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Volume CXXXIII, Number 3 |
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Ask Dr. Jeff
JEFF BENSON, M.D.
Staff Writer
Dear Dr. Jeff: Can someone have genital herpes and not
know it? Could that person infect you with herpes, even if they never
had any sores? J.V.S.
Dear J.V.S.: Unfortunately, the answer is YES to both of
those questions. There is new concern in public health circles about rapid
spread of genital herpes, and you have underlined two of the main reasons
for that increase.
Genital herpes is caused by herpes simplex virus (HSV). There are two
strains, type 1 and type 2. Type 1 causes nearly all oral herpes infections
("fever blisters" or "cold sores"), and probably 40%
of genital herpes infections (transmitted by oral sex). Type 2 causes
about 60% of genital herpes infections and a very small number of oral
outbreaks. After the initial infection, the herpes virus lies dormant
in nerve bundles at the base of the spine, but periodically re-activates,
causing recurrent outbreaks. There is at present no cure or vaccine for
herpes.
About 80% of the population has, at some time, had oral
herpes, caused by HSV-1. The prevalence of genital herpes has increased
significantly over the last 20 years, with more than 20% of adolescents
and adults estimated to be infected in this country. In college student
populations, the prevalence may be even higher.
The "classic" signs of an initial genital herpes
infection are grouped blisters or sores in the genital area that itch
or burn or hurt and which are often accompanied by flu-like aches and
pains and low grade fever. Recurrent outbreaks are usually milder and
briefer and typically occur four to five times per year. They are frequently
triggered by other illnesses, poor diet, or emotional or physical stress.
Over time, recurrent outbreaks become even less frequent and less severe
and may eventually cease altogether.
It is now becoming clear that most cases of genital herpes
do not present with these "classic" signs and symptoms. In fact,
up to 60% of infections are not recognized by patients or diagnosed by
clinicians, because they do not cause the typical sores. In addition,
up to 20% of infections are missed altogether because they cause no symptoms
whatsoever.
Transmission of herpes occurs most readily from skin-to-skin contact with an actively, broken out site. The virus is very fragile and does not live long on surfaces. Herpes cannot be transmitted via contact with a toilet seat, bathtub, or towel. Most skin on our bodies is too thick for the virus to penetrate, but mucosal surfaces (oral and genital) are quite susceptible. Herpes virus can also be shed, and so transmitted, when no signs or symptoms are present.
Fortunately, this asymptomatic shedding is thought to occur
only a few days per year. On the other hand, because most people naturally
tend to avoid sex when they have active sores, most transmission of herpes
(over 70%), occurs in the absence of warning signs or symptoms.
Herpes is diagnosed most reliably by culturing the virus from active lesions. Diagnosis is more problematic in between outbreaks, or in an asymptomatic carrier. Blood tests can be done to measure antibodies to both viral types, but they are not always accurate. More reliable tests are very expensive, and the most reliable tests are currently available only in research settings.
Interpretation of test results can be difficult. For instance,
because nearly 80% of the population have have, at some time, had oral
herpes, nearly 80% of the population have antibodies to HSV-1, whether
or not HSV-1 is also the cause of a possible genital infection. Positive
HSV-2 antibody titers indicate that it is only likely that the individual
has had genital herpes, and even positive antibody titers to both HSV-1
and HSV-2 do not confirm that an individual has had both oral and genital
herpes. Neither HSV-1 nor HSV-2 is anatomically restricted.
Many people who have been diagnosed with genital herpes
find it emotionally and psychologically distressing. Fortunately, for
most, this distress and anxiety fade with time. Genital herpes rarely
leads to other health problems, with two important exceptions. First,
it is thought that genital herpes increases both the sexual acquisition
and the sexual transmission of HIV and presumably plays a similar role
with Hepatitis B. Second, contracting genital herpes during the third
trimester of pregnancy risks potentially devastating transmission of HSV
to the baby. Still, to keep things in perspective, some 25% of pregnant
women are thought to have genital herpes, and very fortunately, fewer
than 0.1% of babies contract neonatal herpes.
There are currently three medications approved for treatment
of herpes. Each can be taken acutely to help speed the healing process
of outbreaks, and each can also be taken daily and long term to prevent
recurrences. It is not yet clear if daily medication also prevents asymptomatic
viral shedding.
Efforts to decrease transmission of herpes through safer
sex practices remain key. Avoiding intimate contact when sores are present
is essential. In between outbreaks, using condoms, dental dams, or female
condoms significantly lowers the risk of viral transmission. Of course,
no safer sex practice can eliminate all infectious risks. But being informed
about those risks, and negotiating the level of risk acceptable to both
people in a relationship, are critical first steps. As "Alice,"
from Columbia University's Health Education Program website has put it,
"Just as falling in love takes some courage and trust, so does choosing
to be sexual with someone. There is always a risk of 'catching something."
Be well, and be safe!
Jeff Benson, M.D.