article_snippet.sent: Information supplied by HealthDirect.gov.au .
article_snippet.sent: In 2013, the Department of Health report said that despite a long-standing immunisation program, 'pertussis remains highly prevalent in Australia and the least well controlled of all vaccine-preventable diseases'. '
article_snippet.sent: Epidemics occur every 3 to 4 years.
article_snippet.sent: In unvaccinated populations, Epidemics can be very large.
article_snippet.sent: In vaccinated populations, outbreaks are smaller, with greatly reduced mortality and morbidity, and may continue to occur every 3 to 4 years or be more widely spaced,' the Department of Health report said.
highlights_snippet.sent: It's Australia's least well-controlled of all vaccine-preventable diseases .
  