Cytomegalovirus

Infectious Agent: 

NAME: Cytomegalovirus
SYNONYM OR CROSS REFERENCE: CMV, Human (beta) herpesvirus 5
CHARACTERISTICS: Herpesviridae, double-stranded linear DNA, 150 nm diameter, enveloped, icosahedral,

Health Hazard: 

PATHOGENICITY: Infection is common and usually asymptomatic; most severe form is congenital with severe generalized infection involving CNS and liver; lethargy, convulsions, jaundice, pneumonitis, encephalitis; high neonatal case fatality rate for severely affected infants; inapparent infections later in life, mononucleosis-like but without pharyngitis; reactivation, infection, or reinfection may occur in immunocompromised patients (bone marrow and other transplants) - pneumonitis, hepatitis are retinitis are most common manifestations in this group
EPIDEMIOLOGY: Worldwide; acquired early in developing countries; serum antibodies in adults 40% in developed areas and 100% in developing countries; higher in women; immunodeficient patients (fetus, newborn, immunocompromised) at high risk
HOST RANGE: Humans
INFECTIOUS DOSE: Not known
MODE OF TRANSMISSION: Intimate exposure by cutaneous or mucosal contact with infectious tissues, secretions or excretions (urine, saliva, breast milk, cervical secretions, semen); fetus infected in utero; postnatal infection at delivery; blood transfusion a common cause of post-transfusion mononucleosis (about 3% risk); organ transplantation
INCUBATION PERIOD: Illness occurs 3-8 weeks after transfusion with infected blood; infections demonstrable 3-12 weeks after delivery
COMMUNICABILITY: Communicable in urine and saliva for months and may persist for several years; after neonatal infection, virus may be excreted for years; adults excrete for shorter periods but virus persists as latent infection; (3% of healthy adults are pharyngeal excreters; excretion recurs with immunodeficiency and immunosuppression)

Dissemination: 

RESERVOIR: Humans; CMVstrains found in many animal species are not infectious for humans
ZOONOSIS: None
VECTORS: None

Viability: 

DRUG SUSCEPTIBILITY: Gancyclovir reduces or interrupts viral replication in vivo
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to disinfectants - 1% sodium hypochlorite, 70% ethanol, glutaraldehyde, formaldehyde
PHYSICAL INACTIVATION: Inactivated by heat (50-60°C for at least 30 min), low pH, lipid solvents, UV light, cycles of freezing/thawing
SURVIVAL OUTSIDE HOST: Survives at room temperature for a few days

Medical: 

SURVEILLANCE: Monitor for symptoms; antibody screening of blood for seropositivity; confirm by virus isolation or PCR detection in blood, urine, respiratory secretions or tissue samples (organs)
FIRST AID/TREATMENT: Gancyclovir available for documented severe CMV infections
IMMUNIZATION: None available
PROPHYLAXIS: CMV specific gamma globulins (only moderate success)

Laboratory Hazards: 

LABORATORY-ACQUIRED INFECTIONS: Low incidence of infections, however the frequency of its presence in clinical materials warrants concern
SOURCES/SPECIMENS: Urine, saliva, blood, cervical secretions, breast milk, tissue in cell cultures, human tissues
PRIMARY HAZARDS: Droplet exposure of mucous membranes, accidental parenteral inoculation, ingestion, inhalation of concentrated aerosolized materials
SPECIAL HAZARDS: None

Handling Information: 

SPILLS: Allow aerosols to settle; wear protective clothing; gently cover spill with paper towel and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time (30 min) before clean up
DISPOSAL: Decontaminate before disposal; steam sterilization, chemical disinfection, incineration
STORAGE: In sealed containers that are appropriately labelled

Miscellaneous Information: 

Date prepared: Created in December 2010-  largely modified from protocols derived from the NIH, the Public Health Agency of Canada, and other related literature. 
Prepared by: Michael McManus, PhD, UCSF
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.