Rubella, also known as German measles or 3-day measles, is a mild often exanthematous disease of infants and children that is severe and associated with complications in adults. It is self-limiting disease associated with a characteristic maculopapular rash.
It is caused by a single-stranded RNA virus classified as a togavirus, genus Rubivirus.
Transmission is through airborne or droplets shed from respiratory secretions.
Highly communicable at the onset of the rash, however viral shedding may also occur 5-7 days before, to 5-7 days or more following appearance of the rash.
The incubation period is 14-21 days.
Chronic hepatitis B virus (HBV) infection is a global problem. Chronic
HBV infection is probably the most common maternal infection encountered
in Hong Kong, China, and Southeast Asia. In Hong Kong, which is one of
the endemic areas, immunisation against HBV was first provided in 1983
to infants born to mothers who were screened positive for hepatitis B
surface antigen (HBsAg). Immunisation became widespread since November
1988, but HBsAg-positive mothers are still encountered frequently.1