key: cord-0897507-5znxj65e
authors: Pazarlı, Ahmet Cemal; Parlak, Zafer; Ekiz, Timur
title: COVID-19 and Crimean Congo Hemorrhagic Fever: Similarities and Differences
date: 2020-06-03
journal: Heart Lung
DOI: 10.1016/j.hrtlng.2020.05.013
sha: 86c31d4e781269898e54e02fc2a49e01c00fbd82
doc_id: 897507
cord_uid: 5znxj65e

nan

The diagnosis of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pneumonia, i.e., COVID-19 pneumonia, is confirmed with the patient's history, clinical manifestation, imaging characteristics as well as laboratory tests. Herein, high-resolution computed tomography (CT) has taken much more attention in the diagnosis of COVID-19 particularly in polymerase chain reaction (PCR) negative patients. Multiple patchy groundglass opacities (bilaterally and multi-lobular) with peripheral involvement are the typical CT finding (1). However, the diagnosis can sometimes bechallenging if the medical history is inconclusive. Besides, CT findings (patchy ground opacities) can be seen in various conditions such as heart failure, rheumatic diseases, interstitial lung disease, other types of viral pneumonia, and Crimean-Congo Hemorrhagic Fever (CCHF) (2) . Herewith, after the novel coronavirus outbreak, the questions as regards who should be applied to PCR tests or CT examination and how the findings should be interpretedremains a debate. Therefore, we deem it important to compare the CT findings of COVID-19 and CCHF. We believe that defining the similarities and differences of COVID-19 and CCHF will guide physicians particularly in endemic countries of CCHF.

SARS-CoV-2 is an enveloped, positive-sense, and single-stranded RNA virus of ~30 kb, and is classified to β coronaviruses. On the other hand, the CCHF,caused by a single-strand enveloped RNA virusbelonging to genus Nairovirus in the Bunyaviridae, is a zoonotic viral disease and is transmitted to people through a tick bite. However, transmission via the blood, secretions, organs, or other bodily fluids of infected persons can also be seen. The diagnosis can be quite challenging in patients without a history of a tick bite (3). The overall mortality rateof CCHF ranges from 3% to30% depending on the virus strain and epidemiological characteristics in various regions around the world (2) . CCHF has acute influences on several organs and can cause diffuse ecchymosis, internal bleeding, and impaired liver function. Main laboratory findingsare consistent withleucopenia, thrombocytopenia, elevated liver enzymes,and prolonged bleeding profile. The release of cytokines, chemokines, and other proinflammatory mediators,leads to endothelial cell activation, endothelial damage, an increase in vascular permeability, activation ofthe coagulation system, and eventually disseminated intravascular coagulation (DIC) (3) . Fever, malaise, nausea, vomiting, abdominal pain, myalgia,petechia, ecchymosisare common presentations of CCHF(3) whereasfever, dry cough, weakness and shortness of breath, loss of taste or smell are common symptoms of Covid-19(4). Cytokine storm syndromes are important and also vital for increased morbidity and mortality in both diseases but have different outcomes. While CCHF results in hemorrhage, Covid-19 can cause thrombosis (5) .

The PCR tests are used for the diagnosis of both diseases. As for the imaging findings, direct invasion of pulmonary interstitial tissue by the CCHF virus has not been shown (6) . Although the appearance of ground-glass opacity is an important finding in the CCHF, it is seen due to alveolar hemorrhage and withpleural effusion and consolidation ( Figure 1 ) (6) . On the other hand, most recent thoracic CTfindings of SARS-CoV-2 comprisesground-glass opacity,consolidation,crazy-paving pattern, air bronchogram,vascular enlargement, bronchial changesare and rarely pleural effusion, air bubble, and cavitary lesions.These findings often tend to be bilateral, peripheral, and dorsal, mostly in the middle, and lower zones and multilobular (7) .

In conclusion, we would like to underscore that CCHF should be kept in mind for the differential diagnosis of ground-glass opacity in endemic regions. Further studies considering the immune mechanism of both diseases are awaited. 

Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2

The relative frequencies of causes of widespread ground-glass opacity: a retrospective cohort

Crimean-Congo hemorrhagic fever: An update

Clinical characteristics of coronavirus disease 2019 in China

COVID-19 and haemostasis: a position paper from Italian Society on Thrombosis and Haemostasis (SISET) Blood Transfus

Thorax CT findings in patients with Crimean-Congo hemorrhagic fever (CCHF)

Coronavirus disease 2019: initial chest CT findings