The most common reason that people develop cold sores on their mouths is due to becoming infected with HSV-1. (4) HSV-1 usually causes cold sore breakouts around the lips or mouth, or what some people describe as “fever blisters.” Someone can become infected with HSV-1 starting as a child, and then the virus can lay dormant in the body until the immune system is weakened, at which point symptoms can surface.
“You don’t want an infant delivered through infected birth canal or vulva because the infant can be infected,” Cullins explains. A neonatal herpes infection is a real risk because it can cause problems with brain development and eye and skin infections, or even be fatal. And since there is more risk for transmission from mother to baby during an initial outbreak than during a recurrent outbreak, the CDC stresses that it’s incredibly important for pregnant women to avoid contracting a new herpes infection.
You should stop having sexual contact as soon as you feel warning signs of an outbreak. Warning signs may include a burning, itching, or tingling feeling on the genitals or around the mouth. Do not have vaginal, anal, or oral sex — even with a condom — until seven days after the warning signs stop or the sore heals. The virus can spread from sores not covered by the condom. It can also spread in sweat or vaginal fluids to places the condom doesn't cover.
In all cases, HSV is never removed from the body by the immune system. Following a primary infection, the virus enters the nerves at the site of primary infection, migrates to the cell body of the neuron, and becomes latent in the ganglion. As a result of primary infection, the body produces antibodies to the particular type of HSV involved, preventing a subsequent infection of that type at a different site. In HSV-1-infected individuals, seroconversion after an oral infection prevents additional HSV-1 infections such as whitlow, genital herpes, and herpes of the eye. Prior HSV-1 seroconversion seems to reduce the symptoms of a later HSV-2 infection, although HSV-2 can still be contracted.
Herpes type 2 (HSV-2) can cause genital herpes. This is one of the most common sexually transmitted infections (STIs) in the US. It causes sores or painful blisters on the penis, vagina, scrotum, anus and buttocks. Along with blisters, people with HSV-2 may experience tingling, itching or pain. Like HSV-1, HSV-2 infections are highly contagious. They can be spread easily through skin-to-skin contact. Sexual intercourse is the main route of transmission.