ASPEK VIRUS RUBELLA

VIROLOGICAL ASPECT OF RUBELLA History From Latin meaning "little red" 1881 Rubella first described by German physicians, Friedrich Hoffmann 1941 Associated with congenital disease (Gregg) 1961 Rubella virus first isolated 1967 Serological tests available 1969 Rubella vaccines available

CHARACTERISTIC RNA enveloped virus member of Rubivirus togavirus family Only a single serotype Rapidly inactivated by (chemical agents, ultraviolet light, low pH, and heat) Occurs primarily in children and adolescents

PATHOPHYSIOLOGY Transmission is by respiratory Replication in nasopharynx and regional lymph nodes Viremia 5-7 days after exposure with spread to tissues Placenta and fetus infected during viremia Incubation period is 2 to 3 weeks

CLINICAL MANIFESTATIONS Malaise Headache Myalgias and arthralgias Post-auricular adenopathy Conjunctivitis non-pruritic, erythematous, maculopapular rash

LABORATORY TEST isolated from the nasopharynx, the blood, the urine, and CSF. Newer tests with a higher specificity latex agglutination fluorescence immunoassay passive hemagglutination hemolysis in gel enzyme immunoassay

Diagnosis of acute infection LABORATORY DIAGNOSIS Diagnosis of acute infection Rising titres of antibody (mainly IgG) Presence of rubella-specific IgM Immune Status Screen latex agglutination are routinely used 15 IU/ml is regarded as the cut-off for immunity

Epidemic Rubella – United States, 1964-1965 12.5 million rubella cases 2,000 encephalitis cases 11,250 abortions (surgical/spontaneous) 2,100 neonatal deaths 20,000 CRS cases deaf - 11,600 blind - 3,580 mentally retarded - 1,800 8

TREATMENT No specific treatment of rubella exists. The disease is usually self-limited. Rest and oral fluids are appropriate.

PREVENTION The best protection is vaccination Given with the measles and mumps vaccine (MMR) at age 12-15 months and again at school entry at 4-6 years. One injection usually imparts lifelong immunity.

CONTRAINDICATIONS TO VACCINATION Pregnant women Patients receiving immunoglobulin Patients who are seriously ill Patients with severe altered immunity Patients on immunosuppressive therapy Patients with HIV

ADVERSE REACTIONS TO VACCINATION Fever 5%-15% Rash 5% Joint symptoms 25% Thrombocytopenia <1/30,000 doses Parotitis rare Deafness rare Encephalopathy <1/1,000,000 doses

COMPLICATION Congenital Rubella Syndrome (CRS) is the most severe and important complication the severity depends on how early the infection occurs. The most common abnormalities ophthalmologic (cataracts, retinopathy). Cardiac (patent ductus arteriosus, pulmonary stenosis) Auditory ( sensineural deafness)

COMPLICATION Neurologic disorders (meningoencephalitis, mental retardation with behavioral disorders)

RISK OF CONGENITAL RUBELLA %

MANIFESTATIONS OF CONGENITAL RUBELLA %

TERIMA KASIH

The Lytic Cycle

The Lysogenic Cycle