PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES
SECTION I - INFECTIOUS AGENT
NAME: Rubella virus
SYNONYM OR CROSS REFERENCE: German measles(1-5), 3 day
PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES
SECTION I - INFECTIOUS AGENT
NAME: Rubella virus
SYNONYM OR CROSS REFERENCE: German measles(1-5), 3 day measles(4), congenital rubella syndrome (CRS)(1-5).
CHARACTERISTICS: Family Togaviridae, Genus Rubivirus. Each virion is 55-89 nm and contains one positive stranded RNA molecule. Genetic material is enveloped in an isometric nucleocapsid. The capsid consists of multiple copies of one virus-specific protein, surrounded in a lipid bilayer containing two virus-specific glycoproteins.
SECTION II - HAZARD IDENTIFICATION
PATHOGENICITY/ TOXICITY: Rubella: Mild infection characterized by rash starting on the face and gradually spreading to the feet, fever, lymphadenopathy, and other flu-like symptoms such as coughing, sore throat, and sneezing(2,3). Older children and adults may experience joint involvement and purpuric rash(2). Rare complications include encephalitis, thrombocytopenia with hemorrhagic manifestations, neuritis, conjunctivitis, and ochitis(3). Individuals are infectious up to 7 days before the onset of the rash and up to 7 days after its disappearance(2).
Congenital rubella syndrome: Women in their first trimester who contract rubella have an increased risk of passing the infection to the developing foetus(3). When contracted during the first trimester the effects on the child are most marked. Ocular, cardiovascular, and central nervous system defects are common, along with deafness and intrauterine growth retardation. Contraction of rubella later in pregnancy reduces the risk and severity of symptoms. Second trimester infections are associated with deafness, retinopathy, microcephaly, and mental retardation, while third trimester infections are associated with intrauterine growth retardation.
EPIDEMIOLOGY: Worldwide(1,3). Epidemics occurred roughly every 6-9 years but immunisation programmes have greatly reduced the number of cases in developed countries(1,3). Infections peaks in late winter and spring(3).
HOST RANGE: Humans(1,5).
INFECTIOUS DOSE: Thirty viral units subcutaneously, >10 viral units by pharyngeal spray, and 60 units by nasal drops are sufficient for infection(6).
MODE OF TRANSMISSION: The virus is transmitted by aerosols from the respiratory tract in infected individuals(7). Transmission may also occur via nasal and respiratory tract secretions carried on hands that come in contact with nasal mucosa.
INCUBATION PERIOD: The incubation period is 14-17 days with a range of 14-21 days(8). Rash is the first symptoms to appear. Rash appears 2 weeks after infection(1,3).
COMMUNICABILITY: Carrier is infectious for 7 days before appearance of rash and for 5-7 days after the appearance of the rash(2,3). Transmission requires close person-to-person contact(7).
SECTION III - DISSEMINATION
SECTION IV - STABILITY AND VIABILITY
DRUG SUSCEPTIBILITY: Susceptibility to antiviral drugs has not been reported(1).
SUSCEPTIBILITY TO DISINFECTANTS: Rubella virions are susceptible to ether, chloroform, sodium dodecyl sulphate (SDS), saponin, formaldehyde, ethylene oxide and beta- propiolactone(1). 1% sodium hypochlorite and 70% ethanol are also effective disinfectants(7).
PHYSICAL INACTIVATION: Temperatures exceeding 56 °C for 2-20 minutes, 37°C for 48 hours, or -20 °C will inactivate the Rubella virus(1). Virions are also susceptible to UV light. Virions are not stable at a pH less than 6.8 or greater than 8.0(1).
SURVIVAL OUTSIDE HOST: Rubella has a half life of 1 hour at 37 °C outside of the host(9). The mean survival time is 0.9 days.
SECTION V - FIRST AID / MEDICAL
SURVEILLANCE: Monitor for symptoms. Confirm diagnosis with serological testing(1). Enzyme-linked immunosorbent assays (ELISA), hemagglutination inhibition test (HI), and immunofluorescent antibody assay (IFA) are common methods used. Serologic testing can also be used to confirm congenital rubella syndrome in an infant, which may yield more harm than the rubella virus itself.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Treatment for rubella