6th Conference Program (Greek)
Created & Hosted
by HR-Net
Hellenic Virology
Volume 5, Number 1, 2000
Abstracts
- Waterborne and foodborne viral
infections
C.V. Papadopoulou - Challenge for prophylaxis against hepatitis A
in Crete
E. Biziagos (1), H. Anastassiadou (2), C. Lionis (3) - Isolation and physicochemical characterization
of a rapidly replicating strain of hepatitis A virus
E. Biziagos (1), H. Anastassiadou (2), A. Bosch (3) - Biological war and bioterrorism. Use of
viruses as biological weapons
A. Tsotsos
Microbiology Laboratory, Medical School, University of Ioannina, 45110 Ioannina
Hellenic Virology, 2000, 5(1): 3-9.
Foodborne viral infections constitute one of the principal causes of foodborne and waterborne outbreaks. The viruses causing foodborne infections have very small size (25-27nm), they usually contain RNA, they invade the gastrointestinal system, they are transmitted through contaminated food and water or from person to person, they are excreted to the environment through the feces and all of them infect humans only. The most common foodborne viruses transmitted mainly through contaminated water are the Hepatitis A (infectious hepatitis) and E viruses (non-A, non-B hepatitis), which can cause massive outbreaks. Other viruses often associated with foodborne infections are the Norwalk viruses, the Rotaviruses and the Astroviruses. Less common viruses implicated in rather rare foodborne infections are the Tick-borne Encephalomyelitis virus, the Enteroviruses, the Parvoviruses, the Adenoviruses 40 and 41 and the Coronaviruses.
(1) Laboratory of Virology, General Clinic, Diagnostic &
Therapeutic Medical Center "Asklepeion of Crete, Heraklion (2)
Laboratory of Food Microbiology & Epidemiology of Foodborne Diseases,
Institute ALA of Heraklion, NAGREF and (3) Department of Social
Medicine, Medical School, University of Crete,
Heraklion
Hellenic Virology, 2000, 5(1):
10-14.
Three-hundred and four children, 12-15 years old, who attended four junior schools at the Agios Vassilios province of Southern Crete and 782 adults (parents, relatives and friends of the children) were tested by enzyme-immunoassay for antibodies against hepatitis A virus (anti-HAV). In the mean-time, a parallel study for the age-specific incidence of anti-HAV was carried out in 2655 persons who visited the University Hospital of Heraklion for tests, excluding liver disease. The results of both studies showed that: (a) the prevalence of anti-HAV among the children of the four junior schools was far too low, since only 6 of 304 children (1.97%) was found to have antibodies against HAV. In contrast, anti-HAV was detected in 88.9% of the adults tested; (b) from those tested in the University Hospital, anti-HAV was found in 9.7, 26.2, 58.7, 91.2 and 99.1% in the age groups <18, 19-25, 26-40, 41-60 and >60 years old respectively; (c) no significant difference (p>0.05) was found in the prevalence of anti-HAV between males and females within each age group. It is concluded that there is a significant decrease of hepatitis A prevalence in Crete that can be attributed to the improvement in living, hygiene and socioeconomic conditions. The substantial decline in the age-specific prevalence rate of anti-HAV in Crete, in parallel with the significant increase of the sensitive young population, should alert the Public Health Authorities for the appearance of epidemics due to the re-entrance of the virus, as well as for the increase of clinical cases among the susceptible adults. Selective immunization would reduce the remaining incidence of the disease. However, only the inclusion of the vaccine into the routine program of childhood immunization would guarantee the elimination of hepatitis A.
(1)
Laboratory of Virology, General Clinic, Diagnostic & Therapeutic
Medical Center "Asklepeion of Crete, Heraklion (2) Laboratory of Food
Microbiology & Epidemiology of Foodborne Diseases, Institute ALA of
Heraklion, NAGREF and (3) Department of Microbiology, University of
Barcelona, Spain
Hellenic Virology, 2000, 5(1): 15-24.
A rapidly replicating isolate of hepatitis A virus (HAV), BAR-38, was isolated by repeated subcultures at two-week intervals, of BSC-1 cells persistently infected with the HM-175 strain of HAV. BAR-38 caused specific CPE upon acute infection of FRhK-4 cells, with complete destruction of the monolayers in less than 24 hours. After high multiplicity of infection, more than 10exp7 PFU/ml are released in the culture medium after a 24-hour incubation. Cytopathic effect of the virus was also observed in BGM, BSC-1, MA-104, PLC/PRF/5 and Frp/3 cells. Electron microscopy studies of supernatants from infected cultures revealed the presence of 24-27 nm viral particles. Buoyant density of these particles in CsCl was 1.34 g/cm3. Nucleic acid extracted from BAR-38 hybridized to a specific HAV cDNA probe. A classical plaque assay for BAR-38 was developed in FRhK-4 cells: visible plaques appeared two days post-infection. Plaques were neutralized by polyclonal and monoclonal antisera to HAV. An altered antigenic behavior was observed with some monoclonal antibodies.
Microbiology
Department, Athens University Medical School
Hellenic Virology,
2000, 5(1): 25-36.
The rise of bioterrorism adds a considerable threat which has been long ignored and denied, but has heightened over the last years. The magnitude of the problem and the gravity of related scenarios have been portrayed by several accidental episodes. Although biological weapons (BW) are not new, the potential use of these agents in the hands of terrorists, threatening communities, cities or even entire nations is extremely worrying. Major cultural or sporting events may easily become targets for bioterrorist attacks. Genetic engineering has borne completely new perspectives for vaccine development and elucidating the genetic information of microbes and viruses. These same new technologies can be abused for the construction of potentially dangerous biological weapons. The medical community and public health officials bear a large portion of responsibility to prevent such abuse. Emergency services and public health authorities must start planning from now to prevent and defend against possible biological attacks. Among many microorganisms that can be used as biological weapons, viruses occupy a prominent position. Several viruses, such as smallpox, flaviviruses (eg yellow fever virus), encephalitis viruses, arenaviruses (eg Lassa, Junin, Machupo), bunyaviruses (eg hantaviruses), filoviruses (Ebola and Marburg) etc are possible candidates. In addition, production of viral variants and their selection as powerful biological weapons is possible.