Herpes
Alternative names:
genital herpes; herpes simplex - genital; herpes virus 2
Definition:
Genital herpes is a sexually transmitted viral infection
that is characterized by repeated eruptions of small and usually
painful blisters on the
genitals, around the rectum, or covering adjacent areas of
skin.
Causes, incidence, and risk factors:
Herpes is caused by two viruses, herpes
simplex virus type 1 (HSV-1), and herpes simplex virus
type 2 (HSV-2). While statistics vary, research shows that
90% of the population has been exposed to HSV-1 ("oral herpes")
and 25% of the population in the United States has been exposed
to infection with HSV-2 ("genital herpes").
HSV-1, the virus responsible for common
cold sores, can be transmitted through oral secretions
either during kissing or by eating and drinking from contaminated
utensils. Additionally, HSV-1 can cause genital herpes through
transmission during oral-genital sex, thus both strains of
the virus may be transmitted by sexual contact. Initial oral
herpes infection, however, usually occurs in childhood; it
is therefore not classified as a sexually transmitted disease.
While HSV-1 is responsible for only 5% to 10% of genital
herpes, HSV-2 causes the majority of genital herpes. HSV-2
can be transmitted through oral or genital secretions. An
estimated 86 million people worldwide are thought to have
genital herpes. Approximately 20% of American Caucasian and
65% of African American adults harbor HSV-2, but only 2.6%
have symptomatic infection.
Because the virus is transmitted through secretions from
the oral or genital mucosa,
common sites of infection in men include the shaft and head
of the penis, the scrotum,
inner thighs, and anus; and the labia, vagina,
cervix, anus, and inner
thighs in women. The mouth can also be a site of infection
in both sexes.
Research suggests that the virus can be transmitted even
in the absence of clinical disease, so that a sexual partner
without obvious genital herpes may still transmit the illness.
In fact, asymptomatic
spread may actually contribute more to the spread of genital
herpes than do active sores.
Various complications are associated with herpes infection.
The herpes virus is of special significance to women in particular.
It has been implicated in causing cancer
of the cervix. The risk increases when HSV is present
in combination with Human
papilloma virus (HPV), the virus responsible for genital
warts (condyloma).
For the pregnant women,
the presence of either HSV-1 or HSV-2 on the genitalia or
in the birth canal is a threat to the infant. Subsequent infection
to the newborn infant can lead to herpetic meningitis,
herpetic viremia, chronic
skin infection and even death.
The herpes infection also poses a serious problem for the
immunocompromised individual (patients with AIDS,
undergoing chemotherapy,
radiation therapy, or
taking high dose cortisone preparation). These people may
suffer infections of various organs including:
- Herpetic keratitis
- herpes infection of the eye leading to scaring within
the cornea and eventual blindness.
- Persistent infection of the mucous membranes and skin
of the nose, mouth and throat
- Herpetic esophagitis
- infection of the esophagus causing painful ulcers to form.
- Herpetic hepatitis
- infection of the liver causing inflammation of the liver
and eventual liver failure.
- Encephalitis- a very serious infection of the brain. If
untreated, approximately 60% to 80% of those who contract
this condition will progress to coma and death within a
few days. Those who recover often suffer some impairment,
ranging from mild neurological impairment to paralysis.
- Pneumonitis - infection of the lung causing a life-threatening
pneumonia.
Update Date: 05/08/00
Luis A. Diaz, Jr., M.D., Junior Assistant Resident, Johns
Hopkins Hospital, Internal MedicineVeriMed Healthcare Network
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