Measles cases linked to Philippines outbreak
Over the past decade, the number of measles cases reported globally has decreased significantly, following a push to eliminate this infection by increasing immunisation rates. There are, however, still regions of the world, such as Asia and Africa, where measles is endemic and where large outbreaks occur.
Although Australia is one of 10 countries that have formally declared elimination of measles, cases continue to occur, particularly in returning unvaccinated travellers and, subsequently, their susceptible contacts. The follow-up of each measles case requires considerable public health resources.
In Western Australia, the annual number of measles cases has remained low, with 6 to 17 notifications per year from 2008 to 2013 (Figure 1).The majority of cases each year have been acquired overseas with the exception of 2010, when there was a local outbreak of measles mostly among healthcare workers following an importation. Of 42 overseas-acquired cases in the period 2008-2013, 69% were acquired in Southeast Asia, mostly from Indonesia and Thailand.
In the first quarter of 2014 alone, 17 measles cases have been notified, equivalent to the total number of cases in 2012. Cases were aged from 7 to 40 years old (median age 26 years) and were predominantly male (82%).Twelve of the cases (71%) were acquired overseas, 4 were locally acquired and one was acquired in the Northern Territory. All the imported cases were acquired in Southeast Asia, with the majority acquired in the Philippines (8) reflecting a widespread outbreak in that country, followed by Indonesia (3) and Singapore (1). Prior to 2014, only one measles case had been imported from the Philippines, in 2011.
Of the 17 measles cases, only 3 cases had documented evidence of having received one dose of measles-containing vaccine, the remaining cases either did not know their vaccination status (8) or were not vaccinated (6) – 3 of the unvaccinated cases were siblings whose parents were vaccine refusers.
This highlights the need for general practitioners to ensure that people planning to travel be encouraged to be appropriately vaccinated prior to departure. 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 a measles-containing vaccine, are considered to be susceptible to measles and should be strongly encouraged to be vaccinated appropriately. Adults born before 1966 are assumed to have natural immunity.
Measles-containing vaccines are safe, very effective and provide lifelong protection following 2 doses of vaccine. The current recommendations for measles vaccination are shown in the table below.
Table 1 – Recommendations for measles vaccination
|Schedule point (age)||Vaccine|
(from July 2013)
|18 months *||MMR-V|
|Adults||MMR-2 doses, at least 4 weeks apart|
MMR = trivalent measles-mumps-rubella vaccine
MMR-V = quadrivalent measles-mumps-rubella-varicella vaccine
* Prior to July 2013, children were recommended a second dose of MMR at 4 years
Figure 1 – Measles notifications by place of acquisition, year and quarter, WA, 2008 to March 2014