Objectives: This study was performed to quantify the development of the number of cases of genital herpes and to assess the impact of different treatment strategies in France.
Method: A model for the natural history of herpes simplex virus genital infection is presented and applied to the French population. The model encompasses infection by herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2), first episodes, recurrences, viral shedding and the effect of treatment on infected individuals.
Results: In the Year 2000, 270,000 individuals would have suffered from genital herpes in France. A total annual cumulated number of 1.5 million episodes of recurrence and 23 million days of viral shedding were estimated. Seventy percent of viral shedding occurred in sub-clinical seropositive individuals. The expected number of attributable neonatal deaths remained very low. Systematic treatment of clinical episodes might reduce the number of days with lesions (- 27 p. 100), and is also effective on viral shedding (symptomatic: - 50 p. 100). Continuous treatment of the most severe patients (>or=6 recurrences per Year) might reduce viral shedding slightly more (- 85 p. 100). Antiviral treatment might have a major impact on the quality of life of these patients but would only slightly curb the number of new infections.
Discussion: This model tries to integrate the various data currently available at international level on the epidemiology of genital herpes. However, many aspects are still not well documented and remain uncertain. It is therefore necessary to define various assumptions in order to simulate the natural history of the disease in a population. The lack of French data especially on the HSV-1 and HSV-2 seroprevalence profiles reinforces these uncertainties. Our results should hence be considered as exploratory. However, this modeling approach is the only possible way to integrate the multiple parameters describing the pathology and predicting of the public health impact of different interventions. This model is an open tool which may be modified when new data become available.