Measles outbreak in young adults in Victoria, 1999

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Control

Background:

• Measles outbreaks can pose significant public health challenges, particularly when they affect populations with suboptimal vaccination coverage.
• Understanding the epidemiology of measles transmission is crucial for effective control strategies.

Purpose of the Study:

• To describe the epidemiology of a measles outbreak in Victoria, Australia.
• To identify transmission patterns, demographic features, and complications associated with the outbreak.

Main Methods:

• A case series approach was employed, utilizing enhanced passive surveillance and active surveillance during the outbreak.
• Data collected included the number of cases, epidemiological links, transmission patterns, patient demographics, vaccination status, and complications.

Main Results:

• A total of 75 measles cases were identified between February and May 1999, originating from international importation.
• The outbreak primarily affected young adults (median age 22 years), with most cases born between 1968 and 1981, indicating a shift in the disease's epidemiology.
• Over a third of cases required hospitalization, and the outbreak spread beyond the initial location to regional Victoria and South Australia.

Conclusions:

• The outbreak underscores the changing epidemiology of measles in Australia, transitioning from a childhood illness to one predominantly impacting young adults.
• While robust childhood vaccination programs and surveillance are vital, the findings suggest a need to consider enhanced measles protection strategies for young adults.