In her more than 25 years of working with the Regional Health Authority, Dr. Shelley Buchan has seen a lot of change.

Buchan recently retired from her position as Medical Officer of Health for Southern Health-Sante Sud. She says the biggest change she's noticed over the years in the region is that we're living longer. Buchan says children born today, compared to those born 25 years ago, will live 2 to 3 years longer.

"That's an improvement in health when you can see that life expectancy increasing," Dr. Buchan says.

Community health assessments also began over Buchan's tenure, allowing the RHA to gather more information about public health in smaller areas in the region.

"Although there is a general increase in health, living longer, we do see pockets within our region that aren't" Buchan explains. "By doing the community health assessment process, it allows (the RHA) to focus our attention and resources to those areas where they aren't seeing the same kind of gains."

Despite the general improvement in overall health, Buchan says there has been a large increase in infectious diseases such as Zika, West Nile, Lyme Disease, and other advanced strains of old diseases.

"Because of climate change, because of global travel, because of how we interact with animals and how insects are responding to environmental changes, we're seeing new diseases," Buchan says. "And we can expect to see more of those."

She says childhood vaccinations 25 years ago covered against seven diseases -- compared to 15 today. Buchan notes vaccine program participation has also decreased, causing pockets of outbreaks of illnesses like measles, mumps and whooping cough. "That's going to be a challenge for us," she says.

Buchan adds the new medical officer of health, Dr. Michael Rutledge, has a wealth of experience he will bring to the role.

"By being able to hand the baton on to him," says Buchan. "I know that I've finished well."