History Hypotheses about source Historian Alfred W. Crosby recorded that the flu originated in the U. In latemilitary pathologists reported the onset of a new disease with high mortality that they later recognized as the flu. It also was home to a live piggery, and poultry were regularly brought in from surrounding villages.
Biosecurity Issues CDC researchers and their colleagues successfully reconstructed the influenza virus that caused the flu pandemic, which killed as many as 50 million people worldwide. The following questions and answers describe this important research and related issues.
Background on the Research What research does the Science article describe? Why is it important? This information is critical to evaluating the effectiveness of current and future public health interventions, which could be used in the event that a like virus reemerges.
The knowledge from this work may also shed light on the pathogenesis of contemporary human influenza viruses with pandemic potential.
The natural emergence of another pandemic virus is considered highly likely by many experts, and therefore insights into pathogenic mechanisms could contribute to the development of prophylactic and therapeutic interventions needed to control pandemic viruses.
What are the reasons for doing these experiments? The influenza pandemic of killed an estimated 20 to 50 million people worldwide, many more than the subsequent pandemics of the 20th century.
The biological properties that confer virulence to pandemic influenza viruses were poorly understood. Research to better understand how the individual genes of the pandemic influenza virus contribute to the disease process could provide important insights into the basis of virulence.
This kind of information will enable us to devise appropriate strategies for early diagnosis, treatment, and prevention, should a similar pandemic virus emerge. Additionally, such research will provide us with general principles with which we can better design antiviral drugs and other interventions against all influenza viruses with enhanced virulence.
Who funded the work described in this article? Work with the reconstructed virus was conducted at and supported by CDC. When did CDC begin research on the virus?
CDC studies of the influenza virus were begun in with the initiation of testing of viruses containing subsets of the eight genes of the virus.
Previous articles describing the properties of such viruses were published before Reconstruction of the entire virus was begun in August Top of Page Could a like H1N1 virus re-emerge and cause a pandemic again? It is impossible to predict with certainly, but the probability of the virus re-emerging from a natural source appears to be remote.
Influenza experts believe that a pandemic is most likely to be caused by an influenza subtype to which there is little, or no, preexisting immunity in the human population. There is evidence that some residual immunity to the virus, or a similar virus, is present in at least a portion of the human population.
Since contemporary H1N1 viruses circulate widely and the current annual influenza vaccines contain an H1N1 component, a like H1N1 virus would not fit the current criteria for a new pandemic strain.
Are current antivirals and vaccines effective against the virus? Two types of antiviral drugs, rimantadine Flumadine and oseltamivir Tamifluhave been shown to be effective against influenza viruses similar to the virus.
Vaccines containing the HA or other subtype H1 HA proteins were effective in protecting mice against the virus. In fact, the current influenza vaccine provided some level of protection against the virus in mice.
Are new prophylactics and therapeutics against the virus under way? The reconstruction of the virus will enable CDC to pursue development of a vaccine candidate reference virus that would provide optimal protection against this or similar viruses. Biosafety Precautions Is the public at risk from the experiments being done on this virus?
The work described in this report was done using stringent biosafety and biosecurity precautions that are designed to protect workers and the public from possible exposure to this virus for example, from accidental release of the virus into the environment. What biosafety and biosecurity precautions for protecting laboratory workers and the public were in place while this work was being done?
Before the experiments were begun, two tiers of internal CDC approval were conducted: Following this recommendation, CDC amended its regulations and designated all reconstructed replication competent forms of the pandemic influenza virus containing any portion of the coding regions of all eight gene segments reconstructed Influenza virus as a select agent.
What are the appropriate biosafety practices and containment conditions for work with the strain of influenza? Biosafety Level 3 or Animal Biosafety Level 3 practices, procedures and facilities, plus enhancements that include special procedures discussed in the next question beloware recommended for work with the strain.
There are four biosafety levels that correspond to the degree of risk posed by the research and involve graded levels of protection for personnel, the environment, and the community.
Biosafety Level 4 provides the most stringent containment conditions, Biosafety Level 1 the least stringent. These biosafety levels consist of a combination of laboratory practices and techniques, safety equipment, and laboratory facilities that are appropriate for the operations being performed.The influenza epidemic that swept the world in killed an estimated 50 million people.
One fifth of the world's population was attacked by this deadly virus. Within months, it had killed more people than any other illness in recorded history. An influenza pandemic is an epidemic of an influenza virus that spreads on a worldwide scale and infects a large proportion of the world population.
In contrast to the regular seasonal epidemics of influenza, these pandemics occur irregularly – there have been about . the wake of the devastating influenza epidemic of –19, a pandemic that took a far heavier toll of Indian life and resources than all of the casualties sustained throughout the war.
(Indians accounted for roughly half of the pandemic’s total deaths worldwide.). The –19 ‘Spanish’ Influenza was the most devastating pandemic in recent history, with estimates of global mortality ranging from 20 to 50 million.
The focal point of the pandemic was India, with an estimated death toll of between 10 and 20 million. We will characterize the pattern of. Causes of the Influenza Epidemic in New Zealand. The Influenza pandemic was a world disaster that affected millions of people worldwide.
There were two strands of the Influenza virus which were thought to have originated as an avian flu passed from pigs in a nearby pen to soldiers in military camp Funston, in Kansas, America. The influenza pandemic (January – December ; colloquially known as: Spanish flu) was an unusually deadly influenza pandemic, the first of the two pandemics involving H1N1 influenza virus.