Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Onder Ergonul is active.

Publication


Featured researches published by Onder Ergonul.


Lancet Infectious Diseases | 2006

Crimean-Congo haemorrhagic fever

Onder Ergonul

Summary Crimean-Congo haemorrhagic fever (CCHF) is an often fatal viral infection described in about 30 countries, and it has the most extensive geographic distribution of the medically important tickborne viral diseases, closely approximating the known global distribution of Hyalomma spp ticks. Human beings become infected through tick bites, by crushing infected ticks, after contact with a patient with CCHF during the acute phase of infection, or by contact with blood or tissues from viraemic livestock. Clinical features commonly show a dramatic progression characterised by haemorrhage, myalgia, and fever. The levels of liver enzymes, creatinine phosphokinase, and lactate dehydrogenase are raised, and bleeding markers are prolonged. Infection of the endothelium has a major pathogenic role. Besides direct infection of the endothelium, indirect damage by viral factors or virus-mediated host-derived soluble factors that cause endothelial activations and dysfunction are thought to occur. In diagnosis, enzyme-linked immunoassay and real-time reverse transcriptase PCR are used. Early diagnosis is critical for patient therapy and prevention of potential nosocomial infections. Supportive therapy is the most essential part of case management. Recent studies suggest that ribavirin is effective against CCHF, although definitive studies are not available. Health-care workers have a serious risk of infection, particularly during care of patients with haemorrhages from the nose, mouth, gums, vagina, and injection sites. Simple barrier precautions have been reported to be effective. Summary Crimean-Congo haemorrhagic fever (CCHF) is an often fatal viral infection described in about 30 countries, and it has the most extensive geographic distribution of the medically important tickborne viral diseases, closely approximating the known global distribution of Hyalomma spp ticks. Human beings become infected through tick bites, by crushing infected ticks, after contact with a patient with CCHF during the acute phase of infection, or by contact with blood or tissues from viraemic livestock. Clinical features commonly show a dramatic progression characterised by haemorrhage, myalgia, and fever. The levels of liver enzymes, creatinine phosphokinase, and lactate dehydrogenase are raised, and bleeding markers are prolonged. Infection of the endothelium has a major pathogenic role. Besides direct infection of the endothelium, indirect damage by viral factors or virus-mediated host-derived soluble factors that cause endothelial activations and dysfunction are thought to occur. In diagnosis, enzyme-linked immunoassay and real-time reverse transcriptase PCR are used. Early diagnosis is critical for patient therapy and prevention of potential nosocomial infections. Supportive therapy is the most essential part of case management. Recent studies suggest that ribavirin is effective against CCHF, although definitive studies are not available. Health-care workers have a serious risk of infection, particularly during care of patients with haemorrhages from the nose, mouth, gums, vagina, and injection sites. Simple barrier precautions have been reported to be effective.


Clinical Infectious Diseases | 2004

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

Onder Ergonul; Aysel Celikbas; Basak Dokuzoguz; Şebnem Eren; Nurcan Baykam; Harika Esener

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.


The Journal of Infectious Diseases | 2006

Evaluation of Serum Levels of Interleukin (IL)–6, IL-10, and Tumor Necrosis Factor–α in Patients with Crimean-Congo Hemorrhagic Fever

Onder Ergonul; Semra Tuncbilek; Nurcan Baykam; Aysel Celikbas; Basak Dokuzoguz

We investigated the role played by cytokines in the mortality of patients with Crimean-Congo hemorrhagic fever (CCHF). Serum levels of several cytokines were measured in 3 patients with fatal CCHF and in 27 patients with nonfatal CCHF. Levels of interleukin (IL)-6 (P< or = .001) and tumor necrosis factor (TNF)-alpha (P = .004) were significantly higher in patients with fatal CCHF than in patients with nonfatal CCHF, whereas levels of IL-10 were not significantly different between the 2 groups (P = .937). Disseminated intravascular coagulation (DIC) scores were also higher in the patients with fatal CCHF (P = .023). Levels of IL-6 and TNF-alpha were positively correlated with DIC scores, whereas levels of IL-10 were negatively correlated with DIC scores. In conclusion, these findings demonstrate that proinflammatory cytokines play a major role in the mortality of patients with CCHF.


Eurosurveillance | 2010

Crimean-Congo hemorrhagic fever in Europe: current situation calls for preparedness.

Helena C. Maltezou; L. Andonova; R Andraghetti; Michèle Bouloy; Onder Ergonul; Frans Jongejan; N. Kalvatchev; Stuart T. Nichol; Matthias Niedrig; A. Platonov; Gail Thomson; Katrin Leitmeyer; Hervé Zeller

During the last decade Crimean-Congo hemorrhagic fever (CCHF) emerged and/or re-emerged in several Balkan countries, Turkey, southwestern regions of the Russian Federation, and the Ukraine, with considerable high fatality rates. Reasons for re-emergence of CCHF include climate and anthropogenic factors such as changes in land use, agricultural practices or hunting activities, movement of livestock that may influence host-tick-virus dynamics. In order to be able to design prevention and control measures targeted at the disease, mapping of endemic areas and risk assessment for CCHF in Europe should be completed. Furthermore, areas at risk for further CCHF expansion should be identified and human, vector and animal surveillance be strengthened.


Current Opinion in Virology | 2012

Crimean–Congo hemorrhagic fever virus: new outbreaks, new discoveries

Onder Ergonul

Crimean-Congo hemorrhagic fever (CCHF) is a fatal viral infection described in Asia, Africa and Europe. Humans become infected through the bites of ticks, by contact with a patient with CCHF during the acute phase of infection, or by contact with blood or tissues from viremic livestock. The occurrence of CCHF closely approximates the known world distribution of Hyalomma spp. ticks. The novel studies of phylogenetic analyses reveal the interesting relations between the strains from distant outbreaks. The clinical features show common dramatic progress characterized by hemorrhage, myalgia, and fever. Besides the direct infection of endothelium, indirect damage by viral or virus mediated host-derived soluble factors that cause endothelial activations and dysfunction occur. In diagnosis, enzyme linked immunoassay and real-time reverse transcription-polymerase chain reaction are used. Early diagnosis is critical for the patient and potential nosocomial infections. Supportive therapy is the essential part of the case management. Ribavirin was suggested as an effective drug in recent studies, and it was found to be beneficial. The health care workers are under serious risk of transmission of the infection, particularly during the follow-up of the patient, with hemorrhages from the nose, mouth, gums, vagina, and injection sites.


BMC Infectious Diseases | 2009

The first clinical case due to AP92 like strain of Crimean-Congo Hemorrhagic Fever virus and a field survey

Kenan Midilli; Aysen Gargili; Onder Ergonul; Murat Elevli; Sevgi Ergin; Nesrin Turan; Gönül Şengöz; Recep Ozturk; Mehmet Bakar

BackgroundCrimean-Congo Hemorrhagic Fever (CCHF) is a fatal infection, but no clinical case due to AP92 strain was reported. We described the first clinical case due to AP92 like CCHFV.MethodsA case infected by a AP92 like CCHFV was detected in Balkanian part of Turkey. Diagnosis was confirmed by RT-PCR and sequencing. A human serologic and tick survey studies were performed in the region, where the case detected.ResultsThirty eight individuals out of 741 were found to be anti CCHFV IgM positive. The attack rate for overall CCHFV was calculated as 5.2%. In univariate analyses, CCHFV IgM positivity was found to be associated with the age (p < 0.001), male gender (p = 0.001), agricultural activity (p = 0.036), and history of tick bite (p = 0.014). In multivariate analysis, older age (OR: 1.03, CI:1.01–1.05, p < 0.001), male gender were found to be the risk factors (OR: 2.5, CI:1.15–5.63, p = 0.020) for CCHFV infection.ConclusionThis is the first human case with AP92 like CCHFV infection. Furthermore, this is the first report of AP92 like strain in Turkey. In the region, elderly males carry the highest risk for CCHFV infection.


Clinical Infectious Diseases | 2013

Neurobrucellosis: Clinical and Diagnostic Features

Tumer Guven; Kenan Ugurlu; Onder Ergonul; Aysel Celikbas; Sebnem Eren Gok; Selçuk Çomoğlu; Nurcan Baykam; Basak Dokuzoguz

BACKGROUND We describe the neurological involvement in brucellosis and revisited diagnostic criteria for neurobrucellosis. METHODS Patients with laboratory-confirmed brucellosis who were consequently hospitalized were observed prospectively in a brucellosis-endemic region. The neurobrucellosis was diagnosed by any one of the following criteria: (1) symptoms and signs consistent with neurobrucellosis; (2) isolation of Brucella species from cerebrospinal fluid (CSF) and/or presence of anti-Brucella antibodies in CSF; (3) the presence of lymphocytosis, increased protein, and decreased glucose levels in CSF; or (4) diagnostic findings in cranial magnetic resonance imaging or CT. RESULTS Lumbar puncture was performed in 128 laboratory-confirmed brucellosis cases who had neurological symptoms and signs, and 48 (37.5%) were diagnosed as neurobrucellosis. The sensitivity of tube agglutination (TA) in CSF was 0.94, specificity 0.96, positive predictive value 0.94, and negative predictive value 0.96. Brucella bacteria were isolated from CSF in 7 of 48 patients (15%). The mean age of 48 neurobrucellosis patients was 42 years (SD, 19 years), and 16 (33%) were female. The most common neurological findings were agitation (25%), behavioral disorders (25%), muscle weakness (23%), disorientation (21%), and neck rigidity (17%). Cranial nerves were involved in 9 of 48 patients (19%). One patient was left with a sequela of peripheral facial paralysis and 2 patients with sensorineural hearing loss. CONCLUSIONS Patients with severe and persistent headache and other neurologic symptoms and signs should be considered for neurobrucellosis in endemic regions and to possibly receive longer therapy than 6 weeks. Brucella TA with Coombs test in CSF is sensitive and specific by using a cutoff of ≥1:8.


Clinical and Vaccine Immunology | 2002

Widal Test in Diagnosis of Typhoid Fever in Turkey

Ayse Willke; Onder Ergonul; Banu Bayar

ABSTRACT We studied the value of the Widal tube agglutination test for the diagnosis of typhoid fever. The subjects were all adults >18 years of age and were divided into four groups: (i) 317 healthy blood donor controls, (ii) 31 bacteriologically confirmed patients with Salmonella enterica serotype Typhi, (iii) 21 patients with a clinical diagnosis of typhoid fever, and (iv) 41 febrile nontyphoid patients. Blood donor controls were screened with a slide agglutination test for the Salmonella enterica serotype Typhi O and H antigens, and positives were then tested with the Widal test. Acute- and convalescent-phase sera from patients in groups 2, 3, and 4 were obtained 7 to 10 days apart and tested by the Widal test. Using a cutoff of ≥1/200 for the O antigen test performed on acute-phase serum gave a sensitivity of 52% and a specificity of 88% with a positive predictive value (PPV) of 76% and a negative predictive value (NPV) of 71%. This increased to 90% sensitivity and specificity with a PPV of 88% and an NPV of 93% when the convalescent-phase serum was tested. We concluded that O and H agglutinin titers of ≥1/200 are of diagnostic significance. The Widal test is easy, inexpensive, and relatively noninvasive. It can be of diagnostic value when blood cultures are not available or practical. The results must be interpreted cautiously because of the low sensitivity of the test. The Widal test done on convalescent-phase serum gave more-reliable results with higher specificity and sensitivity.


International Journal of Antimicrobial Agents | 2003

Evaluation of antibiotic use in a hospital with an antibiotic restriction policy

Ayşe Erbay; Aylin Çolpan; H. Bodur; Mustafa Aydin Cevik; Matthew H. Samore; Onder Ergonul

The study was designed to evaluate rational antibiotic use in relation to diagnosis and bacteriological findings. All hospitalized patients who received antibiotics were evaluated by a cross-sectional study. Of the 713 patients hospitalized, 281 (39.4%) patients received 377 antibiotics. Among 30 different antibiotics the most frequently requested were first generation cephalosporins (19.9%), ampicillin-sulbactam (19.1%) and aminoglycosides (11.7%). Antibiotic use was appropriate in 64.2% of antibiotic requests. In analysis of appropriate use, a request after an infectious diseases consultation was a frequent reason (OR=14, P<0.001, CI=0.02-0.24). Antibiotics requested in conjunction with susceptibility results were found to be more appropriate than those ordered empirically (OR=4.5, P=0.017, CI=0.06-0.76). Inappropriate antibiotic use was significantly higher among unrestricted antibiotics than restricted ones (P<0.001). Irrational antibiotic use was high for unrestricted antibiotics. Additional interventions such as postgraduate training programmes and elaboration of local guidelines could be beneficial.


Journal of Clinical Virology | 2010

Crimean-Congo hemorrhagic fever in children

Hasan Tezer; Iclal Ayrancı Sucaklı; Tulin Revide Sayli; Elif Celikel; Ibrahim Yakut; Ates Kara; Bahattin Tunç; Onder Ergonul

Abstract Background Crimean-Congo hemorrhagic fever (CCHF) virus causes a severe disease in humans with a mortality up to 30%. In Turkey there has been an increase in the number of cases during years since 2002. Humans of all ages living in endemic areas,especially those who are working as shepherds and toddlers, have high risk of acquiring CCHF. Objectives The epidemiological, clinical, and laboratory characteristics of the children, who were diagnosed as Crimean-Congo hemorrhagic fever (CCHF) were described. Study design The children infected with CCHF virus between April 2008 and October 2009, and hospitalised in Ankara Dışkapı Childrens and Research Hospital were included. Results Laboratory diagnosis was set by detection of CCHF IgM antibodies and/or genetic detection of CCHF virus. Thirtyone cases included to the study, and all were from the northeastern Anatolia and the southern parts of Black sea region. The mean age was 9.45±4.9 years, the proportion of females was 38.7%. The majority (87%) of the cases had the history of tick bite. There was no fatal case. All the patients had the history of fever. Malaise,tonsillopharyngitis, nausea-vomiting, headache, diarrhea, myalgia and rash were the most common symptoms. The mean AST and ALT levels on the admission were 116 (range 25–389) and 61 (range 8–180)U/L respectively. The mean platelet count on admission was 125,000/mm3, and the lowest was 23,000/mm3. The mean of the lowest white blood cell count was 2353/mm3 and the mean of the highest lactate dehydrogenase was 861IU/L. Conclusions The clinical course of CCHF among children seems to be milder than in adults. Tonsillopharyngitis is a common symptom among children with CCHF.

Collaboration


Dive into the Onder Ergonul's collaboration.

Top Co-Authors

Avatar

Basak Dokuzoguz

Turkish Ministry of Health

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Tumer Guven

Yıldırım Beyazıt University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge