Measles rises, again
Hear Dr Vicky Sheppeard, Director Communicable Diseases,
talk about measles control
Vicky Sheppeard, Director, Communicable Disease Branch
On New Year’s Eve NSW Health was notified by New Zealand authorities of a case of measles in a teenager who had recently attended the World Supremacy Battlegrounds hip-hop dance competition at Sydney Olympic Park on the weekend of December 7 - 8 2013.
Over the coming days measles cases were notified in competitors that had returned to Adelaide, Melbourne, Canberra, Auckland, Turangi/Taupo and Wellington and in a 9 month old baby from Sutherland Shire who had attended the competition with their family. Information warning of the risk of measles was disseminated to competitors via the festival organiser.
Through this channel it emerged that a competitor from the Philippines had been unwell at the festival and developed a measles rash on his return to the Philippines and had thus unknowingly exposed others at the festival to measles infection.
Figure 1: Number of Measles notifications in NSW record, by month of disease onset and number of notifications. January 2010 to March 2014.*
*Data up until March 2014
Source: Number of Measles notifications in NSW record, by month of disease onset and number of notifications.
During January and February 2014 there were 27 measles notifications in NSW (figure 1). Of these, fifteen measles cases were imported from overseas - more than in any entire year since 2006. A further two were imported from other states within Australia, five were linked to an overseas imported case and five were locally acquired cases with no known source of infection. Of the overseas acquired cases, ten were imported from the Philippines, three from Vietnam, and one each from Bali, Indonesia and Hong Kong or Singapore. Australia-wide measles case notifications have also increased, with over 100 cases notified in the first six weeks of the year.
The rise in imported cases of measles is due to two main factors: Typhoon Haiyan late last year in the Philippines amplified an existing measles outbreak by causing mass population displacement; and many young adult travellers were incompletely vaccinated as children and so are susceptible to measles.
Cases have been reported from seven local health districts across NSW. During February some local transmission of measles has occurred: three cases are related to a person with infectious measles attending “Ground Sounds” on February 15, an outdoor music event on the Central Coast.
Five secondary cases have arisen in the vicinity of where other cases live without any definitive events or places that link them to known cases. This often occurs with measles as it is infectious for 4 or 5 days before the rash appears. If a person with early measles infection goes to a shopping centre, a medical centre, or school they can unwittingly spread the infection to other susceptible people.
Figure 2: Number of Measles notifications in NSW record, by month of disease onset and age group.*
*Data up until March 2014
Source: Number of Measles notifications in NSW record, by month of disease onset and age group.
Further transmission associated with recent cases is anticipated on the Central Coast, metropolitan Sydney, Hunter New England and Bathurst.
Twenty-two of the 27 cases are in older teenagers or young adults (Figure 2). It is thought that up to 10% of people in these age groups in the general population have missed one or more of their routine vaccines when they were children, and so many young people are susceptible to measles. Three cases have occurred in infants too young to be vaccinated.
Measles vaccination is now routinely given at 12 and 18 months of age. Anyone between 18 months of age and 48 years of age who hasn’t received two doses of vaccine (or had measles infection) is considered susceptible to measles. NSW Health offers free measles vaccine to susceptible people through GPs. All young adults who travel should consult their GP beforehand and have a free measles vaccine if there is any uncertainty about their immunity to measles.
NSW Health is implementing a number of strategies to control this outbreak. Communicable Diseases Branch is working closely with public health units to coordinate control activities. A measles vaccine catch-up clinic has been held in an affected high school. Communication campaigns, including one targeting Filipino-Australians aim to have young travellers get vaccinated before they go overseas. Public health units are also working with emergency departments to implement triage systems to more readily identify people presenting with measles so they can be isolated to prevent further spread of infection.