Rubella virus and birth defects

Amidst the fear surrounding Zika virus, remember that there are over 100,000 children born each year with birth defects caused by infection with rubella virus. The virus Rubella virus is a member of the Togaviridae family, which also includes chikungunya virus. The genome is a 9.7 kilobase, positive strand RNA enclosed in a capsid and surrounded by a membrane (illustrated; image from ViralZone). Transmission Humans are the only natural host and reservoir of rubella virus. The virus is transmitted from human to human by respiratory aerosols.  Upon entry into the upper respiratory tract, the virus replicates in the mucosa and local lymph nodes. Virus then enters the blood and spreads to regional lymph nodes, where it replicates and a second viremia ensues. The incubation period is approximately 14 days, after which virus is shed by respiratory secretions, allowing transmission to other hosts. The second viremia brings virus to the skin, where a rash appears after 14-21 days. Signs and Symptoms Rubella is a mild disease associated with low grade fever, swollen lymph nodes and a morbilliform rash. Before a vaccine was available, infection typically occurred between 5-9 years of age. In 1942 the opthalmologist Norman Gregg found that many children with cataracts also had other serious congenital defects. He noticed that an epidemic of congenital cataracts was preceded by a rubella outbreak, and proposed that cataracts and other abnormalities were caused by maternal...
Source: virology blog - Category: Virology Authors: Tags: Basic virology Information birth defects congenital rubella syndrome microcephaly mmr vaccine placenta viral virus viruses Zika zika virus Source Type: blogs