During the bubonic plague (bacterium Yersinia pestis) in England in 1665, Daniel Defoe wrote, in his Journal of the Plague Year, "The contagion despised all medicine; death raged in every corner; and had it gone on as it did then, a few weeks more would have cleared the town of all."1
Are we facing such a threat again with the potential for an H5N1 avian influenza pandemic or are we, as Chicken Little, merely flustered because the sky appears to be falling?
The purpose of this article is to revisit and update an article published in ADVANCE for Medical Laboratory Professionals on Nov. 16, 2004, (Vol. 16, No. 23) entitled "A Plague on Wings: Avian Influenza."
Most experts agree that the probability of such an occurrence is not if, but when it will happen. Historically, avian influenza, or bird flu, has been an extremely dangerous virus. Recent reverse genomic sequencing was performed on influenza virus in lung tissue obtained from a woman's body exhumed from permafrost in Alaska. She died as a result of the 1918 Spanish influenza. The sequencing revealed that the pandemic of 1918, which killed from 20 million to 50 million people worldwide during World War I, was indeed an avian strain of the virus.2
Although the majority of cases thus far have resulted from bird-to-human transmission, the major concern, supported by epidemiologic data gathered from the past, is that the incoming avian influenza virus will swap genes or recombine with the garden variety current human strain (H3N2) and adapt to humans.
Our real threat is that history will repeat itself and avian influenza will, through genetic reshuffling in the human host, gain vital antigenic keys that will enable it to spread rapidly from human to human via a respiratory route. This is why it is vital that population-wide immunization be carried out against the common strain of influenza. If individuals contract this common strain (H3N2) and become superinfected with H5N1, they may serve as a melting pot or incubator for a new recombinant human-adapted avian strain that can more readily spread from human to human by coughing, sneezing or close contact.3
In 1997, the H5N1 virus began its smoldering westward advance out of the East, thanks in part to transmission via seasonal migratory flights of a variety of wild birds, geese, mallards and coots across the pole. Extremely close contact between domestic fowl and humans in China, Hong Kong, Southeast Asia in general and in the Netherlands has fueled the spread.
Millions of domestic birds have been destroyed in an attempt to stem its dissemination. Numerous countries have invoked quarantine by prohibiting importation of both domestic fowl and exotic birds destined for sale as pets.
Recently, the virus was imported into Great Britain by two parrots, both of which died in quarantine. The virus, in its westward flight, has been detected in swans in Croatia and in fowl in Russia, Turkey, Greece and Sweden.
Wild geese in Germany found dead have tested positive for avian influenza, but confirmation that it is the H5N1 strain is still pending. On Oct. 31, H5 antigen-bearing influenza was detected in wild migratory ducks in Quebec and Manitoba. It has not yet been confirmed if this is indeed the H5N1 avian influenza virus.4
A public health official in Tennessee stated that 2,000 to 5,000 deaths statewide might be expected should the virus reach the area through migratory wildfowl.5
What can be done to deal with this influenza virus that has killed more than 60 people and has a mortality rate exceeding 50%? We have never seen a virus of this magnitude in this country since smallpox erupted in the American colonies.
The sidebar details strategies outlined by the CDC and WHO.
Based on epidemiologic data, we are historically well overdue for an influenza pandemic. Knowledge, preparedness and readiness are our most valuable watchwords from the standpoint of the clinical laboratory. Let's do all within our power to prevent a viral Katrina.
Linda Williford Pifer is a professor in the department of clinical laboratory sciences at the College of Allied Health Sciences at the University of Tennessee Health Science Center at Memphis. No endorsement by the author or her academic institution should necessarily be construed for any medication described in this publication.
1. DeFoe D. A Journal of the Plague Year. New York: Modern Library, 2001.
2. Taubenberger JK, Reid AH, Lourens RM, Wang R. Characterization of the 1918 influenza virus polymerase genes. Nature 2005;437(7060):889-893.
3. Adler J. The Fight Against the Flu. Available at www.msnbc.msn.com/id/9787849/site/newsweek. Last accessed Nov. 31, 2005.
4. The Cattle Network. Available at www.cattlenetwork.com/AH_Content.asp?contentid=13691. Last accessed Nov. 31, 2005.
5. Jones B. Epidemiologist discusses threat of avian influenza. The Greeneville Sun. Available at: www.greene.xtn.net. Last accessed Nov. 2, 2005.