Latest Findings
February 1998
The Molecular Pathology Division of the Armed Forces Institute of
Pathology (AFIP) identified material of the 1918 influenza from the
frozen remains of a Native Alaskan woman buried for nearly eighty years in
Brevig Mission, Alaska. This finding came from a group of samples contributed
to the AFIP by Johan V. Hultin, MD, a pathologist who obtained permission to
perform biopsies from the City Council of Brevig Mission (formerly Teller
Mission), Alaska. Brevig Mission lost approximately eighty-five percent of its
population to the flu during one week in November 1918.
Doctor Hultin sent samples from four Breving Mission victims to the AFIP in
guanidinium thiocyanate, a solution that preserves genetic material while
inactivating any live organisms. One of the four victims' samples yielded
genetic material of the 1918 virus. The AFIP archives were the source of the
first case to provide a direct look at the virus, as reported in the journal
Science in March 1997. Recently, another positive case has been
identified by screening formalin-fixed, paraffin-embedded tissue samples from
the AFIP archives. Both archival cases were autopsies of US servicemen who died
during the pandemic--the first in Fort Jackson, SC, the second in Camp Upton,
NY.
"We have now identified three cases: the Brevig Mission case and two archival
cases that represent the only known sources of genetic material of the 1918
influenza virus," said Jeffery K.Taubenberger, MD, PhD, chief of the
institute's molecular pathology division and principal investigator on the
project.While the RNA, the genetic material of the virus, is fragmented into
tiny pieces in all three cases, molecular techniques can be used to identify
complete gene structures. All three cases are from victims of the lethal fall
wave of the pandemic. Available records indicate that all three victims died
within a week of infection. "Analyses of three cases from geographically
separated areas will allow us to evaluate the genetic variability to the
pandemic virus strain," said Ann Reid, a molecular biologist at the institute.
Determining the genetic structure of the virus may shed light on the
exceptional lethality of the flu, and contribute to the understanding
of newly emerging influenza virus strains.
February 1999
A report released on February 15 by the Armed Forces Institute of
Pathology and published in the Proceedings of the National Academy of Sciences,
indicated that researchers have completely analyzed a critical gene from the
1919 influenza virus and have determined that the virus may have
percolated for several years within humans, and perhaps pigs, until it grew
strong enough to become the world's worst influenza pandemic.
Ann Reid, a molecular biologist with the AFIP and the main author of the study
was quoted by the Associated Press as saying the gene probably "was adapting in
humans or in swine for maybe several years before it broke out as a pandemic
virus." Reid added, "We can't tell whether it went from pigs into humans or
from humans into pigs." Reid and her team were studying lung tissue preserved
from the autopsies of two soldiers and an Alaskan woman who died from
influenza. One of the soldiers had been stationed at Fort Jackson, South
Carolina and the other at Camp Upton, New York. Through this investigation,
Reid was able to map a gene called the hemagglutinin, which is key to allowing
the influenza virus to take hold. Reid reported that the hemagglutinin closely
resembles mammal genes.
Reid's report indicates that the 1918 virus apparently evolved in mammals,
either humans or pigs, over a period of years before it matured into a virus
strong enough to kill millions. The study speculates that the virus may have
percolated in humans from as early as 1900. One question left unanswered by the
study is whether humans passed the virus to pigs, or vice-versa. Despite that
lingering mystery, Reid concluded that the virus's long incubation period has
implications for predicting future outbreaks of influenza. Speaking to the
Associated Press, Reid said, "We may have to expand our concept of where
pandemics come from."
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