6th Conference Program (Greek)
Created & Hosted
by HR-Net
Hellenic Virology
Volume 1, Number 2, 1996
Abstracts
- Human and animal spongiform encephalopathies: A review of the present knowledge.
H.B. Papadopoulou. - Emerging viruses and virus diseases.
A. Tsotsos. - Influenza in animals.
O. Papadopoulos and M. Koumbati-Artopiou. - The human immunodeficiency virus: morphology, life
cycle and genetic structure.
A. Roumeliotou. - Approaches for the treatment and prevention of
retrovirus infections.
P. Lianou. - Influenza virus isolation in the National Influenza
Reference Centre of Southern Greece.
N. Spyrou (1), C. Maravelia (1), B. Krikelis (2) and P. Markoulatos (1). - Assessment of serological markers for Epstein-Barr
virus in patients with infectious mononucleosis.
K. Themeli-Digalaki, M. Economou, D. Kairis, Ch. Koutsia-Carouzou. - Evaluation of specific IgM and IgG antibodies to
human parvovirus B19 in hospitalized patients.
K. Themeli-Digalaki, M. Economou, Ch. Koutsia-Carouzou. - Developments in taxonomy of viruses: present
status.
A. Tsotsos. - Laboratory diagnosis of Influenza.
M. Delopoulos. - Foot and mouth disease virus (FMDV): modern
diagnotic methods.
H. Hondrokouki.
Microbiology Laboratory, Medical School, University of Ioannina.
Hellenic Virology, 1996, 1(2): 121-135.
The spongiform encephalopathies are a group of uniformly fatal, neurological degenerative diseases of humans and animals, for which the causative agents have not yet been precisely defined. All spongiform encephalopathies are characterized by the presence in brain tissue of a unique amyloid protein and they are all experimentally transmissible to a variety of primate and non primate hosts. No form of therapy has any effect and there is no laboratory test to detect preclinical infection. The most well studied diseases of this group are Creutzfeld-Jacob disease infecting humans and scrapie infecting sheep. Recently, bovine spongiform encephalitis (BSE), a novel infectious neurological disease of domestic cattle has been included in this group. There is evidence that cattle were exposed to the scrapie agent by consuming feedstuffs produced from infected carcasses of small ruminants. Since BSE and scrapie belong to the same group of transmissible degenerative encephalopathies, which also includes human disease and the transmission appears to proceed through the food chain, fears have been expressed about the profound implications to public health.
Medical School, Athens University.
Hellenic Virology,
1996, 1(2): 136-144.
The concept of "emerging virus diseases" was brought to attention by the appearance of HIV-infection in the early 1980s. The term "emerging viruses" has eventually taken a wider context, embracing not only "new viruses" (if any in a strict sense) but also and mainly viruses that played only a restricted role in the pathology of humans, animals or plants, and have recently acquired a new importance. Man has been encountering emerging virus diseases many years ago, when even this phenomenon was not realised in the sense that it is understood today. That was particularly true when groups of people moved from one larger area to another. Long lists of newly emerging viruses exist. Among them, prominent examples include Influenza A virus, HIV 1 and 2, the new Herpesviruses (HHV 6, 7 and 8) and Hepatitis viruses, several Bunyaviruses, Arenaviruses, Togaviruses, Flaviviruses and Filoviruses (Marburg and Ebola viruses). The reasons for emergence of virus diseases are (1) viral evolution (mutations, gene reassortment etc), (2) ecological factors (deforestation, pollution etc), (3) human factors (migration, travels, trade, urbanisation, budget cuts in prevention), (4) delayed identification of viruses, (5) delayed recognition of the causative role of viruses in the disease and (6) export of livestock and laboratory animals. Most emerging viruses are zoonotic. Rodents and primates are important reservoirs to humans. Human behaviour, like for example changes in agricultural practices or urban conditions, is the most common factor that increases the probability of virus emergence. To face the threat of emerging viruses and their diseases we need to further understand viral pathogenesis and how viruses interact with their hosts. In order to establish effective preventive and therapeutic strategies for emerging virus diseases, a worldwide adequate emerging virus disease early warning system is needed, capable of providing rapid identification and control measures.
Microbiology & Infectious Disease Laboratory,
Veterinary Department, Aristotelian University of
Thessaloniki.
Hellenic Virology, 1996, 1(2): 145-149.
Influenza in swine, horses and birds is reviewed. Swine influenza is caused by three subtypes: H1N1 H3N2 and H1N2. H1N1 and H3N2 circulate in many European countries, while H1N2 was isolated in England in 1994. These viruses remained stable, with the exception of an H1N1 variant (1992). Equine influenza is caused by A/equi1 (H7N7) and A/equi 2 (H3N8). A/equi 1 remained stable, in contrast to A/equi 2, which developed a number of antigenic variants. A large number of influenza viruses has been isolated from birds. Most of them are non-pathogenic. Fowl plague is a severe form caused by H5 and H7 viruses. The role of migratory birds in the epidemiology of influenza is discussed.
AIDS Reference
Centre.
Hellenic Virology, 1996, 1(2): 150-154.
The morphology, life cycle and genetic constitution of HIV are described. The structure of glycoproteins gp120 and gp41 is specifically analysed, as well as their changes and functional meaning. The effect of several antiviral agents is related to the stages of virus replication. The structure and function of the main and regulatory genes of HIV and their interaction is also described.
Hellenic Virology, 1996,
1(2): 155-160.
In this review, the approaches for the treatment and prevention of retrovirus infections with emphasis on the human immunodeficiency virus (HIV) are discussed. It is evident that at present the available antiviral drugs have not produced optimal results. Also, efforts to develop vaccines have not yet been succesful. Finally, antiidiotopic antibodies against CD4, V3LOOP and passive immunization have been proposed and are under investigation.
(1) Department of
Virology, Hellenic Pasteur Institute and (2) Department of Medicine,
University of Thessaly.
Hellenic Virology, 1996, 1(2): 161-165.
The National Influenza Reference Center of Southern Greece, which functions in the framework of the Virology Department of the Hellenic Pasteur Institute, is actively engaged in the detection and surveillance of influenza viruses since 1978. During these years 2816 samples of throat swabs or bronchial washings have reached our laboratory, from which we have isolated 112 influenza viruses. Upon serotyping these isolates, 52 were found to be influenza A and 60 were influenza B. The influenza A subtypes were H3N2 (38) anf H1N1 (14). However, some mixed strains within the H3N2 subtype were also detected (Tables 1 and 2) which is probably explained by the antigenic drift phenomenon.
Microbiology Laboratory, General Hospital
"Asclepeion Voulas".
Hellenic Virology, 1996, 1(2): 166-170.
Serum samples from 340 patients with clinically diagnosed infectious mononucleosis (167 adults and 173 children) were examined for detection of specific Epstein-Barr antibodies (EBNA-IgG) and heterophil antibodies by immunofluorescence and immunosorbent assays. 164 samples (48.2 %) were found to be seropositive. Recent infection was diagnosed in 32.6 % of patients while prior infection in 15.6 %. Acute infection was diagnosed by detecting VCA IgM antibodies in 20.5 % of the examined children and in 25.2 % of the adults. In four patients, infectious mononucleosis was caused by CMV, rubella virus and adenovirus. In conclusion, specific serological markers (mainly VCA-IgM) must be used for the serological diagnosis of EBV infectious mononucleosis. In order to obtain the highest sensitivity, VCA IgM, VCA IgG and EBNA antibodies need to be measured.
Microbiology Laboratory, General
Hospital "Asclepeion Voulas".
Hellenic Virology, 1996, 1(2):
171-174.
Human Parvovirus B19 (HPV B19) is the aetiological agent of the erythema infectiosum (fifth disease) in children, arthralgia, aplastic crisis in patients with chronic haemolytic anemia and fetal hydrops. A total of 190 samples of serum from 162 children with clinical diagnosis of HPV B19 infection and 28 adults (16 had acute arthropathy and 12 were immunodeficient patients) were examined. The specific IgG and IgM antibodies were detected by IFA. Recent infection was diagnosed in 17 patients (8.9 %) while past infection in 52 (27.3 %). In children, IgM antibodies were detected in 8.6 %, while IgG antibodies in 24.6 %. In adults with arthropathy, IgM antibodies were detected in 18.7 %, while IgG in 50 % of the patients. In immunocompromised patients with aplastic crisis, only past infection (33 %) was diagnosed. The clinical presentation of HPV B19 infection in 17 patients was fifth disease (11 children), febrile infection (2 children) and acute arthropathy (3 adults and i child). These results indicate that the determination of IgM and IgG antibodies to HPV B19 is useful in differential diagnosis of acute or recent infection.
Medical School, Athens University;
National Member of the International Committee on Taxonomy of Viruses
(ICTV).
Hellenic Virology, 1996, 1(2): 175-183.
The present universally accepted system of virus taxonomy is set at basically 3 hierarchical levels, i.e. family, genus and species. In some cases, orders, subfamilies and subgenera also exist. 2 orders, 71 families, 9 subfamilies and about 164 genera are recognized at present. About 3600 viruses have been asigned to approved taxa and many others have been designated as probable members of these taxa. Although ICTV has performed a significant task during the 30 years of its life, a considerable number of viruses cannot yet be assigned because of inadequate data, and must await further information to be gathered in order to take a place in the taxonomic system, which is continuously expanded. In this article, several recent developments in the classification and nomenclature of viruses are briefly presented. The resent status of taxonomy of viruses, especially as it has been fromed after the last general meeting of the ICTV, is also outlined.
Virology Laboratory, 401 General Military Hospital of
Athens.
Hellenic Virology, 1996, 1(2): 184-188.
Viral isolation from appropriate respiratory clinical specimens, the demonstration of viral antigens directly on clinical specimens, or in infected cells, and the measurement of the acute production of specific antibody, are all required to confirm the clinical diagnosis of influenza infections. Throat or naspharyngeal washes, nasopharyngeal swabs and lung tissue, are all appropriate clinical specimens. Indirect immunofluorescence on clinical specimens is the oldest and most available rapid test to detect influenza. Other rapid methods include immunoelectron microscopy, enzyme-immunoassay, fluoro-immunoassay, in situ hybridization and the polymerase chain reaction. Embryonated chicken eggs and continuous cell lines are being used for viral isolation. Methods to detect specific antibody against influenza virus on serologic testing are hemagglutination inhibition, neutralization test and complement fixation.
FMDV
Institute.
Hellenic Virology, 1996, 1(2): 189-193.
FMDV belongs to the genus Apthovirus of the Picornaviridae family. There are 7 antigenic types, A, O, C, SAT1, SAT2, SAT3 and Asia. The virus has a strong infectivity and high transmissibility. FMDV affects mainly big ruminants. Man is very rarely affected, especially in close contact with the virus or sensitive animals. The diagnostic methods used are: (1) ELISA, (2) Complement fication test, (3) Monoclonal antibodies, (4) Isolation in tissue cultures, and (5) Biological assays in newborn mice.