NAME: Varicella-zoster virus
SYNONYM OR CROSS REFERENCE: VZV, Human Herpesvirus 3, Herpes Zoster, Chickenpox, Shingles
CHARACTERISTICS: Herpesviridae, Alphaherpesvirinae; dsDNA, 100nm diameter, enveloped, icosahedral capsid
PATHOGENICITY: Chickenpox (Varicella) - acute generalized disease with sudden onset of fever and vesicular eruption of the skin and mucous membranes; rarely fatal except to immunocompromised who are at increased risk. Shingles (Zoster) - local mainfestation following reactivation of varicella present in latent form in sensory ganglia; inflammatory reaction of the posterior nerve roots and ganglia, accompanied by crops of vesicles over skin supplied by the affected nerves
EPIDEMIOLOGY: Worldwide; Varicella chiefly a disease of children (75% of population by age 15 and 90% of young adults had disease) and more frequent In winter and early spring in temperate zones; Zoster occurs more commonly in adults
HOST RANGE: Humans
INFECTIOUS DOSE: Unknown
MODE OF TRANSMISSION: By direct contact, droplet or airbone spread of secretions of respiratory tract (varicella) or vesicle fluid (zoster); indirectly via contaminated fomites; scabs are not infective
INCUBATION PERIOD: From 2-3 weeks (usually 13-17 days); may be prolonged after passive immunization to varicella or in immunodeficient individuals
COMMUNICABILITY: Chickenpox is highly communicable 1-2 days before onset of rash and 6 days after appearance of vesicles; herpes zoster not as infectious but is source of infection 1 week after appearance of lesions
RESERVOIR: Humans
ZOONOSIS: None
VECTORS: None
DRUG SUSCEPTIBILITY: Vidarabine and Acyclovir are effective
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to disinfectants - 1% sodium hypochlorite, 70% ethanol, 2% glutaraldehyde, formaldehyde
PHYSICAL INACTIVATION: Inactivated by heat
SURVIVAL OUTSIDE HOST: Virus can survive in secretions on inanimate surfaces for short periods
SURVEILLANCE: Monitor for symptoms; confirmation by recovery of virus or serology
FIRST AID/TREATMENT: Drug therapy for severe cases of herpes zoster in immunocompromised
IMMUNIZATION: Live vaccine licensed in North America
PROPHYLAXIS: Varicella-zoster immune globulin (VZIG) indicated after exposure to chickenpox or zoster in individuals with risk of serious morbidity or mortality
LABORATORY-ACQUIRED INFECTIONS: Not a demonstrated cause of lab infections
SOURCES/SPECIMENS: Vesicular fluids, extract of crusts, respiratory secretions and other clinical materials
PRIMARY HAZARDS: Direct contact with broken skin or mucous membranes; accidental parenteral inoculation, inhalation of infectious aerosols
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities are recommended for activities utilizing known or potentially infectious clinical materials or cultures
PROTECTIVE CLOTHING: Laboratory coat; gloves when direct contact with infectious materials is unavoidable
OTHER PRECAUTIONS: None
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 (30 min)
DISPOSAL: Decontaminate before disposal; steam sterilization, incineration, chemical disinfection
STORAGE: In sealed containers that are appropriately labelled
Date prepared: September, 1996 Prepared by: Office of Biosafety
LCDC
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.
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