Introduction
The Web of Science covers over 11,000 authoritative
scholarly journals and 130,000 academic conferences from around the
globe, reflecting all fields of scholarly research, and is the
world's leading citation database. The unique capability of the
Web of Science’s citation coverage facilitates the
linking between current research articles and those previous
articles that were utilized by the researchers. Additionally,
citations can instantly uncover the most important high-impact
research.
This article uses the Web of Science to uncover important
research from the past that may help researchers investigate the
current Swine Influenza outbreak.
Historic Trends
Searching article titles in the Web of Science using the
Boolean search: “(influenza or flu) and epidem*”
will find 1,477 unique articles. Looking at the year of
publication of the articles, there is a distinct and large peak in
the number of records published shortly after the outbreak of
A/H1N1 influenza (Spanish Flu) in 1918-1919.
Figure #1: Number of articles per year
relating to influenza epidemics
Source = Thomson Reuters – Web of
Science®
Although early indications1 suggest that it will not
have the virulence of the 1918 influenza epidemic, the 2009
outbreak of Swine Influenza is also the A/H1N12 strain,
unlike the 1957 Asian Flu (A/H2N2 strain) or the 1968 Hong Kong flu
(A/H3N3 strain)3. Both the Asian and Hong Kong Flu
epidemics have also been succeeded by an increase in the number of
scholarly articles published.
The more recent high activity in research may be related to the
repeated outbreaks of the H5N1 strain of influenza, often known as
bird or avian influenza, particularly during 2003
and 2005.
It is worth noting that in general terms the overall volumes of
scholarly articles published, in all fields of research, have been
increasing year on year. Therefore the size of the peak in the
period of 1918-1924 is actually far higher when considered as a
proportion of the overall body of scholarly research published in
the same period. Figure #1 shows the publishing trend normalized to
2008 levels of publishing volumes.
Figure #2: Normalized
number of articles per year relating to influenza
epidemics.
Normalized to represent the number of articles that would have
been published if the global research output at that period of time
were consistent with 2008 levels
Source = Thomson Reuters – Web of
Science®
Highly Cited Articles
Measuring the number of citations to an article gives an indication
of how influential the article has been and can be a useful tool to
quickly identify the most important and groundbreaking research.
There are many relevant and highly cited articles published
throughout the period.
Selected examples of interest are listed below:
Table #1: Selected highly cited articles from the
Web of Science relating to influenza epidemics published
between 1918 and 1980.
J. Houswort, A.D. Langmuir, “Excess mortality
from epidemic influenza,” American
Journal of Epidemiology, 100(1): 40-8,
1974.
Times Cited: 135
|
T.C. Eickhoff, I.L. Sherman, IL, R.E.
Serfling, “Observations on excess mortality
associated with epidemic influenza,”
JAMA-Journal of the American Medical
Association, 176 (9): 776, 1961.
Times Cited: 155
|
F.M. Davenport, A.V Hennessy, T. Francis,
“Epidemiologic and immunologic significance
of age distribution of antibody to antigenic
variants of influenza virus,”
Journal of Experimental Medicine, 98 (6):
641-656, 1953.
Times Cited: 237
|
F.L. Horsfall, “Neutralization of
epidemic influenza virus - The linear relationship
between the quantity of serum and the quantity of
virus neutralized,”
Journal of Experimental Medicine, 70 (2):
209-222, 1939.
Times Cited: 165
|
Many articles published in older literature continue to be cited in
the present day, demonstrating that they are still of value to
current research.
Conclusion
Thankfully, influenza epidemics are a rare occurrence, and the last
epidemic of A/H1N1 strain was in 1918. Scholarly research from that
period of time may be of value to researchers today—however,
research from this period can be difficult to locate because most
literature databases do not cover so far back in time. Furthermore,
narrowing in on the relevant and important articles may prove
difficult because the research has fallen out of institutional
memory. The Web of Science, with its excellent
retrospective coverage and powerful search tools based on
citations, can be a useful aid to discovering this hard-to-locate
information.
Cited References
