Getting Tested for Herpes

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Getting Tested for Herpes By THE NEW YORK TIMES August 27, 2010

Does testing positive for herpes mean you will inevitably have outbreaks? Does a

positive herpes test result always mean you can spread genital herpes to others?

These are among the questions raised by readers of the Consults blog. Dr.

Leone, associate professor at the University of North Carolina School of

Medicine and Public Health, addresses testing for the two types of herpes

simplex virus: HSV-2, the main cause of genital herpes, and HSV-1, responsible

for most cases of oral herpes, or cold sores.

Q. I have had a positive blood test for HSV-2, do not take any suppressive

medications and do not have any outbreaks. What Dr. Leone says about virtually

everyone having four to six outbreaks a year is absolutely not my experience.

This is a nonevent in my life, honestly.

kj, N.Y.

Q. Antibody-positive means the person has the virus because it never clears.

Therefore, antibody-positive means the person can potentially transmit it to

others, symptoms or not (though asymptomatic transmission rates are much lower

than during outbreaks). Most of the people who have herpes were never asked if

they wanted to risk contracting an incurable virus for life. If you have it, you

know you wouldn't wish this on anyone else — at least not out of the blue,

without warning. Please care more for your partners than the person who gave

this to you did — inform them before you expose them and allow them the choice.

Their lifetime sexual health is more important than your shyness/concern your

feelings will get hurt. Right?

Bcereus, Seattle

A. Dr. Leone responds:

As with all human herpes viruses, once an individual is infected with the herpes

simplex virus, or HSV, he or she is infected for life. The presence of

antibodies against herpes simplex means an individual is currently infected with

the virus. A positive antibody test does not indicate merely that one has been

" exposed " to HSV. Nor does it mean you are immune to the virus, without active

infection.

The presence of antibodies for HSV-2, the most common cause of genital herpes,

almost always indicates genital herpes infection with the type 2 virus. We know

that genital HSV-2 infection involves almost continuous shedding of virus from

the genital tract. Therefore, the potential of transmission to uninfected sexual

partners is always present. HSV-2 outbreaks represent only a small fraction of

activated virus that is present.

Although the median number of outbreaks with HSV-2 infection is four to six per

year, many outbreaks go unrecognized. Indeed, 70 percent of individuals with no

self-reported history of outbreaks begin to identify recurrences once they are

educated about the subtle signs and symptoms of genital herpes recurrences.

Women, for example, may have only minor itching, and the symptoms may be even

milder in men.

Serologic, or blood, testing allows us to screen individuals for infection with

herpes simplex. The new tests for herpes, called type-specific serologic tests,

distinguish between HSV-2 and HSV-1, the other type of herpes simplex virus.

These newer tests detect IgG antibodies directed against the cell wall protein

specific for HSV-1 or HSV-2. Older serologic tests did not reliably distinguish

between HSV-1 and HSV-2 and, as a result, were not a reliable way to make a

diagnosis of genital herpes.

Like all tests, the type-specific tests are not perfect. It takes about three to

six weeks for individuals to develop detectable antibodies for herpes simplex.

Virtually everyone will have detectable antibodies by 16 weeks.

Get tested again if you have a recent exposure that falls within the window

period. This also means that a first-time recognized outbreak may represent a

new infection and may be occurring during a period in which your body has not

yet developed a detectable antibody response. Again, the recommendation would be

to get a repeat serologic test in four to eight weeks.

Just to make life a bit more complicated, there are some other considerations

that must be kept in mind with a positive antibody test.

One of the most common brands of type-specific serology is the HerpesSelect

brand. It is a very good test, but there are issues with false positive results

with one form called the HerpesSelect ELISA. (Other forms are the HerpesSelect

Immunoblot and the HerpesSelect Express.) That is, some people who have a

positive test result for the virus are not actually infected.

The Herpes Select ELISA is reported back as an index value. A value greater than

1.1 is considered positive. If you have no history of genital herpes outbreaks,

did not have a positive culture or PCR test for HSV, or have no risk factors for

genital herpes, you should know the index value. False positives have been

reported with values less than 3.5. If your value is less than 3.5, ask to be

tested again with a different test, preferably with another antibody test called

the Western blot.

It all sounds a bit too complicated — but it's not, really. The world is not

perfect, and like all things, tests require some degree of interpretation too.

http://consults.blogs.nytimes.com/2010/08/27/getting-tested-for-herpes/