The herpes simplex virus responsible for an epidemic of venereal disease in this country can survive for long periods of time on toilet seats, towels, clothing and medical equipment, according to a study by University of California researchers.
Dr. Trudy Larson, a research fellow and pediatrician at the Los Angeles campus, said her research appears to provide the first such evidence using herpes virus samples from patients.
The finding challenges the generally accepted wisdom that the genital form of herpes is communicable only through direct sexual contact. It raises the prospect that the disease may be transmitted through non-sexual means, without direct contact with an infected person, she said in an interview.
Larson stressed, however, that such a prospect is "very unlikely," but said, "I think the possibility exists." She added that no proof exists that such transmission is taking place, but urged that herpes victims and others take added hygiene precautions.
Dr. Paul Wiesner, head of venereal disease control for the Centers for Disease Control, questioned the public health significance of the findings, saying, "We don't have evidence that it is transmitted in that fashion."
Wiesner said that new adult genital herpes patients almost always have a history of recent sexual contact. Babies may also get a life-threatening form of the disease during vaginal birth from a mother with active herpes lesions.
Dr. Steven Straus, a National Institutes of Health herpes expert, cautioned that "just because the virus can be recovered from toilet seats doesn't mean it's presented in large enough amounts to be spread to someone else."
Larson agreed, but said that UCLA doctors have encountered genital herpes in children and adults in which no history of direct sexual contact with affected persons was indicated.
Herpes simplex viral disease occurs in two forms, with the best known, type 1, responsible primarily for fever blisters or cold sores in the mouth region. But in recent years another form, type 2, has been transmitted increasingly to the genital region sexually, causing painful, recurring sores.
Although symptomatic relief is available, there is no cure, and more than 300,000 new cases are reported each year in the United States.
The UCLA study was reported this week at a joint meeting here of the American Pediatric Society and the Society for Pediatric Research.
For the study, samples of both forms of herpes were taken from patients' genital lesions and transmitted to various surfaces. For even more realism, one genital herpes patient sat briefly on a toilet seat.
Larson and her colleague, Dr. Yvonne Bryson, collected samples and tried to grow them under laboratory conditions to see if they were still viable.
They found that the virus survived on the toilet seat from 1 1/2 to 4 hours. On a medical instrument commonly used in genital examinations in doctors' offices the survival time increased to 18 hours. On cotton gauze the survival time was as long as 72 hours.
The virus even survived for an hour when transferred from a glove print to a plastic surface.
Because of the long survival period on gauze, Larson said she is most concerned about possible transmission of genital herpes virus on clothing and towels, particularly among roommates or families of individuals with herpes.
To be infectious, the virus would need to enter the body through open cuts on any part of the body or the mucous membranes of the mouth or genital area.
Larson advised herpes victims to pay attention to "good hygiene. They need to be more aware." She suggested using paper covers to provide added protection on toilet seats, and said laundry bleach kills the virus.