WINNIPEG - The Winnipeg Regional Health Authority says it is experiencing the worst and fastest-spreading outbreak of infectious syphilis ever recorded.

In a bulletin to health-care providers, the medical health officer says the region has recorded 60 syphilis cases in the first 10 months of this year -- up from 40 cases the same time last year.

The health authority says there were fewer than three cases a year in the 1990s.

Syphilis is a sexually transmitted disease that can cause serious health problems if left untreated.

The health region says most cases are being diagnosed in men who have sex with men and about one-third are in people who are HIV positive.

There have been reports of increasing numbers of syphilis cases in major Canadian cities from Halifax to Vancouver.