When 5% of new infections are identified through partner notification, partner notification is predicted to avert a total of 18 and 19 infections (interquartile range [IQR] 13–24; 14–26) over the course of 5 years countrywide when initiating at CD4 <500 cells/μl and immediately, respectively compared to treatment at those two thresholds with no partner notification use. The gene discussed is CD4; the disease is infection.