St. Louis encephalitis
Ultrasensitive qualitative detection of St. Louis encephalitis
virus by reverse transcription coupled real time polymerase
virus (WNV) and St. Louis encephalitis (SLE) virus are both
arthropod-borne viruses within the Japanese encephalitis virus
serocomplex (Murphy et al., 1995). They belong to the family
Flaviviridae, genus Flavivirus. This group of viruses possesses
a single positive strand of RNA genome of approximately 11 kb.
Like West Nile virus and Japanese encephalitis virus, SLE is
transmitted primarily through Culex species mosquitoes and
birds. Humans, primates and other mammals are thought to be
incidental hosts (Monath and Heinz, 1996).
endemic SLE virus transmission in nature is silent, with no
reports of avian mortality. Nevertheless, significant endemic
spread of SLE in United States and in several South American
countries has been reported. Over the past 70 years, SLE virus
has been responsible for numerous epidemics throughout the
United States; the largest occurred in 1975, with approximately
2,000 cases reported (Monath and Heinz, 1996).
this SLE virus by virus isolation followed by identification
through immunofluorescence assays can take over a week to
complete. Immunoglobulin M (IgM) capture and IgG enzyme-linked
immunosorbent assays (ELISAs) are also used to detect this
virus. However, confirmation of the infection can only be
inferred by a fourfold or greater rise in virus-specific
neutralizing antibody titers in either cerebrospinal fluid (CSF)
or serum by performing the plaque reduction neutralization assay
(PRNT) with several flaviviruses. Virus culture from CSF or
serum has generally been unsuccessful due to the low level and
short-lived viremia. PCR detection of this virus, thus,
represents a rapid, specific and sensitive approach to detection
of this virus.
Help confirm the disease causing agent
Help ensure that animal colonies are free of SLE virus
Early prevention of spread of the virus among animal
Minimize personnel exposure to the virus
Safety monitoring of biological products and vaccines
that derive from animals
Monath, T.P. and Heinz, F.X. (1996) Flaviviruses, p. 978-984. In
B.N. Fields (ed.), Fields virology, vol. 1, 3rd ed.
Lippincott-Raven Publishers, Philadelphia, Pa.
Fauquet, C.M., Bishop, D.H.L., Ghabrial, S.A., Jarvis, A.W.,
Martelli, G.P., Mayo, M.A. and Summers, M.D. (1995) Virus
taxonomy, classification and nomenclature of viruses. Arch.
Virol. 10 (Suppl): 1-586.
Specimen requirements: 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
tube, or 0.2 ml fresh or frozen CNS tissue, or 0.2 ml CSF, serum
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
Qualitative reverse transcription coupled real time PCR