Two strains of the herpes simplex virus, HSV-1 and HSV-2, can cause genital herpes. Once contracted, the virus remains in the body for life, reactivating from time to time. The American Social Health Administration, or ASHA, explains that the causes of a herpes flare-up, or recurrence, are unique to each person. Illness, stress and friction from clothing may trigger an outbreak.
HSV-1 Infection
HSV-1, or herpes virus type 1, usually causes oral herpes. In about 10 percent of genital herpes cases, however, HSV-1 is the cause. The University of South Carolina credits HSV-2, or herpes simplex virus type 2, with the other 90 percent of cases of genital herpes in the United States. Oral herpes caused by HSV-1 is prevalent. ASHA reports that up to 90 percent of Americans have acquired the virus by the age of 50. The herpes virus can spread through direct physical contact with an infected person who is actively shedding the virus or through contact with the bodily fluids, including saliva, of someone who is infected. Herpes.com reports that HSV-1 particles are present approximately 5 percent of the time in the saliva of an infected person, even when no other symptoms are present. During those times, the infected individual can transmit HSV-1 to the genitals of an unaffected partner when engaging in oral sex.
HSV-2 Infection
HSV-2 is the usual cause of genital herpes. ASHA reports that 20 percent of the U.S. population has genital herpes. Up to 90 percent of those who have the virus are unaware of their infection. In many cases, outbreaks go undetected because symptoms are too mild to be noticed. At other times, the symptoms are misdiagnosed. ASHA lists jock itch, insect bites, abrasions and yeast infections as possible misdiagnoses. Regardless, the virus can be on the surface of the skin and shed from skin at times when no symptoms are present---a process called asymptomatic shedding. During those times, the virus can spread to an uninfected individual and cause an initial outbreak. Herpes.com reports that viral cultures taken from people newly infected with genital HSV-2 show that asymptomatic shedding occurs during 6 to 10 percent of days, or 21 to 36 days, during the first year after infection.
Recurrence
When the virus enters a new host, it quickly begins to replicate, or reproduce. When the host's immune system becomes aware of the pathogen, it launches a counterattack. In response to the immune system, the virus retreats to the nervous system, where it enters a period of latency, or hibernation. Occasionally, the virus reactivates. When it does, it returns to the skin or mucous membrane where the first infection occurred and an outbreak ensues. As reported by the ASHA, herpes symptoms vary from person to person. Triggers that cause a recurrence also vary. For some, emotional or physical stress can set off an episode. For others, steroid medications or poor nutrition may trigger a new outbreak. A person with frequent episodes may learn his triggers and avoid them. Stress management techniques, adequate sleep, and following a healthful diet and exercise routine may help limit recurrences. In general, however, the frequency of recurrences decreases over time.
