Johan Rasmuson

Bio: Johan Rasmuson is an academic researcher from Umeå University. The author has contributed to research in topics: Hantavirus & Puumala virus. The author has an hindex of 7, co-authored 10 publications receiving 223 citations.

Time to revise the paradigm of hantavirus syndromes? Hantavirus pulmonary syndrome caused by European hantavirus

Abstract: Hantaviruses have previously been recognised to cause two separate syndromes: hemorrhagic fever with renal syndrome in Eurasia, and hantavirus pulmonary syndrome (HPS) in the Americas. However, increasing evidence suggests that this dichotomy is no longer fruitful when recognising human hantavirus disease and understanding the pathogenesis. Herein are presented three cases of severe European Puumala hantavirus infection that meet the HPS case definition. The clinical and pathological findings were similar to those found in American hantavirus patients. Consequently, hantavirus infection should be considered as a cause of acute respiratory distress in all endemic areas worldwide.

Cardiopulmonary involvement in Puumala hantavirus infection

Abstract: Hantavirus infections cause potentially life-threatening disease in humans world-wide. Infections with American hantaviruses may lead to hantavirus pulmonary syndrome characterised by severe cardiopulmonary distress with high mortality. Pulmonary involvement in European Puumala hantavirus (PUUV) infection has been reported, whereas knowledge of potential cardiac manifestations is limited. We aimed to comprehensively investigate cardiopulmonary involvement in patients with PUUV-infection. Twenty-seven hospitalised patients with PUUV-infection were examined with lung function tests, chest high-resolution CT (HRCT), echocardiography including speckle tracking strain rate analysis, ECG and measurements of cardiac biomarkers N-terminal pro-B-type natriuretic peptide (NT-ProBNP) and troponin T. Patients were re-evaluated after 3 months. Twenty-five age and sex-matched volunteers acted as controls for echocardiography data. Two-thirds of the patients experienced respiratory symptoms as dry cough or dyspnoea. Gas diffusing capacity was impaired in most patients, significantly improving at follow-up but still subnormal in 38%. HRCT showed thoracic effusions or pulmonary oedema in 46% of the patients. Compared to controls, the main echocardiographic findings in patients during the acute phase were significantly higher pulmonary vascular resistance, higher systolic pulmonary artery pressure, lower left ventricular ejection fraction and impaired left atrial myocardial motion. Pathological ECG, atrial fibrillation or T-wave changes, was demonstrated in 26% of patients. NT-ProBNP concentrations were markedly increased and were inversely associated with gas diffusing capacity but positively correlated to pulmonary vascular resistance. Furthermore, patients experiencing impaired general condition at follow-up had significantly lower gas diffusing capacity and higher pulmonary vascular resistance, compared to those feeling fully recovered. In a majority of patients with PUUV-infection, both cardiac and pulmonary involvement was demonstrated with implications on patients’ recovery. The results demonstrate vascular leakage in the lungs that most likely is responsible for impaired gas diffusing capacity and increased pulmonary vascular resistance with secondary pulmonary hypertension and right heart distress. Interestingly, NT-ProBNP was markedly elevated even in the absence of overt ventricular heart failure. The method of simultaneous investigations of important cardiac and respiratory measurements improves the interpretation of the underlying pathophysiologic mechanisms.

Human hantavirus infection elicits pronounced redistribution of mononuclear phagocytes in peripheral blood and airways

Abstract: Hantaviruses infect humans via inhalation of virus-contaminated rodent excreta. Infection can cause severe disease with up to 40% mortality depending on the viral strain. The virus primarily target ...

Cytotoxic immune responses in the lungs correlate to disease severity in patients with hantavirus infection

Abstract: Hantavirus infections may cause severe and sometime life-threatening lung failure. The pathogenesis is not fully known and there is an urgent need for effective treatment. We aimed to investigate t ...

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Uncovering the mysteries of hantavirus infections

Abstract: Hantaviruses are negative-sense single-stranded RNA viruses that infect many species of rodents, shrews, moles and bats. Infection in these reservoir hosts is almost asymptomatic, but some rodent-borne hantaviruses also infect humans, causing either haemorrhagic fever with renal syndrome (HFRS) or hantavirus cardiopulmonary syndrome (HCPS). In this Review, we discuss the basic molecular properties and cell biology of hantaviruses and offer an overview of virus-induced pathology, in particular vascular leakage and immunopathology.

Hantavirus infections in Europe and their impact on public health.

Abstract: Hantaviruses (genus Hantavirus, family Bunyaviridae) are enveloped tri-segmented negative-stranded RNA viruses each carried by a specific rodent or insectivore host species. Several different hantaviruses known to infect humans circulate in Europe. The most common is Puumala (PUUV) carried by the bank vole; another two important, genetically closely related ones are Dobrava-Belgrade (DOBV) and Saaremaa viruses (SAAV) carried by Apodemus mice (species names follow the International Committee on Taxonomy of Viruses nomenclature). Of the two hantaviral diseases, hemorrhagic fever with renal syndrome (HFRS) and hantaviral cardiopulmonary syndrome, the European viruses cause only HFRS: DOBV with often severe symptoms and a high case fatality rate, and PUUV and SAAV more often mild disease. More than 10,000 HFRS cases are diagnosed annually in Europe and in increasing numbers. Whether this is because of increasing recognition by the medical community or due to environmental factors such as climate change, or both, is not known. Nevertheless, in large areas of Europe, the population has a considerable seroprevalence but only relatively few HFRS cases are reported. Moreover, no epidemiological data are available from many countries. We know now that cardiac, pulmonary, ocular and hormonal disorders are, besides renal changes, common during the acute stage of PUUV and DOBV infection. About 5% of hospitalized PUUV and 16%-48% of DOBV patients require dialysis and some prolonged intensive-care treatment. Although PUUV-HFRS has a low case fatality rate, complications and long-term hormonal, renal, and cardiovascular consequences commonly occur. No vaccine or specific therapy is in general use in Europe. We conclude that hantaviruses have a significant impact on public health in Europe.

β2 integrin mediates hantavirus-induced release of neutrophil extracellular traps

Abstract: Rodent-borne hantaviruses are emerging human pathogens that cause severe human disease. The underlying mechanisms are not well understood, as hantaviruses replicate in endothelial and epithelial cells without causing any cytopathic effect. We demonstrate that hantaviruses strongly stimulated neutrophils to release neutrophil extracellular traps (NETs). Hantavirus infection induced high systemic levels of circulating NETs in patients and this systemic NET overflow was accompanied by production of autoantibodies to nuclear antigens. Analysis of the responsible mechanism using neutrophils from β2 null mice identified β2 integrin receptors as a master switch for NET induction. Further experiments suggested that β2 integrin receptors such as complement receptor 3 (CR3) and 4 (CR4) may act as novel hantavirus entry receptors. Using adenoviruses, we confirmed that viral interaction with β2 integrin induced strong NET formation. Collectively, β2 integrin–mediated systemic NET overflow is a novel viral mechanism of immunopathology that may be responsible for characteristic aspects of hantavirus-associated disease such as kidney and lung damage.

Epidemiology of Hantavirus infections in humans: a comprehensive, global overview.

Abstract: Hantaviruses comprise an emerging global threat for public health, affecting about 30 000 humans annually. Infection may lead to Hantavirus pulmonary syndrome (HPS) in the Americas and hemorrhagic fever with renal syndrome (HFRS) in the Europe and Asia. Humans are spillover hosts, acquiring infection primarily through the inhalation of aerosolized excreta from infected rodents and insectivores. Risk factors for infection include involvement in outdoor activities, such as rural- and forest-related activities, peridomestic rodent presence, exposure to potentially infected dust and outdoor military training; prolonged, intimate contact with infected individuals promotes transmission of Andes virus, the only Hantavirus known to be transmitted from human-to-human. The total number of Hantavirus case reports is generally on the rise, as is the number of affected countries. Knowledge of the geographical distribution, regional incidence and associated risk factors of the disease are crucial for clinicians...