A new coronavirus associated with human respiratory disease in China.

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health1-3. Despite intense research efforts, how, when and where new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing4 of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here 'WH-Human 1' coronavirus (and has also been referred to as '2019-nCoV'). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China5. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.

Neuroimaging of Emergent and Reemergent Infections.

Infectious diseases emerge and reemerge over the years, and many of them can cause neurologic disease. Several factors contribute to the emergence and reemergence of these conditions, including human population growth, an increase in international travel, the geographic expansion of recognized pathogens to areas where they were previously nonendemic, and greater contact with wild animal reservoirs. The antivaccination social movement has played an important role in the reemergence of infectious diseases, especially some viral conditions. The authors review different viral (arboviruses such as dengue, chikungunya, and Zika virus; enterovirus 71; measles; and influenza), bacterial (syphilis, Lyme disease, and listeriosis), and parasitic (Chagas disease) diseases, focusing primarily on their neurologic complications. Although there are several additional infectious diseases with central nervous system manifestations that could be classified as emergent or reemergent, those listed here are the most relevant from an epidemiologic standpoint and are representative of important public health issues on all continents. The infections caused by these pathogens often show a variety of neuroimaging patterns that can be identified at CT and MRI, and radiology is central to the diagnosis and follow-up of such conditions. Given the increasing relevance of emerging and reemerging infections in clinical practice and public health scenarios, radiologists should be familiar with these infections. Online supplemental material is available for this article. ©RSNA, 2019.

Emerging H7N9 influenza A (novel reassortant avian-origin) pneumonia: radiologic findings.

PURPOSE: To determine the radiologic findings of human infection with a novel reassortant avian-origin influenza A H7N9 virus in March 2013, the first outbreak in humans. MATERIALS AND METHODS: The institutional review board approved this retrospective study. Twelve patients (nine men and three women) with novel avian-origin influenza A H7N9 virus infection were enrolled. All patients underwent chest radiography and thin-section computed tomography (CT). Lesion patterns, distributions, and changes at follow-up CT were investigated. Two chest radiologists reviewed the images and clinical data together and reached decisions concerning findings by consensus. RESULTS: At presentation, all patients had progressing infection of the lower respiratory tract, with fever, cough, and shortness of breath, which rapidly progressed to acute respiratory distress syndrome. The imaging findings included ground-glass opacities (GGOs) (in 12 of 12 patients), consolidations (in 11 patients), air bronchograms (in 11 patients), interlobular septal thickening (in 11 patients), centrilobular nodules (in seven patients), reticulations (in seven patients), cystic changes (in four patients), bronchial dilatation (in three patients), and subpleural linear opacities (in three patients). The lung lesions involved three or more lobes in all cases and were mostly detected in the right lower lobe (in 11 patients). Follow-up CT in 10 patients showed interval improvement (in three patients) or worsening (in seven patients) of the lesions. Imaging findings closely mirrored the overall clinical severity of the disease. CONCLUSION: Rapidly progressive GGOs and consolidations with air bronchograms and interlobular septal thickening, with right lower lobe predominance, are the main imaging findings in H7N9 pneumonia. The severity of these findings is associated with the severity of the clinical presentation.

Benefit of CT scanning for assessing pulmonary disease in the immunodepressed patient.

INTRODUCTION: Management of pulmonary disease in immunodepressed patients requires a clear diagnostic and therapeutic strategy and multidisciplinary cooperation. DISCUSSION: The diagnostic approach should take into account the type of immunodepression, the clinical picture, the radiological signs and symptoms, and the microbiological, cytological and even histological examination of the pulmonary or extrapulmonary specimens. The high-resolution CT scan plays a central role and makes it possible to prioritize the diagnostic possibilities. CONCLUSION: The analysis of the literature shows three important points: the chest X-ray has low diagnostic value; the CT scan of the chest can reveal lesions that cannot be detected on a standard chest X-ray; the CT scan is helpful for early detection and monitoring of invasive pulmonary aspergillosis.

Molecular imaging of influenza and other emerging respiratory viral infections.

Research on the pathogenesis and therapy of influenza and other emerging respiratory viral infections would be aided by methods that directly visualize pathophysiologic processes in patients and laboratory animals. At present, imaging of diseases, such as swine-origin H1N1 influenza, is largely restricted to chest radiograph and computed tomography (CT), which can detect pulmonary structural changes in severely ill patients but are more limited in characterizing the early stages of illness, differentiating inflammation from infection or tracking immune responses. In contrast, imaging modalities, such as positron emission tomography, single photon emission CT, magnetic resonance imaging, and bioluminescence imaging, which have become useful tools for investigating the pathogenesis of a range of disease processes, could be used to advance in vivo studies of respiratory viral infections in patients and animals. Molecular techniques might also be used to identify novel biomarkers of disease progression and to evaluate new therapies.

Thoracic radiology of infections emerging after natural disasters.

When natural disasters demolish shelter, destroy sources of clean drinking water, and disrupt the availability of medical care, vast numbers of people are placed at increased risk of disease. The infectious diseases that propagate under these conditions are usually common ones. Occasionally, a natural disaster alters the local environment in ways that markedly increase the prevalence of a disease that is endemic to a geographic region, occurring only as isolated cases under normal conditions. Many of these infections may affect the thorax. In this article, we discuss the radiologic findings of 4 infectious diseases, coccidioidomycosis, leptospirosis, melioidosis, and Chagas disease, which may flourish after natural disasters strike areas where they are endemic.

Radiology of severe acute respiratory syndrome (SARS): the emerging pathologic-radiologic correlates of an emerging disease.

Severe acute respiratory distress syndrome (SARS) caused by SARS-associated coronavirus (SARS-CoV) is a systemic infection that clinically manifests as progressive pneumonia. During the initial phases of infection the virus causes pauci-inflammatory alveolar and interstitial edema that result in imaging abnormalities dominated by ground glass opacities (GGO). Severe SARS cases can develop radiologic and pathologic findings of diffuse alveolar damage. Although radiologic evidence of acute bronchiolitis is absent, SARS-CoV also infects ciliated airway epithelium, probably accounting for respiratory transmissibility of the virus. Radiologic recovery from SARS can be complete, but computed tomography images often show persistent GGO and reticular opacities, some of which reflect pathologic findings of fibrosis. Long-term follow-up imaging of survivors shows gradual decrease of GGO and reticulation with persistent air trapping in some patients. The latter is evidence of small airway disease that is not radiologically evident at the onset of the disease.

Clinical characteristics, management and prognostic factors in patients with probable severe acute respiratory syndrome (SARS) in a SARS center in Taiwan.

BACKGROUND: Severe acute respiratory syndrome (SARS) is an emerging viral infectious disease. We report our experience in treating SARS patients. METHODS: From April 27 to May 24, 2003, a total of 36 patients with probable SARS were admitted and treated in a hospital rearranged as a special center for the management of SARS patients. Medical records for the patients were retrospectively reviewed. Univariate and multivariate analyses were performed to determine factors associated with respiratory failure and intubation. RESULTS: Of the 36 patients with probable SARS (median age, 37 years; range, 22-66 years), 9 were male and 27 were female. Thirty-two patients (88.9%) were infected in the hospital setting. All patients presented with fever, and 33 eventually developed lymphopenia during hospitalization. Chest radiography showed no unique pattern, but pleural effusion was not seen. All patients initially received empiric antibacterial therapy against common causative pathogens of atypical pneumonia. Ribavirin was given to all except 1 patient. Twenty-two patients received immunoglobulin therapy, and 32 were given corticosteroids. A total of 20 patients (55.6%) required supplemental oxygen, and 8 (22.2%) were intubated with mechanical ventilatory support. Two of these patients died. A higher body temperature at presentation (median 39.5 vs 38.6 degrees C), and higher peak values of lactate dehydrogenase (410 vs 282 U/L) and C-reactive protein (10.2 vs 2.5 mg/dL), were associated with subsequent respiratory failure. Multivariate analysis showed that peak level of C-reactive protein was the only independent predictor of respiratory failure and intubation (odds ratio for every increment of 1 mg/dL = 1.45; 95% confidence interval = 1.003, 2.097; p = 0.048). CONCLUSION: All patients with probable SARS who were admitted to hospital presented with fever and lymphopenia. While the efficacy of different treatments could not be evaluated from this retrospective study, a higher value of C-reactive protein was associated with the development of respiratory failure and subsequent intubation.