The influenza A and influenza B viruses cause what
is commonly called "the flu". The flu is a highly contagious,
acute, viral infection of the respiratory tract that is easily
transmitted by aerosol from person to person via coughing and
sneezing.
1 Common symptoms of the flu include: fever;
headache; fatigue; dry, sore throat; and body aches.
Outbreaks usually occur each year through the fall and winter
months,
2 that is between November and March in the
Northern Hemisphere and between May and September in the Southern
Hemisphere. An estimated 10-20% of U.S. residents get the flu each
year; an estimated 114,000 people are hospitalized for flu-related
complications and 36,000 Americans die each year from complications
of the flu.
3 Infection with influenza virus predisposes
people to infection with
Streptococcus
pneumoniae,
4,5 the leading cause bacterial
pneumonia. Notably,
pneumonia and influenza are the
fifth most common cause of death for persons age 65 and
older.
6
For more information about the flu, please follow links indicated
below:
1 Mossad SB. 2003. Common Cold and Influenza, pp.
265-278,
in Medical Management of Infections Disease. C.J.
Grace, ed. Pp 265-278. Marcel Dekker, Inc., New York.
2Williams, KM, Jackson, MA, Hamilton, M.
Rapid
Diagnostic Testing for URIs in Children: Impact on Physician
Decision Making and Cost.2002. Infect. Med. 19(30):109-111
.
3 http:/www.cdc.gov/flu/keyfacts.htm
4 McCullers JA, Bartmess, KC.
Role of neuraminidase in lethal synergism between influenza virus
and Streptococcus pneumoniae. 2003. J Infect Dis. Mar
15:187(6):1000-9. Epub 2003 Mar 06.
5 Reed N, Horvat, R. Influence of influenza A infection
on the binding of
Streptococcus pneumoniae to human lung
epithelial cells. 102nd General Meeting of the American Society for
Microbiology, May 19-23, 2002.
6 Hoyert DL, Kochanek DK, Murphy SL.1999.
National Vital
Statistics Reports. National Center for Health Statistics,
Hyattsvilee, Marlyand.47:19.