Up to 50% percent of people in the United States have been exposed to herpes and many assume they can’t spread it unless they have an outbreak.
A new study from the Journal of the American Medical Association, to be published April 13, 2011, shows that people may spread the infection even when they don't have symptoms.
Doctors Anna Wald and Christine Johnston from the University of Washington in Seattle studied almost 500 people in two separate groups.
One group had a history of active herpes; meaning they experienced recurrent symptoms such as painful blisters. The second did not develop symptoms but did test positive for the herpes antibody meaning they had been exposed to the infection in the past.
Both groups were asked to swab the affected area for at least 30 days to find out how often the virus was active.
Dr Wald said the infection was active in some people whether or not they had symptoms.
"When we take people who are HSV-2 positive so they have the antibody but they don’t have any history of genital herpes, still the virus is active on about 10 percent of the days in most of these persons," said Dr. Wald.
Johnson said in those 10% of people, the virus remained infectious despite a lack of symptoms.
"So even people without a clinical history of genital HSV-2 are capable of spreading the virus to sexual partners."
That means that anyone who has ever had herpes should use protection when having intimate contact with anyone. They can also ask their doctor for a blood test to see how active their virus is and when it is safe to be intimate and when it is not
