NAME: Yellow fever virus
SYNONYM OR CROSS REFERENCE: Arbovirus, Yellow fever, YF
CHARACTERISTICS: Flaviviridae (Flavivirus); 40-50 nm diameter, ssRNA, enveloped virus
PATHOGENICITY: Acute disease of short duration and varying severity; sudden onset fever, aches, prostration, nausea, vomiting; weakened pulse, albuminuria, anuria, leukopenia; hemorrhagic symptoms; jaundice; <5% case fatality rate among indigenous population in endemic areas, but may reach 50% among non-indigenous groups or in epidemics
EPIDEMILOLOGY: No cases of urban yellow fever in Americas since 1942; urban cases reported in Africa where jungle or sylvan yellow fever is enzootic; sylvan yellow fever of tropical America now occurs among adult males who are exposed in the forest - enzootic in South America, no yellow fever in Asia or easternmost coast of Africa; there have been two cases of fatal yellow fever imported into the USA 1996,1999
HOST RANGE: Humans, monkeys, other primates, possibly marsupials
INFECTIOUS DOSE: Unknown
MODE OF TRANSMISSION: By bite of infective mosquitos; virus is transmitted from monkeys to humans
INCUBATION PERIOD: Three to 6 days
COMMUNICABILITY: Blood is infective for mosquitoes shortly before onset of fever and first 3 to 5 days of illness; highly communicable where many susceptible persons and vectors coexist; not communicable by contact or common vehicles; mosquitos become-infective after 9 to 12 days and remain so for life
RESERVOIR: Urban areas - humans, mosquitoes; forest areas - vertebrates other than humans (mainly monkeys) and possibly marsupials, forest mosquitos; transovarial transmission in mosquitos contributes to maintenance of infection
ZOONOSIS: Yes (jungle yellow fever)
VECTORS: Urban areas - Aedes aegypti mosquitoes
South America forests - Haemogogus (sylvan
mosquitoes)
East Africa - Aedes africanus (monkeys)
Aedes bromeliae (Ae. simpsoni) (monkey to
humans)
West Africa - Ae. furcifer-taylori, Ae. luteocephalus (monkeys to humans)
DRUG SUSCEPTIBILITY: N/A
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to many disinfectants - 1% sodium hypochlorite, 2% glutaraldehyde, 70% ethanol, 3-8% formaldehyde, 2-3% hydrogen peroxide, 1% iodine and phenol iodofors; also susceptible to organic solvents and detergents due to lipid envelope; 0.1% formalin - 48 hours
PHYSICAL INACTIVATION: Heating at 60° C for 10 min; ; UV and gamma irradiation
SURVIVAL OUTSIDE HOST: Does not survive out of host
SURVEILLANCE: Monitor for febrile illness: demonstration of viral antigen in blood using serological techniques, rise in antibody titre
FIRST AID/TREATMENT: No specific treatment
IMMUNIZATION: Licensed attenuated live vaccine recommended for all personnel who work with agents or infected animals, and those who enter rooms where agents or infected animals are present; the vaccine is contra-indicated to those who are immunosuppressed, who have known anaphylaxis to the ingestion of eggs, who are taking corticosteroids, and who are pregnant; vaccine is heat sensitive and should be stored between 5° C and -30° C in it's un-reconstituted form
PROPHYLAXIS: None
LABORATORY-ACQUIRED INFECTIONS: 40 reported laboratory-acquired cases with 9 deaths; contact with infected blood was responsible in some infections
SOURCES/SPECIMENS: Blood, CSF, urine and exudates, depending on the stage of disease
PRIMARY HAZARDS: Exposure to aerosols of infectious solutions and animal bedding; accidental parenteral inoculation; broken skin contact
SPECIAL HAZARDS: Laboratory-associated infections have occurred by aerosol route in unvaccinated individuals
CONTAINMENT REQUIREMENTS: Biosafety level 3 practices, containment equipment and facilities for activities using potentially infectious clinical materials and infected tissue cultures, animals or arthropods
PROTECTIVE CLOTHING: Laboratory coat; gloves when direct contact with infectious materials is unavoidable; gown with tight wrists and ties in back when working with infectious materials
OTHER PRECAUTIONS: HEPA filtration of all exhaust air prior to discharge from the laboratory; vaccination of workers
SPILLS: Allow aerosols to settle; wearing protective clothing (respirator), 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 (30 min)
DISPOSAL: Decontaminate before disposal; steam sterilization, incineration
STORAGE: In sealed containers that are appropriately labelled (in locked level 3 facility)
Date prepared: January, 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