Four Alberta babies with syphilis died at birth in the past year, CBC News has learned.

Three of those babies were born in the Edmonton area.

Alberta has the highest rate of syphilis among all Canadian provinces. Figures in the Alberta Health annual report show a steady increase in the sexually transmitted disease in the past five years.

In 2005, the rate was 4.5 cases per 100,000 people. The rate was 7.4 cases per 100,000 in 2009. The highest number of the province's 269 reported cases last year were in Edmonton, Calgary and Fort McMurray.

A former infectious disease specialist with Alberta Health, Dr. Ameeta Singh, said while the increase reflects a global rise in sexually transmitted diseases, the high rate in Alberta is alarming.

"We wouldn't expect to see such rates of infectious syphilis in Alberta today," she said. 

"It's probably a combination of things. It is, in part, related to the fact there have been changes in sexual behaviour with time. This has been attributed to complacency that's occurred around HIV."

Seven of last year's syphilis cases were babies. The three children who survived may face a lifetime of health problems, said Dr. André Corriveau, Alberta's chief medical officer of health.

"We have increased testing but we also have to look at the fact that some of those women, probably two-thirds of them, never had any pre-natal care before they delivered their babies," Corriveau said.

On a per-capita basis, Alberta's syphilis rate is above the national average. The disease had all but disappeared in the mid-1990s.

The province is hiring 13 additional outreach workers in hopes of getting the rate below the national average within five years.

With files from the CBC's Kim Trynacity