However, since severe diarrhoea could be observed in which virus detection was positive, it must be assumed that viraemia can occur with this virus type as well. Such a viraemia is observed in connection with high viral load and fatal outcome [ 52 ].
Whether the cases available are isolated cases or whether a general statement can be made remains to be clarified. In conclusion, it can be stated that viraemia is possible in case of an influenza virus infection, even though the probability is low for the human virus type in case of a normal course of the disease.
For H5N1 infections, the situation is judged differently: Based on the prolonged incubation period of up to 7 days and the apparently more frequent dissemination of the viruses in the blood, the risk potential is rated higher. What remains unclear, however, both for human and for avian influenza viruses, is whether the introduction of virus into the blood circulation will lead to an infection of the blood recipient.
In case of a natural infection, the influenza viruses enter the body via the respiratory epithelium where they replicate. So far, available data on the effectiveness of transmission via the blood are not sufficient.
This question should be taken into account in future studies. Influenza viruses belong to the group of enveloped viruses and are, therefore, inactivated by lipid solvents which are also used e. Transmission of influenza viruses by plasma derivatives can therefore be ruled out, above all thanks to the use of physical and chemical depletion and inactivation steps during manufacture [ 53 ].
In principle, human influenza isolates can be used for the validation of the manufacturing procedures for plasma components. According to the present state of knowledge, viraemia is observed only in serious courses of infection with human influenza viruses.
This viraemia can usually be detected only as late as the first occurrence of symptoms of the disease such as fever. It can be assumed that H5N1 infections in humans involve viraemia. Nothing is known about the onset of this viraemic phase following infection.
Since the incubation period is 1—7 days for previously observed cases of disease, and is, as a rule, 2—5 days, it can be assumed that the viraemic phase is 7—10 days.
In principle, it can be assumed that plasma components are safe both with regard to human influenza viruses and with regard to avian influenza virus. Special steps during the annual influenza epidemics with human influenza viruses with regard to safety of cellular, non-inactivated blood components are not indicated. For the pandemic case, a framework should also be created enabling the blood donor services to co-ordinate their work as fast as possible.
Plans have been made to establish an agreement pursuant to section 3 subsection 2 of the Transfusionsgesetz German Transfusion Act laying down the details of mutual support in the event of disasters and other emergencies. Such an agreement is currently being compiled by the organisations that run the blood donor services. Brunhilde Schweiger Robert KochInstitut.
National Center for Biotechnology Information , U. Journal List Transfus Med Hemother v. Transfus Med Hemother. Copyright and License information Disclaimer. Karger GmbH, Freiburg. This article has been cited by other articles in PMC. Table 1 Pandemic phases according to the WHO pandemic preparedness plan [ 39 ]. Inter-pandemic period Phase 1 No new influenza virus subtypes have been detected in humans.
An influenza virus subtype that has caused human infection may be present in animals. If present in animals, the risk of human infection or disease is considered to be low. Phase 2 No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease. Pandemic alert period Phase 3 Human infection s with a new subtype, but no human-to-human spread, or at most rare instances of spread to a close contact.
Phase 4 Small cluster s with limited human-to-human transmission, but spread is highly localised, suggesting that the virus is not well adapted to humans. Phase 5 Larger cluster s but human-to-human spread still localised, suggesting that the virus is becoming increasingly better adapted to humans, but may not yet be fully transmissible substantial pandemic risk.
Pandemic period Phase 6 Pandemic: increased and sustained transmission in general population. Decisions to be made in Phase 6 whether a country is not yet affected, a country is affected or has close trade relations or travel between an affected country, activity has decreased, or a second pandemic wave has occurred Post-pandemic phase Return to inter-pandemic period.
Open in a separate window. Special Situation during the Pandemic Period Donor screening with nucleic acid amplification techniques for the detection of viraemia cannot be introduced immediately from a technical point of view. Special Situation during the Pandemic Period To prevent masses of people from meeting in one site, special appointments should be made for blood collection activities.
Reinhard Burger Dr. Christian Drosten Dr. Margarethe Heiden PD Dr. Martin Hildebrandt Prof. Bernd Jansen Dr. Horst Klamm Dr. Thomas Montag-Lessing Dr. Ruth Offergeld Prof. Georg Pauli Prof. Rainer Seitz Dr. Uwe Schlenkrich Dr. Volkmar Schottstedt Dr. Hannelore Willkommen Prof. References 1. Fields Virology. Philadelphia: Lippincott Williams and Wilkins; Scholtissek C. Stability of infectious influenza A viruses at low pH and at elevated temperature.
Characterization of a novel influenza A virus hemagglutinin subtype H16 obtained from black-headed gulls. J Virol. Cocirculation of two distinct evolutionary lineages of influenza type B virus since Evolutionary characteristics of influenza B virus since its first isolation in dynamic circulation of deletion and insertion mechanism. Arch Virol. On the origin of the human influenza virus subtypes H2N2 and H3N2. Avian-to-human transmission of the PB1 gene of influenza A viruses in the and pandemics.
World Health Organization: Avian Influenza. Influenza A outbreak among adolescents in a ski hostel. Fatal influenza A virus infection in a child vaccinated against influenza. Pediatr Infect Dis J. Community-acquired pneumonia in Christchurch and Waikato — microbiology and epidemiology. Influenza pneumonia: a descriptive study. Fatal avian influenza A H5N1 in a child presenting with diarrhea followed by coma.
N Engl J Med. Webster RG. Influenza: An Emerging Disease. Emerg Infect Dis. The importance of animal influenza for human disease. Emergence of influenza A H1N2 reassortant viruses in the human population during Fauci AS. Seasonal and pandemic influenza preparedness: science and countermeasures. J Infect Dis. Influenza associated excess mortality in Germany, — Emerg Themes Epidemiol. Mortality associated with influenza and respiratory syncytial virus in the United States.
Antigenic drift and variability of influenza viruses. Med Microbiol Immunol. Schweiger B. Molecular characterization of human influenza viruses — a look back on the last 10 years.
Berl Munch Tierarztl Wochenschr. Bundesgesundheitsbl Gesundheitsforsch Gesundheitsschutz. Enzyme-linked immunosorbent assay of core antigens for clinical diagnosis of influenza.
J Med Virology. A comparison of direct immunofluorescence, shell vial culture, and conventional cell culture for the rapid detection of influenza A and B. Diagn Microbiol Infect Dis. Detection of influenza A in clinical specimens and cell culture fluid by a commercial EIA. Clin Diagn Virol. J Clin Microbiol. J Med Virol. MDCK cells were pre-incubated with the reagents to assess the inhibitory activity at adsorption viral attachment.
Similarly, anti-HIV activity and the inhibitory mechanism at adsorption were assessed by MT-2 cell culture system. Mixture of HIV and bamboo leaf extract solution was fixed and examined by transmission electron microscopy. The solution inhibited the influenza virus adsorption at the concentration of 0.
Luminescence was measured and correlated with viral dilutions. The dilutions containing infectious virus demonstrated low cell viability and therefore low luminescence values due to widespread CPE. Conversely, dilutions containing no or limiting virus displayed higher luminescence values. The off-target set of wells received medium without virus to address dose-dependent agent effects. After the appropriate exposure periods, the ATP Detection Reagent was prepared and added to plates as described previously.
Luminescence was measured and correlated to antiviral agent concentration for both viral on-target and medium off-target exposures. Off-target toxicity data were plotted on the same graphs and fitted in the case where cytotoxicity was present ribavirin on BHK-1 cells. Thirty thousand compounds from the Enamine chemical diversity library were screened as single doses in well plates against three influenza A strains.
Infected and uninfected control wells were arrayed on each plate to statistically assess assay robustness. After the cells were incubated for 72 hours with the library compounds, the ATP Detection Reagent was added to the well plates and luminescence measured. It offers a highly sensitive, precise and quantitative method of measuring CPE with an easy and fast workflow, an advantage compared to alternate methods.
The assay successfully established both TCID50 and on- and off-target potencies for known antiviral compounds against medically relevant viral targets. We use these cookies to ensure our site functions securely and properly; they are necessary for our services to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as logging in, using a shopping cart or filling in forms.
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