Imagine that you go to the doctor, get the news that you have an STI - and it's not true.
According to the Centres for Disease Control and Prevention in the United States that's the situation for hundreds of people who may have been diagnosed falsely with syphilis. A study of five labs in the country found that 18 per cent of the positive results in a traditional test method used for three decades got the diagnosis wrong.
The sexually-transmitted disease is treated with penicillin, and most people would never know that they didn't really have it. The test for syphilis is given to pregnant women and other high risk patients, as well as tested on blood donations.
A Florida man, who received a letter saying incorrectly that he had syphilis after donating blood, points out the complications this caused with his wife of six years: "She was distraught," Ken Bird, 58, told the St. Petersburg Times. "Her reaction was distrust."
All blood donated in Canada is also tested for syphilis, along with other illnesses such as HIV. A positive result is forwarded to the donor's doctor. A 2009 memo from the Ontario Agency for Health Protection and Promotion also identified the risk of false positive testing, saying that additional testing would be done for positive results.