Syphilis rates have escalated across Alberta over the past five years and are now at their highest since 1948, prompting the province's chief medical officer of health to declare an outbreak and encourage people to get tested.

A total of 1,536 cases of infectious syphilis were reported in 2018, compared to 161 in 2014, almost a tenfold increase, Alberta Health Services said Tuesday in a news release.

The Edmonton and North zones saw the biggest year-to-year increases last year, with the number of cases up more 300 per cent compared to 2017.

"We need to emphasize for all Albertans: sexually transmitted infections (STIs) are a risk to anyone who is sexually active, particularly people who have new sex partners and are not using protection," Dr. Deena Hinshaw, the chief medical officer of health, said in the news release.

"I encourage anyone who is sexually active to get tested regularly. Anyone in Alberta can access STI testing and treatment for free."

A provincial outbreak committee composed of Alberta Health, Alberta Health Services and other provincial officials has been activated, the news release said.

Over the next three months, the committee plans to develop a strategy and determine how to increase testing, promote public awareness and reduce the overall number of syphilis cases.

The 2018 case counts for infectious syphilis by AHS zone broke down like this:

Edmonton Zone — 977 cases, an increase of 305.4 per cent compared to 2017;

North Zone — 208 cases, an increase of 324.5 per cent compared to 2017;

Calgary Zone — 206 cases, an increase of 7.3 per cent compared to 2017;

Central Zone — 88 cases, an increase of 266.7 per cent compared to 2017;

South Zone — 31 cases, an increase of 138.5 per cent compared to 2017.

Congenital syphilis, which occurs when a child is born to a mother with syphilis, is a severe, disabling and life-threatening disease, the news release said.

There were 22 congenital syphilis cases between 2014 and 2018, one of which was stillborn.