In their lifetimes, most human beings will be exposed to a
herpesvirus. This family of viruses (Herpesviridae) has been implicated
in a wide range of diseases and conditions, including chickenpox, oral
or facial herpes, genital herpes, mononucleosis, and corneal blindness.
It is also likely that we haven’t yet discovered all herpesviruses. One
variety was discovered as recently as 1990, and researchers still
aren’t sure which diseases, if any, it causes in humans.
Herpesviruses are distinguished by their ability to lay dormant, or
“hide” in the human body after primary infection. They then reappear
during periods of reactivation. Researchers don’t really understand the
mechanism of reactivation. Although there is no effective cure for
herpes, many studies have shown that herpes reactivation is more common
among patients who have compromised immune systems, suggesting that a
strong immune system is a good defense against herpes reactivation. To
manage herpes, physicians try to reduce the number and severity of
outbreaks.
Among the most well-known herpesviruses are:
- Herpes simplex virus 1 (HSV1)—HSV1 is extremely
common, with the vast majority of adults showing evidence of exposure
to the virus (eg, antibodies in their blood), even if they are not
positive for HSV1 (Kasper DL et al 2004). This form of the virus is
most often associated with oral or facial lesions that appear during
childhood, although it can also cause genital infection.
- Herpes simplex virus 2 (HSV2)—Researchers
estimate that about 20 percent of the US population has antibodies to
HSV2 (Kasper DL et al 2004). This form of the virus is closely
associated with genital herpes. Genital herpes caused by HSV2 is twice
as likely to reactivate and recurs 8 to 10 times more frequently than
genital infection with HSV1 (Kasper DL et al 2004).
- Varicella-zoster virus—This relatively
common virus is responsible for chickenpox infections (varicella) and
shingles (herpes zoster). The varicella-zoster virus is extremely
common. Up to 90 percent of people are attacked by this virus, about
half of them between the ages of 5 and 9 years. Almost all of the
clinical cases of chickenpox are diagnosed in children and adolescents
younger than 14 years. For more information on varicella-zoster virus,
see the section in this chapter on Chickenpox and Shingles.
Although infection with herpes is primarily associated with oral,
facial, or genital herpes, the herpesvirus can also cause infections in
the following ways:
- Herpetic whitlow—Infection of the finger.
- Herpes gladiatorum—Also known as traumatic
herpes. Infection anywhere on the chest, ears, face, and hands. This
form of herpes is sometimes associated with wrestling because the rough
contact between wrestlers helps spread the virus.
- Herpes of the eye—The most common cause of corneal blindness in the United States.
- Infection of the central or peripheral nervous systems—The
herpesvirus accounts for up to 20 percent of the cases of sporadic
viral encephalitis (swelling of the brain due to a virus) in the United
States. Herpes can also cause herpetic meningitis.
- Infection of the internal organs—This includes herpes infection of the esophagus (HSV esophagitis), the lung (HSV pneumonitis), and the liver.
- Neonatal herpes—Neonates (infants younger
than 6 weeks) can contract herpes during birth (if their mothers are
infected with the virus) or if they are handled by someone who has oral
or facial herpes. Neonates are the most likely to have herpes
infections that affect the central nervous system or internal organs.
Mortality among neonates with untreated herpes is 65 percent (Kasper DL
et al 2004).
Genital herpes, which may be the most highly publicized form of the
disease, is a widely misunderstood condition. Many people believe that
genital herpes is only transmissible during active outbreaks of herpes
(when herpes lesions are visible). They may also believe that herpes is
relatively rare. In fact, herpes is much more common than many assume.
Many people who have antibodies to herpes (they have been exposed to
the virus) are not aware they have the disease; they suspect the
condition only when they have seen pictures of herpetic lesions (Kasper
DL et al 2004). Also contrary to popular belief, herpes is not
transmitted only by direct contact with active lesions. It can be
transmitted by people who do not have manifestations of the disease but
who are shedding the virus or have subclinical symptoms or tiny lesions
that are not visible to the naked eye. Studies have shown that HSV2 can
be located on the genital tract on regardless of the presence of
symptoms (Kasper DL et al 2004). Condoms have been shown to reduce the
transmission of herpes during periods of nonsymptomatic shedding.
Herpes symptoms depend on the form of the disease. Oral or facial
herpes is often accompanied by inflammation of the gums and throat
during the initial outbreak. Children who have this condition may have
fever, malaise, inability to eat, irritability, and lesions in and
around the mouth. Genital herpes is accompanied by similar symptoms, as
well as lesions on the genitals. Among newly infected women, the cervix
and urethra are usually involved. If the central or peripheral nervous
systems are infected, a fever and neurological symptoms are often
present during periods of virus activation.
Because herpes sometimes resembles other diseases (especially herpes
that affects the skin, mouth, or central nervous system), it can be
challenging to correctly diagnose. The most common method used to
diagnose herpes is to isolate the virus in a tissue culture or to
demonstrate HSV antibodies or DNA in scrapings from active lesions.
Antiviral Drugs
Conventional treatment of herpes relies on antiviral drugs that have
been shown to reduce the severity of outbreaks and, in some cases,
reduce the likelihood of transmission. These drugs include:
- Acyclovir—Acyclovir interferes with the virus’
ability to replicate (Kasper DL et al 2004). Common side effects
include nausea, vomiting, headache, diarrhea, dizziness, fatigue,
anorexia, edema, and sore throat (Sra KK et al 2004).
- Valacyclovir—Valacyclovir is the salt
version of acyclovir; it becomes acyclovir after being metabolized by
the liver. Valacyclovir has a bioavailability three to five times
greater than oral acyclovir. Common side effects, such as nausea,
vomiting, headache, dizziness, and abdominal pain, are similar to those
of acyclovir (Sra et al 2004).
- Famciclovir—Famciclovir is a precursor to
the antiviral drug penciclovir. Penciclovir works in a similar manner
to acyclovir. Side effects are the same as those for acyclovir and
valacyclovir.
These antiviral drugs may be given intravenously or orally,
depending on the severity of the outbreak and the location. They are
effective in treating both herpes and shingles. In addition to these
antiviral drugs, a number of topical medications are used in the
treatment of herpes infections of the eye. These include trifluridine,
vidarabine, idoxuridine, acyclovir, penciclovir, and interferon.
In recent years, clinicians have discovered strains of herpes that
are resistant to acyclovir. Because the drugs are closely related,
acyclovir-resistant strains of herpes are also cross-resistant to
valacyclovir and famciclovir. These strains are most often detected in
patients who have weakened immune systems, such as those with HIV or
AIDS (Kasper DL et al 2004). In these cases, treatment with a very
powerful antiviral called foscarnet, which must be administered with an
intravenous (IV) pump, is sometimes effective. Foscarnet can cause
severe adverse effects, including kidney disorders.
Chickenpox and Shingles
Chickenpox and shingles are both caused by the varicella-zoster
virus, and infection is strongly reminiscent of infection with either
HSV1 or HSV2. However, unlike HSV1 or HSV2, the virus is often
transmitted through the respiratory tract.
Chickenpox is an extremely common and highly contagious childhood
disease. It is usually benign, with an incubation period of up to 21
days after initial infection, and a disease course of 14 to 17 days.
During the time the varicella-zoster virus is most active, the patient
has characteristic skin lesions. The lesions cause intense itching, and
there is a risk that the lesions will become infected due to
scratching. The severity of the disease and the number of lesions
varies from person to person. Adults with the disease who have weakened
immune systems might run a fever. In fact, chickenpox in adults is
considerably more dangerous than the benign childhood variety. Adults
are more likely to have symptoms such as headache and pain as a result
of chickenpox. A form of pneumonia (varicella pneumonia) is seen in
about 20 percent of adults who contract chickenpox (Kasper DL et al
2004). The virus can also cause brain inflammation.
In the future, chickenpox will likely become less of a health issue.
Since 1995, children in large numbers across the United States have
been vaccinated against the varicella-zoster virus. The results of this
vaccination program have been dramatic: hospitalizations have declined
by 88 percent and direct medical expenditures by 74 percent (Zhou F et
al 2005). These benefits were seen across all age groups.
However, researchers still don’t know the impact of the chickenpox
vaccine on shingles. Shingles occurs when the varicella-zoster virus
reactivates, usually in adulthood, and it characterized by a painful
skin rash. Reactivation occurs in about 15 percent of people who have
had chickenpox, and most often occurs in people aged 60 to 69, although
it can occur in any age group.
Some researchers have hypothesized that vaccination in childhood
would actually make an adult more susceptible to shingles later in
life. However, this has yet to be proven in clinical studies (Jumaan AO
et al 2005). In the meantime, vaccination against herpes zoster in
adults has been shown to reduce the incidence of shingles (Oxman MN et
al 2005).
Shingles is nine times more likely to develop in those infected with
HIV. In the early stages of HIV infection, shingles symptoms are fairly
typical (Wilkerson MG et al 1987). In more advanced infection, herpes
zoster may take the form of repeated episodes of severe, prolonged, and
sometimes atypical disease (such as varicella-zoster virus retinitis).
Shingles is also more common in immunocompromised children and adults
(including organ recipients and chemotherapy patients). It is important
to treat these patients early and aggressively with antiviral drugs.
Like chickenpox, shingles is characterized by skin lesions. The
lesions may be accompanied by severe, sometimes debilitating pain. An
outbreak of shingles usually lasts between 7 and 10 days. It can take
up to 2 weeks for the skin to appear and feel normal. Herpes zoster can
also infect the nerves in the eye. This serious condition can result in
blindness if not treated with antiviral therapy (Cunningham AL et al
2000; Liesegang TJ 1984; Liesegang TJ 2004; Ostler HB 1976; Schmader K
2001; Weinhoff ML 1976).
Pain associated with shingles that persists more than 3 months after
other symptoms subside is known as postherpetic neuralgia. The
characteristics of postherpetic neuralgia are spontaneous aching and
burning, intermittent shooting pains, and extreme sensitivity (Johnson
RW 2003). Postherpetic neuralgia is more common in older people.
However, at least 50 percent of patients older than age 50 who had
shingles report some degree of pain months after the resolution of the
skin rashes (Kasper DL et al 2004). Several drug classes are used to
treat postherpetic neuralgia, including tricyclic antidepressants
(Baldessarini RJ 2001) and painkillers such as acetaminophen,
glucocorticoids, and lidocaine.
Herpes and the Immune System
It appears that herpes-specific T-cell immunity might be related to
reactivation. Animal studies have shown that ultraviolet light, a
weakened immune system, and trauma all contribute to reactivation of
the virus (Kasper DL et al 2004). At this time, there are no drugs or
agents that can cause a latent virus to stay hidden forever. The number
and frequency of reactivation events depends on the site and on the
nutrition and immune status of the host (Isada CM et al 2003; Murray PR
et al 2002).
The Vitamin Depot Online.com Foundation’s approach to herpes management is
based on the premise that a strong immune system can help reduce viral
reactivation. People who have herpes can benefit from a nutritional
regimen of supplements that studies suggest may fight the virus
directly, as well as support a healthy immune system.
Antioxidant Defenses
Although there is no cure for herpesvirus infection, various
supplements have shown the ability to reduce the severity and even the
frequency of outbreaks. This might be due to their ability to support a
healthy immune system (a weakened immune system has been associated
with herpes reactivation).
Antioxidants are particularly important immune-boosting supplements.
Multiple clinical studies support the theory that antioxidants are of
benefit in the management of herpesviruses (Bhaskaram P 2001; Elmadfa I
et al 1994; Grimble RF 1997; Sheridan J et al 1997).
Vitamin A and beta-carotene
Vitamin A plays a role in protecting the skin and mucous membranes
from invasion of microorganisms. In 178 HIV-positive women with genital
herpes, who were neither pregnant nor taking oral contraceptives,
vitamin A levels were closely associated with cervical HSV shedding.
Increased shedding was associated with decreased vitamin A (Mostad SB
et al 2000).
Experimental studies have documented vitamin A’s effectiveness
against other herpesviruses. The strong antiproliferative activity
exerted by retinoids (vitamin A derivatives) indicates these compounds
may be useful tools in the management of EBV–related disorders in
immunosuppressed patients (Pomponi F et al 1996).
Beta-carotene is the major precursor of vitamin A (Meisenberg G et
al 1998). Studies show that long-term beta-carotene supplementation may
be beneficial for immune, viral, and tumoral surveillance in aging
individuals. In a controlled, double-blind study, the effects of 10 to
12 years of beta-carotene supplementation on natural killer (NK) cell
activity were evaluated. Although no significant difference was seen in
NK cell activity in the middle-aged groups, elderly men who took
supplements of beta-carotene had significantly greater NK cell activity
than the control group receiving placebo (Santos MS et al 1996).