There are two types of herpes simplex virus, type 1 (HSV-1) and type 2 (HSV-2). HSV-1 more commonly causes infections around the mouth while HSV-2 more commonly causes genital infections. They are transmitted by direct contact with body fluids or lesions of an infected individual. Transmission may still occur when symptoms are not present. Genital herpes is classified as a sexually transmitted infection. It may be spread to an infant during childbirth. After infection, the viruses are transported along sensory nerves to the nerve cell bodies, where they reside lifelong. Causes of recurrence may include: decreased immune function, stress, and sunlight exposure. Oral and genital herpes is usually diagnosed based on the presenting symptoms. The diagnosis may be confirmed by viral culture or detecting herpes DNA in fluid from blisters. Testing the blood for antibodies against the virus can confirm a previous infection but will be negative in new infections.
The annual incidence in Canada of genital herpes due to HSV-1 and HSV-2 infection is not known (for a review of HSV-1/HSV-2 prevalence and incidence studies worldwide, see Smith and Robinson 2002). As many as one in seven Canadians aged 14 to 59 may be infected with herpes simplex type 2 virus and more than 90 per cent of them may be unaware of their status, a new study suggests. In the United States, it is estimated that about 1,640,000 HSV-2 seroconversions occur yearly (730,000 men and 910,000 women, or 8.4 per 1,000 persons).
Herpes “triggers” (determining exactly what leads to an outbreak) are highly individual, but with time, many people learn to recognize, and sometimes avoid, factors that seem to reactivate HSV in their own bodies. Illness, poor diet, emotional or physical stress, friction in the genital area, prolonged exposure to ultraviolet light (commonly for oral herpes, such as a beach trip or skiing weekend), surgical trauma, and steroidal medication (such as asthma treatment) may trigger a herpes outbreak.
When herpes flares up again, it is called a "recurrence" or "outbreak." Herpes does not always recur, and if it does recur, the timing and severity are different from person to person. Some people rarely have recurrences. Others have them often. Herpes is most likely to recur in the first year after infection. Recurrences may be more frequent for people with weakened immune systems.
Genital herpes is so common. It’s affecting more than 3 million Americans each year. And 1 out of 5 people is estimated to have this disease at some point in their lives. Your partner can also have the chances of contracting genital herpes. Many people may be shocked and disappointed when their partners have this disease. But, remember that people with genital herpes really need acceptance and support. Here’s what you should do when you find out your partner has genital herpes.
However, asymptomatic carriers of the HSV-2 virus are still contagious. In many infections, the first symptom people will have of their own infections is the horizontal transmission to a sexual partner or the vertical transmission of neonatal herpes to a newborn at term. Since most asymptomatic individuals are unaware of their infection, they are considered at high risk for spreading HSV.
A person may show symptoms within days after contracting genital herpes, or it may take weeks, months, or years. Some people may have a severe outbreak within days after contracting the virus while others may have a first outbreak so mild that they do not notice it. Because of these possibilities, it can be difficult for people to know when and from whom they may have contracted the virus.