Longitudinal study of herpes simplex virus type 2 infection using viral dynamic modelling

Area of Science:

• Virology
• Epidemiology
• Mathematical Modeling

Background:

• Herpes simplex virus type 2 (HSV-2) reactivation rates fluctuate, impacting transmission and management.
• Understanding longitudinal changes in HSV-2 shedding and recurrence is crucial for clinical strategies.
• Novel within-host viral dynamics models offer new insights into HSV-2 infection.

Purpose of the Study:

• To longitudinally quantify changes in HSV-2 reactivation, mucosal shedding, and genital lesion recurrences.
• To utilize a new within-host viral dynamics model for precise estimation of HSV-2 infection parameters.
• To assess the impact of time on HSV-2 reactivation and shedding rates.

Main Methods:

• A longitudinal study of 18 women over two 2-year periods.
• Daily mucosal swabs for HSV PCR and patient diaries for lesion recurrences.
• Bayesian fitting of a viral dynamics model to shedding data, validated in 67 individuals.

Main Results:

• HSV-2 reactivation rates varied >10-fold among women, with reactivation rates higher than shedding episodes.
• Mucosal shedding episodes lasted 1-3 days.
• Reactivation frequency declined by approximately 3 episodes/year; median recurrences dropped from 6.8 to 2.1 per year.

Conclusions:

• HSV-2 reactivation, shedding, and recurrence rates generally decrease over time.
• Some individuals maintain high rates 4-5 years post-infection.
• Viral dynamic modeling provides essential quantitative insights into HSV-2 infection dynamics.