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       Murray Valley Encephalitis is a Flavivirus that is related but less viral than the Kunjin Virus. is endemic in northern portions of Australia and New Guinea.  Earlier designations for the disease were Australian Encephalitis and Australian "X" Disease.  The virus may cause neurological disease or even death in humans.  Although endemic in Northern Australia the virus sometimes spreads to more southerly areas during periods of high rainfall in summer.  Outbreaks of the disease are spaced by decades and little or no cases between.


       Mosquitoes are the vectors with a bird to mosquito to bird cycle.  Birds inhabiting aquatic areas are the natural reservoir for the virus.  Culex annultrostris is the principal vector, and infection can only occur through mosquito bites and not from infected persons.




       Epidemics first were reported in 1917-1918 in Southeastern Australia after several years of heavy rainfall.  Virus isolation from humans was made in 1951 following an epidemic in the Murray Valley.  Epidemic threats increase when infected birds or mosquitoes migrate from more northerly parts of Australia.  Therefore, public health personnel in southern Australia test "sentinel chickens" that are placed near bird breeding sites for virus to warn of pending epidemics.




       No vaccines were available as of 2017.  Cover exposed parts of the body by wearing long-sleeved shirts, a hat and long trousers. Products such as DEET, Picaridin and Oil of Lemon Eucalyptus are useful repellents. Clothing that is treated with Permethrin remain protective even after several washings.  For areas with large mosquito populations it is advisable to have screened or air-conditioned rooms.  Netting is required if sleeping outdoors.


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 Key References:     <medvet.ref.htm>    <Hexapoda>


Burnet, F. M.  1952.  Murray Valley encephalitis.  Nations Health.  Amer. J. Publ. Health 42(12):  1519-1521.

French, E. L.  1952.  Murray Valley encephalitis isolation and characterization of the aetiological agent.  Med. J. Australia 1(4):  100-103.

Hurrelbrink, R. J., A. Nestorowicz & P. C. McMinn.  1999.  Characterization of infectious Murray Valley encephalitis virus derived from a stably cloned genome length cDNA.  J. Gen. Virol. 80 (12):  3115-1325.

Matheson, R. 1950.  Medical Entomology.  Comstock Publ. Co, Inc.  610 p.

Service, M.  2008.  Medical Entomology For Students.  Cambridge Univ. Press.  289 p

Legner, E. F.  1995.  Biological control of Diptera of medical and veterinary importance.  J. Vector Ecology 20(1): 59_120.

Legner, E. F.  2000.  Biological control of aquatic Diptera.  p. 847_870.  Contributions to a Manual of Palaearctic Diptera,

          Vol. 1, Science  Herald, Budapest.  978 p.

Marshall, I. D., B. K. Brown, K. Deith, G. P. Gard & E. Thibos.  1982.  Variation in arbovirus infection rates in species of birds sampled in a

     serological  survey during an encephalitis epidemic in the Murray Vally of South-eastern Australia, Feb. 1974.  Australian J. Exptal. Biol.

     Med. Sci. 60(5):  471-78.