biomarkers for autoimmunity and course of disease in patients with CCHF.

METHODS

Seventy CCHF patients and 39 healthy control volunteers were included in the study.

RESULTS

Serum MDA and TAS levels were significantly higher (p < .0001) and serum TOS and OSI levels were significantly lower (p < .0001) in both the acute period and at 6th-month follow-up in the CCHF patients compared to the healthy volunteers. CA II levels were significantly higher in the acute period compared to the healthy volunteers (p < .005) and were significantly lower at 6th-month follow-up (p < .05).

CONCLUSION

Serum MDA and CA II autoantibodies appear to reflect oxidative stress status and disease progression in CCHF and may be used as biomarkers for oxidative stress and disease progression.

Serological and Virological Evidence of Crimean-Congo Haemorrhagic Fever Virus Circulation in the Human Population of Borno State, Northeastern Nigeria

Background

Despite several studies on the seroprevalence of antibodies against Crimean-Congo Haemorrhagic Fever virus (CCHFV) from humans and cattle in Nigeria, detailed investigation looking at IgG and IgM have not been reported. Additionally, there have been no confirmed cases of human CCHFV infection reported from Nigeria.

Principal Findings

Samples from sera (n = 1189) collected from four Local Government Areas in Borno State (Askira/Uba, Damboa, Jere and Maiduguri) were assessed for the presence of IgG and IgM antibodies. The positivity rates for IgG and IgM were 10.6% and 3.5%, respectively. Additionally, sera from undiagnosed febrile patients (n = 380) were assessed by RT-PCR assay for the presence of CCHFV RNA. One positive sample was characterised by further by next generation sequencing (NGS) resulting in complete S, M and L segment sequences.

Conclusions

This article provides evidence for the continued exposure of the human population of Nigeria to CCHFV. The genomic analysis provides the first published evidence of a human case of CCHFV in Nigeria and its phylogenetic context.

Crimean-Congo haemorrhagic fever (CCHF) is an acute tick-borne zoonotic disease. The causative agent, CCHF virus (CCHFV), has the most extensive geographical distribution of the medically important tick-borne viral diseases with a distribution over much of Asia, the Middle East, Africa and expanding areas of south-eastern Europe. Whilst the main route of human infection with CCHFV is predominantly through tick bite, it can also be spread via bodily fluids and it has a reputation for causing nosocomial outbreaks in healthcare settings. Whilst CCHFV has been identified in ticks from Nigeria since 1970, there is scarce information on human infection. Within this report, the prevalence of CCHFV-reactive antibodies has been assessed in human sera providing evidence of continued circulation of the virus in the human population of Borno state, Nigeria. Additionally, in one sample the presence of viral RNA was detected which allowed a full sequence of the CCHFV to be obtained. This is the first report of CCHFV being associated in a human case from Nigeria and the full genetic characterisation of the virus being completed. The evidence within supports the hypothesis that CCHFV is endemic in Nigeria and should be considered as an aetiological agent in febrile patients.

HMGB1 Is a Potential Biomarker for Severe Viral Hemorrhagic Fevers

Hemorrhagic fever with renal syndrome (HFRS) and Crimean-Congo hemorrhagic fever (CCHF) are common representatives of viral hemorrhagic fevers still often neglected in some parts of the world. Infection with Dobrava or Puumala virus (HFRS) and Crimean-Congo hemorrhagic fever virus (CCHFV) can result in a mild, nonspecific febrile illness or as a severe disease with hemorrhaging and high fatality rate. An important factor in optimizing survival rate in patients with VHF is instant recognition of the severe form of the disease for which significant biomarkers need to be elucidated. To determine the prognostic value of High Mobility Group Box 1 (HMGB1) as a biomarker for disease severity, we tested acute serum samples of patients with HFRS or CCHF. Our results showed that HMGB1 levels are increased in patients with CCHFV, DOBV or PUUV infection. Above that, concentration of HMGB1 is higher in patients with severe disease progression when compared to the mild clinical course of the disease. Our results indicate that HMGB1 could be a useful prognostic biomarker for disease severity in PUUV and CCHFV infection, where the difference between the mild and severe patients group was highly significant. Even in patients with severe DOBV infection concentrations of HMGB1 were 2.8-times higher than in the mild group, but the difference was not statistically significant. Our results indicated HMGB1 as a potential biomarker for severe hemorrhagic fevers.

Serum β-Defensin-2 Levels and Their Relationship with the Clinical Course and Prognosis in Patients with Crimean-Congo Hemorrhagic Fever

OBJECTIVE

The aim of this study was to investigate the role of the clinical course and prognosis of serum levels of β-defensin-2 (BD-2) in patients with Crimean-Congo hemorrhagic fever (CCHF).

SUBJECTS AND METHODS

Patients who were hospitalized in the Department of Infectious Diseases and Clinical Microbiology of the Faculty of Medicine, Ataturk University, were considered for inclusion in this study. The patients had positive real-time reverse transcription polymerase chain reaction and/or enzyme-linked immunosorbent assay results of the CCHF virus. There were 60 patients with CCHF in the study group and 25 healthy participants in the control group. Serum BD-2 levels were measured using ELISA. Data were analyzed using the Student t test or Mann-Whitney U test.

RESULTS

Of the 60 patients, 6 (10%) died and 54 (90%) were discharged following their recovery. The mean BD-2 level of the patient group was significantly higher (4,180.30 ± 3,944.19 pg/ml) than that of the control group (964.45 ± 266.07 pg/ml; p = 0.001). Serum BD-2 levels of the patients with fatal (1,529.81 ± 1,028.14) and nonfatal disease (4,474.80 ± 4,041.58) differed, but this difference showed only borderline significance (p = 0.055). The mean BD-2 level of the severe group was 5,507.45 ± 4,327.06 pg/ml, while it was 3,611.52 ± 3,676.73 pg/ml in the mild/moderate group, and both were significantly higher than that of the control group (p = 0.001).

CONCLUSION

In this study, the expression of serum BD-2 was raised in patients with CCHF, and this increase may beneficially affect survival. Studies with larger sample sizes are needed to confirm the association of serum BD-2 with CCHF prognosis.

Predictors of Crimean-Congo hemorrhagic fever in the Emergency Department

OBJECTIVE

Crimean-Congo hemorrhagic fever (CCHF) is an acute illness affecting multiple organ systems characterized by thrombocytopenia, and/or leukopenia, elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) and it has a case-fatality of 8% to 80%. In this article, we aimed to determine the clinical and laboratory findings that predicts the disease on admission.

PATIENTS AND METHODS

We retrospectively analyzed the medical data of the patients admitted to our emergency department (ED) due to tick bite. These patients were divided into two groups according to their transcriptase-polymerase chain reaction (RT-PCR) test results. Findings of PCR (+) (Group 1) and PCR (-) (Group 2) patients were compared.

RESULTS

Epistaxis was found to be statistically significant clinical finding in Group 1. Also, while aspartate transaminase (AST) levels and potassium (K) level were significantly higher, platelet count and white blood count (WBC) were significantly lower in Group 1 when compared to Group 2.

CONCLUSIONS

Predictors of CCHF in the ED are epistaxis, leukopenia, thrombocytopenia and elevated K and AST levels. In our study, the fatality rate of CCHF was found to be 21.6%.

Doppler ultrasonographic evaluation of the carotid and vertebral arteries in children with Crimean-Congo hemorrhagic fever

AIM

In children with Crimean-Congo hemorrhagic fever (CCHF), the aim of present study was to determine the cerebral hemodynamic changes assessed with Doppler ultrasonography with measurements of lumen diameter (LD), peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), and total cerebral blood flow volume (tCBFV) of common carotid artery (CCA), internal carotid artery (ICA, and vertebral artery (VA).

METHODS

This case-control study examined children with clinically defined CCHF as cases (N.=24) and healthy children as controls (N.=17). The CCHF and healthy children underwent ultrasonography of the CCA, ICA and VA for the measurements of flow velocity and cerebral blood flow volume. Doppler ultrasonography were performed in the CCHF children if vital signs were stable and fever lower than 37.5 °C.

RESULTS

There was no significant difference between the CCHF and healthy children in the lumen diameter of study arteries (P>0.05). PSV and EDV values were significantly higher in the CCHF children compared to the controls (P<0.05). Overall, the CCHF did not cause considerable change in RI and PI values (P>0.05). tCBFV values of CCHF children was found higher compared to healthy controls (P<0.05).

CONCLUSION

Overall, in children, CCHF causes an increase in the cerebral blood flow as determined by Doppler ultrasonography with flow velocity and cerebral blood flow volume measurements; however, this increase need to be accepted as mild to moderate degree. Several pathophysiological derangements may be contributory to the increased cerebral blood flow in children with CCHF.

The global distribution of Crimean-Congo hemorrhagic fever

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne infection caused by a virus (CCHFV) from the Bunyaviridae family. Domestic and wild vertebrates are asymptomatic reservoirs for the virus, putting animal handlers, slaughter-house workers and agricultural labourers at highest risk in endemic areas, with secondary transmission possible through contact with infected blood and other bodily fluids. Human infection is characterized by severe symptoms that often result in death. While it is known that CCHFV transmission is limited to Africa, Asia and Europe, definitive global extents and risk patterns within these limits have not been well described.

METHODS

We used an exhaustive database of human CCHF occurrence records and a niche modeling framework to map the global distribution of risk for human CCHF occurrence.

RESULTS

A greater proportion of shrub or grass land cover was the most important contributor to our model, which predicts highest levels of risk around the Black Sea, Turkey, and some parts of central Asia. Sub-Saharan Africa shows more focalized areas of risk throughout the Sahel and the Cape region.

CONCLUSIONS

These new risk maps provide a valuable starting point for understanding the zoonotic niche of CCHF, its extent and the risk it poses to humans.

Clinical significance of neutrophil gelatinase-associated lipocalin in Crimean-Congo hemorrhagic Fever

Neutrophil gelatinase-associated lipocalin (NGAL), which is an important prognostic marker for sepsis and inflammatory diseases, is mostly released from neutrophils. Crimean-Congo hemorrhagic fever (CCHF) patients are generally neutropenic. We aimed to investigate whether there is a change in serum NGAL level and to investigate its effect on the recovery time (RT) during the course of CCHF. A total of 40 CCHF patients (19 females and 21 males) and 34 healthy controls (17 females and 17 males) were included in the study. The serum NGAL level and biochemical and hematological parameters were checked. The NGAL level of CCHF patients was significantly higher than that of the healthy controls (P < 0.001). A multivariate analysis showed that the independent prognostic factor for the prediction of the RT is the NGAL level (odds ratio [OR] 0.3, 95% confidence interval [Cl] 0.1-0.4, P < 0.001). An elevated NGAL level was found to be associated with an increased RT in CCHF patients. The NGAL levels of CHHF patients might be elevated due to increased cytokine release, the presence of a tissue injury, and the release of immature neutrophils from the bone marrow into the peripheral stream. This may be a good prognostic factor in CHHF patients.

First report on the seroprevalence of the Crimean-Congo haemorrhagic fever virus, a tick-borne virus, in Malaysia's Orang Asli population

OBJECTIVE

The Crimean-Congo haemorrhagic fever virus (CCHFV), which is transmitted by the ticks of Hyalomma spp. in general and H. marginatumin particular, can cause severe disease in humans, with mortality rates of 3-30%. Other than from the bites of infected ticks, CCHFV can also be transmitted through contact with patients with the acute phase of infection or contact with blood or tissues from viraemic livestock.  Outbreaks of human cases of haemorrhagic manifestations have been documented since 1945 and described in parts of Africa, Asia, Eastern Europe and the Middle East and most recently India in 2011. In addition, serological evidence of the disease has been reported in some countries where no human cases were reported. As regional neighbours China and India have been affected by this virus, this study was conducted to determine the seroprevalence of CCHFV among Orang Asli population of Malaysia as the most at risk people who residing in the deep forests.

PATIENTS AND METHODS

A total of 682 serum samples were collected from the Orang Asli population residing in eight states in peninsular Malaysia and analysed for the presence of anti-CCHFV immunoglobulin G (IgG) using a commercial enzyme-linked immunosorbent assay kit.

RESULTS

The study subjects comprised 277 (40.6%) men and 405 (59.4%) women. However, anti-CCHFV IgG was detected in only one female serum sample (0.1%). The presence of anti-CCHFV IgG could not be correlated to age or sex from these findings.

CONCLUSIONS

The results of this screening survey showed that the seroprevalence of the anti-CCHFV IgG among Malaysia's Orang Asli population is too low for detection or totally negative compared with that in neighbouring countries, such as India and China.

Crimean-Congo hemorrhagic fever virus, Greece

Seroprevalence of Crimean-Congo hemorrhagic fever virus (CCHFV) is high in some regions of Greece, but only 1 case of disease has been reported. We used 4 methods to test 118 serum samples that were positive for CCHFV IgG by commercial ELISA and confirmed the positive results. A nonpathogenic or low-pathogenicity strain may be circulating.

A case of Crimean-Congo haemorrhagic fever with normal laboratory findings

Crimean-Congo haemorrhagic fever (CCHF) is a tick-borne disease caused by Nairovirus, of the family Bunyaviridae. This is the first case report of a confirmed CCHF case without laboratory abnormality. A 36-year-old woman was admitted to our clinic with the complaints of fever, chills, myalgia and vomiting. She was living in a CCHF-endemic region and had received a tick bite ten days previously. Her complaints had started five days after the tick bite, and bleeding of the nose and vagen followed. Under laboratory analysis, serum white blood cell (WBC) was 7300/mm3, haemoglobin (Hb)11.9 gr/dL, platelet (Plt) count 293000/mm3, aspartate transaminase (AST) was 23 U/L, alanine transaminase (ALT) 14 U/L, lactate dehydrogenase (LDH) 139 U/L, creatinine phosphokinase (CPK) 39 U/L, INR 0.8 and APTT 26.2 seconds. Based on these clinical and epidemiological findings, a diagnosis of CCHF infection was suspected, and the diagnosis of CCHF was confirmed with a blood sample tested by TaqMan-based one-step RT-PCR positivity and IgM antibody positivity. We suggest that patients from an endemic region who have typical epidemiological and clinical findings should be evaluated as a possible case for CCHF even if the laboratory findings are not compatible.

Novel molecular beacon probe-based real-time RT-PCR assay for diagnosis of Crimean-Congo hemorrhagic fever encountered in India

Crimean-Congo hemorrhagic fever (CCHF) is an emerging zoonotic disease in India and requires immediate detection of infection both for preventing further transmission and for controlling the infection. The present study describes development, optimization, and evaluation of a novel molecular beacon-based real-time RT-PCR assay for rapid, sensitive, and specific diagnosis of Crimean-Congo hemorrhagic fever virus (CCHFV). The developed assay was found to be a better alternative to the reported TaqMan assay for routine diagnosis of CCHF.

Evaluation of complement system in children with Crimean-Congo hemorrhagic fever

OBJECTIVES

The complement system participates in the defense of the body against viral infections through various mechanisms. In the present study conducted on children having Crimean-Congo Hemorrhagic Fever (CCHF), the aim was to evaluate whether the complement system had a role in the pathogenesis of the disease.

PATIENTS AND METHODS

Forty-one patients diagnosed with CCHF and 32 healthy controls were included in the study. Serum complement component 3 (C3), 4 (C4) and complement product Bb (Bb) levels were measured in both groups.

RESULTS

Compared to the control group, serum C3 levels were lower and Bb levels were higher in CCHF patients (p < 0.01). Moreover, in the patient group, C3 levels were positively correlated with WBC and PLT counts, and Bb levels were positively correlated with AST, ALT and LDH activities. In the patient group, serum Bb levels were negatively correlated with WBC and PLT counts.

CONCLUSIONS

The results of the present study suggest that increased activity of the alternative pathway of the complement system in children with CCHF may have a role in the pathogenesis of the disease.

Role of matrix metalloproteinases and tissue inhibitor of matrix metalloproteinases-1 in Crimean-Congo hemorrhagic fever disease

AIM

Crimean-Congo hemorrhagic fever is a potentially fatal viral disease in humans caused by CCHF virus. We aimed to demonstrate change in serum levels of matrix metallopeinase/tissue matrix metalloproteinase inhibitor (MMP/TIMP) associated with CCHF.

PATIENTS AND METHODS

Blood specimens were collected in acute and convalescence periods from the patients presented to Cumhuriyet University Hospital, Department of Emergency and Infection Diseases with presumed as CCHF between May 2010 and September 2010. Forty-one age and gender matched healthy individuals had not any viral, bacterial, acute or chronic disease were enrolled as the controls. Blood specimens were centrifuged at 4000 rpm for 5 min with in "Hettich universal 32" centrifuge. Serum samples obtained were kept at -80°C. All the specimens were brought to room temperature during the study and MMP-1, 2, 7, 9, 10 and TIMP-1 tests were studied at one time using "RayBiotech" brand kit in "Grifols" brand "Triturus" model ELISA device. Acute, convalescence and control groups were compared in terms of the serum levels of MMP-1, 2, 7, 9, 10 and TIMP-1.

RESULTS

There was a statistically significant increase in serum levels of MMP-1, 7, 9, 10 and TIMP-1 in the convalescence period (p < 0.05) compared to the controls, while the increase in levels of MMP-2 was not statistically significant (p > 0.05). In acute period of CCHF, mean TIMP-1 levels of severe patients was significantly lower than that of the non-severe patients (207913 ± 31051 versus 231300 ± 13267, respectively, p = 0.023).

CONCLUSIONS

High serum levels of MMP and TIMP in CCHF disease were found to decrease as progressed to convalescence from the acute period. It is thought MMP and TIMP plays a significant role in pathogenesis of CCHF.

Relationship between total thiol status and thrombocytopenia in patients with Crimean-Congo hemorrhagic fever

The objective of this study was to investigate the relationship between serum total thiol level and total oxidant status (TOS) and thrombocytopenia among patients with Crimean-Congo hemorrhagic fever (CCHF). Eighty-three subjects and 56 controls were enrolled in the study. Thiol levels were measured with the DTNB method and TOS was measured with the Erel's method among subjects and controls. Thiol levels were lower in subjects than controls and TOS levels were higher in subjects than controls. There was a significant correlation between total thiol levels and platelet counts (r = 0.84, p < 0.0001) among subjects. Further investigations are needed into the link between total thiol level and TOS and the pathogenesis of hemorrhage in CCHF.

[Detection of Crimean-Congo hemorrhagic fever virus RNA in the hyalomma marginatum ticks taken from bitten people]

Among 1076 imagoes of the Hyalomma marginatum ticks taken from bitten people in the Astrakhan Region in 2006-2010, 10 (0.9%) ticks contained Crimean-Congo hemorrhagic fever (CCHF) virus RNA, as evidenced by RT-PCR. The diagnosis of CCHF was made on the basis of clinical data and the results of examination of sera in RT-PCR, ELISA-IgM, and ELISA-IgA in three of the 10 persons bitten by infected ticks. Two more patients were observed to have acute febrile diseases, but their sera were not examined in RT-PCR and ELISA, so their etiological association with CCHF virus RNA was not reliably established.

Evaluation of respiratory findings in Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic disease with a high mortality rate causing viral hemorrhagic fever. We studies the respiratory system findings, demographics, clinical and laboratory findings of patients with CCHF admitted to our hospital. In this retrospective study we evaluated 108 patients with CCHF confirmed by laboratory findings. The charts of all hospitalized patients were reviewed, and the age, sex, occupation, city of residence, history of tick bite or of removing a tick, smoking history, chest X-ray results, outcome and clinical and laboratory findings were recorded for each patient. Sixty of the chest radiographs were read as normal, 33 were read as showing unilateral pathology and 15 showed bilateral pathology. Seven of the 108 patients died due to severe pulmonary infection and hemorrhage. The frequency of pathological chest radiographs was higher among the CCHF patients who died than among the survivors, but the difference was not significant. Pulmonary parenchyma hemorrhage can occur in CCHF patients with hemoptysis, dyspnea, chest pain and infiltration on chest radiographs and may lead to morality.

[A case of Crimean-Congo hemorrhagic fever in the Anapa District, Krasnodar Territory]

The paper gives information on the first case of Crimean-Congo hemorrhagic fever detected in a female resident of the Anapa District, Krasnodar Territory, in 2005 in the past 57 years.

[PHOSPHAN microplate technology-based microarray for the determination of IgG antibodies against West Nile and Crimean-Congo hemorrhagic fever viruses]

The paper demonstrates it possible to work out a phosphorescence analysis (PHOSPHAN) microplate technology-based microarray for concurrently examining human sera and detection of their specific IgG antibodies against two heterological West Nile and Crimean-Congo hemorrhagic fever viruses. The sensitivity and specificity of the microarray were comparable with those of enzyme immunoassay with separate sample testing. The advantages of PHOSPHAN were associated with the microplate format of an immunoassay and its enhanced multiplexity, which may contribute to the lower cost of clinical sample testing.

Viral load as a predictor of outcome in Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal disease affecting multiple organ systems. To determine the association between viral load and severity of CCHF infection, quantitative measurement of CCHF virus was performed using 1-step reverse-transcriptase polymerase chain reaction for 36 patients with CCHF infection. Viral loads ranged from 1.1x10(3) copies/mL to > or = 9.9x10(9) copies/mL. Nine (25%) of 36 patients died. In 8 of the 9 patients with fatal outcomes, viral loads were detected that were > or = 1x10(9) copies/mL, whereas in 25 of the 26 patients with nonfatal outcomes, viral loads were detected that were < 1x10(9) copies/mL (P<.001). A viral load > or = 1x10(9) RNA copies/mL can be considered to predict a fatal outcome with a positive predictive value of 80%, with 88.9% sensitivity and 92.6% specificity. We suggest that viral load is a measure of the severity of CCHF.

[ELISA and PCR test systems used to detect Crimean-Congo hemorrhagic fever virus]

Studying the sensitivity and specificity of enzyme-linked immunosorbent assay (ELISA) for the indication of Crimean-Congo hemorrhagic fever (CCHF) virus antigens and those of reverse transcription and polymerase chain reaction (RT-PCR) for the detection of CCHF virus RNA, and those of a intercerebral infection method in newborn albino mice systems for the determination of viral infectious activity established that the sensitivity of ELISA was 1-2 orders of magnitude less than that of RP-PCR. The latter proved to be better in studying the sera sampled from patients with CCHF. The results of studying the samples of H. marginatum ticks, the CCHF virus vectors by ELISA and RT-PCR were similar.

Plasma activity of thrombin activatable fibrinolysis inhibitor in Crimean-Congo hemorrhagic fever

OBJECTIVES

Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal viral infection. The exact mechanism for hemorrhage remains unknown. Thrombin activatable fibrinolysis inhibitor (TAFI) is a plasma procarboxypeptidase B-like proenzyme and synthesized in the liver, down-regulating fibrinolysis. In this study, we measured the TAFI activity in plasma of patients with CCHF to examine the relationship between hemorrhage and the pathogenesis of CCHF.

METHODS

Twenty-one patients and similar number of controls were included in the study. The diagnosis of CCHF was confirmed through detection of IgM by ELISA and/or PCR. TAFI activity was measured in plasma samples.

RESULTS

TAFI activity in CCHF patient group was mean 7.2+/-2.3 microg/ml (range: 0.95-10.31 microg/ml) and in the control group was mean 11.7+/-4.1 microg/ml (range: 3.07-23.9 microg/ml). There was a significant decrease of TAFI activity in CCHF patients when compared to controls. A positive correlation between CRP, PT, INR, serum albumin and TAFI activity levels were found. We suggest that the decrease of TAFI activity may be due to liver dysfunction during viral active disease state.

CONCLUSIONS

Low TAFI activity may be an attributable factor, leading to imbalance in fibrinolysis, resulting in bleeding complications in CCHF.

Analysis of risk-factors among patients with Crimean-Congo haemorrhagic fever virus infection: severity criteria revisited

The aim of this study was to determine the predictors of mortality among patients infected with Crimean-Congo haemorrhagic fever (CCHF) virus. Among patients with acute febrile syndrome, characterised by malaise, bleeding, leukopenia and thrombocytopenia, who were admitted to hospital during the spring and summer of 2002-2004, 54 had positive IgM and/or PCR results for CCHF virus in blood or tissue. The overall case fatality rate was 7.4%. Among the fatalities, haematemesis (p 0.009), melaena (p 0.001) and somnolence (p 0.022) were more common, the median platelet count was significantly lower (10,600/mL vs. 20,000/mL; p 0.038), the mean prothrombin time (27 s vs. 16 s; p 0.002) and mean activated partial thromboplastin time (73 s vs. 44 s; p < 0.001) were longer, and the mean alanine transferase (ALT) level (1,125 vs. 331; p < 0.001), the mean aspartate transferase (AST) level (3,118 vs. 913; p 0.004) and the mean fibrinogen level (119 vs. 340; p 0.012) were higher. Serum IgM and IgG against CCHF virus was detected in 25% and 0%, respectively, of fatal cases, compared with 94% and 62%, respectively, of cases with favourable outcomes. Oral ribavirin was prescribed to 22 (41%) patients. Of the four fatal cases, it was the intention to prescribe ribavirin to three patients, but this was not possible because of haematemesis and melaena. Higher levels of AST (>or= 700 U/L) and ALT (>or= 900 U/L) are suggested for use as severity criteria. Oral ribavirin was not effective for patients with haematemesis, and intravenous ribavirin is necessary for treatment of CCHF.

Novel one-step real-time RT-PCR assay for rapid and specific diagnosis of Crimean-Congo hemorrhagic fever encountered in the Balkans

Early and accurate diagnosis of Crimean-Congo hemorrhagic fever (CCHF) is essential for the treatment and outcome of the disease and prevention of its further transmission. Molecular-based diagnostic assays now serve as the front-line tool in the diagnosis of CCHF. However, the development of real-time RT-PCR assay for the detection of Crimean-Congo hemorrhagic fever virus (CCHFV) has been hampered by a virus strain variation. The development of a one-step real-time RT-PCR assay for the detection of CCHFV is described herein. The technique is based on the fluorescence resonance energy transfer probe technology employing the endonuclease activity of Taq polymerase enzyme. The assay was designed to detect specifically the strains from a phylogenetic cluster of CCHFV which encompasses the known CCHFV strains circulating in the Balkan region. The detection system was tested using CCHFV strain Kosovo Hoti, clinical serum samples and ticks. The real-time assay described is rapid, specific and sensitive. Since the Balkan peninsula is also an endemic region for hemorrhagic fever with renal syndrome (HFRS), this method is suggested as convenient for early differential diagnosis of suspected viral hemorrhagic fever patients.

Rapid and quantitative detection of Crimean-Congo hemorrhagic fever virus by one-step real-time reverse transcriptase-PCR

In this article, the development of a new TaqMan-based one-step real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay for detection and quantification of Crimean-Congo hemorrhagic fever virus (CCHFV) RNA is described. Selected oligos targeting the highly conserved S region of CCHFV were designed by using our oligo design and analysis software, Oligoware 1.0. None of the primer sequences showed genomic cross-reactivity with other viruses or cells in a BLAST (NCBI) search analysis. The sensitivity and specificity of the primers and the probe were tested using 18 serum samples from patients from East Anatolian who were suspected of having CCHFV, including 2 samples that had already been confirmed to be positive for CCHFV. Among the 16 previously unconfirmed samples, 5 were positive by TaqMan-based one-step real-time RT-PCR and 1 was positive by non-nested RT-PCR, and these results were confirmed with DNA sequencing analysis. The 2 previously confirmed CCHFV RNA samples were also positive by both TaqMan-based one-step real-time RT-PCR and non-nested RT-PCR tests. To ensure the quantitative reproducibility of TaqMan-based one-step real-time RT-PCR, the procedure was repeated several times and the same results were obtained (SD = 0.84 [maximum value]). The developed assay was able to sensitively quantify the concentration of CCHFV RNA, which ranged from 10(2) to 10(7) copies/ml per reaction, using plasmid standards generated from the CCHFV RNA (correlation coefficiency = 0.989). The results of the one-step real-time RT-PCR assay were more sensitive than those of the non-nested RT-PCR assay. It can be concluded that our one-step real-time RT-PCR assay is a reliable, reproducible, specific, sensitive and simple tool for the detection and quantification of CCHFV.

[Circulation of Crimean-Congo hemorrhagic fever virus in the Stavropol territory in the seasons of 1999-2000]

After the prolonged (about 30 years) absence of Crimean-Congo hemorrhagic fever (CCHF) morbidity in the Stavropol territory cases of this infection were registered, and received laboratory confirmation, in summer of 1999-2000. At the end of the 1999 season antibodies to CCHF virus were detected among cattle-breeders in all 7 inspected regions of the territory. According to the data of the determination of virus contamination of Ixodes ticks (the season of 2000), the circulation of CCHF on the territory of 14 regions out of 24 expected was established. An essential factor of the exacerbation of the epidemic situation was a rise in the number of Hyalomma marginatum ticks, the main vector of the causative agent of CCHF in the south of Russia.

Crimean-Congo haemorrhagic fever outbreak in Middle Anatolia: a multicentre study of clinical features and outcome measures

A Crimean-Congo haemorrhagic fever (CCHF) outbreak emerged from 2001 to 2003 in the Middle Anatolia region of Turkey. This study describes the clinical characteristics and outcome features of CCHF patients admitted to four tertiary care hospitals in Turkey. Definitive diagnosis was based on the detection of CCHF virus-specific IgM by ELISA or of genomic segments of the CCHF virus by RT-PCR. Related data were collected by a retrospective chart review. Hospital costs were extracted from the final discharge bills. Univariate and multivariate analyses were conducted to determine the independent predictors of mortality. CCHF virus-specific antibodies or genomic segments were detected in the sera of 99 cases. Seven cases that were treated with ribavirin were excluded from the study. Cases were mostly farmers (83 cases, 90 %), and 60 % had a tick-bite history before the onset of fever. Impaired consciousness and splenomegaly were independent predictors of a fatal outcome.

Characteristics of Patients with Crimean-Congo Hemorrhagic Fever in a Recent Outbreak in Turkey and Impact of Oral Ribavirin Therapy

We describe the epidemiological, clinical, and laboratory findings and the role of ribavirin therapy for 35 patients who received a diagnosis of Crimean-Congo hemorrhagic fever (CCHF). All patients had immunoglobulin M antibodies and/or PCR results positive for CCHF virus in blood or tissue specimens. Eighty-six percent of the patients were considered to have severe cases of CCHF. The overall case-fatality rate was 2.8%. Eight patients were given ribavirin, and all 8 survived. We suggest using ribavirin to treat patients with CCHF, particularly those with severe cases.

[Laboratory diagnostics of Crimean hemorrhagic fever by polymerase chain reaction]

Our group developed, within the present case study, two techniques' variations, i.e. a single-step RT-PCR and nested RT-PCR assays, for the purpose of detecting the Crimean-Congo hemorrhagic fever RNA virus in human samples. The above assays as well as those previously recommended by the Ministry of Health of the Russian Federation were simultaneously used in 14 clinical samples obtained from patients with Crimean hemorrhagic fever. After assessing the detection accuracy, it was found that the developed-by-us test system displayed the same or even better diagnostic values versus the previously recommended nested RT-PCR and a 1000-fold advantage over the previously recommended single-step RT-PCA. The single-step RT-PCR assay variation is always more preferable in sense of technical and economic motivations. Finally, the test system developed by us has every reason to become the method of choice in routine PCR diagnosis of Crimean hemorrhagic fever after all official trials and approvals are duly complied with.

[Serologic studies of Xinjiang hemorrhagic fever in Bachu county, 2001]

OBJECTIVE

To investigate the situation of Xinjiang hemorrhagic fever (XHF) in patients who have been diagnosed as XHF by clinical methods and to predict the condition in people who were liable to infection and in the host-animals.

METHODS

Sera collected from XHF patients and some peasants under the risk of contracting the disease, followed by checking the specific antibody against XHF with IgG-ELISA and IgM capture ELISA, and XHF viral antigen with antigen capture ELISA. In addition, 80 sheep/goats serums were collected from two places where there were more XHF cases and specific IgG antibody against XHF checked by ELISA method.

RESULTS

Positive rate of IgG and IgM antibodies were 39.62% (21/53) and 20.75% (11/53) respectively in the serums of patients; one patient's serum showed XHFV antigen positive by antigen capture ELISA. IgG antibody positive rate for peasants' sera was 21.05% (4/19), but IgM antibody detection showed negative for all sera. In sera from 80 sheep and goats, 70% (56/80) showed IgG positive.

CONCLUSION

Results showed that XHF broke out in Bachu county from April to June 2001 while recessive infection of the disease remained serious.

[Laboratory diagnostics of the outbreak of Crimean haemorrhagic fever in Southern Russia]

The results of the serological analysis of blood sera taken from patients with Crimean haemorrhagic fever (CHF) and from persons suspected for this disease are presented. These results made it possible to confirm that during the period of April 16-September 04, 2000, the outbreak of CHF occurred on the territory of Southern Russia. In addition to the laboratory confirmation of the outbreak of CHF by means of the enzyme immunoassay and the indirect immunofluorescence test the diagnostic work was completed by the isolation, and subsequent identification, of 3 strains of CHF virus from the blood of patients and 1 strain from the pool of ticks Hyalomma marginatum.

[Clinico-epidemiological characterization of Crimean haemorrhagic fever in Stavropol' region]

The clinico-epidemiological analysis of morbidity in Crimean haemorrhagic fever in the Stavropol Territory is presented. Information on the clinical features, epidemiological characteristics and diagnostic criteria of the disease, as well as trends in its treatment, is given.

The use of a reverse transcription-polymerase chain reaction for the detection of viral nucleic acid in the diagnosis of Crimean-Congo haemorrhagic fever

A reverse transcription-polymerase chain reaction (RT-PCR) was applied retrospectively to 80 stored serum samples from 45 confirmed Crimean-Congo haemorrhagic fever (CCHF) patients in southern Africa, and it was found that viral RNA could be detected in a proportion of samples up to day 16 of illness. Early in the disease there is relatively good correlation between the results obtained by RT-PCR and virus isolation, but after the first week it appears that infective virus is progressively cleared from serum while nucleic acid remains demonstrable in a proportion of patients well into convalescence. A further 47 serum samples from 38 patients with suspected viral haemorrhagic fever, 19 of whom proved to be cases of CCHF, were tested prospectively on being received at the laboratory. The combined use of RT-PCR with ethidium bromide stained gels for the detection of viral RNA, plus indirect immunofluorescence for the detection of IgG and IgM antibodies to CCHF virus, permitted a presumptive diagnosis to be reported within 8 h of receiving the first specimen from 18/19 cases of the disease studied prospectively. The nineteenth case was confirmed within 48 h when antibody response was demonstrated in a second serum sample. Viral nucleic acid was not detected in serum samples from 19 patients in whom alternative diagnoses were established.

Detection of human antibodies to Crimean-Congo haemorrhagic fever virus using expressed viral nucleocapsid protein

Diagnosis of Crimean-Congo haemorrhagic fever (CCHF) virus infections is hampered by the problems of handling this human pathogen, which requires the highest levels of biological containment. Recombinant antigens were examined for their potential as non-hazardous diagnostic reagents. The nucleocapsid (N) gene of the Greek AP92 isolate of CCHF virus was sequenced from cloned PCR products and the open reading frame was identified by homology to the N protein of a Chinese isolate of CCHF virus. The N protein was expressed to high levels in a baculovirus expression system. Three N protein-derived peptides were expressed in Escherichia coli as fusions with glutathione S-transferase and the antigenicities of these proteins and the baculovirus-expressed protein were tested by ELISA. When tested with laboratory animal sera representing all seven serogroups of nairoviruses, the only reactive sera were those raised to CCHF virus (Greek, Nigerian and Chinese isolates) and, more weakly, Hazara virus. When tested with a panel of known positive and negative human sera, the baculovirus-expressed N protein, and the peptide derived from the central region of the N protein, proved to be the best for identifying CCHF virus-specific IgG.

The clinical pathology of Crimean-Congo hemorrhagic fever

Observations were made of 15 fatal and 35 nonfatal Crimean-Congo hemorrhagic fever (CCHF) infections diagnosed from February 1981 to March 1987 in Kimberly and Sandringham, Republic of South Africa. Following an incubation period of 2-9 days after exposure to infection, patients had a sudden onset of disease with fever, nausea, severe headache, and myalgia. Petechial rash and hemorrhagic signs such as epistaxis, hematemesis, and melena supervened on days 3-6 of illness. Deaths occurred on days 5-14 of illness. Patients with fatal infections had thrombocytopenia and markedly elevated levels of serum aspartate and alanine aminotransaminases, gamma-glutamyltransferase, lactic dehydrogenase, creatine kinase, bilirubin, creatinine, and urea. Total protein, albumin, fibrinogen, and hemoglobin levels were depressed. Values for prothrombin ratio, activated partial thromboplastin time, thrombin time, and fibrin degradation products were grossly elevated, findings that indicate the occurrence of disseminated intravascular coagulopathy. Many of the clinical pathologic changes were evident at an early stage of the disease and had a highly predictive value for fatal outcome of infection. Changes were present but less marked in nonfatal infections.

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part III. Clinical pathology and pathogenesis

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in 8 patients; 7 were staff members at Tygerberg Hospital who had been infected by a patient in whom the disease had not initially been diagnosed. Two patients, the initial case and a staff member, died and 4 became seriously ill. The immunopathogenesis of CCHF appears to be multifactorial. Certain features were common to all patients--leucopenia, thrombocytopenia, elevated liver enzyme values and low serum total protein levels. Ultrastructural changes in and around skin capillaries, including intracytoplasmic endothelial tuboreticulated bodies, were found. Virus-like particles were found on electron microscopy. Important individual factors related to prognosis were identified. The patients who survived all mounted a good antibody response, and manifested no coagulation defect extensive enough to explain the haemorrhagic tendency. In the patients who died no evidence of antibody production was detected; both developed diffuse intravascular coagulation and in 1 evidence of immune complex formation and complement consumption was found. Hepatorenal failure and cardiovascular collapse characterized the terminal period. Early clinical recognition of CCHF with specific attention to factors amenable to treatment may vastly improve the prognosis.

Congo/Crimean haemorrhagic fever in Iraq: a seroepidemiological survey

A seroepidemiological survey to determine the prevalence of Congo/Crimean haemorrhagic fever virus activity in Iraq was carried out during 1979 and 1980. Sera were collected from 1680 people including contacts of known patients, abattoir workers and animal husbandry workers in various parts of the country. These were tested by complement fixation and agar gel precipitin tests. Among patients' relatives and contacts, 29% had antibodies to Congo/Crimean haemorrhagic fever; 11% of hospital staff, 7% of abattoir workers and 29% of those engaged in animal husbandry had antibodies. Inapparent infections were common in hospital staff caring for patients known to have had the disease. No antibodies were detected in the sera of 151 people who were not believed to have had contact with a known case of the disease.