Veterinary and Biomedical Sciences, Department of


Date of this Version

January 2003


Published in CLINICAL MICROBIOLOGY REVIEWS, Jan. 2003, p. 79–95 Vol. 16, No. 1. Copyright © 2003, American Society for Microbiology. Used by permission.


A high percentage of the world’s population are infected with herpes simplex virus type 1 (HSV-1), and infection can cause a variety of disorders (35, 187). Recurrent ocular HSV-1 is the leading cause of infectious corneal blindness in industrialized nations (190). In a murine model, ocular infection induces autoimmune disorders, leading to corneal antigen destruction and stromal keratitis (275). HSV-1 infections also cause gastrointestinal disorders, esophageal disorders, and approximately 25% of the genital herpes infections (67, 158). HSV-1 infections can cause sporadic encephalitis, but this is relatively rare compared to other diseases resulting from infection. Further evidence for its involvement in central nervous disorders comes from epidemiological studies that suggest a link between Alzheimer’s disease and HSV-1 infection (108, 151). The apolipoprotein E type 4 allele is hypothesized to be a cofactor because it makes an individual susceptible to HSV-1 spread in the brain. The same regions of the brain affected by acute HSV-1 encephalitis are those most severely affected in Alzheimer’s disorder. Finally, infection of neonate mice with an attenuated virus strain leads to hyperactivity and learning deficits, suggesting that this could be a concern when infants become infected (34). In summary, HSV-1 continues to be a significant public health problem.