MATERIAL SAFETY DATA SHEET - INFECTIOUS SUBSTANCES

SECTION I - INFECTIOUS AGENT

NAME: Murray Valley encephalitis

SYNONYM OR CROSS REFERENCE: Australian X disease, mosquito-borne encephalitis, arbovirus, viral encephalitis, Australian encephalitis is a proposed name

CHARACTERISTICS: Family Flaviviridae (formerly Togaviridae); 40-50 nm diameter, enveloped, positive sense ssRNA; member of the Japanese encephalitis (JE) antigenic complex

SECTION II - HEALTH HAZARD

PATHOGENICITY: Acute inflammatory disease of short duration involving brain, spinal cord and meninges; acute onset, headache, high fever, followed by nuchal rigidity, neurologic signs, stupor, coma, spastic quadriplegia, convulsions and paralysis including respiratory, progressive CNS damage; progresses rapidly in infants; up to 60% case fatality rate; neurologic sequelae in up to 40% of mild cases and all severe cases including paraplegia, impaired gait and motor control, decreased intellect; no asymptomatic infections have been recorded.

EPIDEMIOLOGY: Murray Valley encephalitis recognized in parts of Australia, New Zealand and New Guinea

HOST RANGE: Humans, wild birds, other mammals

INFECTIOUS DOSE: Unknown

MODE OF TRANSMISSION: By bite of infective mosquitoes

INCUBATION PERIOD: Usually 5-15 days

COMMUNICABILITY: Not directly transmitted from person-to-person; virus is not demonstrated in blood of human after onset of disease; viremia in birds 2-5 days; mosquitoes are infective for life

SECTION III - DISSEMINATION

RESERVOIR: Principally large water birds, other mammals may contribute

ZOONOSIS: Yes, from infected animals via mosquitoes; infected animals do not develop disease

VECTORS: Mosquitoes - Culex spp. especially Culex annulirostris

SECTION IV - VIABILITY

DRUG SUSCEPTIBILITY: N/A

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to disinfectants - 1% sodium hypochlorite, 2% glutaraldehyde, 3-8% formaldehyde, alcohol, iodine, phenol iodophors, and organic solvents/detergents

PHYSICAL INACTIVATION: Inactivated by heat; 50% reduction in 10 min at 50^o C, complete inactivation in 30 min at 56^o C; inactivated by UV and gamma irradiation

SURVIVAL OUTSIDE HOST: Does not survive out of host

SECTION V - MEDICAL

SURVEILLANCE: Monitor for symptoms of arthropod-borne viral fever; serological identification and antibody titre

FIRST AID/TREATMENT: No specific treatment; supportive care

IMMUNIZATION: None

PROPHYLAXIS: None

SECTION VI - LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: 3 reported infections with Murray Valley

SOURCES/SPECIMENS: Blood, CSF, urine and exudates

PRIMARY HAZARDS: Exposure to aerosols of infectious solutions and animal bedding, accidental parenteral inoculation, broken skin contact

SPECIAL HAZARDS: None

SECTION VII - RECOMMENDED PRECAUTIONS

CONTAINMENT REQUIREMENTS: Biosafety level 3 practices, containment equipment and facilities for activities using potentially infectious clinical materials and infected tissue culture, animals or arthropods

PROTECTIVE CLOTHING: Laboratory coat; gloves and gown with ties in back and tight wrists when working with agent

OTHER PRECAUTIONS: None

SECTION VIII - HANDLING INFORMATION

SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with paper towels and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time before clean up

DISPOSAL: Decontaminate before disposal; steam sterilization, incineration

STORAGE: In sealed containers that are appropriately labeled (in a locked level 3 facility)

SECTION IX - MISCELLANEOUS INFORMATION

Date prepared: March, 2001

Prepared by: Office of Laboratory Security, PHAC

Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Health Canada, 2001

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