Question

HSV-1 and HSV-2 are incredibly common viruses, with 90% of Americans of all economic backgrounds at age 60 infected with HSV-1, and 25% of sexually active adults in the USA infected with HSV-2. Based on what you’ve read about these viruses, explain why these infections are so common. If 90% of Americans are infected with HSV-1, does this mean that 90% of Americans will show symptoms of this viral infection? Explain why or why not.

Answer 1

1. Herpes simplex virus infection is very common due to its highly contagious property and can be transmitted from direct contact (oral contact or sexual contact), sharing lip balm and eating from the same utensils. Once infected, the virus remains in the host body for the rest of their lives as it can't be eradicated. After initial infection, the virus remains dormant deep inside the cell bodies of neurons, escaping from the host's immune system. Both oral herpes and genital herpes are common. Individual with oral form of herpes can give a partner genital herpes by performing oral sex. Most importantly, the transmission occurs not only from the person with cold sores but also from a person with no symptoms. Reports suggest that the virus can sometimes block the production of signaling molecules so that the infected cell is not identified by the immune system.
2. If 90% of Americans are infected with HSV-1 , this doesn't mean that 90% of Americans will show symptoms of this viral infection. The vast majority of people infected with HSV-1 or HSV-2 virus are asymptomatic. The striking feature of the virus is latency. After the initial infection, it travels to or gets into the nerve roots and spreads to the sensory nerve ganglia (the nerve junctions). The virus can invade and replicate inside the central nervous system. This characteristic of virus leads to infection without symptoms.