Infectious Diseases

Herpes Simplex Virus

Herpes Simplex Virus or “HSV” can cause oral herpes (cold sores or fever blisters on the mouth or facial area) as well as genital herpes (similar symptoms in the genital region). The majority of oral herpes cases are caused by HSV-1 and the majority of genital herpes cases are caused by HSV-2, although both type-1 and type-2 can occur in the genitals, oral area or both. 

Genital herpes is a sexually transmitted disease (STD) caused by the herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2). Most people infected with HSV-2 are asymptomatic. When signs do occur, they typically appear as one or more blisters on or around the genitals or rectum. The first outbreak usually occurs within two weeks after the virus is transmitted, and the sores typically heal within two to four weeks. Other signs and symptoms during the primary episode may include a second crop of sores, and flu-like symptoms, including fever and swollen glands. Most people diagnosed with a first episode of genital herpes can expect to have several outbreaks a year. Over time these recurrences usually decrease in frequency.

Prevalence & Incidence

The American Social Health Association estimates that about 50 to 80% of the adult population in the United States has oral herpes. Most people contract oral herpes when they are children by receiving a kiss from a friend or relative. 

According to the US CDC, at least 45 million people in the USA aged 12 and older, or one out of five adolescents and adults, have had genital HSV infection. Between the late 1970s and the early 1990s, the number of Americans with genital herpes infection increased 30%.  HSV-2 infection is more common in women (approximately one out of four women) than in men (almost one out of five). This may be due to male-to-female transmissions being more efficient than female-to-male transmission. There is no treatment that can cure herpes, but antiviral medications can shorten and prevent outbreaks during the period of time the person takes the medication.

Economic Cost In a paper published in the October 2002 edition of the Journal of American Sexually Transmitted Disease Association, Fisman et. al. modelled the future health and economic consequences attributable to the HSV-2 epidemic in the absence of interventions in the USA. They found that without intervention, the prevalence of HSV-2 infection among individuals aged 15 to 39 years was projected to increase to 39% among men and 49% among women by 2025 and the annual incidence was projected to increase steadily between 2000 and 2025. The cost of incident infections in the year 2000 were estimated to be $1.8 billion. These were predicted to rise to US$2.5 billion by 2015 and US$2.7 billion by 2025. The authors concluded that the projected cumulative cost of incident HSV-2 infections occurring over the next 25 years was estimated to be US$61 billion.