Table 1.

Statistics on the epidemiology of HSK.

Statistics	Prevalence and percentages	References
Prevalence of HSK in US	150 in 100,000, and 20K new cases annually	(Liesegang et al. 1989)
Annual incidence in western countries	10–30 per 100,000	(Labetoulle et al. 2005, Liesegang et al. 1989, Young et al. 2010)
% of people with antibodies to HSV-1 by middle age	More than 90%	(Liesegang. 2001b)
% of primary HSV-1 infections that are asymptomatic and not recognized	More than 90%	(Liesegang. 2001b)
% Recurrence at 1 yr, 2 yrs, 5 yrs, and 10 yrs	9.6%, 22.9%, 40.0%, 67.0%	(Farooq and Shukla. 2012, Labetoulle et al. 2005, Liesegang. 2001b, Shuster et al. 1981, Stanzel et al. 2014)
Global lifetime risk of developing HSK	1%	(Reynaud et al. 2017)
Patients who experience 2–5 relapses of HSK over their lifetime vs 6–15 relapses	40% vs 11%	(Wishart et al. 1987)
% of patients with HSK who develop severe complications	15%	(Darougar et al. 1985)
Incidence of ACV-resistant strains among immunocompetent patients	0–0.6%	(Christophers et al. 1998, Nugier et al. 1992)
Incidence of ACV-resistant strains among immunocompromised patients	3–6% with 14% for bone marrow transplant recipients	(Christophers et al. 1998, Nugier et al. 1992)