Measles outbreak highlights importance of immunisation
The recent measles outbreak in New South Wales has highlighted the importance of promoting the measles-mumps-rubella (MMR) vaccine for children under 5 years of age, adolescents and young adults.
A young adult returning home from overseas while infectious with measles caused the NSW outbreak in April. This person transmitted the virus to other susceptible contacts, which resulted in further clusters of cases in metropolitan Sydney.
In Australia, most measles cases occur in unvaccinated people who are infected overseas. However, most of the recent NSW cases had no history of overseas travel. This indicates the disease was spread within the local community to people who were unvaccinated or not fully vaccinated.
The highest notification rates of measles in NSW were in children younger than 5 years of age. This was largely as a result of transmission to infants under a year old who were too young to be vaccinated. The 15 to 19 year age group has also had high rates of measles, with several high schools affected. Persons of Pacific Island and Aboriginal backgrounds have been disproportionately affected. The majority of these cases were unvaccinated.
Measles is caused by a highly contagious virus that is spread from an infected person via respiratory droplets (through coughing and sneezing) or through the air. It can be a very severe disease. About 1 in 10 children with measles will get an ear infection and as many as 1 in 20 will develop pneumonia. About 1 in 1,000 will get encephalitis, and half in this group will die. Worldwide, there are an estimated 20 million cases of measles each year and 164,000 deaths resulting from the disease. More than half of these deaths occur in India.
Anyone exposed to measles who is not immune to the virus is likely to become infected with the disease. The infectious period is from 2 days before the onset of symptoms until 4 days after the rash has appeared. Measles symptoms include fever, followed by runny nose, conjunctivitis, cough and Koplic spots in the mouth. A few days later a rash appears on the face and works its way down the body and limbs.
It is important to recognise the early signs and symptoms of measles to prevent further spread. Anybody suspected of having measles should be encouraged to undertake appropriate testing (PDF 511KB), with specimens sent to PathWest for urgent processing. In addition, a notification form should be completed and sent to the Communicable Disease Control Directorate in metropolitan areas, and the local public health unit in regional areas.
Anybody who is infected, or is suspected of being infected, should be isolated from non-immune people and kept away from places such as the workplace, school and day care centres. They should remain isolated until the results of tests are available to determine appropriate management. This includes contact tracing of immediate household and social contacts. Local public health staff can assist with contact tracing.
The MMR vaccine is safe and effective and is recommended to be given at 12 months and 3.5 to 4 years of age. Two doses of vaccine, at least a month apart, will provide lifelong protection.
Children or adults born during or since 1966, who do not have evidence of measles infection or documented evidence of having received two doses of the MMR vaccine, are considered to be susceptible to measles and should be strongly encouraged to have the MMR vaccine.
Measles can be prevented by immunisation. Health service providers are encouraged to alert parents to the importance of having their children fully immunised.
People planning overseas travel should be encouraged to ensure that they have received 2 doses of the MMR vaccine at least 1 month apart.