Thursday, April 3, 2008

Herpes Simplex Virus (HSV)

HSV is a member of the family of viruses responsible for chicken pox, shingles, and infectious mononucleosis. The strain HSV-1 of this common virus is also responsible for cold sores, canker sores, and fever blisters that appear on the mouth. HSV-1 may be responsible for the genital sores we think of in relation to herpes, but more often the strain HSV-2 is the cause of sores and blisters below the waist. Like other viruses, there is no cure for HSV, but there are drugs to help manage most infections.

The virus which causes herpes lives in nerve cells at the bottom of the spine, and “creeps” to the surface once in a while to cause sores and blisters. In fact, herpes is named after the Greek word for “creeping”. Recent studies have shown that most people with a herpes infection — probably as many as three-quarters — don't even know they have the disease because they have no symptoms: they never have any sores or blisters to alert them to the infection.

People who are unaware that they are infectious can unwittingly spread the disease. But even people who are aware of their infection can unknowingly spread it because viral particles are “shed,” meaning they are present on the skin of the genitals, even when no sore or blister is apparent. This “asymptomatic” shedding happens prior to reappearance of the sore.

Because of its ease of transmission, the virus has become extremely common. HSV is not a reportable disease, but an estimated 30 million Americans or more are thought to have it. More than 200,000 new cases are expected each year.

• Risk factors: You are more likely to get herpes if you or your partner have multiple or casual sexual partners. Rates are high among all racial groups. Approximately one in every five 30-year-old white females has HSV.

• Signs and symptoms: Many people with HSV have no signs or symptoms. If and when trademark sores appear, they can be on the vulva, in or around the vagina, in the anus, or on the cervix. Many women notice itching or a tingling sensation in the genital area before the sores appear. These are known as “prodromal symptoms.”

The first “outbreak” of a herpes infection is always the most severe, often lasting for three weeks or longer. The average length of time for a first episode is 12 days. Fever, headaches, swollen lymph glands, and sore muscles (especially in the legs) are common, in addition to the painful blisters. Some people will have one blister during an outbreak, while others will have many. Blisters deep in the vagina or cervix may not cause any pain. Recurrent episodes, during which the virus is reactivated, are milder and usually last about five days. For many people, the recurrences will occur less frequently over time.

• Cause: HSV is spread by skin to skin contact, especially during vaginal, anal, or oral intercourse. HSV-1 and HSV-2 are almost identical, so someone with a cold sore performing oral sex can give his or her partner genital herpes. It is thought that 20 percent of genital herpes is transmitted during oral sex.

Once the virus enters the genital area, it quickly camps out in clumps of nerves at the base of the spine. It can lie dormant there for the rest of one's life, as it does in about 10 percent of all cases, or it can reappear sporadically. Many things can trigger recurrence of symptoms: surgery, illness, stress, fatigue, skin irritation (such as sunburn), dietary imbalance, menstruation, hormonal imbalance, or vigorous sexual intercourse.

• Incubation period: Symptoms usually start appearing within a week after infection if they are going to appear at all (remember, as many as 75 percent of people with HSV may be asymptomatic.) However, symptoms have been known to start one day to 26 days after exposure to the virus.

• Possible health affects: One complication from HSV is very rare and easily avoided: accidentally spreading the infection to the eyes. This can occur if you should happen to rub your eyes or put in contact lenses after touching an HSV sore. The herpes virus is easily killed with soap and water, though, so an eye infection can be avoided through stringent hygiene during outbreaks.

HELP WITH HERPES
Having trouble paying for acyclovir treatment? Burroughs Wellcome Co., the makers of Zovirax, offers a patient assistance program for hardship cases. Request an application by calling 1-800-722-9294.

Although an association between herpes and cervical cancer has not been established, women with the virus should have regular Pap tests because of their increased risk of other infections such as HPV.

• Diagnosis: It is important to see your doctor while symptoms are still present, because diagnosis is made by viewing sores and by taking a sample from the sore to look at under a microscope. Blood tests that detect antibodies to HSV are also reliable. You can request a specific culture for HSV, but it is fairly expensive and takes about a week to give results.

• Treatments: Although nothing is available to rid the body of a virus, acyclovir (Zovirax) can alter the herpes virus' ability to cause damage once it comes out of its hiding place in the nerve ganglia.

Zovirax is the most frequently prescribed drug for an initial herpes outbreak. Duration of symptoms can be reduced from nine days to about five; healing time is reduced from about three weeks to about two weeks; and viral shedding can be cut down from 10 days to about two.

The topical cream form of Zovirax can be effective for the initial outbreak, but rarely works well for recurrences. Taking oral Zovirax for recurrent outbreaks, while it can still be effective, has a less significant impact for some people.

The recommended regimen for an initial herpes outbreak is 200 milligrams orally five times a day for seven to 10 days or until symptoms disappear. If you are aware enough of your body and can know when a herpes attack is about to strike, taking Zovirax within two days of onset can help lessen the severity of recurrences. Usually the initial warning symptoms — muscle aches, genital itching and tingling — will alert you. For recurrent outbreaks, you will probably take Zovirax for five days, at a dose of either 200 milligrams five times a day, 400 milligrams three times a day, or 800 milligrams twice a day. This conservative therapeutic approach can reduce shedding time by almost half, from nearly four days to slightly over two days.

Taking Zovirax only at the onset of an outbreak is referred to as “episodic” therapy. If you suffer from many outbreaks a year — once every month or two — or if having herpes is causing you great psychological distress, you might consider “suppressive” therapy. Taking the drug suppressively (400 milligrams twice a day, every day), reduces outbreaks by at least 75 percent among patients with frequent outbreaks. It has not, however, been shown to cut down on viral shedding, so you could still pass the disease to a partner, and the outbreak will resume when therapy stops.

There is varying opinion on how long a person should stay on suppressive therapy. The U.S. Food and Drug Administration currently recommends only one year, although studies have shown that patients do well with three or even seven years. Additionally, suppressive therapy's expensive, costing between $2 and $4 a day. Talk with your doctor to decide what is best for you.

Drug companies are working hard to come up with new drugs to fight herpes outbreaks. Zovirax was a breakthrough that helped many people, but it has its flaws. Only 15 percent of the drug is actually absorbed into your body for use against the virus. For this reason, it is important to understand that if your bowels are moving more quickly than normal (as with gastrointestinal problems), you may not be getting a high enough level of the drug.

A new drug called valacyclovir is being studied, and researchers believe it will have an absorption rate of about 80 percent. Neither valacyclovir, or another drug, famcyclovir, will be available until clinical studies are completed and the drugs have received FDA approval.

• Follow-up: If an initial outbreak warns that you have herpes, tell all sex partners from the prior three weeks. If you find out some other way, from a blood test for example, you may not know when you were infected. It is up to you and your doctor to decide which partners to tell. It is also up to you to decide when and if to tell a new partner about your infection.

• Prevention: People with herpes are most likely to shed the virus asymptomatically for up to three months after the initial outbreak. It is not known exactly how often asymptomatic shedding occurs, though researchers believe it is a major cause of the high numbers of herpes cases. However, in long-standing marriages where one partner is infected and the other is not, the uninfected partner often stays herpes-free. Use of condoms and spermicides (which kill the herpes virus) is an important part of any prevention strategy.

HSV-1 and HSV-2 can easily migrate through the body, so oral sex should be avoided when there is an active sore on the mouth or genitals.

• Pregnancy: The most serious known complication of herpes threatens infants born to HSV-infected mothers. An HSV-infected baby is at risk for blindness, brain damage, and even death. Fortunately, the risk of transmitting the infection to a newborn at birth is low, even for women who have long-standing, recurrent outbreaks. If the baby does get infected (a less than 3 percent chance for women with recurrent infections), Zovirax will probably be used as treatment. HSV also increases the risk of miscarriage or premature labor and delivery.

The group at highest risk are women who acquire HSV late in their pregnancy, particularly those who have no immune defense to the virus (developed from having had diseases like chickenpox, or cold sores, etc.). Women with immune defense, which can be measured by antibodies to HSV in the blood, pass immunity to the baby through the placenta during the third trimester of pregnancy. Infants born to HSV-infected and antibody-carrying mothers are thus protected from the disease should they come into contact with it as they pass through the birth canal. Most HSV-infected women can have normal, vaginal deliveries. Having an active sore at the time of delivery will warrant a cesarean delivery.

If you are pregnant and either have HSV or have sex with an infected partner during your pregnancy, or if you or your partner have sex with more than one partner during your pregnancy, be sure to tell your doctor. He or she will then test to see if you are shedding the virus when it comes time to deliver the baby.

Zovirax has not been thoroughly studied for use by pregnant women, so your doctor will probably advise stopping suppressive or episodic therapy during pregnancy.

Featured Post

HISTORY OF DIABETES

FIRST REPORT ON DIABETES IN 1552 BC ! 1552 BC Egyptian Papyrus Oldest preserved medical document 20.23 m length X 30 cm height 110...