ASPEK VIRUS RUBELLA VIROLOGICAL ASPECT OF RUBELLA History

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 p. H, 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

LABORATORY DIAGNOSIS Diagnosis of acute infection Rising titres of antibody (mainly Ig. G) Presence of rubella-specific Ig. M 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

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 Rash Joint symptoms Thrombocytopenia Parotitis Deafness Encephalopathy 5%-15% 5% 25% <1/30, 000 doses rare <1/1, 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)