The 2014–2015 outbreak of the Ebola virus disease (EVD) in West Africa has been considered a major global health emergency by the WHO. Implications for health care providers including oral and ...maxillo-facial surgeons have been published by the WHO, the Centers for Disease Control and Prevention (USA), and other medical societies and public health organizations. While the risk of infection with the Ebola virus seems to be rather small in Europe, maxillo-facial and plastic surgeons often travel to Africa to treat patients with facial burns, cleft-lip and palate, and noma. The likelihood of an encounter with patients infected by Ebola virus in subsaharan and West Africa, therefore, has increased during the last 2 years. The purpose of this short overview was to summarize the virology of the Ebola virus, transmission, epidemiology, clinical features, oral manifestations, treatment, and possible implications for maxillo-facial surgeons of EDV.
Previously, we have demonstrated that hepatitis B virus (HBV) core particles tolerate the insertion of the amino-terminal 120 amino acids (aa) of the Puumala hantavirus nucleocapsid (N) protein. ...Here, we demonstrate that the insertion of 120 amino-terminal aa of N proteins from highly virulent Dobrava and Hantaan hantaviruses allows the formation of chimeric core particles. These particles expose the inserted foreign protein segments, at least in part, on their surface. Analysis by electron cryomicroscopy of chimeric particles harbouring the Puumala virus (PUUV) N segment revealed 90%
T = 3 and 10%
T = 4 shells. A map computed from
T = 3 shells shows additional density splaying out from the tips of the spikes producing the effect of an extra shell of density at an outer radius compared with wild-type shells. The inserted Puumala virus N protein segment is flexibly linked to the core spikes and only partially icosahedrally ordered. Immunisation of mice of two different haplotypes (BALB/c and C57BL/6) with chimeric core particles induces a high-titered and highly cross-reactive N-specific antibody response in both mice strains.
Even though smallpox was declared eradicated by WHO in 1980, it cannot be ruled out that the etiological variola virus could be used as a biological weapon. Undestroyed viruses from biowarfare ...programmes, virus strains left undetected in a freezer or dangerous recombinant poxvirus constructs could cause dangerous outbreaks in a relatively unprotected population.
Despite an abundance of studies performed during the eradication of smallpox, epidemiological data for preparedness planning and outbreak control in modern, industrialized countries are scarce.
Full-text hand search for the period from 1945 to 1975 in the main German public health journals.
After World War II 12 smallpox outbreaks occurred in Germany. They were studied with the focus on the period of contagiousness, the protective effect of vaccination, booster-effect of revaccination and the place of infection. A total of 95 individuals contracted smallpox, including 10 fatalities. Despite having been previously vaccinated, 81 vaccinated persons came down with smallpox, yet 91% of them developed only mild symptoms. These patients presented a high risk for spreading the infection to contact persons due to misinterpretation of symptoms and the continuing social contacts. Basically, the risk of transmission in the first 2 to 3 days after onset of symptoms was low, thus facilitating antiepidemic measures. The importance of hospital preparedness is emphasized by the fact that most infections occurred in hospitals.
The data analyzed provide valuable information for today's outbreak response planning and counter bioterrorism preparedness.
A herpesvirus of smelt (Osmerus eperlanus) was identified by thin section electron microscopy. Degenerated cells of skin lesions located on the back fin of smelt showed either intranucleic- or ...cytoplasmic herpesvirus-specific structures. In the nuclei “naked” virus capsids with a diameter of about 100 nm were observed. The diameter of the complete virion including its unilaterally extended envelope ranged from 200 to 350 nm. Remarkably, in complete virions the electron-opaque tegument is completely filling the region between nucleocapsid and envelope and as another unique feature the virion shows a “comet-shape” due to a long unilateral extension of its envelope. This kind of shape had been not reported for any of herpesviruses known so far. Consequently this virus was termed herpesvirus of Osmerus eperlanus (HVOE1) or Comet herpesvirus of smelt. Due to the long time storage at the nonstandard temperature of smelt virus the biological and genomic analysis of the HVOE1 was hampered. All attempts to study host range of HVOE1 failed as no virus replication was observed, indicating that infectivity was lost or the suitable cell culture was missing. The genomic DNA of HVOE1 was analyzed by DNA restriction endonucleases.
A cytopathic infectious agent was isolated from the kidneys of an apparently healthy tree shrew (Tupaia belangeri) that had been captured in the area around Bangkok. The infectivity was propagated in ...Tupaia fibroblast and kidney cell cultures. Paramyxovirus-like pleomorphic enveloped particles and helical nucleocapsids were observed by electron microscopy and accordingly the infectious agent was termed Tupaia paramyxovirus (TPMV). However, no serological cross-reactions were detected between TPMV and known paramyxoviruses. For the molecular characterization of TPMV an experimental strategy that allows the random-primed synthesis of relatively large cDNA molecules from viral genomic RNA was applied. Nucleotide sequence analysis of a TPMV-specific cDNA fragment (1544 bp) revealed two nonoverlapping partial open reading frames corresponding to paramyxoviral N and P transcription units. Using modified rapid amplification of cDNA ends techniques, a substantial contiguous portion of the viral genome (4065 nt) was elucidated including the complete N and P/V/C genes. The coding strategy of TPMV as well as significant amino acid sequence homologies clearly indicates an evolutionary relationship between TPMV and members of the genus Morbillivirus. Highest homologies were detected between TPMV and Hendra virus (equine morbillivirus), which recently emerged in Australia, causing outbreaks of fatal respiratory and neurological disease in horses and humans.
Starting in the 1960, electron microscopy (EM) became widely applied also in viral diagnosis. During the 1970th and 80th, many new agents were characterized from diagnostic cell cultures and clinical ...specimens. The wide introduction of ELISA- and PCR-techniques as well as cost-arguments recently reduced the role of EM in routine viral diagnosis. Compared to other diagnostic techniques, however, EM excells by speed and "open view", i.e. by the ability to detect also the "un-expected" without the need for specific reagents. As shown in 2003 by the elucidation of the SARS pandemia and the human monkeypox outbreak in US, EM is well suited as a safe, front-line diagnostic method in infectious diseases emergencies and/or in possible bioterrorist attacks.
1 Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany
2 Robert Koch-Institut, Berlin, Germany
Correspondence Georg Kochs ...georg.kochs{at}uniklinik-freiburg.de
The sixth genomic segment of Thogoto virus (THOV) encodes two proteins, the viral matrix protein (M) and an accessory protein with an interferon (IFN)-antagonistic function named ML. M and ML are shown in this study to be structural components of the virion. Using an in vivo system based on the reconstitution of functional THOV ribonucleoprotein complexes from cloned cDNAs, it was demonstrated that M has an inhibitory effect on the viral RNA-dependent RNA polymerase (RdRP) and is essential for the formation of virus-like particles (VLPs). The functional domain responsible for the regulation of RdRP activity resides within the C-terminal half of M, while full-length M protein is required for VLP formation. The ML protein cannot complement M with respect to either RdRP downregulation or particle formation, although it is identical to M apart from a 38 aa extension at the C terminus. In contrast, ML, but not M, is able to prevent the induction of IFN- by double-stranded RNA. This function is contained within the C-terminal half of ML. These data suggest major structural differences between M and ML that could explain the different activities of the two proteins.
Present address: Centre for Biomolecular Sciences, University of St Andrews, St Andrews, UK.
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